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diff --git a/2740.txt b/2740.txt new file mode 100644 index 0000000..c2cc924 --- /dev/null +++ b/2740.txt @@ -0,0 +1,27060 @@ +The Project Gutenberg EBook of More Letters of Charles Darwin Volume II, by +Charles Darwin + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: More Letters of Charles Darwin Volume II + Volume II (of II) + +Author: Charles Darwin + +Editor: Francis Darwin and A.C. Seward + +Posting Date: December 1, 2008 [EBook #2740] +Release Date: July, 2001 + +Language: English + +Character set encoding: ASCII + +*** START OF THIS PROJECT GUTENBERG EBOOK MORE LETTERS OF CHARLES DARWIN *** + + + + +Produced by Sue Asscher + + + + + +MORE LETTERS OF CHARLES DARWIN + +By Charles Darwin + + +A RECORD OF HIS WORK IN A SERIES OF HITHERTO UNPUBLISHED LETTERS + +EDITED BY FRANCIS DARWIN, FELLOW OF CHRIST'S COLLEGE, AND A.C. SEWARD, +FELLOW OF EMMANUEL COLLEGE, CAMBRIDGE + +IN TWO VOLUMES + + + +Transcriber's Notes: + + +All biographical footnotes of both volumes appear at the end of Volume +II. + +All other notes by Charles Darwin's editors appear in the text, in +brackets () with a Chapter/Note or Letter/Note number. + + +VOLUME II. + + +DEDICATED WITH AFFECTION AND RESPECT, TO + +SIR JOSEPH HOOKER + +IN REMEMBRANCE OF HIS LIFELONG FRIENDSHIP WITH CHARLES DARWIN + + +"You will never know how much I owe to you for your constant kindness +and encouragement" + +CHARLES DARWIN TO SIR JOSEPH HOOKER, SEPTEMBER 14, 1862 + + + + +MORE LETTERS OF CHARLES DARWIN + + + + +VOLUME II + + + +CHAPTER 2.VII.--GEOGRAPHICAL DISTRIBUTION. + +1843-1882 (Continued) (1867-1882.) + + +LETTER 378. J.D. HOOKER TO CHARLES DARWIN. Kew, January 20th, 1867. + +Prof. Miquel, of Utrecht, begs me to ask you for your carte, and offers +his in return. I grieve to bother you on such a subject. I am sick and +tired of this carte correspondence. I cannot conceive what Humboldt's +Pyrenean violet is: no such is mentioned in Webb, and no alpine one at +all. I am sorry I forgot to mention the stronger African affinity of +the eastern Canary Islands. Thank you for mentioning it. I cannot admit, +without further analysis, that most of the peculiar Atlantic Islands +genera were derived from Europe, and have since become extinct there. +I have rather thought that many are only altered forms of existing +European genera; but this is a very difficult point, and would require +a careful study of such genera and allies with this object in view. The +subject has often presented itself to me as a grand one for analytic +botany. No doubt its establishment would account for the community of +the peculiar genera on the several groups and islets, but whilst so +many species are common we must allow for a good deal of migration of +peculiar genera too. + +By Jove! I will write out next mail to the Governor of St. Helena for +boxes of earth, and you shall have them to grow. Thanks for telling me +of having suggested to me the working out of proportions of plants with +irregular flowers in islands. I thought it was a deuced deal too good +an idea to have arisen spontaneously in my block, though I did not +recollect your having done so. No doubt your suggestion was crystallised +in some corner of my sensorium. I should like to work out the point. + +Have you Kerguelen Land amongst your volcanic islands? I have a curious +book of a sealer who was wrecked on the island, and who mentions a +volcanic mountain and hot springs at the S.W. end; it is called the +"Wreck of the Favourite." (378/1. "Narrative of the Wreck of the +'Favourite' on the Island of Desolation; detailing the Adventures, +Sufferings and Privations of John Munn; an Historical Account of the +Island and its Whale and Sea Fisheries." Edited by W.B. Clarke: London, +1850.) + + +LETTER 379. TO J.D. HOOKER. Down, March 17th, 1867. + +It is a long time since I have written, but I cannot boast that I have +refrained from charity towards you, but from having lots of work...You +ask what I have been doing. Nothing but blackening proofs with +corrections. I do not believe any man in England naturally writes so +vile a style as I do... + +In your paper on "Insular Floras" (page 9) there is what I must think an +error, which I before pointed out to you: viz., you say that the plants +which are wholly distinct from those of nearest continent are often +very common instead of very rare. (379/1. "Insular Floras," pamphlet +reprinted from the "Gardeners' Chronicle," page 9: "As a general +rule the species of the mother continent are proportionally the most +abundant, and cover the greatest surface of the islands. The peculiar +species are rarer, the peculiar genera of continental affinity are rarer +still; whilst the plants having no affinity with those of the mother +continent are often very common." In a letter of March 20th, 1867, +Sir Joseph explains that in the case of the Atlantic islands it is the +"peculiar genera of EUROPEAN AFFINITY that are so rare," while Clethra, +Dracaena and the Laurels, which have no European affinity, are common.) +Etty (379/2. Mr. Darwin's daughter, now Mrs. Litchfield.), who has read +your paper with great interest, was confounded by this sentence. By the +way, I have stumbled on two old notes: one, that twenty-two species of +European birds occasionally arrive as chance wanderers to the Azores; +and, secondly, that trunks of American trees have been known to be +washed on the shores of the Canary Islands by the Gulf-stream, which +returns southward from the Azores. What poor papers those of A. Murray +are in "Gardeners' Chronicle." What conclusions he draws from a single +Carabus (379/3. "Dr. Hooker on Insular Floras" ("Gardeners' Chronicle," +1867, pages 152, 181). The reference to the Carabidous beetle +(Aplothorax) is at page 181.), and that a widely ranging genus! He seems +to me conceited; you and I are fair game geologically, but he refers to +Lyell, as if his opinion on a geological point was worth no more than +his own. I have just bought, but not read a sentence of, Murray's +big book (379/4. "Geographical Distribution of Mammals," 1866.), +second-hand, for 30s., new, so I do not envy the publishers. It is clear +to me that the man cannot reason. I have had a very nice letter from +Scott at Calcutta (379/5. See Letter 150.): he has been making some +good observations on the acclimatisation of seeds from plants of same +species, grown in different countries, and likewise on how far European +plants will stand the climate of Calcutta. He says he is astonished +how well some flourish, and he maintains, if the land were unoccupied, +several could easily cross, spreading by seed, the Tropics from north to +south, so he knows how to please me; but I have told him to be cautious, +else he will have dragons down on him... + +As the Azores are only about two-and-a-half times more distant from +America (in the same latitude) than from Europe, on the occasional +migration view (especially as oceanic currents come directly from +West Indies and Florida, and heavy gales of wind blow from the same +direction), a large percentage of the flora ought to be American; as it +is, we have only the Sanicula, and at present we have no explanation of +this apparent anomaly, or only a feeble indication of an explanation in +the birds of the Azores being all European. + + +LETTER 380. TO J.D. HOOKER. Down, March 21st [1867]. + +Many thanks for your pleasant and very amusing letter. You have been +treated shamefully by Etty and me, but now that I know the facts, +the sentence seems to me quite clear. Nevertheless, as we have both +blundered, it would be well to modify the sentence something as follows: +"whilst, on the other hand, the plants which are related to those +of distant continents, but have no affinity with those of the mother +continent, are often very common." I forget whether you explain this +circumstance, but it seems to me very mysterious (380/1. Sir Joseph +Hooker wrote (March 23rd, 1867): "I see you 'smell a rat' in the matter +of insular plants that are related to those of [a] distant continent +being common. Yes, my beloved friend, let me make a clean breast of +it. I only found it out after the lecture was in print!...I have +been waiting ever since to 'think it out,' and write to you about it, +coherently. I thought it best to squeeze it in, anyhow or anywhere, +rather than leave so curious a fact unnoticed.")...Do always remember +that nothing in the world gives us so much pleasure as seeing you here +whenever you can come. I chuckle over what you say of And. Murray, but I +must grapple with his book some day. + + +LETTER 381. TO C. LYELL. Down, October 31st [1867]. + +Mr. [J.P. Mansel] Weale sent to me from Natal a small packet of dry +locust dung, under 1/2 oz., with the statement that it is believed that +they introduce new plants into a district. (381/1. See Volume I., Letter +221.) This statement, however, must be very doubtful. From this packet +seven plants have germinated, belonging to at least two kinds of +grasses. There is no error, for I dissected some of the seeds out of +the middle of the pellets. It deserves notice that locusts are sometimes +blown far out to sea. I caught one 370 miles from Africa, and I have +heard of much greater distances. You might like to hear the following +case, as it relates to a migratory bird belonging to the most wandering +of all orders--viz. the woodcock. (381/2. "Origin," Edition VI., page +328.) The tarsus was firmly coated with mud, weighing when dry 9 grains, +and from this the Juncus bufonius, or toad rush, germinated. By the way, +the locust case verifies what I said in the "Origin," that many possible +means of distribution would be hereafter discovered. I quite agree about +the extreme difficulty of the distribution of land mollusca. You will +have seen in the last edition of "Origin" (381/3. "Origin," Edition IV., +page 429. The reference is to MM. Marten's (381/4. For Marten's read +Martins' [the name is wrongly spelt in the "Origin of Species."]) +experiments on seeds "in a box in the actual sea.") that my observations +on the effects of sea-water have been confirmed. I still suspect that +the legs of birds which roost on the ground may be an efficient means; +but I was interrupted when going to make trials on this subject, and +have never resumed it. + +We shall be in London in the middle of latter part of November, when I +shall much enjoy seeing you. Emma sends her love, and many thanks for +Lady Lyell's note. + + +LETTER 382. TO J.D. HOOKER. Down, Wednesday [1867]. + +I daresay there is a great deal of truth in your remarks on the glacial +affair, but we are in a muddle, and shall never agree. I am bigoted to +the last inch, and will not yield. I cannot think how you can attach so +much weight to the physicists, seeing how Hopkins, Hennessey, Haughton, +and Thomson have enormously disagreed about the rate of cooling of the +crust; remembering Herschel's speculations about cold space (382/1. +The reader will find some account of Herschel's views in Lyell's +"Principles," 1872, Edition XI., Volume I., page 283.), and bearing in +mind all the recent speculations on change of axis, I will maintain to +the death that your case of Fernando Po and Abyssinia is worth ten +times more than the belief of a dozen physicists. (382/2. See "Origin," +Edition VI., page 337: "Dr. Hooker has also lately shown that several of +the plants living on the upper parts of the lofty island of Fernando Po +and on the neighbouring Cameroon mountains, in the Gulf of Guinea, are +closely related to those in the mountains of Abyssinia, and likewise to +those of temperate Europe." Darwin evidently means that such facts as +these are better evidence of the gigantic periods of time occupied by +evolutionary changes than the discordant conclusions of the physicists. +See "Linn. Soc. Journ." Volume VII., page 180, for Hooker's general +conclusions; also Hooker and Ball's "Marocco," Appendix F, page 421. For +the case of Fernando Po see Hooker ("Linn. Soc. Journ." VI., 1861, page +3, where he sums up: "Hence the result of comparing Clarence Peak flora +[Fernando Po] with that of the African continent is--(1) the intimate +relationship with Abyssinia, of whose flora it is a member, and from +which it is separated by 1800 miles of absolutely unexplored country; +(2) the curious relationship with the East African islands, which are +still farther off; (3) the almost total dissimilarity from the Cape +flora." For Sir J.D. Hooker's general conclusions on the Cameroon plants +see "Linn. Soc. Journ." VII., page 180. More recently equally striking +cases have come to light: for instance, the existence of a Mediterranean +genus, Adenocarpus, in the Cameroons and on Kilima Njaro, and nowhere +else in Africa; and the probable migration of South African forms along +the highlands from the Natal District to Abysinnia. See Hooker, "Linn. +Soc. Journ." XIV., 1874, pages 144-5.) Your remarks on my regarding +temperate plants and disregarding the tropical plants made me at first +uncomfortable, but I soon recovered. You say that all botanists would +agree that many tropical plants could not withstand a somewhat cooler +climate. But I have come not to care at all for general beliefs without +the special facts. I have suffered too often from this: thus I found in +every book the general statement that a host of flowers were fertilised +in the bud, that seeds could not withstand salt water, etc., etc. I +would far more trust such graphic accounts as that by you of the mixed +vegetation on the Himalayas and other such accounts. And with respect to +tropical plants withstanding the slowly coming on cool period, I trust +to such facts as yours (and others) about seeds of the same species +from mountains and plains having acquired a slightly different climatal +constitution. I know all that I have said will excite in you savage +contempt towards me. Do not answer this rigmarole, but attack me to your +heart's content, and to that of mine, whenever you can come here, and +may it be soon. + + +LETTER 383. J.D. HOOKER TO CHARLES DARWIN. Kew, 1870. + +(383/1. The following extract from a letter of Sir J.D. Hooker shows the +tables reversed between the correspondents.) + +Grove is disgusted at your being disquieted about W. Thomson. Tell +George from me not to sit upon you with his mathematics. When I +threatened your tropical cooling views with the facts of the physicists, +you snubbed me and the facts sweetly, over and over again; and now, +because a scarecrow of x+y has been raised on the selfsame facts, you +boo-boo. Take another dose of Huxley's penultimate G. S. Address, and +send George back to college. (383/2. Huxley's Anniversary Address to the +Geological Society, 1869 ("Collected Essays," VIII., page 305). This is +a criticism of Lord Kelvin's paper "On Geological Time" ("Trans. Geolog. +Soc. Glasgow," III.). At page 336 Mr. Huxley deals with Lord Kelvin's +"third line of argument, based on the temperature of the interior of the +earth." This was no doubt the point most disturbing to Mr. Darwin, since +it led Lord Kelvin to ask (as quoted by Huxley), "Are modern geologists +prepared to say that all life was killed off the earth 50,000, 100,000, +or 200,000 years ago?" Mr. Huxley, after criticising Lord Kelvin's data +and conclusion, gives his conviction that the case against Geology has +broken down. With regard to evolution, Huxley (page 328) ingeniously +points out a case of circular reasoning. "But it may be said that it +is biology, and not geology, which asks for so much time--that the +succession of life demands vast intervals; but this appears to me to +be reasoning in a circle. Biology takes her time from geology. The only +reason we have for believing in the slow rate of the change in living +forms is the fact that they persist through a series of deposits which, +geology informs us, have taken a long while to make. If the geological +clock is wrong, all the naturalist will have to do is to modify his +notions of the rapidity of change accordingly.") + + +LETTER 384. TO J.D. HOOKER. February 3rd [1868]. + +I am now reading Miquel on "Flora of Japan" (384/1. Miquel, "Flore du +Japon": "Archives Neerlandaises" ii., 1867.), and like it: it is rather +a relief to me (though, of course, not new to you) to find so very +much in common with Asia. I wonder if A. Murray's (384/2. "Geographical +Distribution of Mammals," by Andrew Murray, 1866. See Chapter V., page +47. See Letter 379.) notion can be correct, that a [profound] arm of +the sea penetrated the west coast of N. America, and prevented the +Asiatico-Japan element colonising that side of the continent so much +as the eastern side; or will climate suffice? I shall to the day of my +death keep up my full interest in Geographical Distribution, but I doubt +whether I shall ever have strength to come in any fuller detail than in +the "Origin" to this grand subject. In fact, I do not suppose any man +could master so comprehensive a subject as it now has become, if all +kingdoms of nature are included. I have read Murray's book, and am +disappointed--though, as you said, here and there clever thoughts occur. +How strange it is, that his view not affording the least explanation of +the innumerable adaptations everywhere to be seen apparently does not +in the least trouble his mind. One of the most curious cases which he +adduces seems to me to be the two allied fresh-water, highly peculiar +porpoises in the Ganges and Indus; and the more distantly allied form +of the Amazons. Do you remember his explanation of an arm of the sea +becoming cut off, like the Caspian, converted into fresh-water, and then +divided into two lakes (by upheaval), giving rise to two great rivers. +But no light is thus thrown on the affinity of the Amazon form. I now +find from Flower's paper (384/3. "Zoolog. Trans." VI., 1869, page 115. +The toothed whales are divided into the Physeteridae, the Delphinidae, +and the Platanistidae, which latter is placed between the two +other families, and is divided into the sub-families Iniinae and +Platanistinae.) that these fresh-water porpoises form two sub-families, +making an extremely isolated and intermediate, very small family. Hence +to us they are clearly remnants of a large group; and I cannot doubt +we here have a good instance precisely like that of ganoid fishes, of a +large ancient marine group, preserved exclusively in fresh-water, where +there has been less competition, and consequently little modification. +(384/4. See Volume I., Letter 95.) What a grand fact that is which +Miquel gives of the beech not extending beyond the Caucasus, and then +reappearing in Japan, like your Himalayan Pinus, and the cedar of +Lebanon. (384/5. For Pinus read Deodar. The essential identity of the +deodar and the cedar of Lebanon was pointed out in Hooker's "Himalayan +Journals" in 1854 (Volume I., page 257.n). In the "Nat. History Review," +January, 1862, the question is more fully dealt with by him, and the +distribution discussed. The nearest point at which cedars occur is the +Bulgar-dagh chain of Taurus--250 miles from Lebanon. Under the name of +Cedrus atlantica the tree occurs in mass on the borders of Tunis, and as +Deodar it first appears to the east in the cedar forests of Afghanistan. +Sir J.D. Hooker supposes that, during a period of greater cold, the +cedars on the Taurus and on Lebanon lived many thousand feet nearer the +sea-level, and spread much farther to the east, meeting similar belts +of trees descending and spreading westward from Afghanistan along the +Persian mountains.) I know of nothing that gives one such an idea of the +recent mutations in the surface of the land as these living "outlyers." +In the geological sense we must, I suppose, admit that every yard of +land has been successively covered with a beech forest between the +Caucasus and Japan! + +I have not yet seen (for I have not sent to the station) Falconer's +works. When you say that you sigh to think how poor your reprinted +memoirs would appear, on my soul I should like to shake you till your +bones rattled for talking such nonsense. Do you sigh over the "Insular +Floras," the Introduction to New Zealand Flora, to Australia, your +Arctic Flora, and dear Galapagos, etc., etc., etc.? In imagination I am +grinding my teeth and choking you till I put sense into you. Farewell. I +have amused myself by writing an audaciously long letter. By the way, we +heard yesterday that George has won the second Smith's Prize, which I am +excessively glad of, as the Second Wrangler by no means always succeeds. +The examination consists exclusively of [the] most difficult subjects, +which such men as Stokes, Cayley, and Adams can set. + + +LETTER 385. A.R. WALLACE TO CHARLES DARWIN. March 8th, 1868. + +...While writing a few pages on the northern alpine forms of plants +on the Java mountains I wanted a few cases to refer to like Teneriffe, +where there are no northern forms and scarcely any alpine. I expected +the volcanoes of Hawaii would be a good case, and asked Dr. Seemann +about them. It seems a man has lately published a list of Hawaiian +plants, and the mountains swarm with European alpine genera and +some species! (385/1. "This turns out to be inaccurate, or greatly +exaggerated. There are no true alpines, and the European genera are +comparatively few. See my 'Island Life,' page 323."--A.R.W.) Is not this +most extraordinary, and a puzzler? They are, I believe, truly oceanic +islands, in the absence of mammals and the extreme poverty of birds and +insects, and they are within the Tropics. + +Will not that be a hard nut for you when you come to treat in detail on +geographical distribution? I enclose Seemann's note, which please return +when you have copied the list, if of any use to you. + + +LETTER 386. TO J.D. HOOKER. Down, February 21st [1870]. + +I read yesterday the notes on Round Island (386/1. In Wallace's "Island +Life," page 410, Round Island is described as an islet "only about a +mile across, and situated about fourteen miles north-east of Mauritius." +Wallace mentions a snake, a python belonging to the peculiar and +distinct genus Casarea, as found on Round Island, and nowhere else in +the world. The palm Latania Loddigesii is quoted by Wallace as "confined +to Round Island and two other adjacent islets." See Baker's "Flora of +the Mauritius and the Seychelles." Mr. Wallace says that, judging from +the soundings, Round Island was connected with Mauritius, and that when +it was "first separated [it] would have been both much larger and much +nearer the main island.") which I owe to you. Was there ever such an +enigma? If, in the course of a week or two, you can find time to let me +hear what you think, I should very much like to hear: or we hope to be +at Erasmus' on March 4th for a week. Would there be any chance of your +coming to luncheon then? What a case it is. Palms, screw-pines, four +snakes--not one being in main island--lizards, insects, and not one +land bird. But, above everything, such a proportion of individual +monocotyledons! The conditions do not seem very different from the Tuff +Galapagos Island, but, as far as I remember, very few monocotyledons +there. Then, again, the island seems to have been elevated. I wonder +much whether it stands out in the line of any oceanic current, which +does not so forcibly strike the main island? But why, oh, why should so +many monocotyledons have come there? or why should they have survived +there more than on the main island, if once connected? So, again, I +cannot conceive that four snakes should have become extinct in Mauritius +and survived on Round Island. For a moment I thought that Mauritius +might be the newer island, but the enormous degradation which the outer +ring of rocks has undergone flatly contradicts this, and the marine +remains on the summit of Round Island indicate the island to be +comparatively new--unless, indeed, they are fossil and extinct marine +remains. Do tell me what you think. There never was such an enigma. +I rather lean to separate immigration, with, of course, subsequent +modification; some forms, of course, also coming from Mauritius. +Speaking of Mauritius reminds me that I was so much pleased the day +before yesterday by reading a review of a book on the geology of St. +Helena, by an officer who knew nothing of my hurried observations, but +confirms nearly all that I have said on the general structure of the +island, and on its marvellous denudation. The geology of that island was +like a novel. + + + +LETTER 387. TO A. BLYTT. Down, March 28th, 1876. + +(387/1. The following refers to Blytt's "Essay on the Immigration of the +Norwegian Flora during Alternating Rainy and Dry Periods," Christiania, +1876.) + +I thank you sincerely for your kindness in having sent me your work on +the "Immigration of the Norwegian Flora," which has interested me in the +highest degree. Your view, supported as it is by various facts, appears +to me the most important contribution towards understanding the present +distribution of plants, which has appeared since Forbes' essay on the +effects of the Glacial Period. + + +LETTER 388. TO AUG. FOREL. Down, June 19th, 1876. + +I hope you will allow me to suggest an observation, should any +opportunity occur, on a point which has interested me for many +years--viz., how do the coleoptera which inhabit the nests of ants +colonise a new nest? Mr. Wallace, in reference to the presence of such +coleoptera in Madeira, suggests that their ova may be attached to the +winged female ants, and that these are occasionally blown across the +ocean to the island. It would be very interesting to discover whether +the ova are adhesive, and whether the female coleoptera are guided by +instinct to attach them to the female ants (388/1. Dr. Sharp is good +enough to tell us that he is not aware of any such adaptation. Broadly +speaking, the distribution of the nest-inhabiting beetles is due to +co-migration with the ants, though in some cases the ants transport the +beetles. Sitaris and Meloe are beetles which live "at the expense of +bees of the genus Anthophora." The eggs are laid not in but near the +bees' nest; in the early stage the larva is active and has the instinct +to seize any hairy object near it, and in this way they are carried by +the Anthophora to the nest. Dr. Sharp states that no such preliminary +stage is known in the ant's-nest beetles. For an account of Sitaris and +Meloe, see Sharp's "Insects," II., page 272.); or whether the larvae +pass through an early stage, as with Sitaris or Meloe, or cling to the +bodies of the females. This note obviously requires no answer. I trust +that you continue your most interesting investigations on ants. + + +(PLATE: MR. A.R. WALLACE, 1878. From a photograph by Maull & Fox.) + + +LETTER 389. TO A.R. WALLACE. + +(389/1. Published in "Life and Letters," III., page 230.) + +(389/2. The following five letters refer to Mr. Wallace's "Geographical +Distribution of Animals," 1876.) + +[Hopedene] (389/3. Mr. Hensleigh Wedgwood's house in Surrey.), June 5th, +1876. + +I must have the pleasure of expressing to you my unbounded admiration +of your book (389/4. "Geographical Distribution," 1876.), though I have +read only to page 184--my object having been to do as little as +possible while resting. I feel sure that you have laid a broad and safe +foundation for all future work on Distribution. How interesting it will +be to see hereafter plants treated in strict relation to your views; and +then all insects, pulmonate molluscs and fresh-water fishes, in greater +detail than I suppose you have given to these lower animals. The point +which has interested me most, but I do not say the most valuable point, +is your protest against sinking imaginary continents in a quite +reckless manner, as was stated by Forbes, followed, alas, by Hooker, +and caricatured by Wollaston and [Andrew] Murray! By the way, the main +impression that the latter author has left on my mind is his utter want +of all scientific judgment. I have lifted up my voice against the above +view with no avail, but I have no doubt that you will succeed, owing +to your new arguments and the coloured chart. Of a special value, as it +seems to me, is the conclusion that we must determine the areas, chiefly +by the nature of the mammals. When I worked many years ago on this +subject, I doubted much whether the now-called Palaearctic and Nearctic +regions ought to be separated; and I determined if I made another region +that it should be Madagascar. I have, therefore, been able to appreciate +your evidence on these points. What progress Palaeontology has made +during the last twenty years! but if it advances at the same rate in the +future, our views on the migration and birthplace of the various groups +will, I fear, be greatly altered. I cannot feel quite easy about the +Glacial period, and the extinction of large mammals, but I must hope +that you are right. I think you will have to modify your belief about +the difficulty of dispersal of land molluscs; I was interrupted when +beginning to experimentise on the just hatched young adhering to the +feet of ground-roosting birds. I differ on one other point--viz. in the +belief that there must have existed a Tertiary Antarctic continent, from +which various forms radiated to the southern extremities of our present +continents. But I could go on scribbling forever. You have written, as +I believe, a grand and memorable work, which will last for years as the +foundation for all future treatises on Geographical Distribution. + +P.S.--You have paid me the highest conceivable compliment, by what +you say of your work in relation to my chapters on distribution in the +"Origin," and I heartily thank you for it. + + +LETTER 390. FROM A.R. WALLACE TO CHARLES DARWIN. The Dell, Grays, Essex, +June 7th, 1876. + +Many thanks for your very kind letter. So few people will read my book +at all regularly, that a criticism from one who does so will be very +welcome. If, as I suppose, it is only to page 184 of Volume I. that you +have read, you cannot yet quite see my conclusions on the points you +refer to (land molluscs and Antarctic continent). My own conclusion +fluctuated during the progress of the book, and I have, I know, +occasionally used expressions (the relics of earlier ideas) which are +not quite consistent with what I say further on. I am positively against +any Southern continent as uniting South America with Australia or New +Zealand, as you will see at Volume I., pages 398-403, and 459-66. My +general conclusions as to distribution of land mollusca are at Volume +II., pages 522-9. (390/1. "Geographical Distribution" II., pages 524, +525. Mr. Wallace points out that "hardly a small island on the globe but +has some land-shells peculiar to it"--and he goes so far as to say that +probably air-breathing mollusca have been chiefly distributed by air- +or water-carriage, rather than by voluntary dispersal on the land.) When +you have read these passages, and looked at the general facts which lead +to them, I shall be glad to hear if you still differ from me. + +Though, of course, present results as to the origin and migrations of +genera of mammals will have to be modified owing to new discoveries, I +cannot help thinking that much will remain unaffected, because in all +geographical and geological discoveries the great outlines are soon +reached, the details alone remain to be modified. I also think much of +the geological evidence is now so accordant with, and explanatory of, +Geographical Distribution, that it is prima facie correct in outline. +Nevertheless, such vast masses of new facts will come out in the next +few years that I quite dread the labour of incorporating them in a new +edition. + +I hope your health is improved; and when, quite at your leisure, you +have waded through my book, I trust you will again let me have a few +lines of friendly criticism and advice. + + +LETTER 391. TO A.R. WALLACE. Down, June 17th, 1876. + +I have now finished the whole of Volume I., with the same interest and +admiration as before; and I am convinced that my judgment was right +and that it is a memorable book, the basis of all future work on the +subject. I have nothing particular to say, but perhaps you would like to +hear my impressions on two or three points. Nothing has struck me more +than the admirable and convincing manner in which you treat Java. To +allude to a very trifling point, it is capital about the unadorned head +of the Argus-pheasant. (391/1. See "Descent of Man," Edition I., pages +90 and 143, for drawings of the Argus pheasant and its markings. The +ocelli on the wing feathers were favourite objects of Mr. Darwin, +and sometimes formed the subject of the little lectures which on rare +occasions he would give to a visitor interested in Natural History. In +Mr. Wallace's book the meaning of the ocelli comes in by the way, in the +explanation of Plate IX., "A Malayan Forest with some of its peculiar +Birds." Mr. Wallace (volume i., page 340) points out that the head of +the Argus pheasant is, during the display of the wings, concealed from +the view of a spectator in front, and this accounts for the absence of +bright colour on the head--a most unusual point in a pheasant. The case +is described as a "remarkable confirmation of Mr. Darwin's views, that +gaily coloured plumes are developed in the male bird for the purpose +of attractive display." For the difference of opinion between the two +naturalists on the broad question of coloration see "Life and Letters," +III., page 123. See Letters 440-453.) How plain a thing is, when it is +once pointed out! What a wonderful case is that of Celebes: I am glad +that you have slightly modified your views with respect to Africa. +(391/2. "I think this must refer to the following passage in 'Geog. +Dist. of Animals,' Volume I., pages 286-7. 'At this period (Miocene) +Madagascar was no doubt united with Africa, and helped to form a great +southern continent which must at one time have extended eastward as far +as Southern India and Ceylon; and over the whole of this the lemurine +type no doubt prevailed.' At the time this was written I had not paid +so much attention to islands, and in my "Island Life" I have given ample +reasons for my belief that the evidence of extinct animals does not +require any direct connection between Southern India and Africa."--Note +by Mr. Wallace.) And this leads me to say that I cannot swallow the +so-called continent of Lemuria--i.e., the direct connection of Africa +and Ceylon. (391/3. See "Geographical Distribution," I., page 76. The +name Lemuria was proposed by Mr. Sclater for an imaginary submerged +continent extending from Madagascar to Ceylon and Sumatra. Mr. Wallace +points out that if we confine ourselves to facts Lemuria is reduced to +Madagascar, which he makes a subdivision of the Ethiopian Region.) The +facts do not seem to me many and strong enough to justify so immense a +change of level. Moreover, Mauritius and the other islands appear to +me oceanic in character. But do not suppose that I place my judgment +on this subject on a level with yours. A wonderfully good paper was +published about a year ago on India, in the "Geological Journal," I +think by Blanford. (391/4. H.F. Blanford "On the Age and Correlations +of the Plant-bearing Series of India and the Former Existence of an +Indo-Oceanic Continent" ("Quart. Journ. Geol. Soc." XXXI., 1875, page +519). The name Gondwana-Land was subsequently suggested by Professor +Suess for this Indo-Oceanic continent. Since the publication of +Blanford's paper, much literature has appeared dealing with the evidence +furnished by fossil plants, etc., in favour of the existence of a vast +southern continent.) Ramsay agreed with me that it was one of the +best published for a long time. The author shows that India has been a +continent with enormous fresh-water lakes, from the Permian period to +the present day. If I remember right, he believes in a former connection +with S. Africa. + +I am sure that I read, some twenty to thirty years ago in a French +journal, an account of teeth of Mastodon found in Timor; but the +statement may have been an error. (391/5. In a letter to Falconer +(Letter 155), January 5th, 1863, Darwin refers to the supposed +occurrence of Mastodon as having been "smashed" by Falconer.) + +With respect to what you say about the colonising of New Zealand, +I somewhere have an account of a frog frozen in the ice of a Swiss +glacier, and which revived when thawed. I may add that there is an +Indian toad which can resist salt-water and haunts the seaside. Nothing +ever astonished me more than the case of the Galaxias; but it does +not seem known whether it may not be a migratory fish like the salmon. +(391/6. The only genus of the Galaxidae, a family of fresh-water fishes +occurring in New Zealand, Tasmania, and Tierra del Fuego, ranging north +as far as Queensland and Chile (Wallace's "Geographical Distribution," +II., page 448).) + + +LETTER 392. TO A.R. WALLACE. Down, June 25th, 1876. + +I have been able to read rather more quickly of late, and have finished +your book. I have not much to say. Your careful account of the temperate +parts of South America interested me much, and all the more from knowing +something of the country. I like also much the general remarks towards +the end of the volume on the land molluscs. Now for a few criticisms. + +Page 122. (392/1. The pages refer to Volume II. of Wallace's +"Geographical Distribution.")--I am surprised at your saying that +"during the whole Tertiary period North America was zoologically far +more strongly contrasted with South America than it is now." But we know +hardly anything of the latter except during the Pliocene period; and +then the mastodon, horse, several great edentata, etc., etc., were +common to the north and south. If you are right, I erred greatly in my +"Journal," where I insisted on the former close connection between the +two. + +Page 252 and elsewhere.--I agree thoroughly with the general principle +that a great area with many competing forms is necessary for much and +high development; but do you not extend this principle too far--I should +say much too far, considering how often several species of the same +genus have been developed on very small islands? + +Page 265.--You say that the Sittidae extend to Madagascar, but there +is no number in the tabular heading. [The number (4) was erroneously +omitted.--A.R.W.] + +Page 359.--Rhinochetus is entered in the tabular heading under No. 3 +of the neotropical subregions. [An error: should have been the +Australian.--A.R.W.] + +Reviewers think it necessary to find some fault; and if I were to +review you, the sole point which I should blame is your not giving very +numerous references. These would save whoever follows you great +labour. Occasionally I wished myself to know the authority for certain +statements, and whether you or somebody else had originated certain +subordinate views. Take the case of a man who had collected largely on +some island, for instance St. Helena, and who wished to work out the +geographical relations of his collections: he would, I think, feel very +blank at not finding in your work precise references to all that had +been written on St. Helena. I hope you will not think me a confoundedly +disagreeable fellow. + +I may mention a capital essay which I received a few months ago +from Axel Blytt (392/2. Axel Blytt, "Essay on the Immigration of +the Norwegian Flora." Christiania, 1876. See Letter 387.) on the +distribution of the plants of Scandinavia; showing the high probability +of there having been secular periods alternately wet and dry, and of the +important part which they have played in distribution. + +I wrote to Forel (392/3. See Letter 388.), who is always at work +on ants, and told him your views about the dispersal of the blind +coleoptera, and asked him to observe. + +I spoke to Hooker about your book, and feel sure that he would like +nothing better than to consider the distribution of plants in relation +to your views; but he seemed to doubt whether he should ever have time. + +And now I have done my jottings, and once again congratulate you on +having brought out so grand a work. I have been a little disappointed at +the review in "Nature." (392/4. June 22nd, 1876, pages 165 et seq.) + + +LETTER 393. A.R. WALLACE TO CHARLES DARWIN. Rosehill, Dorking, July +23rd, 1876. + +I should have replied sooner to your last kind and interesting letters, +but they reached me in the midst of my packing previous to removal here, +and I have only just now got my books and papers in a get-at-able state. + +And first, many thanks for your close observation in detecting the two +absurd mistakes in the tabular headings. + +As to the former greater distinction of the North and South American +faunas, I think I am right. The edentata being proved (as I hold) +to have been mere temporary migrants into North America in the +post-Pliocene epoch, form no part of its Tertiary fauna. Yet in South +America they were so enormously developed in the Pliocene epoch that +we know, if there is any such thing as evolution, etc., that strange +ancestral forms must have preceded them in Miocene times. + +Mastodon, on the other hand, represented by one or two species only, +appears to have been a late immigrant into South America from the north. + +The immense development of ungulates (in varied families, genera, and +species) in North America during the whole Tertiary epoch is, however, +the great feature which assimilates it to Europe, and contrasts it +with South America. True camels, hosts of hog-like animals, true +rhinoceroses, and hosts of ancestral horses, all bring the North +American [fauna] much nearer to the Old World than it is now. Even the +horse, represented in all South America by Equus only, was probably a +temporary immigrant from the north. + +As to extending too far the principle (yours) of the necessity of +comparatively large areas for the development of varied faunas, I may +have done so, but I think not. There is, I think, every probability that +most islands, etc., where a varied fauna now exists, have been once more +extensive--eg., New Zealand, Madagascar: where there is no such evidence +(e.g., Galapagos), the fauna is very restricted. + +Lastly, as to want of references: I confess the justice of your +criticism; but I am dreadfully unsystematic. It is my first large work +involving much of the labour of others. I began with the intention of +writing a comparatively short sketch, enlarged it, and added to it bit +by bit; remodelled the tables, the headings, and almost everything else, +more than once, and got my materials in such confusion that it is a +wonder it has not turned out far more crooked and confused than it is. +I, no doubt, ought to have given references; but in many cases I found +the information so small and scattered, and so much had to be combined +and condensed from conflicting authorities, that I hardly knew how +to refer to them or where to leave off. Had I referred to all authors +consulted for every fact, I should have greatly increased the bulk of +the book, while a large portion of the references would be valueless +in a few years, owing to later and better authorities. My experience +of referring to references has generally been most unsatisfactory. One +finds, nine times out of ten, the fact is stated, and nothing more; or a +reference to some third work not at hand! + +I wish I could get into the habit of giving chapter and verse for every +fact and extract; but I am too lazy, and generally in a hurry, having to +consult books against time, when in London for a day. + +However, I will try to do something to mend this matter, should I have +to prepare another edition. + +I return you Forel's letter. It does not advance the question much; +neither do I think it likely that even the complete observation he +thinks necessary would be of much use, because it may well be that the +ova, or larvae, or imagos of the beetles are not carried systematically +by the ants, but only occasionally, owing to some exceptional +circumstances. This might produce a great effect in distribution, yet be +so rare as never to come under observation. + +Several of your remarks in previous letters I shall carefully consider. +I know that, compared with the extent of the subject, my book is in +many parts crude and ill-considered; but I thought, and still think, it +better to make some generalisations wherever possible, as I am not at +all afraid of having to alter my views in many points of detail. I was +so overwhelmed with zoological details, that I never went through the +Geological Society's "Journal" as I ought to have done, and as I mean to +do before writing more on the subject. + + +LETTER 394. TO F. BUCHANAN WHITE. + +(394/1. "Written in acknowledgment of a copy of a paper (published by me +in the "Proceedings of the Zoological Society") on the Hemiptera of St. +Helena, but discussing the origin of the whole fauna and flora of that +island."--F.B.W.) + +Down, September 23rd. [1878]. + +I have now read your paper, and I hope that you will not think me +presumptuous in writing another line to say how excellent it seems to +me. I believe that you have largely solved the problem of the affinities +of the inhabitants of this most interesting little island, and this is a +delightful triumph. + + +LETTER 395. TO J.D. HOOKER. Down, July 22nd [1879]. + +I have just read Ball's Essay. (395/1. The late John Ball's lecture +"On the Origin of the Flora of the Alps" in the "Proceedings of the R. +Geogr. Soc." 1879. Ball argues (page 18) that "during ancient Palaeozoic +times, before the deposition of the Coal-measures, the atmosphere +contained twenty times as much carbonic acid gas and considerably less +oxygen than it does at present." He further assumes that in such an +atmosphere the percentage of CO2 in the higher mountains would be +excessively different from that at the sea-level, and appends the result +of calculations which gives the amount of CO2 at the sea-level as 100 +per 10,000 by weight, at a height of 10,000 feet as 12.5 per 10,000. +Darwin understands him to mean that the Vascular Cryptogams and +Gymnosperms could stand the sea-level atmosphere, whereas the +Angiosperms would only be able to exist in the higher regions where the +percentage of CO2 was small. It is not clear to us that Ball relies so +largely on the condition of the atmosphere as regards CO2. If he does +he is clearly in error, for everything we know of assimilation points +to the conclusion that 100 per 10,000 (1 per cent.) is by no means a +hurtful amount of CO2, and that it would lead to an especially vigorous +assimilation. Mountain plants would be more likely to descend to the +plains to share in the rich feast than ascend to higher regions to avoid +it. Ball draws attention to the imperfection of our plant records as +regards the floras of mountain regions. It is, he thinks, conceivable +that there existed a vegetation on the Carboniferous mountains of which +no traces have been preserved in the rocks. See "Fossil Plants as Tests +of Climate," page 40, A.C. Seward, 1892. + +Since the first part of this note was written, a paper has been read +(May 29th, 1902) by Dr. H.T. Brown and Mr. F. Escombe, before the Royal +Society on "The Influence of varying amounts of Carbon Dioxide in the +Air on the Photosynthetic Process of Leaves, and on the Mode of Growth +of Plants." The author's experiments included the cultivation of several +dicotyledonous plants in an atmosphere containing in one case 180 to 200 +times the normal amount of CO2, and in another between three and four +times the normal amount. The general results were practically identical +in the two sets of experiments. "All the species of flowering plants, +which have been the subject of experiment, appear to be accurately +'tuned' to an atmospheric environment of three parts of CO2 per 10,000, +and the response which they make to slight increases in this amount +are in a direction altogether unfavourable to their growth and +reproduction." The assimilation of carbon increases with the increase in +the partial pressure of the CO2. But there seems to be a disturbance +in metabolism, and the plants fail to take advantage of the increased +supply of CO2. The authors say:--"All we are justified in concluding is, +that if such atmospheric variations have occurred since the advent +of flowering plants, they must have taken place so slowly as never +to outrun the possible adaptation of the plants to their changing +conditions." + +Prof. Farmer and Mr. S.E. Chandler gave an account, at the same meeting +of the Royal Society, of their work "On the Influence of an Excess of +Carbon Dioxide in the Air on the Form and Internal Structure of Plants." +The results obtained were described as differing in a remarkable way +from those previously recorded by Teodoresco ("Rev. Gen. Botanique," +II., 1899 + +It is hoped that Dr. Horace Brown and Mr. Escombe will extend their +experiments to Vascular Cryptogams, and thus obtain evidence bearing +more directly upon the question of an increased amount of CO2 in the +atmosphere of the Coal-period forests.) It is pretty bold. The rapid +development as far as we can judge of all the higher plants within +recent geological times is an abominable mystery. Certainly it would be +a great step if we could believe that the higher plants at first could +live only at a high level; but until it is experimentally [proved] that +Cycadeae, ferns, etc., can withstand much more carbonic acid than the +higher plants, the hypothesis seems to me far too rash. Saporta believes +that there was an astonishingly rapid development of the high plants, +as soon [as] flower-frequenting insects were developed and favoured +intercrossing. I should like to see this whole problem solved. I +have fancied that perhaps there was during long ages a small isolated +continent in the S. Hemisphere which served as the birthplace of the +higher plants--but this is a wretchedly poor conjecture. It is odd +that Ball does not allude to the obvious fact that there must have +been alpine plants before the Glacial period, many of which would have +returned to the mountains after the Glacial period, when the climate +again became warm. I always accounted to myself in this manner for the +gentians, etc. + +Ball ought also to have considered the alpine insects common to the +Arctic regions. I do not know how it may be with you, but my faith in +the glacial migration is not at all shaken. + + +LETTER 396. A.R. WALLACE TO CHARLES DARWIN. + +(396/1. This letter is in reply to Mr. Darwin's criticisms on Mr. +Wallace's "Island Life," 1880.) + +Pen-y-Bryn, St. Peter's Road, Croydon, November 8th, 1880. + +Many thanks for your kind remarks and notes on my book. Several of the +latter will be of use to me if I have to prepare a second edition, which +I am not so sure of as you seem to be. + +1. In your remark as to the doubtfulness of paucity of fossils being due +to coldness of water, I think you overlook that I am speaking only of +water in the latitude of the Alps, in Miocene and Eocene times, when +icebergs and glaciers temporarily descended into an otherwise warm sea; +my theory being that there was no Glacial epoch at that time, but merely +a local and temporary descent of the snow-line and glaciers owing to +high excentricity and winter in aphelion. + +2. I cannot see the difficulty about the cessation of the Glacial +period. + +Between the Miocene and the Pleistocene periods geographical changes +occurred which rendered a true Glacial period possible with high +excentricity. When the high excentricity passed away the Glacial epoch +also passed away in the temperate zone; but it persists in the arctic +zone, where, during the Miocene, there were mild climates, and this +is due to the persistence of the changed geographical conditions. The +present arctic climate is itself a comparatively new and abnormal state +of things, due to geographical modification. + +As to "epoch" and "period," I use them as synonyms to avoid repeating +the same word. + +3. Rate of deposition and geological time. Here no doubt I may have +gone to an extreme, but my "28 million years" may be anything under 100 +millions, as I state. There is an enormous difference between mean and +maximum denudation and deposition. In the case of the great faults +the upheaval along a given line would itself facilitate the denudation +(whether sub-aerial or marine) of the upheaved portion at a rate perhaps +a hundred times above the average, just as valleys have been denuded +perhaps a hundred times faster than plains and plateaux. So local +subsidence might itself lead to very rapid deposition. Suppose a portion +of the Gulf of Mexico, near the mouths of the Mississippi, were to +subside for a few thousand years, it might receive the greater portion +of the sediment from the whole Mississippi valley, and thus form strata +at a very rapid rate. + +4. You quote the Pampas thistles, etc., against my statement of the +importance of preoccupation. But I am referring especially to St. +Helena, and to plants naturally introduced from the adjacent continents. +Surely if a certain number of African plants reached the island, and +became modified into a complete adaptation to its climatic conditions, +they would hardly be expelled by other African plants arriving +subsequently. They might be so, conceivably, but it does not seem +probable. The cases of the Pampas, New Zealand, Tahiti, etc., are +very different, where highly developed aggressive plants have been +artificially introduced. Under nature it is these very aggressive +species that would first reach any island in their vicinity, and, being +adapted to the island and colonising it thoroughly, would then hold +their own against other plants from the same country, mostly less +aggressive in character. + +I have not explained this so fully as I should have done in the book. +Your criticism is therefore useful. + +5. My Chapter XXIII. is no doubt very speculative, and I cannot wonder +at your hesitating at accepting my views. To me, however, your theory of +hosts of existing species migrating over the tropical lowlands from the +N. temperate to the S. temperate zone appears more speculative and +more improbable. For where could the rich lowland equatorial flora have +existed during a period of general refrigeration sufficient for this? +and what became of the wonderfully rich Cape flora, which, if the +temperature of tropical Africa had been so recently lowered, would +certainly have spread northwards, and on the return of the heat +could hardly have been driven back into the sharply defined and very +restricted area in which it now exists. + +As to the migration of plants from mountain to mountain not being so +probable as to remote islands, I think that is fully counterbalanced by +two considerations:-- + +a. The area and abundance of the mountain stations along such a range +as the Andes are immensely greater than those of the islands in the N. +Atlantic, for example. + +b. The temporary occupation of mountain stations by migrating plants +(which I think I have shown to be probable) renders time a much more +important element in increasing the number and variety of the plants so +dispersed than in the case of islands, where the flora soon acquires +a fixed and endemic character, and where the number of species is +necessarily limited. + +No doubt direct evidence of seeds being carried great distances through +the air is wanted, but I am afraid can hardly be obtained. Yet I feel +the greatest confidence that they are so carried. Take, for instance, +the two peculiar orchids of the Azores (Habenaria sp.) What other mode +of transit is conceivable? The whole subject is one of great difficulty, +but I hope my chapter may call attention to a hitherto neglected factor +in the distribution of plants. + +Your references to the Mauritius literature are very interesting, and +will be useful to me; and I again thank you for your valuable remarks. + + +LETTER 397. TO J.D. HOOKER. + +(397/1. The following letters were written to Sir J.D. Hooker when he +was preparing his Address as President of the Geographical Section of +the British Association at its fiftieth meeting, at York. The second +letter (August 12th) refers to an earlier letter of August 6th, +published in "Life and Letters," III., page 246.) + +4, Bryanston Street, W., Saturday, 26th [February, 1881]. + +I should think that you might make a very interesting address on +Geographical Distribution. Could you give a little history of the +subject. I, for one, should like to read such history in petto; but I +can see one very great difficulty--that you yourself ought to figure +most prominently in it; and this you would not do, for you are just the +man to treat yourself in a dishonourable manner. I should very much like +to see you discuss some of Wallace's views, especially his ignoring +the all-powerful effects of the Glacial period with respect to alpine +plants. (397/2. "Having been kindly permitted by Mr. Francis Darwin to +read this letter, I wish to explain that the above statement applies +only to my rejection of Darwin's view that the presence of arctic and +north temperate plants in the SOUTHERN HEMISPHERE was brought about +by the lowering of the temperature of the tropical regions during the +Glacial period, so that even 'the lowlands of these great continents +were everywhere tenanted under the equator by a considerable number of +temperate forms ("Origin of Species," Edition VI., page 338). My +own views are fully explained in Chapter XXIII. of my "Island Life," +published in 1880. I quite accept all that Darwin, Hooker, and Asa Gray +have written about the effect of the Glacial epoch in bringing about +the present distribution of alpine and arctic plants in the NORTHERN +HEMISPHERE."--Note by Mr. Wallace.) I do not know what you think, but it +appears to me that he exaggerates enormously the influence of debacles +or slips and new surface of soil being exposed for the reception of +wind-blown seeds. What kinds of seeds have the plants which are common +to the distant mountain-summits in Africa? Wallace lately wrote to me +about the mountain plants of Madagascar being the same with those on +mountains in Africa, and seemed to think it proved dispersal by the +wind, without apparently having inquired what sorts of seeds the plants +bore. (397/3. The affinity with the flora of the Eastern African islands +was long ago pointed out by Sir J.D. Hooker, "Linn. Soc. Journal," VI., +1861, page 3. Speaking of the plants of Clarence Peak in Fernando Po, he +says, "The next affinity is with Mauritius, Bourbon, and Madagascar: +of the whole 76 species, 16 inhabit these places and 8 more are closely +allied to plants from there. Three temperate species are peculiar to +Clarence Peak and the East African islands..." The facts to which +Mr. Wallace called Darwin's attention are given by Mr. J.G. Baker in +"Nature," December 9th, 1880, page 125. He mentions the Madagascar +Viola, which occurs elsewhere only at 7,000 feet in the Cameroons, at +10,000 feet in Fernando Po and in the Abyssinian mountains; and the same +thing is true of the Madagascar Geranium. In Mr. Wallace's letter +to Darwin, dated January 1st, 1881, he evidently uses the expression +"passing through the air" in contradistinction to the migration of a +species by gradual extension of its area on land. "Through the air" +would moreover include occasional modes of transport other than simple +carriage by wind: e.g., the seeds might be carried by birds, either +attached to the feathers or to the mud on their feet, or in their crops +or intestines.) + +I suppose it would be travelling too far (though for the geographical +section the discussion ought to be far-reaching), but I should like +to see the European or northern element in the Cape of Good Hope +flora discussed. I cannot swallow Wallace's view that European plants +travelled down the Andes, tenanted the hypothetical Antarctic continent +(in which I quite believe), and thence spread to South Australia and the +Cape of Good Hope. + +Moseley told me not long ago that he proposed to search at Kerguelen +Land the coal beds most carefully, and was absolutely forbidden to do +so by Sir W. Thomson, who said that he would undertake the work, and he +never once visited them. This puts me in a passion. I hope that you will +keep to your intention and make an address on distribution. Though I +differ so much from Wallace, his "Island Life" seems to me a wonderful +book. + +Farewell. I do hope that you may have a most prosperous journey. Give my +kindest remembrances to Asa Gray. + + + +LETTER 398. TO J.D. HOOKER. Down, August 12th, 1881. + +...I think that I must have expressed myself badly about Humboldt. +I should have said that he was more remarkable for his astounding +knowledge than for originality. I have always looked at him as, in fact, +the founder of the geographical distribution of organisms. I thought +that I had read that extinct fossil plants belonging to Australian forms +had lately been found in Australia, and all such cases seem to me very +interesting, as bearing on development. + +I have been so astonished at the apparently sudden coming in of the +higher phanerogams, that I have sometimes fancied that development might +have slowly gone on for an immense period in some isolated continent or +large island, perhaps near the South Pole. I poured out my idle thoughts +in writing, as if I had been talking with you. + +No fact has so interested me for a heap of years as your case of the +plants on the equatorial mountains of Africa; and Wallace tells me that +some one (Baker?) has described analogous cases on the mountains of +Madagascar (398/1. See Letter 397, note.)...I think that you ought to +allude to these cases. + +I most fully agree that no problem is more interesting than that of +the temperate forms in the southern hemisphere, common to the north. I +remember writing about this after Wallace's book appeared, and hoping +that you would take it up. The frequency with which the drainage from +the land passes through mountain-chains seems to indicate some general +law--viz., the successive formation of cracks and lines of elevation +between the nearest ocean and the already upraised land; but that is too +big a subject for a note. + +I doubt whether any insects can be shown with any probability to have +been flower feeders before the middle of the Secondary period. Several +of the asserted cases have broken down. + +Your long letter has stirred many pleasant memories of long past days, +when we had many a discussion and many a good fight. + + +LETTER 399. TO J.D. HOOKER. Down, August 21st, 1881. + +I cannot aid you much, or at all. I should think that no one could +have thought on the modification of species without thinking of +representative species. But I feel sure that no discussion of any +importance had been published on this subject before the "Origin," +for if I had known of it I should assuredly have alluded to it in the +"Origin," as I wished to gain support from all quarters. I did not then +know of Von Buch's view (alluded to in my Historical Introduction in all +the later editions). Von Buch published his "Isles Canaries" in 1836, +and he here briefly argues that plants spread over a continent and +vary, and the varieties in time come to be species. He also argues that +closely allied species have been thus formed in the SEPARATE valleys of +the Canary Islands, but not on the upper and open parts. I could lend +you Von Buch's book, if you like. I have just consulted the passage. + +I have not Baer's papers; but, as far as I remember, the subject is not +fully discussed by him. + +I quite agree about Wallace's position on the ocean and continent +question. + +To return to geographical distribution: As far as I know, no one ever +discussed the meaning of the relation between representative species +before I did, and, as I suppose, Wallace did in his paper before the +Linnean Society. Von Buch's is the nearest approach to such discussion +known to me. + + +LETTER 400. TO W.D. CRICK. + +(400/1. The following letters are interesting not only for their own +sake, but because they tell the history of the last of Mr. Darwin's +publications--his letter to "Nature" on the "Dispersal of Freshwater +Bivalves," April 6th, 1882.) + +Down, February 21st, 1882. + +Your fact is an interesting one, and I am very much obliged to you for +communicating it to me. You speak a little doubtfully about the name of +the shell, and it would be indispensable to have this ascertained with +certainty. Do you know any good conchologist in Northampton who could +name it? If so I should be obliged if you would inform me of the result. + +Also the length and breadth of the shell, and how much of leg (which +leg?) of the Dytiscus [a large water-beetle] has been caught. If you +cannot get the shell named I could take it to the British Museum when I +next go to London; but this probably will not occur for about six weeks, +and you may object to lend the specimen for so long a time. + +I am inclined to think that the case would be worth communicating to +"Nature." + +P.S.--I suppose that the animal in the shell must have been alive when +the Dytiscus was captured, otherwise the adductor muscle of the shell +would have relaxed and the shell dropped off. + + +LETTER 401. TO W.D. CRICK. Down, February 25th, 1882. + +I am much obliged for your clear and distinct answers to my questions. +I am sorry to trouble you, but there is one point which I do not fully +understand. Did the shell remain attached to the beetle's leg from the +18th to the 23rd, and was the beetle kept during this time in the air? + +Do I understand rightly that after the shell had dropped off, both being +in water, that the beetle's antenna was again temporarily caught by the +shell? + +I presume that I may keep the specimen till I go to London, which will +be about the middle of next month. + +I have placed the shell in fresh-water, to see if the valve will open, +and whether it is still alive, for this seems to me a very interesting +point. As the wretched beetle was still feebly alive, I have put it in +a bottle with chopped laurel leaves, that it may die an easy and quicker +death. I hope that I shall meet with your approval in doing so. + +One of my sons tells me that on the coast of N. Wales the bare fishing +hooks often bring up young mussels which have seized hold of the points; +but I must make further enquiries on this head. + + +LETTER 402. TO W.D. CRICK. Down, March 23rd, 1882. + +I have had a most unfortunate and extraordinary accident with your +shell. I sent it by post in a strong box to Mr. Gwyn Jeffreys to be +named, and heard two days afterwards that he had started for Italy. +I then wrote to the servant in charge of his house to open the parcel +(within which was a cover stamped and directed to myself) and return +it to me. This servant, I suppose, opened the box and dropped the glass +tube on a stone floor, and perhaps put his foot on it, for the tube and +shell were broken into quite small fragments. These were returned to me +with no explanation, the box being quite uninjured. I suppose you would +not care for the fragments to be returned or the Dytiscus; but if you +wish for them they shall be returned. I am very sorry, but it has not +been my fault. + +It seems to me almost useless to send the fragments of the shell to the +British Museum to be named, more especially as the umbo has been lost. +It is many years since I have looked at a fresh-water shell, but I +should have said that the shell was Cyclas cornea. (402/1. It was Cyclas +cornea.) Is Sphaenium corneum a synonym of Cyclas? Perhaps you could +tell by looking to Mr. G. Jeffreys' book. If so, may we venture to call +it so, or shall I put an (?) to the name? + +As soon as I hear from you I will send my letter to "Nature." Do you +take in "Nature," or shall I send you a copy? + + + +CHAPTER 2.VIII.--MAN. + +I. Descent of Man.--II. Sexual Selection.--III. Expression of the +Emotions. + + +2.VIII.I. DESCENT OF MAN, 1860-1882. + + +LETTER 403. TO C. LYELL. Down, April 27th [1860]. + +I cannot explain why, but to me it would be an infinite satisfaction to +believe that mankind will progress to such a pitch that we should [look] +back at [ourselves] as mere Barbarians. I have received proof-sheets +(with a wonderfully nice letter) of very hostile review by Andrew +Murray, read before the Royal Society of Edinburgh. (403/1. "On Mr. +Darwin's Theory of the Origin of Species," by Andrew Murray. "Proc. Roy. +Soc., Edinb." Volume IV., pages 274-91, 1862. The review concludes with +the following sentence: "I have come to be of opinion that Mr. Darwin's +theory is unsound, and that I am to be spared any collision between my +inclination and my convictions" (referring to the writer's belief in +Design).) But I am tired with answering it. Indeed I have done nothing +the whole day but answer letters. + + +LETTER 404. TO L. HORNER. + +(404/1. The following letter occurs in the "Memoir of Leonard Horner, +edited by his daughter Katherine M. Lyell," Volume II., page 300 +(privately printed, 1890).) + +Down, March 20th [1861]. + +I am very much obliged for your Address (404/2. Mr. Horner's Anniversary +Address to the Geological Society ("Proc. Geol. Soc." XVII., 1861).) +which has interested me much...I thought that I had read up pretty well +on the antiquity of man; but you bring all the facts so well together in +a condensed focus, that the case seems much clearer to me. How curious +about the Bible! (404/3. At page lxviii. Mr. Horner points out that the +"chronology, given in the margin of our Bibles," i.e., the statement +that the world was created 4004 B.C., is the work of Archbishop Usher, +and is in no way binding on those who believe in the inspiration of +Scripture. Mr. Horner goes on (page lxx): "The retention of the marginal +note in question is by no means a matter of indifference; it is untrue, +and therefore it is mischievous." It is interesting that Archbishop +Sumner and Dr. Dawes, Dean of Hereford, wrote with approbation of Mr. +Horner's views on Man. The Archbishop says: "I have always considered +the first verse of Genesis as indicating, rather than denying, a +PREADAMITE world" ("Memoir of Leonard Horner, II.", page 303).) I declare +I had fancied that the date was somehow in the Bible. You are coming out +in a new light as a Biblical critic. I must thank you for some remarks +on the "Origin of Species" (404/4. Mr. Horner (page xxxix) begins by +disclaiming the qualifications of a competent critic, and confines +himself to general remarks on the philosophic candour and freedom from +dogmatism of the "Origin": he does, however, give an opinion on the +geological chapters IX. and X. As a general criticism he quotes Mr. +Huxley's article in the "Westminster Review," which may now be read in +"Collected Essays," II., page 22.) (though I suppose it is almost as +incorrect to do so as to thank a judge for a favourable verdict): what +you have said has pleased me extremely. I am the more pleased, as I +would rather have been well attacked than have been handled in the +namby-pamby, old-woman style of the cautious Oxford Professor. (404/5. +This no doubt refers to Professor Phillips' "Life on the Earth," 1860, a +book founded on the author's "Rede Lecture," given before the University +of Cambridge. Reference to this work will be found in "Life and +Letters," II., pages 309, 358, 373.) + + +LETTER 405. TO J.D. HOOKER. + +(405/1. Mr. Wallace was, we believe, the first to treat the evolution of +Man in any detail from the point of view of Natural Selection, +namely, in a paper in the "Anthropological Review and Journal of the +Anthropological Society," May 1864, page clviii. The deep interest with +which Mr. Darwin read his copy is graphically recorded in the continuous +series of pencil-marks along the margins of the pages. His views are +fully given in Letter 406. The phrase, "in this case it is too far," +refers to Mr. Wallace's habit of speaking of the theory of Natural +Selection as due entirely to Darwin.) + +May 22nd 1864. + +I have now read Wallace's paper on Man, and think it MOST striking and +original and forcible. I wish he had written Lyell's chapters on Man. +(405/2. See "Life and Letters," III., page 11 et seq. for Darwin's +disappointment over Lyell's treatment of the evolutionary question in +his "Antiquity of Man"; see also page 29 for Lyell's almost pathetic +words about his own position between the discarded faith of many years +and the new one not yet assimilated. See also Letters 132, 164, 170.) I +quite agree about his high-mindedness, and have long thought so; but in +this case it is too far, and I shall tell him so. I am not sure that +I fully agree with his views about Man, but there is no doubt, in my +opinion, on the remarkable genius shown by the paper. I agree, however, +to the main new leading idea. + + +LETTER 406. TO A.R. WALLACE. + +(406/1. This letter was published in "Life and Letters," III., page 89.) + +Down, [May] 28th [1864]. + +I am so much better that I have just finished a paper for the Linnean +Society (406/2. On the three forms, etc., of Lythrum.); but I am not yet +at all strong, I felt much disinclination to write, and therefore you +must forgive me for not having sooner thanked you for your paper on +Man (406/3. "Anthropological Review," May 1864.) received on the 11th. +(406/4. Mr. Wallace wrote, May 10th, 1864: "I send you now my little +contribution to the theory of the origin of man. I hope you will be able +to agree with me. If you are able [to write] I shall be glad to have +your criticisms. I was led to the subject by the necessity of explaining +the vast mental and cranial differences between man and the apes +combined with such small structural differences in other parts of the +body,--and also by an endeavour to account for the diversity of human +races combined with man's almost perfect stability of form during all +historical epochs." But first let me say that I have hardly ever in my +life been more struck by any paper than that on "Variation," etc., etc., +in the "Reader." (406/5. "Reader," April 16th, 1864, an abstract of Mr. +Wallace: "On the Phenomena of Variation and Geographical Distribution +as illustrated by the Papilionidae of the Malayan Region." "Linn. +Soc. Trans." XXV.) I feel sure that such papers will do more for the +spreading of our views on the modification of species than any separate +treatises on the simple subject itself. It is really admirable; but you +ought not in the Man paper to speak of the theory as mine; it is just +as much yours as mine. One correspondent has already noticed to me your +"high-minded" conduct on this head. + +But now for your Man paper, about which I should like to write more than +I can. The great leading idea is quite new to me--viz. that during late +ages the mind will have been modified more than the body; yet I had got +as far as to see with you, that the struggle between the races of man +depended entirely on intellectual and moral qualities. The latter part +of the paper I can designate only as grand and most eloquently done. I +have shown your paper to two or three persons who have been here, and +they have been equally struck with it. I am not sure that I go with you +on all minor points: when reading Sir G. Grey's account of the constant +battles of Australian savages, I remember thinking that Natural +Selection would come in, and likewise with the Esquimaux, with whom the +art of fishing and managing canoes is said to be hereditary. I rather +differ on the rank, under a classificatory point of view, which you +assign to man; I do not think any character simply in excess ought ever +to be used for the higher divisions. Ants would not be separated from +other hymenopterous insects, however high the instinct of the one, and +however low the instincts of the other. With respect to the differences +of race, a conjecture has occurred to me that much may be due to the +correlation of complexion (and consequently hair) with constitution. +Assume that a dusky individual best escaped miasma, and you will +readily see what I mean. I persuaded the Director-General of the Medical +Department of the Army to send printed forms to the surgeons of all +regiments in tropical countries to ascertain this point, but I daresay +I shall never get any returns. Secondly, I suspect that a sort of sexual +selection has been the most powerful means of changing the races of man. +I can show that the different races have a widely different standard of +beauty. Among savages the most powerful men will have the pick of +the women, and they will generally leave the most descendants. I have +collected a few notes on man, but I do not suppose I shall ever use +them. Do you intend to follow out your views? and if so, would you like +at some future time to have my few references and notes? I am sure I +hardly know whether they are of any value, and they are at present in a +state of chaos. + +There is much more that I should like to write, but I have not strength. + +P.S. Our aristocracy is handsomer (more hideous according to a Chinese +or Negro) than the middle classes, from [having the] pick of the women; +but oh, what a scheme is primogeniture for destroying Natural Selection! +I fear my letter will be barely intelligible to you. + + +LETTER 406* A.R. WALLACE TO CHARLES DARWIN. 5, Westbourne Grove Terrace, +W., May 29th [1864]. + +You are always so ready to appreciate what others do, and especially to +overestimate my desultory efforts, that I cannot be surprised at your +very kind and flattering remarks on my papers. I am glad, however, that +you have made a few critical observations (and am only sorry that you +were not well enough to make more), as that enables me to say a few +words in explanation. + +My great fault is haste. An idea strikes me, I think over it for a few +days, and then write away with such illustrations as occur to me while +going on. I therefore look at the subject almost solely from one +point of view. Thus, in my paper on Man (406*/1. Published in the +"Anthropological Review," 1864.), I aim solely at showing that brutes +are modified in a great variety of ways by Natural Selection, but that +in none of these particular ways can Man be modified, because of the +superiority of his intellect. I therefore no doubt overlook a few +smaller points in which Natural Selection may still act on men and +brutes alike. Colour is one of them, and I have alluded to this in +correlation to constitution, in an abstract I have made at Sclater's +request for the "Natural History Review." (406*/2. "Nat. Hist. Review," +1864, page 328.) At the same time, there is so much evidence of +migrations and displacements of races of man, and so many cases of +peoples of distinct physical characters inhabiting the same or similar +regions, and also of races of uniform physical characters inhabiting +widely dissimilar regions,--that the external characteristics of the +chief races of man must, I think, be older than his present geographical +distribution, and the modifications produced by correlation to +favourable variations of constitution be only a secondary cause of +external modification. I hope you may get the returns from the Army. +(406*/3. Measurements taken of more than one million soldiers in the +United States showed that "local influences of some kind act directly +on structure."--"Descent of Man," 1901, page 45.) They would be very +interesting, but I do not expect the results would be favourable to your +view. + +With regard to the constant battles of savages leading to selection of +physical superiority, I think it would be very imperfect and subject to +so many exceptions and irregularities that it would produce no definite +result. For instance: the strongest and bravest men would lead, and +expose themselves most, and would therefore be most subject to wounds +and death. And the physical energy which led to any one tribe delighting +in war, might lead to its extermination, by inducing quarrels with +all surrounding tribes and leading them to combine against it. Again, +superior cunning, stealth, and swiftness of foot, or even better +weapons, would often lead to victory as well as mere physical strength. +Moreover, this kind of more or less perpetual war goes on amongst savage +peoples. It could lead, therefore, to no differential characters, but +merely to the keeping up of a certain average standard of bodily and +mental health and vigour. + +So with selection of variations adapted to special habits of life as +fishing, paddling, riding, climbing, etc., etc., in different races, +no doubt it must act to some extent, but will it be ever so rigid as to +induce a definite physical modification, and can we imagine it to have +had any part in producing the distinct races that now exist? + +The sexual selection you allude to will also, I think, have been equally +uncertain in its results. In the very lowest tribes there is rarely much +polygamy, and women are more or less a matter of purchase. There is also +little difference of social condition, and I think it rarely happens +that any healthy and undeformed man remains without wife and children. +I very much doubt the often-repeated assertion that our aristocracy +are more beautiful than the middle classes. I allow that they present +specimens of the highest kind of beauty, but I doubt the average. I have +noticed in country places a greater average amount of good looks among +the middle classes, and besides we unavoidably combine in our idea of +beauty, intellectual expression, and refinement of manner, which often +makes the less appear the more beautiful. Mere physical beauty--i.e. a +healthy and regular development of the body and features approaching to +the mean and type of European man, I believe is quite as frequent in one +class of society as the other, and much more frequent in rural districts +than in cities. + +With regard to the rank of man in zoological classification, I fear I +have not made myself intelligible. I never meant to adopt Owen's or any +other such views, but only to point out that from one point of view he +was right. I hold that a distinct family for Man, as Huxley allows, is +all that can possibly be given him zoologically. But at the same time, +if my theory is true, that while the animals which surrounded him have +been undergoing modification in all parts of their bodies to a generic +or even family degree of difference, he has been changing almost wholly +in the brain and head--then in geological antiquity the SPECIES man may +be as old as many mammalian families, and the origin of the FAMILY man +may date back to a period when some of the ORDERS first originated. + +As to the theory of Natural Selection itself, I shall always maintain it +to be actually yours and yours only. You had worked it out in details I +had never thought of, years before I had a ray of light on the subject, +and my paper would never have convinced anybody or been noticed as more +than an ingenious speculation, whereas your book has revolutionised the +study of Natural History, and carried away captive the best men of +the present age. All the merit I claim is the having been the means of +inducing you to write and publish at once. I may possibly some day go a +little more into this subject (of Man), and if I do will accept the kind +offer of your notes. + +I am now, however, beginning to write the "Narrative of my Travels," +which will occupy me a long time, as I hate writing narrative, and after +Bates' brilliant success rather fear to fail. + +I shall introduce a few chapters on Geographical Distribution and other +such topics. Sir C. Lyell, while agreeing with my main argument on Man, +thinks I am wrong in wanting to put him back into Miocene times, and +thinks I do not appreciate the immense interval even to the later +Pliocene. But I still maintain my view, which in fact is a logical +result of my theory; for if man originated in later Pliocene, when +almost all mammalia were of closely allied species to those now living, +and many even identical, then man has not been stationary in bodily +structure while animals have been varying, and my theory will be proved +to be all wrong. + +In Murchison's address to the Geographical Society, just delivered, he +points out Africa as being the oldest existing land. He says there is +no evidence of its having been ever submerged during the Tertiary epoch. +Here then is evidently the place to find early man. I hope something +good may be found in Borneo, and that the means may be found to explore +the still more promising regions of tropical Africa, for we can expect +nothing of man very early in Europe. + +It has given me great pleasure to find that there are symptoms of +improvement in your health. I hope you will not exert yourself too soon +or write more than is quite agreeable to you. I think I made out every +word of your letter, though it was not always easy. + +(406*/4. For Wallace's later views see Letter 408, note.) + + +LETTER 407. TO W. TURNER. + +(407/1. Sir William Turner is frequently referred to in the "Descent of +Man" as having supplied Mr. Darwin with information.) + +Down, December 14th [1866]. + +Your kindness when I met you at the Royal Society makes me think that +you would grant me the favour of a little information, if in your power. +I am preparing a book on Domestic Animals, and as there has been so much +discussion on the bearing of such views as I hold on Man, I have some +thoughts of adding a chapter on this subject. The point on which I +want information is in regard to any part which may be fairly called +rudimentary in comparison with the same part in the Quadrumana or any +other mammal. Now the os coccyx is rudimentary as a tail, and I am +anxious to hear about its muscles. Mr. Flower found for me in some work +that its one muscle (with striae) was supposed only to bring this bone +back to its proper position after parturition. This seems to me hardly +credible. He said he had never particularly examined this part, and when +I mentioned your name, he said you were the most likely man to give me +information. + +Are there any traces of other muscles? It seems strange if there are +none. Do you know how the muscles are in this part in the anthropoid +apes? The muscles of the ear in man may, I suppose, in most cases be +considered as rudimentary; and so they seem to be in the anthropoids; +at least, I am assured in the Zoological Gardens they do not erect their +ears. I gather there are a good many muscles in various parts of the +body which are in this same state: could you specify any of the best +cases? The mammae in man are rudimentary. Are there any other glands or +other organs which you can think of? I know I have no right whatever to +ask all these questions, and can only say that I should be grateful for +any information. If you tell me anything about the os coccyx or other +structures, I hope that you will permit me to quote the statement on +your authority, as that would add so greatly to its value. + +Pray excuse me for troubling you, and do not hurry yourself in the least +in answering me. + +I do not know whether you would care to possess a copy, but I told my +publisher to send you a copy of the new edition of the "Origin" last +month. + + +LETTER 408. TO W. TURNER. Down, February 1st [1867]. + +I thank you cordially for all your full information, and I regret much +that I have given you such great trouble at a period when your time is +so much occupied. But the facts were so valuable to me that I cannot +pretend that I am sorry that I did trouble you; and I am the less so, +as from what you say I hope you may be induced some time to write a full +account of all rudimentary structures in Man: it would be a very curious +and interesting memoir. I shall at present give only a brief abstract +of the chief facts which you have so very kindly communicated to me, and +will not touch on some of the doubtful points. I have received far more +information than I ventured to anticipate. There is one point which has +occurred to me, but I suspect there is nothing in it. If, however, there +should be, perhaps you will let me have a brief note from you, and if +I do not hear I will understand there is nothing in the notion. I have +included the down on the human body and the lanugo on the foetus as a +rudimentary representation of a hairy coat. (408/1. "Descent of Man" +I., page 25; II., page 375.) I do not know whether there is any direct +functional connection between the presence of hair and the panniculus +carnosus (408/2. Professor Macalister draws our attention to the fact +that Mr. Darwin uses the term panniculus in the generalised sense of any +sheet of muscle acting on the skin.) (to put the question under +another point of view, is it the primary or aboriginal function of the +panniculus to move the dermal appendages or the skin itself?); but both +are superficial, and would perhaps together become rudimentary. I was +led to think of this by the places (as far as my ignorance of anatomy +has allowed me to judge) of the rudimentary muscular fasciculi which you +specify. Now, some persons can move the skin of their hairy heads; and +is this not effected by the panniculus? How is it with the eyebrows? You +specify the axillae and the front region of the chest and lower part of +scapulae: now, these are all hairy spots in man. On the other hand, +the neck, and as I suppose the covering of the gluteus medius, are not +hairy; so, as I said, I presume there is nothing in this notion. If +there were, the rudiments of the panniculus ought perhaps to occur more +plainly in man than in woman... + +P.S.--If the skin on the head is moved by the panniculus, I think I +ought just to allude to it, as some men alone having power to move the +skin shows that the apparatus is generally rudimentary. + +(408/3. In March 1869 Darwin wrote to Mr. Wallace: "I shall be intensely +curious to read the "Quarterly." I hope you have not murdered too +completely your own and my child." The reference is to Mr. Wallace's +review, in the April number of the "Quarterly," of Lyell's "Principles +of Geology" (tenth edition), and of the sixth edition of the "Elements +of Geology." Mr. Wallace points out that here for the first time Sir C. +Lyell gave up his opposition to evolution; and this leads Mr. Wallace to +give a short account of the views set forth in the "Origin of Species." +In this article Mr. Wallace makes a definite statement as to his views +on the evolution of man, which were opposed to those of Mr. Darwin. He +upholds the view that the brain of man, as well as the organs of speech, +the hand and the external form, could not have been evolved by Natural +Selection (the child he is supposed to murder). At page 391 he writes: +"In the brain of the lowest savages, and, as far as we know, of the +prehistoric races, we have an organ...little inferior in size and +complexity to that of the highest types...But the mental requirements +of the lowest savages, such as the Australians or the Andaman Islanders, +are very little above those of many animals...How, then, was an organ +developed so far beyond the needs of its possessor? Natural Selection +could only have endowed the savage with a brain a little superior +to that of an ape, whereas he actually possesses one but very little +inferior to that of the average members of our learned societies." This +passage is marked in Mr. Darwin's copy with a triply underlined "No," +and with a shower of notes of exclamation. It was probably the first +occasion on which he realised the extent of this great and striking +divergence in opinion between himself and his colleague. + +He had, however, some indication of it in Wallace's paper on Man, +"Anthropological Review," 1864. (See Letter 406). He wrote to Lyell, +May 4th, 1869, "I was dreadfully disappointed about Man; it seems to me +incredibly strange." And to Mr. Wallace, April 14th, 1869, "If you had +not told me, I should have thought that [your remarks on Man] had been +added by some one else. As you expected, I differ grievously from you, +and I am very sorry for it." + + +LETTER 409. TO T.H. HUXLEY. Down, Thursday, February 21st [1868-70?]. + +I received the Jermyn Street programme, but have hardly yet considered +it, for I was all day on the sofa on Tuesday and Wednesday. Bad though +I was, I thought with constant pleasure of your very great kindness in +offering to read the proofs of my essay on man. I do not know whether +I said anything which might have appeared like a hint, but I assure you +that such a thought had never even momentarily passed through my mind. +Your offer has just made all the difference, that I can now write, +whether or no my essay is ever printed, with a feeling of satisfaction +instead of vague dread. + +Beg my colleague, Mrs. Huxley, not to forget the corrugator supercilii: +it will not be easy to catch the exact moment when the child is on the +point of crying, and is struggling against the wrinkling up [of] its +little eyes; for then I should expect the corrugator, from being little +under the command of the will, would come into play in checking or +stopping the wrinkling. An explosion of tears would tell nothing. + + +LETTER 410. TO FRANCIS GALTON. Down, December 23rd [1870?]. + +I have only read about fifty pages of your book (to the Judges) (410/1. +"Hereditary Genius: an Inquiry into its Laws and Consequences," by +Francis Galton, London, 1869. "The Judges of England between 1660 and +1865" is the heading of a section of this work (page 55). See "Descent +of Man" (1901), page 41.), but I must exhale myself, else something +will go wrong in my inside. I do not think I ever in all my life read +anything more interesting and original. And how well and clearly you +put every point! George, who has finished the book, and who expressed +himself just in the same terms, tells me the earlier chapters are +nothing in interest to the later ones! It will take me some time to get +to these later chapters, as it is read aloud to me by my wife, who is +also much interested. You have made a convert of an opponent in one +sense, for I have always maintained that, excepting fools, men did not +differ much in intellect, only in zeal and hard work; and I still think +[this] is an eminently important difference. I congratulate you on +producing what I am convinced will prove a memorable work. I look +forward with intense interest to each reading, but it sets me thinking +so much that I find it very hard work; but that is wholly the fault of +my brain, and not of your beautifully clear style. + + +LETTER 411. TO W.R. GREG. March 21st [1871?]. + +Many thanks for your note. I am very glad indeed to read remarks made by +a man who possesses such varied and odd knowledge as you do, and who is +so acute a reasoner. I have no doubt that you will detect blunders of +many kinds in my book. (411/1. "The Descent of Man.") Your MS. on the +proportion of the sexes at birth seems to me extremely curious, and I +hope that some day you will publish it. It certainly appears that the +males are decreasing in the London districts, and a most strange fact +it is. Mr. Graham, however, I observe in a note enclosed, does not seem +inclined to admit your conclusion. I have never much considered the +subject of the causes of the proportion. When I reflected on queen +bees producing only males when not impregnated, whilst some other +parthenogenetic insects produced, as far as known, only females, the +subject seemed to me hopelessly obscure. It is, however, pretty clear +that you have taken the one path for its solution. I wished only to +ascertain how far with various animals the males exceeded the females, +and I have given all the facts which I could collect. As far as I +know, no other data have been published. The equality of the sexes with +race-horses is surprising. My remarks on mankind are quite superficial, +and given merely as some sort of standard for comparison with the lower +animals. M. Thury is the writer who makes the sex depend on the period +of impregnation. His pamphlet was sent me from Geneva. (411/2. "Memoire +sur la loi de Production des Sexes," 2nd edition, 1863 (a pamphlet +published by Cherbuliez, Geneva).) I can lend it you if you like. I +subsequently read an account of experiments which convinced me that +M. Thury was in error; but I cannot remember what they were, only the +impression that I might safely banish this view from my mind. Your +remarks on the less ratio of males in illegitimate births strikes me +as the most doubtful point in your MS.--requiring two assumptions, viz. +that the fathers in such cases are relatively too young, and that the +result is the same as when the father is relatively too old. + +My son, George, who is a mathematician, and who read your MS. with much +interest, has suggested, as telling in the right direction, but whether +sufficient is another question, that many more illegitimate children +are murdered and concealed shortly after birth, than in the case of +legitimate children; and as many more males than females die during the +first few days of life, the census of illegitimate children practically +applies to an older age than with legitimate children, and would thus +slightly reduce the excess of males. This might possibly be worth +consideration. By a strange coincidence a stranger writes to me this +day, making the very same suggestion. + +I am quite delighted to hear that my book interests you enough to lead +you to read it with some care. + + +LETTER 412. TO FRANCIS GALTON. Down, January 4th, 1873. + +Very many thanks for "Fraser" (412/1. "Hereditary Improvement," by +Francis Galton, "Fraser's Magazine," January 1873, page 116.): I have +been greatly interested by your article. The idea of castes being +spontaneously formed and leading to intermarriage (412/2. "My object is +to build up, by the mere process of extensive enquiry and publication of +results, a sentiment of caste among those who are naturally gifted, +and to procure for them, before the system has fairly taken root, such +moderate social favours and preference, no more no less, as would seem +reasonable to those who were justly informed of the precise measure of +their importance to the nation" (loc. cit., page 123).) is quite new +to me, and I should suppose to others. I am not, however, so hopeful +as you. Your proposed Society (412/3. Mr. Galton proposes that "Some +society should undertake three scientific services: the first, by +means of a moderate number of influential local agencies, to institute +continuous enquiries into the facts of human heredity; the second to be +a centre of information on heredity for breeders of animals and plants; +and the third to discuss and classify the facts that were collected" +(loc. cit., page 124).) would have awfully laborious work, and I doubt +whether you could ever get efficient workers. As it is, there is much +concealment of insanity and wickedness in families; and there would +be more if there was a register. But the greatest difficulty, I think, +would be in deciding who deserved to be on the register. How few are +above mediocrity in health, strength, morals and intellect; and how +difficult to judge on these latter heads. As far as I see, within the +same large superior family, only a few of the children would deserve +to be on the register; and these would naturally stick to their own +families, so that the superior children of distinct families would have +no good chance of associating much and forming a caste. Though I see so +much difficulty, the object seems a grand one; and you have pointed out +the sole feasible, yet I fear utopian, plan of procedure in improving +the human race. I should be inclined to trust more (and this is part +of your plan) to disseminating and insisting on the importance of the +all-important principle of inheritance. I will make one or two minor +criticisms. Is it not possible that the inhabitants of malarious +countries owe their degraded and miserable appearance to the bad +atmosphere, though this does not kill them, rather than to "economy of +structure"? I do not see that an orthognathous face would cost more +than a prognathous face; or a good morale than a bad one. That is a fine +simile (page 119) about the chip of a statue (412/4. "...The life of the +individual is treated as of absolutely no importance, while the race is +as everything; Nature being wholly careless of the former except as a +contributor to the maintenance and evolution of the latter. Myriads +of inchoate lives are produced in what, to our best judgment, seems a +wasteful and reckless manner, in order that a few selected specimens +may survive, and be the parents of the next generation. It is as though +individual lives were of no more consideration than are the senseless +chips which fall from the chisel of the artist who is elaborating some +ideal form from a rude block" (loc. cit., page 119).); but surely Nature +does not more carefully regard races than individuals, as (I believe I +have misunderstood what you mean) evidenced by the multitude of races +and species which have become extinct. Would it not be truer to say that +Nature cares only for the superior individuals and then makes her new +and better races? But we ought both to shudder in using so freely the +word "Nature" (412/5. See Letter 190, Volume I.) after what De Candolle +has said. Again let me thank you for the interest received in reading +your essay. + +Many thanks about the rabbits; your letter has been sent to Balfour: +he is a very clever young man, and I believe owes his cleverness to +Salisbury blood. This letter will not be worth your deciphering. I have +almost finished Greg's "Enigmas." (412/6. "The Enigmas of Life," 1872.) +It is grand poetry--but too Utopian and too full of faith for me; so +that I have been rather disappointed. What do you think about it? He +must be a delightful man. + +I doubt whether you have made clear how the families on the Register are +to be kept pure or superior, and how they are to be in course of time +still further improved. + + +LETTER 413. TO MAX MULLER. Down, July 3rd, 1873. + +(413/1. In June, 1873, Professor Max Muller sent to Mr. Darwin a copy of +the sixth edition of his "Lectures on the Science of Language" (413/2. +A reference to the first edition occurs in "Life and Letters," II., page +390.), with a letter concluding with these words: "I venture to send +you my three lectures, trusting that, though I differ from some of your +conclusions, you will believe me to be one of your diligent readers and +sincere admirers.") + +I am much obliged for your kind note and present of your lectures. I +am extremely glad to have received them from you, and I had intended +ordering them. + +I feel quite sure from what I have read in your works that you would +never say anything of an honest adversary to which he would have any +just right to object; and as for myself, you have often spoken highly of +me--perhaps more highly than I deserve. + +As far as language is concerned I am not worthy to be your adversary, as +I know extremely little about it, and that little learnt from very few +books. I should have been glad to have avoided the whole subject, +but was compelled to take it up as well as I could. He who is fully +convinced, as I am, that man is descended from some lower animal, is +almost forced to believe a priori that articulate language has been +developed from inarticulate cries (413/3. "Descent of Man" (1901), page +133.); and he is therefore hardly a fair judge of the arguments opposed +to this belief. + +(413/4. In October, 1875, Mr. Darwin again wrote cordially to Professor +Max Muller on receipt of a pamphlet entitled "In Self-Defence" (413/5. +Printed in "Chips from a German Workshop," Volume IV., 1875, page 473.), +which is a reply to Professor Whitney's "Darwinism and Language" in the +"North American Review," July 1874. This essay had been brought before +the "general reader" in England by an article of Mr. G. Darwin's in the +"Contemporary Review," November, 1874, page 894, entitled, "Professor +Whitney on the Origin of Language." The article was followed by +"My reply to Mr. Darwin," contributed by Professor Muller to the +"Contemporary Review," January, 1875, page 305.) + + +LETTER 414. G. ROLLESTON TO CHARLES DARWIN. British Association, +Bristol, August 30th, 1875. + +(414/1. In the first edition of the "Descent of Man" Mr. Darwin wrote: +"It is a more curious fact that savages did not formerly waste away, as +Mr. Bagehot has remarked, before the classical nations, as they now +do before modern civilised nations..."(414/2. Bagehot, "Physics and +Politics," "Fortnightly Review," April, 1868, page 455.) In the second +edition (page 183) the statement remains, but a mass of evidence +(pages 183-92) is added, to which reference occurs in the reply to the +following letter.) + +At pages 4-5 of the enclosed Address (414/3. "British Association +Reports," 1875, page 142.) you will find that I have controverted Mr. +Bagehot's view as to the extinction of the barbarians in the times of +classical antiquity, as also the view of Poppig as to there being +some occult influence exercised by civilisation to the disadvantage of +savagery when the two come into contact. + +I write to say that I took up this subject without any wish to impugn +any views of yours as such, but with the desire of having my say upon +certain anti-sanitarian transactions and malfeasance of which I had had +a painful experience. + +On reading however what I said, and had written somewhat hastily, it has +struck me that what I have said might bear the former interpretation in +the eyes of persons who might not read other papers of mine, and indeed +other parts of the same Address, in which my adhesion, whatever it +is worth, to your views in general is plainly enough implied. I have +ventured to write this explanation to you for several reasons. + + +LETTER 415. TO G. ROLLESTON. Bassett, Southampton, September 2nd [1875]. + +I am much obliged to you for having sent me your Address, which has +interested me greatly. I quite subscribe to what you say about Mr. +Bagehot's striking remark, and wish I had not quoted it. I can perceive +no sort of reflection or blame on anything which I have written, and I +know well that I deserve many a good slap on the face. The decrease of +savage populations interests me much, and I should like you some time +to look at a discussion on this subject which I have introduced in the +second edition of the "Descent of Man," and which you can find (for I +have no copy here) in the list of additions. The facts have convinced me +that lessened fertility and the poor constitution of the children is one +chief cause of such decrease; and that the case is strictly parallel to +the sterility of many wild animals when made captive, the civilisation +of savages and the captivity of wild animals leading to the same result. + + +LETTER 416. TO ERNST KRAUSE. Down, June 30th, 1877. + +I have been much interested by your able argument against the belief +that the sense of colour has been recently acquired by man. (416/1. +See "Kosmos," June 1877, page 264, a review of Dr. Hugo Magnus' "Die +Geschichtliche Entwickelung des Farbensinnes," 1877. The first part is +chiefly an account of the author's views; Dr. Krause's argument begins +at page 269. The interest felt by Mr. Darwin is recorded by the numerous +pencil-marks on the margin of his copy.) The following observation bears +on this subject. + +I attended carefully to the mental development of my young children, and +with two, or as I believe three of them, soon after they had come to the +age when they knew the names of all common objects, I was startled by +observing that they seemed quite incapable of affixing the right names +to the colours in coloured engravings, although I tried repeatedly to +teach them. I distinctly remember declaring that they were colour-blind, +but this afterwards proved a groundless fear. + +On communicating this fact to another person he told me that he had +observed a nearly similar case. Therefore the difficulty which young +children experience either in distinguishing, or more probably in naming +colours, seems to deserve further investigation. I will add that it +formerly appeared to me that the gustatory sense, at least in the +case of my own infants, and very young children, differed from that of +grown-up persons. This was shown by their not disliking rhubarb mixed +with a little sugar and milk, which is to us abominably nauseous; and +in their strong taste for the sourest and most austere fruits, such as +unripe gooseberries and crabapples. + + +(PLATE: G.J. ROMANES, 1891. Elliott & Fry, photo. Walker and Cockerell, +ph. sc.) + + +LETTER 417. TO G.J. ROMANES. [Barlaston], August 20th, 1878. + +(417/1. Part of this letter (here omitted) is published in "Life and +Letters," III., page 225, and the whole in the "Life and Letters of G.J. +Romanes," page 74. The lecture referred to was on animal intelligence, +and was given at the Dublin meeting of the British Association.) + +...The sole fault which I find with your lecture is that it is too +short, and this is a rare fault. It strikes me as admirably clear and +interesting. I meant to have remonstrated that you had not discussed +sufficiently the necessity of signs for the formation of abstract ideas +of any complexity, and then I came on the discussion on deaf mutes. This +latter seems to me one of the richest of all the mines, and is worth +working carefully for years, and very deeply. I should like to read +whole chapters on this one head, and others on the minds of the higher +idiots. Nothing can be better, as it seems to me, than your several +lines or sources of evidence, and the manner in which you have arranged +the whole subject. Your book will assuredly be worth years of hard +labour; and stick to your subject. By the way, I was pleased at your +discussing the selection of varying instincts or mental tendencies; +for I have often been disappointed by no one having ever noticed this +notion. + +I have just finished "La Psychologie, son Present et son Avenir," +1876, by Delboeuf (a mathematician and physicist of Belgium) in about a +hundred pages. It has interested me a good deal, but why I hardly know; +it is rather like Herbert Spencer. If you do not know it, and would care +to see it, send me a postcard. + +Thank Heaven, we return home on Thursday, and I shall be able to go on +with my humdrum work, and that makes me forget my daily discomfort. + +Have you ever thought of keeping a young monkey, so as to observe its +mind? At a house where we have been staying there were Sir A. and Lady +Hobhouse, not long ago returned from India, and she and he kept [a] +young monkey and told me some curious particulars. One was that her +monkey was very fond of looking through her eyeglass at objects, and +moved the glass nearer and further so as to vary the focus. This struck +me, as Frank's son, nearly two years old (and we think much of his +intellect!!) is very fond of looking through my pocket lens, and I have +quite in vain endeavoured to teach him not to put the glass close down +on the object, but he always will do so. Therefore I conclude that a +child under two years is inferior in intellect to a monkey. + +Once again I heartily congratulate you on your well-earned present, and +I feel assured, grand future success. + +(417/2. Later in the year Mr. Darwin wrote: "I am delighted to hear that +you mean to work the comparative Psychology well. I thought your letter +to the "Times" very good indeed. (417/3. Romanes wrote to the "Times" +August 28th, 1878, expressing his views regarding the distinction +between man and the lower animals, in reply to criticisms contained in +a leading article in the "Times" of August 23rd on his lecture at the +Dublin meeting of the British Association.) Bartlett, at the Zoological +Gardens, I feel sure, would advise you infinitely better about +hardiness, intellect, price, etc., of monkey than F. Buckland; but with +him it must be viva voce. + +"Frank says you ought to keep a idiot, a deaf mute, a monkey, and a baby +in your house.") + + +LETTER 418. TO G.A. GASKELL. Down, November 15th, 1878. + +(418/1. This letter has been published in Clapperton's "Scientific +Meliorism," 1885, page 340, together with Mr. Gaskell's letter of +November 13th (page 337). Mr. Gaskell's laws are given in his letter of +November 13th, 1878. They are:-- + + I. The Organological Law: + Natural Selection, or the Survival of the Fittest. + + II. The Sociological Law: + Sympathetic Selection, or Indiscriminate Survival. + + III. The Moral Law: + Social Selection, or the Birth of the Fittest.) + +Your letter seems to me very interesting and clearly expressed, and I +hope that you are in the right. Your second law appears to be largely +acted on in all civilised countries, and I just alluded to it in my +remarks to the effect (as far as I remember) that the evil which would +follow by checking benevolence and sympathy in not fostering the weak +and diseased would be greater than by allowing them to survive and then +to procreate. + +With regard to your third law, I do not know whether you have read an +article (I forget when published) by F. Galton, in which he proposes +certificates of health, etc., for marriage, and that the best should be +matched. I have lately been led to reflect a little, (for, now that I +am growing old, my work has become [word indecipherable] special) on the +artificial checks, but doubt greatly whether such would be advantageous +to the world at large at present, however it may be in the distant +future. Suppose that such checks had been in action during the last +two or three centuries, or even for a shorter time in Britain, what a +difference it would have made in the world, when we consider America, +Australia, New Zealand, and S. Africa! No words can exaggerate the +importance, in my opinion, of our colonisation for the future history of +the world. + +If it were universally known that the birth of children could be +prevented, and this were not thought immoral by married persons, would +there not be great danger of extreme profligacy amongst unmarried women, +and might we not become like the "arreoi" societies in the Pacific? In +the course of a century France will tell us the result in many ways, and +we can already see that the French nation does not spread or increase +much. + +I am glad that you intend to continue your investigations, and I hope +ultimately may publish on the subject. + + +LETTER 419. TO K. HOCHBERG. Down, January 13th, 1879. + +I am much obliged for your note and for the essay which you have sent +me. I am a poor german scholar, and your german is difficult; but I +think that I understand your meaning, and hope at some future time, when +more at leisure, to recur to your essay. As far as I can judge, you have +made a great advance in many ways in the subject; and I will send your +paper to Mr. Edmund Gurney (The late Edmund Gurney, author of "The Power +of Sound," 1880.), who has written on and is much interested in the +origin of the taste for music. In reading your essay, it occurred to me +that facility in the utterance of prolonged sounds (I do not think that +you allude to this point) may possibly come into play in rendering them +musical; for I have heard it stated that those who vary their voices +much, and use cadences in long continued speaking, feel less fatigued +than those who speak on the same note. + + +LETTER 420. TO G.J. ROMANES. Down, February 5th, 1880. + +(420/1. Romanes was at work on what ultimately came to be a book on +animal intelligence. Romanes's reply to this letter is given in his +"Life," page 95. The table referred to is published as a frontispiece to +his "Mental Evolution in Animals," 1885.) + +As I feared, I cannot be of the least use to you. I could not venture to +say anything about babies without reading my Expression book and paper +on Infants, or about animals without reading the "Descent of Man" and +referring to my notes; and it is a great wrench to my mind to change +from one subject to another. + +I will, however, hazard one or two remarks. Firstly, I should have +thought that the word "love" (not sexual passion), as shown very low in +the scale, to offspring and apparently to comrades, ought to have come +in more prominently in your table than appears to be the case. Secondly, +if you give any instance of the appreciation of different stimulants by +plants, there is a much better case than that given by you--namely, +that of the glands of Drosera, which can be touched roughly two or three +times and do not transmit any effect, but do so if pressed by a weight +of 1/78000 grain ("Insectivorous Plants" 263). On the other hand, the +filament of Dionoea may be quietly loaded with a much greater weight, +while a touch by a hair causes the lobes to close instantly. This has +always seemed to me a marvellous fact. Thirdly, I have been accustomed +to look at the coming in of the sense of pleasure and pain as one of the +most important steps in the development of mind, and I should think it +ought to be prominent in your table. The sort of progress which I have +imagined is that a stimulus produced some effect at the point affected, +and that the effect radiated at first in all directions, and then that +certain definite advantageous lines of transmission were acquired, +inducing definite reaction in certain lines. Such transmission +afterwards became associated in some unknown way with pleasure or pain. +These sensations led at first to all sorts of violent action, such as +the wriggling of a worm, which was of some use. All the organs of sense +would be at the same time excited. Afterwards definite lines of action +would be found to be the most useful, and so would be practised. But it +is of no use my giving you my crude notions. + + +LETTER 421. TO S. TOLVER PRESTON. Down, May 22nd, 1880. + +(421/1. Mr. Preston wrote (May 20th, 1880) to the effect that +"self-interest as a motive for conduct is a thing to be commended--and +it certainly [is] I think...the only conceivable rational motive of +conduct: and always is the tacitly recognised motive in all rational +actions." Mr. Preston does not, of course, commend selfishness, which is +not true self-interest. + +There seem to be two ways of looking at the case given by Darwin. The +man who knows that he is risking his life,--realising that the personal +satisfaction that may follow is not worth the risk--is surely admirable +from the strength of character that leads him to follow the social +instinct against his purely personal inclination. But the man who +blindly obeys the social instinct is a more useful member of a social +community. He will act with courage where even the strong man will +fail.) + +Your letter appears to me an interesting and valuable one; but I have +now been working for some years exclusively on the physiology of plants, +and all other subjects have gone out of my head, and it fatigues me +much to try and bring them back again into my head. I am, moreover, +at present very busy, as I leave home for a fortnight's rest at the +beginning of next week. My conviction as yet remains unchanged, that +a man who (for instance) jumps into a river to save a life without a +second's reflection (either from an innate tendency or from one gained +by habit) is deservedly more honoured than a man who acts deliberately +and is conscious, for however short a time, that the risk and sacrifice +give him some inward satisfaction. + +You are of course familiar with Herbert Spencer's writings on Ethics. + + +(422/1. The observations to which the following letters refer were +continued by Mr. Wallis, who gave an account of his work in an +interesting paper in the "Proceedings of the Zoological Society," March +2nd, 1897. The results on the whole confirm the belief that traces of an +ancestral pointed ear exist in man.) + + +LETTER 422. TO H.M. WALLIS. Down, March 22nd, 1881. + +I am very much obliged for your courteous and kind note. The fact which +you communicate is quite new to me, and as I was laughed at about the +tips to human ears, I should like to publish in "Nature" some time your +fact. But I must first consult Eschricht, and see whether he notices +this fact in his curious paper on the lanugo on human embryos; and +secondly I ought to look to monkeys and other animals which have tufted +ears, and observe how the hair grows. This I shall not be able to do for +some months, as I shall not be in London until the autumn so as to go to +the Zoological Gardens. But in order that I may not hereafter throw away +time, will you be so kind as to inform me whether I may publish your +observation if on further search it seems desirable? + + +LETTER 423. TO H.M. WALLIS. Down, March 31st, 1881. + +I am much obliged for your interesting letter. I am glad to hear that +you are looking to other ears, and will visit the Zoological Gardens. +Under these circumstances it would be incomparably better (as more +authentic) if you would publish a notice of your observations in +"Nature" or some scientific journal. Would it not be well to confine +your attention to infants, as more likely to retain any primordial +character, and offering less difficulty in observing. I think, though, +it would be worth while to observe whether there is any relation (though +probably none) between much hairiness on the ears of an infant and +the presence of the "tip" on the folded margin. Could you not get an +accurate sketch of the direction of the hair of the tip of an ear? + +The fact which you communicate about the goat-sucker is very curious. +About the difference in the power of flight in Dorkings, etc., may it +not be due merely to greater weight of body in the adults? + +I am so old that I am not likely ever again to write on general and +difficult points in the theory of Evolution. + +I shall use what little strength is left me for more confined and easy +subjects. + + +LETTER 424. TO MRS. TALBOT. + +(Mrs. Emily Talbot was secretary of the Education Department of the +American Social Science Association, Boston, Mass. A circular and +register was issued by the Department, and answers to various questions +were asked for. See "Nature," April 28th, page 617, 1881. The above +letter was published in "The Field Naturalist," Manchester, 1883, page +5, edited by Mr. W.E. Axon, to whom we are indebted for a copy.) + +Down, July 19th [1881?] + +In response to your wish, I have much pleasure in expressing the +interest which I feel in your proposed investigation on the mental and +bodily development of infants. Very little is at present accurately +known on this subject, and I believe that isolated observations will add +but little to our knowledge, whereas tabulated results from a very large +number of observations, systematically made, would probably throw +much light on the sequence and period of development of the several +faculties. This knowledge would probably give a foundation for some +improvement in our education of young children, and would show us +whether the system ought to be followed in all cases. + +I will venture to specify a few points of inquiry which, as it seems to +me, possess some scientific interest. For instance, does the education +of the parents influence the mental powers of their children at any +age, either at a very early or somewhat more advanced stage? This could +perhaps be learned by schoolmasters and mistresses if a large number +of children were first classed according to age and their mental +attainments, and afterwards in accordance with the education of their +parents, as far as this could be discovered. As observation is one of +the earliest faculties developed in young children, and as this power +would probably be exercised in an equal degree by the children of +educated and uneducated persons, it seems not impossible that any +transmitted effect from education could be displayed only at a somewhat +advanced age. It would be desirable to test statistically, in a similar +manner, the truth of the oft-repeated statement that coloured children +at first learn as quickly as white children, but that they afterwards +fall off in progress. If it could be proved that education acts not only +on the individual, but, by transmission, on the race, this would be a +great encouragement to all working on this all-important subject. It is +well known that children sometimes exhibit, at a very early age, +strong special tastes, for which no cause can be assigned, although +occasionally they may be accounted for by reversion to the taste or +occupation of some progenitor; and it would be interesting to learn how +far such early tastes are persistent and influence the future career +of the individual. In some instances such tastes die away without +apparently leaving any after effect, but it would be desirable to know +how far this is commonly the case, as we should then know whether it +were important to direct as far as this is possible the early tastes +of our children. It may be more beneficial that a child should follow +energetically some pursuit, of however trifling a nature, and thus +acquire perseverance, than that he should be turned from it because +of no future advantage to him. I will mention one other small point of +inquiry in relation to very young children, which may possibly prove +important with respect to the origin of language; but it could be +investigated only by persons possessing an accurate musical ear. +Children, even before they can articulate, express some of their +feelings and desires by noises uttered in different notes. For instance, +they make an interrogative noise, and others of assent and dissent, +in different tones; and it would, I think, be worth while to ascertain +whether there is any uniformity in different children in the pitch of +their voices under various frames of mind. + +I fear that this letter can be of no use to you, but it will serve to +show my sympathy and good wishes in your researches. + + + +2.VIII.II. SEXUAL SELECTION, 1866-1872. + + +LETTER 425. TO JAMES SHAW. Down, February 11th [1866]. + +I am much obliged to you for your kindness in sending me an abstract of +your paper on beauty. (425/1. A newspaper report of a communication to +the "Dumfries Antiquarian and Natural History Society.") In my opinion +you take quite a correct view of the subject. It is clear that Dr. +Dickson has either never seen my book, or overlooked the discussion +on sexual selection. If you have any precise facts on birds' "courtesy +towards their own image in mirror or picture," I should very much like +to hear them. Butterflies offer an excellent instance of beauty being +displayed in conspicuous parts; for those kinds which habitually display +the underside of the wing have this side gaudily coloured, and this is +not so in the reverse case. I daresay you will know that the males of +many foreign butterflies are much more brilliantly coloured than the +females, as in the case of birds. I can adduce good evidence from two +large classes of facts (too large to specify) that flowers have become +beautiful to make them conspicuous to insects. (425/2. This letter is +published in "A Country Schoolmaster, James Shaw." Edited by Robert +Wallace, Edinburgh, 1899.) + +(425/3. Mr. Darwin wrote again to Mr. Shaw in April, 1866:--) + +I am much obliged for your kind letter and all the great trouble which +you have taken in sending to all the various and interesting facts on +birds admiring themselves. I am very glad to hear of these facts. I have +just finished writing and adding to a new edition of the "Origin," and +in this I have given, without going into details (so that I shall not be +able to use your facts), some remarks on the subject of beauty. + + +LETTER 426. TO A.D. BARTLETT. Down, February 16th [1867?] + +I want to beg two favours of you. I wish to ascertain whether the +Bower-Bird discriminates colours. (426/1. Mr. Bartlett does not seem to +have supplied any information on the point in question. The evidence for +the Bower-Bird's taste in colour is in "Descent of Man," II., page 112.) +Will you have all the coloured worsted removed from the cage and bower, +and then put all in a row, at some distance from bower, the enclosed +coloured worsted, and mark whether the bird AT FIRST makes any +selection. Each packet contains an equal quantity; the packets had +better be separate, and each thread put separate, but close +together; perhaps it would be fairest if the several colours were put +alternately--one thread of bright scarlet, one thread of brown, etc., +etc. There are six colours. Will you have the kindness to tell me +whether the birds prefer one colour to another? + +Secondly, I very much want several heads of the fancy and +long-domesticated rabbits, to measure the capacity of skull. I want +only small kinds, such as Himalaya, small Angora, Silver Grey, or any +small-sized rabbit which has long been domesticated. The Silver Grey +from warrens would be of little use. The animals must be adult, and the +smaller the breed the better. Now when any one dies would you send me +the carcase named; if the skin is of any value it might be skinned, but +it would be rather better with skin, and I could make a present to +any keeper to whom the skin is a perquisite. This would be of great +assistance to me, if you would have the kindness thus to aid me. + + +LETTER 427. TO W.B. TEGETMEIER. + +(427/1. We are not aware that the experiment here suggested has ever +been carried out.) + +Down, March 5th [1867]. + +I write on the bare and very improbable chance of your being able +to try, or get some trustworthy person to try, the following little +experiment. But I may first state, as showing what I want, that it has +been stated that if two long feathers in the tail of the male Widow-Bird +at the Cape of Good Hope are pulled out, no female will pair with him. + +Now, where two or three common cocks are kept, I want to know, if the +tail sickle-feathers and saddle-feathers of one which had succeeded in +getting wives were cut and mutilated and his beauty spoiled, whether he +would continue to be successful in getting wives. This might be tried +with drakes or peacocks, but no one would be willing to spoil for a +season his peacocks. I have no strength or opportunity of watching my +own poultry, otherwise I would try it. I would very gladly repay all +expenses of loss of value of the poultry, etc. But, as I said, I have +written on the most improbable chance of your interesting any one to +make the trial, or having time and inclination yourself to make it. +Another, and perhaps better, mode of making the trial would be to turn +down to some hens two or three cocks, one being injured in its plumage. + +I am glad to say that I have begun correcting proofs. (427/2. "The +Variation of Animals and Plants.") I hope that you received safely the +skulls which you so kindly lent me. + + +LETTER 428. TO W.B. TEGETMEIER. Down, March 30th [1867]. + +I am much obliged for your note, and shall be truly obliged if you will +insert any question on the subject. That is a capital remark of yours +about the trimmed game cocks, and shall be quoted by me. (428/1. +"Descent of Man," Edition I., Volume II., page 117. "Mr. Tegetmeier is +convinced that a game cock, though disfigured by being dubbed with his +hackles trimmed, would be accepted as readily as a male retaining all +his natural ornaments.") Nevertheless I am still inclined from many +facts strongly to believe that the beauty of the male bird determines +the choice of the female with wild birds, however it may be under +domestication. Sir R. Heron has described how one pied peacock was extra +attentive to the hens. This is a subject which I must take up as soon as +my present book is done. + +I shall be most particularly obliged to you if you will dye with magenta +a pigeon or two. (428/2. "Mr. Tegetmeier, at my request, stained some +of his birds with magenta, but they were not much noticed by the +others."--"Descent of Man" (1901), page 637.) Would it not be better +to dye the tail alone and crown of head, so as not to make too great +difference? I shall be very curious to hear how an entirely crimson +pigeon will be received by the others as well as his mate. + +P.S.--Perhaps the best experiment, for my purpose, would be to colour a +young unpaired male and turn him with other pigeons, and observe whether +he was longer or quicker than usual in mating. + + +LETTER 429. TO A.R. WALLACE. Down, April 29th [1867]. + +I have been greatly interested by your letter, but your view is not new +to me. (429/1. We have not been able to find Mr. Wallace's letter to +which this is a reply. It evidently refers to Mr. Wallace's belief in +the paramount importance of protection in the evolution of colour. This +is clear from the P.S. to the present letter and from the passages in +the "Origin" referred to. The first reference, Edition IV., page 240, +is as follows: "We can sometimes plainly see the proximate cause of the +transmission of ornaments to the males alone; for a pea-hen with the +long tail of the male bird would be badly fitted to sit on her eggs, and +a coal-black female capercailzie would be far more conspicuous on her +nest, and more exposed to danger, than in her present modest attire." +The passages in Edition I. (pages 89, 101) do not directly bear on the +question of protection.) If you will look at page 240 of the fourth +edition of the "Origin" you will find it very briefly given with +two extreme examples of the peacock and black grouse. A more general +statement is given at page 101, or at page 89 of the first edition, +for I have long entertained this view, though I have never had space to +develop it. But I had not sufficient knowledge to generalise as far as +you do about colouring and nesting. In your paper perhaps you will just +allude to my scanty remark in the fourth edition, because in my Essay +on Man I intend to discuss the whole subject of sexual selection, +explaining as I believe it does much with respect to man. I have +collected all my old notes, and partly written my discussion, and it +would be flat work for me to give the leading idea as exclusively from +you. But, as I am sure from your greater knowledge of Ornithology and +Entomology that you will write a much better discussion than I could, +your paper will be of great use to me. Nevertheless I must discuss the +subject fully in my Essay on Man. When we met at the Zoological Society, +and I asked you about the sexual differences in kingfishers, I had this +subject in view; as I had when I suggested to Bates the difficulty about +gaudy caterpillars, which you have so admirably (as I believe it will +prove) explained. (429/2. See a letter of February 26th, 1867, to Mr. +Wallace, "Life and Letters" III., page 94.) I have got one capital case +(genus forgotten) of a [Australian] bird in which the female has long +tail-plumes, and which consequently builds a different nest from all her +allies. (429/3. Menura superba: see "Descent of Man" (1901), page 687. +Rhynchoea, mentioned a line or two lower down, is discussed in the +"Descent," page 727. The female is more brightly coloured than the male, +and has a convoluted trachea, elsewhere a masculine character. There +seems some reason to suppose that "the male undertakes the duty of +incubation.") With respect to certain female birds being more brightly +coloured than the males, and the latter incubating, I have gone a little +into the subject, and cannot say that I am fully satisfied. I remember +mentioning to you the case of Rhynchoea, but its nesting seems unknown. +In some other cases the difference in brightness seemed to me hardly +sufficiently accounted for by the principle of protection. At the +Falkland Islands there is a carrion hawk in which the female (as I +ascertained by dissection) is the brightest coloured, and I doubt +whether protection will here apply; but I wrote several months ago to +the Falklands to make enquiries. The conclusion to which I have been +leaning is that in some of these abnormal cases the colour happened to +vary in the female alone, and was transmitted to females alone, and that +her variations have been selected through the admiration of the male. + +It is a very interesting subject, but I shall not be able to go on with +it for the next five or six months, as I am fully employed in correcting +dull proof-sheets. When I return to the work I shall find it much better +done by you than I could have succeeded in doing. + +It is curious how we hit on the same ideas. I have endeavoured to show +in my MS. discussion that nearly the same principles account for young +birds not being gaily coloured in many cases, but this is too complex a +point for a note. + +On reading over your letter again, and on further reflection, I do not +think (as far as I remember my words) that I expressed myself nearly +strongly enough on the value and beauty of your generalisation (429/4. +See Letter 203, Volume I.), viz., that all birds in which the female +is conspicuously or brightly coloured build in holes or under domes. I +thought that this was the explanation in many, perhaps most cases, but +do not think I should ever have extended my view to your generalisation. +Forgive me troubling you with this P.S. + + +LETTER 430. TO A.R. WALLACE. Down, May 5th [1867]. + +The offer of your valuable notes is most generous, but it would vex me +to take so much from you, as it is certain that you could work up +the subject very much better than I could. Therefore I earnestly, and +without any reservation, hope that you will proceed with your paper, so +that I return your notes. You seem already to have well investigated the +subject. I confess on receiving your note that I felt rather flat at my +recent work being almost thrown away, but I did not intend to show this +feeling. As a proof how little advance I had made on the subject, I may +mention that though I had been collecting facts on the colouring, and +other sexual differences in mammals, your explanation with respect to +the females had not occurred to me. I am surprised at my own stupidity, +but I have long recognised how much clearer and deeper your insight into +matters is than mine. I do not know how far you have attended to the +laws of inheritance, so what follows may be obvious to you. I have begun +my discussion on sexual selection by showing that new characters often +appear in one sex and are transmitted to that sex alone, and that from +some unknown cause such characters apparently appear oftener in the +male than in the female. Secondly, characters may be developed and be +confined to the male, and long afterwards be transferred to the female. +Thirdly, characters may arise in either sex and be transmitted to both +sexes, either in an equal or unequal degree. In this latter case I have +supposed that the survival of the fittest has come into play with female +birds and kept the female dull-coloured. With respect to the absence of +spurs in the female gallinaceous birds, I presume that they would be +in the way during incubation; at least I have got the case of a German +breed of fowls in which the hens were spurred, and were found to disturb +and break their eggs much. With respect to the females of deer not +having horns, I presume it is to save the loss of organised matter. In +your note you speak of sexual selection and protection as sufficient to +account for the colouring of all animals, but it seems to me doubtful +how far this will come into play with some of the lower animals, such as +sea anemones, some corals, etc., etc. On the other hand Hackel (430/1. +See "Descent of Man" (1901) page 402.) has recently well shown that +the transparency and absence of colour in the lower oceanic animals, +belonging to the most different classes, may be well accounted for on +the principle of protection. + +Some time or other I should like much to know where your paper on the +nests of birds has appeared, and I shall be extremely anxious to read +your paper in the "Westminster Review." (430/2. "Westminster Review," +July, 1867.) Your paper on the sexual colouring of birds will, I have +no doubt, be very striking. Forgive me, if you can, for a touch of +illiberality about your paper. + + +LETTER 431. TO A.R. WALLACE. March 19th, 1868. + +(431/1. "The Variation of Animals and Plants" having been published on +January 30th, 1868, Mr. Darwin notes in his diary that on February 4th +he "Began on Man and Sexual Selection." He had already (in 1864 and +1867) corresponded with Mr. Wallace on these questions--see for +instance the "Life and Letters," III., page 89; but, owing to various +interruptions, serious work on the subject did not begin until 1869. The +following quotations show the line of work undertaken early in 1868. + +Mr. Wallace wrote (March 19th, 1868): "I am glad you have got good +materials on sexual selection. It is no doubt a difficult subject. +One difficulty to me is, that I do not see how the constant MINUTE +variations, which are sufficient for Natural Selection to work with, +could be SEXUALLY selected. We seem to require a series of bold and +abrupt variations. How can we imagine that an inch in the tail of the +peacock, or 1/4-inch in that of the Bird of Paradise, would be noticed +and preferred by the female.") + +In regard to sexual selection. A girl sees a handsome man, and without +observing whether his nose or whiskers are the tenth of an inch longer +or shorter than in some other man, admires his appearance and says she +will marry him. So, I suppose, with the pea-hen; and the tail has been +increased in length merely by, on the whole, presenting a more gorgeous +appearance. J. Jenner Weir, however, has given me some facts showing +that birds apparently admire details of plumage. + + +LETTER 432. TO F. MULLER. March 28th [1868]. + +I am particularly obliged to you for your observations on the +stridulation of the two sexes of Lamellicorns. (432/1. We are unable +to find any mention of F. Muller's observations on this point; but +the reference is clearly to Darwin's observations on Necrophorus and +Pelobius, in which the stridulating rasp was bigger in the males in the +first individuals examined, but not so in succeeding specimens. "Descent +of Man," Edition II., Volume I., page 382.) I begin to fear that I am +completely in error owing to that common cause, viz. mistaking at first +individual variability for sexual difference. + +I go on working at sexual selection, and, though never idle, I am able +to do so little work each day that I make very slow progress. I knew +from Azara about the young of the tapir being striped, and about young +deer being spotted (432/2. Fritz Muller's views are discussed in the +"Descent of Man," Edition II., Volume II., page 305.); I have often +reflected on this subject, and know not what to conclude about the loss +of the stripes and spots. From the geographical distribution of the +striped and unstriped species of Equus there seems to be something very +mysterious about the loss of stripes; and I cannot persuade myself +that the common ass has lost its stripes owing to being rendered more +conspicuous from having stripes and thus exposed to danger. + + +LETTER 433. TO J. JENNER WEIR. + +(433/1. Mr. John Jenner Weir, to whom the following letters are +addressed, is frequently quoted in the "Descent of Man" as having +supplied Mr. Darwin with information on a variety of subjects.) + +Down, February 27th [1868]. + +I must thank you for your paper on apterous lepidoptera (433/2. +Published by the West Kent Natural History, Microscopical and +Photographic Society, Greenwich, 1867. Mr. Weir's paper seems chiefly to +have interested Mr. Darwin as affording a good case of gradation in +the degree of degradation of the wings in various species.), which has +interested me exceedingly, and likewise for the very honourable mention +which you make of my name. It is almost a pity that your paper was +not published in some Journal in which it would have had a wider +distribution. It contained much that was new to me. I think the part +about the relation of the wings and spiracles and tracheae might have +been made a little clearer. Incidentally, you have done me a good +service by reminding me of the rudimentary spurs on the legs of the +partridge, for I am now writing on what I have called sexual selection. +I believe that I am not mistaken in thinking that you have attended much +to birds in confinement, as well as to insects. If you could call to +mind any facts bearing on this subject, with birds, insects, or any +animals--such as the selection by a female of any particular male--or +conversely of a particular female by a male, or on the rivalry between +males, or on the allurement of the females by the males, or any such +facts, I should be most grateful for the information, if you would have +the kindness to communicate it. + +P.S.--I may give as instance of [this] class of facts, that Barrow +asserts that a male Emberiza (?) at the Cape has immensely long +tail-feathers during the breeding season (433/3. Barrow describes the +long tail feathers of Emberiza longicauda as enduring "but the season +of love." "An Account of Travels into the Interior of Southern Africa": +London, 1801, Volume I., page 244.); and that if these are cut off, he +has no chance of getting a wife. I have always felt an intense wish to +make analogous trials, but have never had an opportunity, and it is not +likely that you or any one would be willing to try so troublesome an +experiment. Colouring or staining the fine red breast of a bullfinch +with some innocuous matter into a dingy tint would be an analogous +case, and then putting him and ordinary males with a female. A +friend promised, but failed, to try a converse experiment with white +pigeons--viz., to stain their tails and wings with magenta or other +colours, and then observe what effect such a prodigious alteration would +have on their courtship. (433/4. See Letter 428.) It would be a fairer +trial to cut off the eyes of the tail-feathers of male peacocks; but who +would sacrifice the beauty of their bird for a whole season to please a +mere naturalist? + + +LETTER 434. TO J. JENNER WEIR. Down, February 29th [1868]. + +I have hardly ever received a note which has interested me more than +your last; and this is no exaggeration. I had a few cases of birds +perceiving slight changes in the dress of their owners, but your facts +are of tenfold value. I shall certainly make use of them, and need not +say how much obliged I should be for any others about which you feel +confident. + +Do you know of any birds besides some of the gallinaceae which are +polygamous? Do you know of any birds besides pigeons, and, as it is +said, the raven, which pair for their whole lives? + +Many years ago I visited your brother, who showed me his pigeons and +gave me some valuable information. Could you persuade him (but I fear +he would think it high treason) to stain a male pigeon some brilliant +colour, and observe whether it excited in the other pigeons, especially +the females, admiration or contempt? + +For the chance of your liking to have a copy and being able to find some +parts which would interest you, I have directed Mr. Murray to send you +my recent book on "Variation under Domestication." + +P.S.--I have somewhere safe references to cases of magpies, of which +one of a pair has been repeatedly (I think seven times) killed, and yet +another mate was always immediately found. (434/1. On this subject see +"Descent of Man," Edition I., Volume II., page 104, where Mr. Weir's +observations were made use of. This statement is quoted from Jenner +("Phil. Trans." 1824) in the "Descent of Man" (1901), page 620.) A +gamekeeper told me yesterday of analogous case. This perplexes me much. +Are there many unmarried birds? I can hardly believe it. Or will one of +a pair, of which the nest has been robbed, or which are barren, always +desert his or her mate for a strange mate with the attraction of a nest, +and in one instance with young birds in the nest? The gamekeeper said +during breeding season he had never observed a single or unpaired +partridge. How can the sexes be so equally matched? + +P.S. 2nd.--I fear you will find me a great bore, but I will be as +reasonable as can be expected in plundering one so rich as you. + +P.S. 3rd.--I have just received a letter from Dr. Wallace (434/2. +See "Descent of Man," Edition I., Volume I., pages 386-401, where +Dr. Wallace's observations are quoted.), of Colchester, about the +proportional numbers of the two sexes in Bombyx; and in this note, +apropos to an incidental remark of mine, he stoutly maintains that +female lepidoptera never notice the colours or appearance of the male, +but always receive the first male which comes; and this appears very +probable. He says he has often seen fine females receive old battered +and pale-tinted males. I shall have to admit this very great objection +to sexual selection in insects. His observations no doubt apply to +English lepidoptera, in most of which the sexes are alike. The brimstone +or orange-tip would be good to observe in this respect, but it is +hopelessly difficult. I think I have often seen several males following +one female; and what decides which male shall succeed? How is this about +several males; is it not so? + + +LETTER 435. TO J. JENNER WEIR. 6, Queen Anne Street, Cavendish Square, +W. [March 6th, 1868]. + +I have come here for a few weeks, for a little change and rest. Just as +I was leaving home I received your first note, and yesterday a second; +and both are most interesting and valuable to me. That is a very curious +observation about the goldfinch's beak (435/1. "Descent of Man," +Edition I., Volume I., page 39. Mr. Weir is quoted as saying that the +birdcatchers can distinguish the males of the goldfinch, Carduelis +elegans, by their "slightly longer beaks."), but one would hardly like +to trust it without measurement or comparison of the beaks of several +male and female birds; for I do not understand that you yourself assert +that the beak of the male is sensibly longer than that of the female. If +you come across any acute birdcatchers (I do not mean to ask you to +go after them), I wish you would ask what is their impression on the +relative numbers of the sexes of any birds which they habitually catch, +and whether some years males are more numerous and some years females. +I see that I must trust to analogy (an unsafe support) for sexual +selection in regard to colour in butterflies. You speak of the brimstone +butterfly and genus Edusa (435/2. Colias Edusa.) (I forget what this is, +and have no books here, unless it is Colias) not opening their wings. +In one of my notes to Mr. Stainton I asked him (but he could or did not +answer) whether butterflies such as the Fritillaries, with wings bright +beneath and above, opened and shut their wings more than Vanessae, most +of which, I think, are obscure on the under surface. That is a most +curious observation about the red underwing moth and the robin (435/3. +"Descent of Man," Edition I., Volume I., page 395. Mr. Weir describes +the pursuit of a red-underwing, Triphoena pronuba, by a robin which was +attracted by the bright colour of the moth, and constantly missed the +insect by breaking pieces off the wing instead of seizing the body. Mr. +Wallace's facts are given on the same page.), and strongly supports a +suggestion (which I thought hardly credible) of A.R. Wallace, viz. that +the immense wings of some exotic lepidoptera served as a protection from +difficulty of birds seizing them. I will probably quote your case. + +No doubt Dr. Hooker collected the Kerguelen moth, for I remember he told +me of the case when I suggested in the "Origin," the explanation of +the coleoptera of Madeira being apterous; but he did not know what had +become of the specimens. + +I am quite delighted to hear that you are observing coloured birds +(435/4. "Descent of Man," Edition I., Volume II., page 110.), though the +probability, I suppose, will be that no sure result will be gained. I am +accustomed with my numerous experiments with plants to be well satisfied +if I get any good result in one case out of five. + +You will not be able to read all my book--too much detail. Some of the +chapters in the second volume are curious, I think. If any man wants to +gain a good opinion of his fellow-men, he ought to do what I am doing, +pester them with letters. + + +LETTER 436. TO J. JENNER WEIR. 4, Chester Place, Regent's Park, N.W., +March 13th [1868]. + +You make a very great mistake when you speak of "the risk of your notes +boring me." They are of the utmost value to me, and I am sure I shall +never be tired of receiving them; but I must not be unreasonable. I +shall give almost all the facts which you have mentioned in your two +last notes, as well as in the previous ones; and my only difficulty +will be not to give too much and weary my readers. Your last note is +especially valuable about birds displaying the beautiful parts of their +plumage. Audubon (436/1. In his "Ornithological Biography," 5 volumes, +Edinburgh, 1831-49.) gives a good many facts about the antics of birds +during courtship, but nothing nearly so much to the purpose as yours. +I shall never be able to resist giving the whole substance of your last +note. It is quite a new light to me, except with the peacock and Bird +of Paradise. I must now look to turkey's wings; but I do not think that +their wings are beautiful when opened during courtship. Its tail is +finely banded. How about the drake and Gallus bankiva? I forget how +their wings look when expanded. Your facts are all the more valuable +as I now clearly see that for butterflies I must trust to analogy +altogether in regard to sexual selection. But I think I shall make out a +strong case (as far as the rather deceitful guide of analogy will serve) +in the sexes of butterflies being alike or differing greatly--in moths +which do not display the lower surface of their wings not having them +gaudily coloured, etc., etc.--nocturnal moths, etc.--and in some male +insects fighting for the females, and attracting them by music. + +My discussion on sexual selection will be a curious one--a mere +dovetailing of information derived from you, Bates, Wallace, etc., etc., +etc. + +We remain at above address all this month, and then return home. In the +summer, could I persuade you to pay us a visit of a day or two, and I +would try and get Bates and some others to come down? But my health is +so precarious, I can ask no one who will not allow me the privilege of +a poor old invalid; for talking, I find by long and dear-bought +experience, tries my head more than anything, and I am utterly incapable +of talking more than half an hour, except on rare occasions. + +I fear this note is very badly written; but I was very ill all +yesterday, and my hand shakes to-day. + + +LETTER 437. TO J. JENNER WEIR. 4, Chester Place, Regent's Park, N.W., +March 22nd [1868]. + +I hope that you will not think me ungrateful that I have not sooner +answered your note of the 16th; but in fact I have been overwhelmed both +with calls and letters; and, alas! one visit to the British Museum of an +hour or hour and a half does for me for the whole day. + +I was particularly glad to hear your and your brother's statement about +the "gay" deceiver-pigeons. (437/1. Some cock pigeons "called by our +English fanciers gay birds are so successful in their gallantries that, +as Mr. H. Weir informs me, they must be shut up, on account of the +mischief which they cause.") I did not at all know that certain birds +could win the affections of the females more than other males, except, +indeed, in the case of the peacock. Conversely, Mr. Hewitt, I remember, +states that in making hybrids the cock pheasant would prefer certain hen +fowls and strongly dislike others. I will write to Mr. H. in a few days, +and ask him whether he has observed anything of this kind with pure +unions of fowls, ducks, etc. I had utterly forgotten the case of the +ruff (437/2. The ruff, Machetes pugnax, was believed by Montague to be +polygamous. "Descent of Man," Edition I., Volume I., page 270.), but now +I remember having heard that it was polygamous; but polygamy with birds, +at least, does not seem common enough to have played an important part. +So little is known of habits of foreign birds: Wallace does not even +know whether Birds of Paradise are polygamous. Have you been a large +collector of caterpillars? I believe so. I inferred from a letter from +Dr. Wallace, of Colchester, that he would account for Mr. Stainton +and others rearing more female than male by their having collected the +larger and finer caterpillars. But I misunderstood him, and he maintains +that collectors take all caterpillars, large and small, for that they +collect the caterpillars alone of the rarer moths or butterflies. What +think you? I hear from Professor Canestrini (437/3. See "Descent of Man" +(1901), page 385.) in Italy that females are born in considerable excess +with Bombyx mori, and in greater excess of late years than formerly! +Quatrefages writes to me that he believes they are equal in France. +So that the farther I go the deeper I sink into the mire. With cordial +thanks for your most valuable letters. + +We remain here till April 1st, and then hurrah for home and quiet work. + + +LETTER 438. TO J. JENNER WEIR. 4, Chester Place, N.W., March 27th +[1868]. + +I hardly know which of your three last letters has interested me most. +What splendid work I shall have hereafter in selecting and arranging +all your facts. Your last letter is most curious--all about the +bird-catchers--and interested us all. I suppose the male chaffinch +in "pegging" approaches the captive singing-bird, from rivalry or +jealousy--if I am wrong please tell me; otherwise I will assume so. Can +you form any theory about all the many cases which you have given me, +and others which have been published, of when one [of a] pair is killed, +another soon appearing? Your fact about the bullfinches in your garden +is most curious on this head. (438/1. Mr. Weir stated that at Blackheath +he never saw or heard a wild bullfinch, yet when one of his caged males +died, a wild one in the course of a few days generally came and perched +near the widowed female, whose call-note is not loud. "Descent of Man" +(1901), page 623.) Are there everywhere many unpaired birds? What can +the explanation be? + +Mr. Gould assures me that all the nightingales which first come over are +males, and he believes this is so with other migratory birds. But this +does not agree with what the bird-catchers say about the common linnet, +which I suppose migrates within the limits of England. + +Many thanks for very curious case of Pavo nigripennis. (438/2. See +"Animals and Plants," Edition II., Volume I., page 306.) I am very glad +to get additional evidence. I have sent your fact to be inserted, if +not too late, in four foreign editions which are now printing. I am +delighted to hear that you approve of my book; I thought every mortal +man would find the details very tedious, and have often repented of +giving so many. You will find pangenesis stiff reading, and I fear will +shake your head in disapproval. Wallace sticks up for the great god Pan +like a man. + +The fertility of hybrid canaries would be a fine subject for careful +investigation. + + +LETTER 439. TO J. JENNER WEIR. Down, April 4th [1868]. + +I read over your last ten (!) letters this morning, and made an index +of their contents for easy reference; and what a mine of wealth you +have bestowed on me. I am glad you will publish yourself on gay-coloured +caterpillars and birds (439/1. See "Descent of Man," Edition I., Volume +I., page 417, where Mr. Weir's experiments are given; they were made to +test Mr. Wallace's theory that caterpillars, which are protected against +birds by an unpleasant taste, have been rendered conspicuous, so that +they are easily recognised. They thus escape being pecked or tasted, +which to soft-skinned animals would be as fatal as being devoured. See +Mr. Jenner Weir's papers, "Transact. Entomolog. Soc." 1869, page 2; +1870, page 337. In regard to one of these papers Mr. Darwin wrote (May +13th, 1869): "Your verification of Wallace's suggestion seems to me +to amount to quite a discovery."); it seems to me much the best plan; +therefore, I will not forward your letter to Mr. Wallace. I was much +in the Zoological Gardens during my month in London, and picked up +what scraps of knowledge I could. Without my having mentioned your most +interesting observations on the display of the Fringillidae (439/2. +"Descent of Man" (1901), page 738.), Mr. Bartlett told me how the Gold +Pheasant erects his collar and turns from side to side, displaying it +to the hen. He has offered to give me notes on the display of all +Gallinaceae with which he is acquainted; but he is so busy a man that I +rather doubt whether he will ever do so. + +I received about a week ago a remarkably kind letter from your brother, +and I am sorry to hear that he suffers much in health. He gave me some +fine facts about a Dun Hen Carrier which would never pair with a bird of +any other colour. He told me, also, of some one at Lewes who paints his +dog! and will inquire about it. By the way, Mr. Trimen tells me that as +a boy he used to paint butterflies, and that they long haunted the same +place, but he made no further observations on them. As far as colour is +concerned, I see I shall have to trust to mere inference from the males +displaying their plumage, and other analogous facts. I shall get +no direct evidence of the preference of the hens. Mr. Hewitt, of +Birmingham, tells me that the common hen prefers a salacious cock, but +is quite indifferent to colour. + +Will you consider and kindly give me your opinion on the two following +points. Do very vigorous and well-nourished hens receive the male +earlier in the spring than weaker or poorer hens? I suppose that they +do. Secondly, do you suppose that the birds which pair first in the +season have any advantage in rearing numerous and healthy offspring over +those which pair later in the season? With respect to the mysterious +cases of which you have given me so many, in addition to those +previously collected, of when one bird of a pair is shot another +immediately supplying its place, I was drawing to the conclusion that +there must be in each district several unpaired birds; yet this seems +very improbable. You allude, also, to the unknown causes which keep down +the numbers of birds; and often and often have I marvelled over this +subject with respect to many animals. + + +LETTER 440. TO A.R. WALLACE. + +(440/1. The following refers to Mr. Wallace's article "A Theory of +Birds' Nests," in Andrew Murray's "Journal of Travel," Volume I., page +73. He here treats in fuller detail the view already published in the +"Westminster Review," July 1867, page 38. The rule which Mr. Wallace +believes, with very few exceptions, to hold good is, "that when both +sexes are of strikingly gay and conspicuous colours, the nest is...such +as to conceal the sitting bird; while, whenever there is a striking +contrast of colours, the male being gay and conspicuous, the female dull +and obscure, the nest is open, and the sitting bird exposed to view." +At this time Mr. Wallace allowed considerably more influence to sexual +selection (in combination with the need of protection) than in his later +writings. The following extract from a letter from Mr. Wallace to Darwin +(July 23rd, 1877) fixes the period at which the change in his views +occurred: "I am almost afraid to tell you that in going over the subject +of the colours of animals, etc., etc., for a small volume of essays, +etc., I am preparing, I have come to conclusions directly opposed to +voluntary sexual selection, and believe that I can explain (in a general +way) all the phenomena of sexual ornaments and colours by laws of +development aided by simple 'Natural Selection.'" He finally rejected +Mr. Darwin's theory that colours "have been developed by the preference +of the females, the more ornamented males becoming the parents of each +successive generation." "Darwinism," 1889, page 285. See also Letters +442, 443, 449, 450, etc.) + +Down, April 15th, [1868]. + +I have been deeply interested by your admirable article on birds' nests. +I am delighted to see that we really differ very little,--not more than +two men almost always will. You do not lay much or any stress on new +characters spontaneously appearing in one sex (generally the male), and +being transmitted exclusively, or more commonly only in excess, to that +sex. I, on the other hand, formerly paid far too little attention to +protection. I had only a glimpse of the truth; but even now I do not +go quite as far as you. I cannot avoid thinking rather more than you +do about the exceptions in nesting to the rule, especially the partial +exceptions, i.e., when there is some little difference between the sexes +in species which build concealed nests. I am not quite satisfied about +the incubating males; there is so little difference in conspicuousness +between the sexes. I wish with all my heart I could go the whole length +with you. You seem to think that male birds probably select the most +beautiful females; I must feel some doubt on this head, for I can find +no evidence of it. Though I am writing so carping a note, I admire the +article thoroughly. + +And now I want to ask a question. When female butterflies are more +brilliant than their males you believe that they have in most cases, or +in all cases, been rendered brilliant so as to mimic some other species, +and thus escape danger. But can you account for the males not having +been rendered equally brilliant and equally protected? (440/2. See +Wallace in the "Westminster Review," July, 1867, page 37, on the +protection to the female insect afforded by its resemblance either to an +inanimate object or to another insect protected by its unpalatableness. +The cases are discussed in relation to the much greater importance (to +the species as a whole) of the preservation of the female insect with +her load of eggs than the male who may safely be sacrificed after +pairing. See Letter 189, note.) Although it may be most for the welfare +of the species that the female should be protected, yet it would be some +advantage, certainly no disadvantage, for the unfortunate male to enjoy +an equal immunity from danger. For my part, I should say that the female +alone had happened to vary in the right manner, and that the beneficial +variations had been transmitted to the same sex alone. Believing in +this, I can see no improbability (but from analogy of domestic animals +a strong probability) that variations leading to beauty must often have +occurred in the males alone, and been transmitted to that sex alone. +Thus I should account in many cases for the greater beauty of the male +over the female, without the need of the protective principle. I should +be grateful for an answer on the point. + + +LETTER 441. TO J. JENNER WEIR. Down, April 18th [1868]. + +You see that I have taken you at your word, and have not (owing to heaps +of stupid letters) earlier noticed your three last letters, which as +usual are rich in facts. Your letters make almost a little volume on my +table. I daresay you hardly knew yourself how much curious information +was lying in your mind till I began the severe pumping process. The case +of the starling married thrice in one day is capital, and beats the +case of the magpies of which one was shot seven times consecutively. A +gamekeeper here tells me that he has repeatedly shot one of a pair of +jays, and it has always been immediately replaced. I begin to think that +the pairing of birds must be as delicate and tedious an operation as +the pairing of young gentlemen and ladies. If I can convince myself that +there are habitually many unpaired birds, it will be a great aid to me +in sexual selection, about which I have lately had many troubles, and +am therefore rejoiced to hear in your last note that your faith keeps +staunch. That is a curious fact about the bullfinches all appearing to +listen to the German singer (441/1. See Letter 445, note.); and this +leads me to ask how much faith may I put in the statement that male +birds will sing in rivalry until they injure themselves. Yarrell +formerly told me that they would sometimes even sing themselves to +death. I am sorry to hear that the painted bullfinch turns out to be a +female; though she has done us a good turn in exhibiting her jealousy, +of which I had no idea. + +Thank you for telling me about the wildness of the hybrid canaries: +nothing has hardly ever surprised me more than the many cases of +reversion from crossing. Do you not think it a very curious subject? I +have not heard from Mr. Bartlett about the Gallinaceae, and I daresay I +never shall. He told me about the Tragopan, and he is positive that the +blue wattle becomes gorged with blood, and not air. + +Returning to the first of the last three letters. It is most curious the +number of persons of the name of Jenner who have had a strong taste for +Natural History. It is a pity you cannot trace your connection with the +great Jenner, for a duke might be proud of his blood. + +I heard lately from Professor Rolleston of the inherited effects of an +injury in the same eye. Is the scar on your son's leg on the same side +and on exactly the same spot where you were wounded? And did the wound +suppurate, or heal by the first intention? I cannot persuade myself +of the truth of the common belief of the influence of the mother's +imagination on the child. A point just occurs to me (though it does +not at present concern me) about birds' nests. Have you read Wallace's +recent articles? (441/2. A full discussion of Mr. Wallace's views is +given in "Descent of Man," Edition I., Volume II., Chapter XV. Briefly, +Mr. Wallace's point is that the dull colour of the female bird is +protective by rendering her inconspicuous during incubation. Thus the +relatively bright colour of the male would not simply depend on sexual +selection, but also on the hen being "saved, through Natural Selection, +from acquiring the conspicuous colours of the male" (loc. cit., page +155).) I always distrust myself when I differ from him; but I cannot +admit that birds learn to make their nests from having seen them +whilst young. I must think it as true an instinct as that which leads a +caterpillar to suspend its cocoon in a particular manner. Have you had +any experience of birds hatched under a foster-mother making their nests +in the proper manner? I cannot thank you enough for all your kindness. + + +LETTER 442. TO A.R. WALLACE. + +(442/1. Dr. Clifford Allbutt's view probably had reference to the fact +that the sperm-cell goes, or is carried, to the germ-cell, never vice +versa. In this letter Darwin gives the reason for the "law" referred +to. Mr. A.R. Wallace has been good enough to give us the following +note:--"It was at this time that my paper on 'Protective Resemblance' +first appeared in the 'Westminster Review,' in which I adduced the +greater, or rather, the more continuous, importance of the female +(in the lower animals) for the race, and my 'Theory of Birds' Nests' +('Journal of Travel and Natural History,' No. 2) in which I applied this +to the usually dull colours of female butterflies and birds. It is +to these articles as well as to my letters that Darwin chiefly +refers."--Note by Mr. Wallace, May 27th, 1902.) + +Down, April 30th [1868]. + +Your letter, like so many previous ones, has interested me much. Dr. +Allbutt's view occurred to me some time ago, and I have written a short +discussion on it. It is, I think, a remarkable law, to which I have +found no exception. The foundation lies in the fact that in many cases +the eggs or seeds require nourishment and protection by the mother-form +for some time after impregnation. Hence the spermatozoa and antherozoids +travel in the lower aquatic animals and plants to the female, and pollen +is borne to the female organ. As organisms rise in the scale it seems +natural that the male should carry the spermatozoa to the female in his +own body. As the male is the searcher, he has required and gained more +eager passions than the female; and, very differently from you, I look +at this as one great difficulty in believing that the males select the +more attractive females; as far as I can discover, they are always ready +to seize on any female, and sometimes on many females. Nothing would +please me more than to find evidence of males selecting the more +attractive females. I have for months been trying to persuade myself of +this. There is the case of man in favour of this belief, and I know in +hybrid unions of males preferring particular females, but, alas, not +guided by colour. Perhaps I may get more evidence as I wade through my +twenty years' mass of notes. + +I am not shaken about the female protected butterflies. I will grant +(only for argument) that the life of the male is of very little +value,--I will grant that the males do not vary, yet why has not the +protective beauty of the female been transferred by inheritance to the +male? The beauty would be a gain to the male, as far as we can see, as +a protection; and I cannot believe that it would be repulsive to the +female as she became beautiful. But we shall never convince each other. +I sometimes marvel how truth progresses, so difficult is it for one man +to convince another, unless his mind is vacant. Nevertheless, I myself +to a certain extent contradict my own remark, for I believe far more in +the importance of protection than I did before reading your articles. + +I do not think you lay nearly stress enough in your articles on what +you admit in your letters: viz., "there seems to be some production of +vividness...of colour in the male independent of protection." This I +am making a chief point; and have come to your conclusion so far that +I believe that intense colouring in the female sex is often checked by +being dangerous. + +That is an excellent remark of yours about no known case of male alone +assuming protective colours; but in the cases in which protection has +been gained by dull colours, I presume that sexual selection would +interfere with the male losing his beauty. If the male alone had +acquired beauty as a protection, it would be most readily overlooked, as +males are so often more beautiful than their females. Moreover, I grant +that the life of the male is somewhat less precious, and thus there +would be less rigorous selection with the male, so he would be less +likely to be made beautiful through Natural Selection for protection. +(442/2. This does not apply to sexual selection, for the greater the +excess of males, and the less precious their lives, so much the better +for sexual selection. [Note in original.]) But it seems to me a good +argument, and very good if it could be thoroughly established. I do not +know whether you will care to read this scrawl. + + +LETTER 443. TO A.R. WALLACE. Down, May 5th [1868?]. + +I am afraid I have caused you a great deal of trouble in writing to me +at such length. I am glad to say that I agree almost entirely with +your summary, except that I should put sexual selection as an equal, +or perhaps as even a more important agent in giving colour than Natural +Selection for protection. As I get on in my work I hope to get clearer +and more decided ideas. Working up from the bottom of the scale, I have +as yet only got to fishes. What I rather object to in your articles is +that I do not think any one would infer from them that you place sexual +selection even as high as No. 4 in your summary. It was very natural +that you should give only a line to sexual selection in the summary to +the "Westminster Review," but the result at first to my mind was that +you attributed hardly anything to its power. In your penultimate +note you say "in the great mass of cases in which there is great +differentiation of colour between the sexes, I believe it is due almost +wholly to the need of protection to the female." Now, looking to the +whole animal kingdom, I can at present by no means admit this view; but +pray do not suppose that because I differ to a certain extent, I do not +thoroughly admire your several papers and your admirable generalisation +on birds' nests. With respect to this latter point, however, although, +following you, I suspect that I shall ultimately look at the whole case +from a rather different point of view. + +You ask what I think about the gay-coloured females of Pieris. (443/1. +See "Westminster Review," July, 1867, page 37; also Letter 440.) I +believe I quite follow you in believing that the colours are wholly due +to mimicry; and I further believe that the male is not brilliant from +not having received through inheritance colour from the female, and from +not himself having varied; in short, that he has not been influenced by +selection. + +I can make no answer with respect to the elephants. With respect to +the female reindeer, I have hitherto looked at the horns simply as the +consequence of inheritance not having been limited by sex. + +Your idea about colour being concentrated in the smaller males seems +good, and I presume that you will not object to my giving it as your +suggestion. + + +LETTER 444. TO J. JENNER WEIR. Down, May 7th [1868]. + +I have now to thank you for no less than four letters! You are so kind +that I will not apologise for the trouble I cause you; but it has lately +occurred to me that you ought to publish a paper or book on the habits +of the birds which you have so carefully observed. But should you do +this, I do not think that my giving some of the facts for a special +object would much injure the novelty of your work. There is such a +multitude of points in these last letters that I hardly know what to +touch upon. Thanks about the instinct of nidification, and for your +answers on many points. I am glad to hear reports about the ferocious +female bullfinch. I hope you will have another try in colouring males. +I have now finished lepidoptera, and have used your facts about +caterpillars, and as a caution the case of the yellow-underwings. I +have now begun on fishes, and by comparing different classes of facts my +views are getting a little more decided. In about a fortnight or three +weeks I shall come to birds, and then I dare say that I shall be extra +troublesome. I will now enclose a few queries for the mere chance of +your being able to answer some of them, and I think it will save you +trouble if I write them on a separate slip, and then you can sometimes +answer by a mere "no" or "yes." + +Your last letter on male pigeons and linnets has interested me much, for +the precise facts which you have given me on display are of the utmost +value for my work. I have written to Mr. Bartlett on Gallinaceae, but I +dare say I shall not get an answer. I had heard before, but am glad to +have confirmation about the ruffs being the most numerous. I am greatly +obliged to your brother for sending out circulars. I have not heard from +him as yet. I want to ask him whether he has ever observed when several +male pigeons are courting one female that the latter decides with which +male she will pair. The story about the black mark on the lambs must be +a hoax. The inaccuracy of many persons is wonderful. I should like to +tell you a story, but it is too long, about beans growing on the wrong +side of the pod during certain years. + +Queries: + +Does any female bird regularly sing? + +Do you know any case of both sexes, more especially of the female, +[being] more brightly coloured whilst young than when come to maturity +and fit to breed? An imaginary instance would be if the female +kingfisher (or male) became dull coloured when adult. + +Do you know whether the male and female wild canary bird differ in +plumage (though I believe I could find this out for myself), and do any +of the domestic breeds differ sexually? + +Do you know any gallinaceous bird in which the female has well developed +spurs? + +It is very odd that my memory should fail me, but I cannot remember +whether, in accordance with your views, the wing of Gallus bankiva (or +Game-Cock, which is so like the wild) is ornamental when he opens and +scrapes it before the female. I fear it is not; but though I have often +looked at wing of the wild and tame bird, I cannot call to mind the +exact colours. What a number of points you have attended to; I did +not know that you were a horticulturist. I have often marvelled at the +different growth of the flowering and creeping branches of the ivy; but +had no idea that they kept their character when propagated by cuttings. +There is a S. American genus (name forgotten just now) which differs +in an analogous manner but even greater degree, but it is difficult to +cultivate in our hot-house. I have tried and failed. + + +LETTER 445. TO J. JENNER WEIR. Down, May 30th [1868]. + +I am glad to hear your opinion on the nest-making instinct, for I am +Tory enough not to like to give up all old beliefs. Wallace's view +(445/1. See Letter 440, etc.) is also opposed to a great mass of +analogical facts. The cases which you mention of suddenly reacquired +wildness seem curious. I have also to thank you for a previous valuable +letter. With respect to spurs on female Gallinaceae, I applied to Mr. +Blyth, who has wonderful systematic knowledge, and he tells me that the +female Pavo muticus and Fire-back pheasants are spurred. From various +interruptions I get on very slowly with my Bird MS., but have already +often and often referred to your volume of letters, and have used +various facts, and shall use many more. And now I am ashamed to say +that I have more questions to ask; but I forget--you told me not to +apologise. + +1. In your letter of April 14th you mention the case of about twenty +birds which seemed to listen with much interest to an excellent piping +bullfinch. (445/2. Quoted in the "Descent of Man" (1901), page 564. "A +bullfinch which had been taught to pipe a German waltz...when this bird +was first introduced into a room where other birds were kept and he +began to sing, all the others, consisting of about twenty linnets and +canaries, ranged themselves on the nearest side of their cages, and +listened with the greatest interest to the new performer.") What kind of +birds were these twenty? + +2. Is it true, as often stated, that a bird reared by foster-parents, +and who has never heard the song of its own species, imitates to a +certain extent the song of the species which it may be in the habit of +hearing? + +Now for a more troublesome point. I find it very necessary to make +out relation of immature plumage to adult plumage, both when the sexes +differ and are alike in the adult state. Therefore, I want much to learn +about the first plumage (answering, for instance, to the speckled state +of the robin before it acquires the red breast) of the several varieties +of the canary. Can you help me? What is the character or colour of the +first plumage of bright yellow or mealy canaries which breed true to +these tints? So with the mottled-brown canaries, for I believe that +there are breeds which always come brown and mottled. Lastly, in the +"prize-canaries," which have black wing- and tail-feathers during their +first (?) plumage, what colours are the wings and tails after the first +(?) moult or when adult? I should be particularly glad to learn this. +Heaven have mercy on you, for it is clear that I have none. I am going +to investigate this same point with all the breeds of fowls, as Mr. +Tegetmeier will procure for me young birds, about two months old, of all +the breeds. + +In the course of this next month I hope you will come down here on the +Saturday and stay over the Sunday. Some months ago Mr. Bates said +he would pay me a visit during June, and I have thought it would be +pleasanter for you to come here when I can get him, so that you would +have a companion if I get knocked up, as is sadly too often my bad habit +and great misfortune. + +Did you ever hear of the existence of any sub-breed of the canary in +which the male differs in plumage from the female? + + +LETTER 446. TO F. MULLER. Down, June 3rd [1868]. + +Your letter of April 22nd has much interested me. I am delighted that +you approve of my book, for I value your opinion more than that of +almost any one. I have yet hopes that you will think well of pangenesis. +I feel sure that our minds are somewhat alike, and I find it a great +relief to have some definite, though hypothetical view, when I reflect +on the wonderful transformations of animals, the re-growth of parts, and +especially the direct action of pollen on the mother form, etc. It often +appears to me almost certain that the characters of the parents are +"photographed" on the child, only by means of material atoms derived +from each cell in both parents, and developed in the child. I am sorry +about the mistake in regard to Leptotes. (446/1. See "Animals and +Plants," Edition I., Volume II., page 134, where it is stated that +Oncidium is fertile with Leptotes, a mistake corrected in the 2nd +edition.) I daresay it was my fault, yet I took pains to avoid such +blunders. Many thanks for all the curious facts about the unequal number +of the sexes in crustacea, but the more I investigate this subject +the deeper I sink in doubt and difficulty. Thanks, also, for the +confirmation of the rivalry of Cicadae. (446/2. See "Descent of Man," +Edition I., Volume I., page 351, for F. Muller's observations; and for +a reference to Landois' paper.) I have often reflected with surprise on +the diversity of the means for producing music with insects, and still +more with birds. We thus get a high idea of the importance of song in +the animal kingdom. Please to tell me where I can find any account of +the auditory organs in the orthoptera? Your facts are quite new to me. +Scudder has described an annectant insect in Devonian strata, furnished +with a stridulating apparatus. (446/3. The insect is no doubt Xenoneura +antiquorum, from the Devonian rocks of New Brunswick. Scudder compared +a peculiar feature in the wing of this species to the stridulating +apparatus of the Locustariae, but afterwards stated that he had been led +astray in his original description, and that there was no evidence in +support of the comparison with a stridulating organ. See the "Devonian +Insects of New Brunswick," reprinted in S.H. Scudder's "Fossil Insects +of N. America," Volume I., page 179, New York, 1890.) I believe he is to +be trusted, and if so the apparatus is of astonishing antiquity. After +reading Landois' paper I have been working at the stridulating organ in +the lamellicorn beetles, in expectation of finding it sexual, but I have +only found it as yet in two cases, and in these it was equally developed +in both sexes. I wish you would look at any of your common lamellicorns +and take hold of both males and females and observe whether they make +the squeaking or grating noise equally. If they do not, you could +perhaps send me a male and female in a light little box. How curious +it is that there should be a special organ for an object apparently so +unimportant as squeaking. Here is another point: have you any Toucans? +if so, ask any trustworthy hunter whether the beaks of the males, or of +both sexes, are more brightly coloured during the breeding season than +at other times of the year? I have also to thank you for a previous +letter of April 3rd, with some interesting facts on the variation of +maize, the sterility of Bignonia and on conspicuous seeds. Heaven knows +whether I shall ever live to make use of half the valuable facts which +you have communicated to me... + + +LETTER 447. TO J. JENNER WEIR. Down, June 18th [1868]. + +Many thanks. I am glad that you mentioned the linnet, for I had much +difficulty in persuading myself that the crimson breast could be due to +change in the old feathers, as the books say. I am glad to hear of the +retribution of the wicked old she-bullfinch. You remember telling me how +many Weirs and Jenners have been naturalists; now this morning I have +been putting together all my references about one bird of a pair being +killed, and a new mate being soon found; you, Jenner Weir, have given +me some most striking cases with starlings; Dr. Jenner gives the most +curious case of all in "Philosophical Transactions" (447/1. "Phil. +Trans." 1824.), and a Mr. Weir gives the next most striking in +Macgillivray. (447/2. Macgillivray's "History of British Birds," Volume +I., page 570. See "Descent of Man" (1901), page 621.) Now, is this not +odd? Pray remember how very glad we shall be to see you here whenever +you can come. + +Did some ancient progenitor of the Weirs and Jenners puzzle his brains +about the mating of birds, and has the question become indelibly fixed +in all your minds? + + +LETTER 448. TO A.R. WALLACE. August 19th [1868]. + +I had become, before my nine weeks' horrid interruption of all work, +extremely interested in sexual selection, and was making fair progress. +In truth it has vexed me much to find that the farther I get on the more +I differ from you about the females being dull-coloured for protection. +I can now hardly express myself as strongly, even, as in the "Origin." +This has much decreased the pleasure of my work. In the course of +September, if I can get at all stronger, I hope to get Mr. J. Jenner +Weir (who has been wonderfully kind in giving me information) to pay +me a visit, and I will then write for the chance of your being able to +come, and I hope bring with you Mrs. Wallace. If I could get several of +you together it would be less dull for you, for of late I have found +it impossible to talk with any human being for more than half an hour, +except on extraordinary good days. + +(448/1. On September 16th Darwin wrote to Wallace on the same +subject:--) + +You will be pleased to hear that I am undergoing severe distress about +protection and sexual selection; this morning I oscillated with joy +towards you; this evening I have swung back to the old position, out of +which I fear I shall never get. + + +LETTER 449. TO A.R. WALLACE. + +(449/1. From "Life and Letters," Volume III., page 123.) + +Down, September 23rd [1868]. + +I am very much obliged for all your trouble in writing me your long +letter, which I will keep by me and ponder over. To answer it would +require at least 200 folio pages! If you could see how often I have +rewritten some pages you would know how anxious I am to arrive as near +as I can to the truth. I lay great stress on what I know takes place +under domestication; I think we start with different fundamental +notions on inheritance. I find it is most difficult, but not, I think, +impossible to see how, for instance, a few red feathers appearing on the +head of a male bird, and which are at first transmitted to both sexes, +would come to be transmitted to males alone. It is not enough that +females should be produced from the males with red feathers, which +should be destitute of red feathers; but these females must have a +latent tendency to produce such feathers, otherwise they would cause +deterioration in the red head-feathers of their male offspring. Such +latent tendency would be shown by their producing the red feathers when +old, or diseased in their ovaria. But I have no difficulty in making the +whole head red if the few red feathers in the male from the first tended +to be sexually transmitted. I am quite willing to admit that the female +may have been modified, either at the same time or subsequently, +for protection by the accumulation of variations limited in their +transmission to the female sex. I owe to your writings the consideration +of this latter point. But I cannot yet persuade myself that females +alone have often been modified for protection. Should you grudge the +trouble briefly to tell me, whether you believe that the plainer head +and less bright colours of female chaffinch, the less red on the head +and less clean colours of female goldfinch, the much less red on the +breast of the female bullfinch, the paler crest of golden-crested wren, +etc., have been acquired by them for protection? I cannot think so, any +more than I can that the considerable differences between female and +male house-sparrow, or much greater brightness of male Parus caeruleus +(both of which build under cover) than of female Parus, are related to +protection. I even misdoubt much whether the less blackness of female +blackbird is for protection. + +Again, can you give me reasons for believing that the moderate +differences between the female pheasant, the female Gallus bankiva, +the female of black grouse, the pea-hen, the female partridge, have all +special references to protection under slightly different conditions? I, +of course, admit that they are all protected by dull colours, derived, +as I think, from some dull-ground progenitor; and I account partly for +their difference by partial transference of colour from the male, and by +other means too long to specify; but I earnestly wish to see reason +to believe that each is specially adapted for concealment to its +environment. + +I grieve to differ from you, and it actually terrifies me and makes me +constantly distrust myself. I fear we shall never quite understand each +other. I value the cases of bright-coloured, incubating male fisher, and +brilliant female butterflies, solely as showing that one sex may be made +brilliant without any necessary transference of beauty to the other sex; +for in these cases I cannot suppose that beauty in the other sex was +checked by selection. + +I fear this letter will trouble you to read it. A very short answer +about your belief in regard to the female finches and Gallinaceae would +suffice. + + +LETTER 450. A.R. WALLACE TO CHARLES DARWIN. 9, St. Mark's Crescent, +N.W., September 27th, 1868. + +Your view seems to be that variations occurring in one sex are +transmitted either to that sex exclusively or to both sexes equally, or +more rarely partially transferred. But we have every gradation of +sexual colours, from total dissimilarity to perfect identity. If this is +explained solely by the laws of inheritance, then the colours of one or +other sex will be always (in relation to the environment) a matter of +chance. I cannot think this. I think selection more powerful than laws +of inheritance, of which it makes use, as shown by cases of two, three +or four forms of female butterflies, all of which have, I have little +doubt, been specialised for protection. + +To answer your first question is most difficult, if not impossible, +because we have no sufficient evidence in individual cases of slight +sexual difference, to determine whether the male alone has acquired his +superior brightness by sexual selection, or the female been made duller +by need of protection, or whether the two causes have acted. Many of the +sexual differences of existing species may be inherited differences from +parent forms, which existed under different conditions and had greater +or less need of protection. + +I think I admitted before, the general tendency (probably) of males to +acquire brighter tints. Yet this cannot be universal, for many female +birds and quadrupeds have equally bright tints. + +To your second question I can reply more decidedly. I do think the +females of the Gallinaceae you mention have been modified or been +prevented from acquiring the brighter plumage of the male, by need of +protection. I know that the Gallus bankiva frequents drier and more open +situations than the pea-hen of Java, which is found among grassy and +leafy vegetation, corresponding with the colours of the two. So the +Argus pheasant, male and female, are, I feel sure, protected by their +tints corresponding to the dead leaves of the lofty forest in which +they dwell, and the female of the gorgeous fire-back pheasant Lophura +viellottii is of a very similar rich brown colour. + +I do not, however, at all think the question can be settled by +individual cases, but by only large masses of facts. The colours of the +mass of female birds seem to me strictly analogous to the colours of +both sexes of snipes, woodcocks, plovers, etc., which are undoubtedly +protective. + +Now, supposing, on your view, that the colours of a male bird become +more and more brilliant by sexual selection, and a good deal of that +colour is transmitted to the female till it becomes positively injurious +to her during incubation, and the race is in danger of extinction; do +you not think that all the females who had acquired less of the male's +bright colours, or who themselves varied in a protective direction, +would be preserved, and that thus a good protective colouring would soon +be acquired? + +If you admit that this could occur, and can show no good reason why it +should not often occur, then we no longer differ, for this is the main +point of my view. + +Have you ever thought of the red wax-tips of the Bombycilla beautifully +imitating the red fructification of lichens used in the nest, and +therefore the FEMALES have it too? Yet this is a very sexual-looking +character. + +If sexes have been differentiated entirely by sexual selection the +females can have no relation to environment. But in groups when both +sexes require protection during feeding or repose, as snipes, woodcock, +ptarmigan, desert birds and animals, green forest birds, etc., arctic +birds of prey, and animals, then both sexes are modified for protection. +Why should that power entirely cease to act when sexual differentiation +exists and when the female requires protection, and why should the +colour of so many FEMALE BIRDS seem to be protective, if it has not been +made protective by selection. + +It is contrary to the principles of "Origin of Species," that colour +should have been produced in both sexes by sexual selection and +never have been modified to bring the female into harmony with the +environment. "Sexual selection is less rigorous than Natural Selection," +and will therefore be subordinate to it. + +I think the case of female Pieris pyrrha proves that females alone can +be greatly modified for protection. (450/1. My latest views on this +subject, with many new facts and arguments, will be found in the later +editions of my "Darwinism," Chapter X. (A.R.W.)) + + +LETTER 451. A.R. WALLACE TO CHARLES DARWIN. + +(451/1. On October 4th, 1868, Mr. Wallace wrote again on the same +subject without adding anything of importance to his arguments of +September 27th. We give his final remarks:--) + +October 4th, 1868. + +I am sorry to find that our difference of opinion on this point is a +source of anxiety to you. Pray do not let it be so. The truth will come +out at last, and our difference may be the means of setting others to +work who may set us both right. After all, this question is only an +episode (though an important one) in the great question of the "Origin +of Species," and whether you or I are right will not at all affect the +main doctrine--that is one comfort. + +I hope you will publish your treatise on "Sexual Selection" as a +separate book as soon as possible; and then, while you are going on with +your other work, there will no doubt be found some one to battle with me +over your facts on this hard problem. + + +LETTER 452. TO A.R. WALLACE. Down, October 6th [1868]. + +Your letter is very valuable to me, and in every way very kind. I will +not inflict a long answer, but only answer your queries. There are +breeds (viz. Hamburg) in which both sexes differ much from each other +and from both sexes of Gallus bankiva; and both sexes are kept constant +by selection. The comb of the Spanish male has been ordered to be +upright, and that of Spanish female to lop over, and this has been +effected. There are sub-breeds of game fowl, with females very distinct +and males almost identical; but this, apparently, is the result of +spontaneous variation, without special selection. I am very glad to hear +of case of female Birds of Paradise. + +I have never in the least doubted possibility of modifying female birds +alone for protection, and I have long believed it for butterflies. I +have wanted only evidence for the female alone of birds having had their +colour modified for protection. But then I believe that the variations +by which a female bird or butterfly could get or has got protective +colouring have probably from the first been variations limited in their +transmission to the female sex. And so with the variations of the +male: when the male is more beautiful than the female, I believe the +variations were sexually limited in their transmission to the males. + + +LETTER 453. TO B.D. WALSH. Down, October 31st, 1868. + +(453/1. A short account of the Periodical Cicada (C. septendecim) is +given by Dr. Sharp in the Cambridge Natural History, Insects II., page +570. We are indebted to Dr. Sharp for calling our attention to Mr. C.L. +Marlatt's full account of the insect in "Bulletin No. 14 [NS.] of the +U.S. Department of Agriculture," 1898. The Cicada lives for long periods +underground as larva and pupa, so that swarms of the adults of one +race (septendecim) appear at intervals of 17 years, while those of the +southern form or race (tredecim) appear at intervals of 13 years. +This fact was first made out by Phares in 1845, but was overlooked or +forgotten, and was only re-discovered by Walsh and Riley in 1868, who +published a joint paper in the "American Entomologist," Volume I., page +63. Walsh appears to have adhered to the view that the 13- and 17-year +forms are distinct species, though, as we gather from Marlatt's paper +(page 14), he published a letter to Mr. Darwin in which he speaks of the +13-year form as an incipient species; see "Index to Missouri Entomolog. +Reports Bull. 6," U.S.E.C., page 58 (as given by Marlatt). With regard +to the cause of the difference in period of the two forms, Marlatt +(pages 15, 16) refers doubtfully to difference of temperature as the +determining factor. Experiments have been instituted by moving 17-year +eggs to the south, and vice versa with 13-year eggs. The results were, +however, not known at the time of publication of Marlatt's paper.) + +I am very much obliged for the extracts about the "drumming," which will +be of real use to me. + +I do not at all know what to think of your extraordinary case of the +Cicadas. Professor Asa Gray and Dr. Hooker were staying here, and I told +them of the facts. They thought that the 13-year and the 17-year forms +ought not to be ranked as distinct species, unless other differences +besides the period of development could be discovered. They thought the +mere rarity of variability in such a point was not sufficient, and I +think I concur with them. The fact of both the forms presenting the same +case of dimorphism is very curious. I have long wished that some one +would dissect the forms of the male stag-beetle with smaller mandibles, +and see if they were well developed, i.e., whether there was an +abundance of spermatozoa; and the same observations ought, I think, +to be made on the rarer form of your Cicada. Could you not get some +observer, such as Dr. Hartman (453/2. Mr. Walsh sent Mr. Darwin +an extract from Dr. Hartman's "Journal of the doings of a Cicada +septendecim," in which the females are described as flocking round the +drumming males. "Descent of Man" (1901), page 433.), to note whether the +females flocked in equal numbers to the "drumming" of the rarer form as +to the common form? You have a very curious and perplexing subject of +investigation, and I wish you success in your work. + + +LETTER 454. TO A.R. WALLACE. Down, June 15th [1869?]. + +You must not suppose from my delay that I have not been much interested +by your long letter. I write now merely to thank you, and just to say +that probably you are right on all the points you touch on, except, as +I think, about sexual selection, which I will not give up. My belief in +it, however, is contingent on my general belief in sexual selection. It +is an awful stretcher to believe that a peacock's tail was thus formed; +but, believing it, I believe in the same principle somewhat modified +applied to man. + + +LETTER 455. TO G.H.K. THWAITES. Down, February 13th [N.D.] + +I wrote a little time ago asking you an odd question about elephants, +and now I am going to ask you an odder. I hope that you will not think +me an intolerable bore. It is most improbable that you could get me +an answer, but I ask on mere chance. Macacus silenus (455/1. Macacus +silenus L., an Indian ape.) has a great mane of hair round neck, and +passing into large whiskers and beard. Now what I want most especially +to know is whether these monkeys, when they fight in confinement (and +I have seen it stated that they are sometimes kept in confinement), are +protected from bites by this mane and beard. Any one who watched them +fighting would, I think, be able to judge on this head. My object is to +find out with various animals how far the mane is of any use, or a mere +ornament. Is the male Macacus silenus furnished with longer hair than +the female about the neck and face? As I said, it is a hundred or a +thousand to one against your finding out any one who has kept these +monkeys in confinement. + + +LETTER 456. TO F. MULLER. Down, August 28th [1870]. + +I have to thank you very sincerely for two letters: one of April 25th, +containing a very curious account of the structure and morphology of +Bonatea. I feel that it is quite a sin that your letters should not all +be published! but, in truth, I have no spare strength to undertake any +extra work, which, though slight, would follow from seeing your letters +in English through the press--not but that you write almost as clearly +as any Englishman. This same letter also contained some seeds for Mr. +Farrer, which he was very glad to receive. + +Your second letter, of July 5th, was chiefly devoted to mimicry in +lepidoptera: many of your remarks seem to me so good, that I have +forwarded your letter to Mr. Bates; but he is out of London having his +summer holiday, and I have not yet heard from him. Your remark about +imitators and imitated being of such different sizes, and the lower +surface of the wings not being altered in colour, strike me as the most +curious points. I should not be at all surprised if your suggestion +about sexual selection were to prove true; but it seems rather too +speculative to be introduced in my book, more especially as my book is +already far too speculative. The very same difficulty about brightly +coloured caterpillars had occurred to me, and you will see in my book +what, I believe, is the true explanation from Wallace. The same view +probably applies in part to gaudy butterflies. My MS. is sent to the +printers, and, I suppose, will be published in about three months: +of course I will send you a copy. By the way, I settled with Murray +recently with respect to your book (456/1. The translation of "Fur +Darwin," published in 1869.), and had to pay him only 21 pounds +2 shillings 3 pence, which I consider a very small price for the +dissemination of your views; he has 547 copies as yet unsold. This most +terrible war will stop all science in France and Germany for a long +time. I have heard from nobody in Germany, and know not whether your +brother, Hackel, Gegenbaur, Victor Carus, or my other friends are +serving in the army. Dohrn has joined a cavalry regiment. I have not yet +met a soul in England who does not rejoice in the splendid triumph of +Germany over France (456/2. See Letter 239, Volume I.): it is a most +just retribution against that vainglorious, war-liking nation. As the +posts are all in confusion, I will not send this letter through +France. The Editor has sent me duplicate copies of the "Revue des Cours +Scientifiques," which contain several articles about my views; so I send +you copies for the chance of your liking to see them. + + +LETTER 457. A.R. WALLACE TO CHARLES DARWIN. Holly House, Barking, E., +January 27th, 1871. + +Many thanks for your first volume (457/1. "The Descent of Man".), which +I have just finished reading through with the greatest pleasure and +interest; and I have also to thank you for the great tenderness with +which you have treated me and my heresies. + +On the subject of "sexual selection" and "protection," you do not yet +convince me that I am wrong; but I expect your heaviest artillery will +be brought up in your second volume, and I may have to capitulate. You +seem, however, to have somewhat misunderstood my exact meaning, and I +do not think the difference between us is quite so great as you seem to +think it. There are a number of passages in which you argue against the +view that the female has in any large number of cases been "specially +modified" for protection, or that colour has generally been obtained by +either sex for purposes of protection. But my view is, as I thought +I had made it clear, that the female has (in most cases) been simply +prevented from acquiring the gay tints of the male (even when there was +a tendency for her to inherit it), because it was hurtful; and that, +when protection is not needed, gay colours are so generally acquired +by both sexes as to show that inheritance by both sexes of colour +variations is the most usual, when not prevented from acting by Natural +Selection. The colour itself may be acquired either by sexual selection +or by other unknown causes. + +There are, however, difficulties in the very wide application you give +to sexual selection which at present stagger me, though no one was or +is more ready than myself to admit the perfect truth of the principle or +the immense importance and great variety of its applications. + +Your chapters on "Man" are of intense interest--but as touching my +special heresy, not as yet altogether convincing, though, of course, I +fully agree with every word and every argument which goes to prove +the "evolution" or "development" of man out of a lower form. My ONLY +difficulties are, as to whether you have accounted for EVERY STEP of the +development by ascertained laws. + +I feel sure that the book will keep up and increase your high +reputation, and be immensely successful, as it deserves to be... + + +LETTER 458. TO G.B. MURDOCH. Down, March 13th, 1871. + +(458/1. We are indebted to Mr. Murdoch for a draft of his letter dated +March 10th, 1871. It is too long to be quoted at length; the following +citations give some idea of its contents: "In your 'Descent of Man,' in +treating of the external differences between males and females of the +same variety, have you attached sufficient importance to the different +amount and kind of energy expended by them in reproduction?" Mr. Murdoch +sums up: "Is it wrong, then, to suppose that extra growth, complicated +structure, and activity in one sex exist as escape-valves for surplus +vigour, rather than to please or fight with, though they may serve these +purposes and be modified by them?") + +I am much obliged for your valuable letter. I am strongly inclined to +think that I have made a great and complete oversight with respect to +the subject which you discuss. I am the more surprised at this, as I +remember reflecting on some points which ought to have led me to your +conclusion. By an odd chance I received the day before yesterday a +letter from Mr. Lowne (author of an excellent book on the anatomy of +the Blow-fly) (458/2. "The Anatomy and Physiology of the Blow-fly (Musca +vomitaria L.)," by B.T. Lowne. London, 1870.) with a discussion very +nearly to the same effect as yours. His conclusions were drawn from +studying male insects with great horns, mandibles, etc. He informs me +that his paper on this subject will soon be published in the "Transact. +Entomolog. Society." (458/3. "Observations on Immature Sexuality and +Alternate Generation in Insects." By B.T. Lowne. "Trans. Entomolog. +Soc." 1871 [Read March 6th, 1871]. "I believe that certain cutaneous +appendages, as the gigantic mandibles and thoracic horns of many males, +are complemental to the sexual organs; that, in point of fact, they are +produced by the excess of nutriment in the male, which in the female +would go to form the generative organs and ova" (loc. cit., page 197).) +I am inclined to look at your and Mr. Lowne's view as specially valuable +from probably throwing light on the greater variability of male than +female animals, which manifestly has much bearing on sexual selection. +I will keep your remarks in mind whenever a new edition of my book is +demanded. + + +LETTER 459. TO GEORGE FRASER. + +(459/1. The following letter refers to two letters to Mr. Darwin, in +which Mr. Fraser pointed out that illustrations of the theory of Sexual +Selection might be found amongst British butterflies and moths. Mr. +Fraser, in explanation of the letters, writes: "As an altogether unknown +and far from experienced naturalist, I feared to send my letters +for publication without, in the first place, obtaining Mr. Darwin's +approval." The information was published in "Nature," Volume III., April +20th, 1871, page 489. The article was referred to in the second edition +of the "Descent of Man" (1874), pages 312, 316, 319. Mr. Fraser +adds: "This is only another illustration of Mr. Darwin's great +conscientiousness in acknowledging suggestions received by him from the +most humble sources." (Letter from Mr. Fraser to F. Darwin, March 21, +1888.) + +Down, April 14th [1871]. + +I am very much obliged for your letter and the interesting facts which +it contains, and which are new to me. But I am at present so much +engaged with other subjects that I cannot fully consider them; and, even +if I had time, I do not suppose that I should have anything to say worth +printing in a scientific journal. It would obviously be absurd in me to +allow a mere note of thanks from me to be printed. Whenever I have +to bring out a corrected edition of my book I will well consider +your remarks (which I hope that you will send to "Nature"), but +the difficulty will be that my friends tell me that I have already +introduced too many facts, and that I ought to prune rather than to +introduce more. + + +LETTER 460. TO E.S. MORSE. Down, December 3rd, 1871. + +I am much obliged to you for having sent me your two interesting papers, +and for the kind writing on the cover. I am very glad to have my error +corrected about the protective colouring of shells. (460/1. "On Adaptive +Coloration of the Mollusca," "Boston Society of Natural History Proc." +Volume XIV., April 5th, 1871. Mr. Morse quotes from the "Descent of +Man," I., page 316, a passage to the effect that the colours of the +mollusca do not in general appear to be protective. Mr. Morse goes on to +give instances of protective coloration.) It is no excuse for my broad +statement, but I had in my mind the species which are brightly or +beautifully coloured, and I can as yet hardly think that the colouring +in such cases is protective. + + +LETTER 461. TO AUG. WEISMANN. Down, February 29th, 1872. + +I am rejoiced to hear that your eyesight is somewhat better; but I fear +that work with the microscope is still out of your power. I have often +thought with sincere sympathy how much you must have suffered from your +grand line of embryological research having been stopped. It was very +good of you to use your eyes in writing to me. I have just received your +essay (461/1. "Ueber der Einfluss der Isolirung auf die Artbildung": +Leipzig, 1872.); but as I am now staying in London for the sake of rest, +and as German is at all times very difficult to me, I shall not be able +to read your essay for some little time. I am, however, very curious to +learn what you have to say on isolation and on periods of variation. +I thought much about isolation when I wrote in Chapter IV. on the +circumstances favourable to Natural Selection. No doubt there remains +an immense deal of work to do on "Artbildung." I have only opened a path +for others to enter, and in the course of time to make a broad and clear +high-road. I am especially glad that you are turning your attention to +sexual selection. I have in this country hardly found any naturalists +who agree with me on this subject, even to a moderate extent. They think +it absurd that a female bird should be able to appreciate the splendid +plumage of the male; but it would take much to persuade me that the +peacock does not spread his gorgeous tail in the presence of the female +in order to fascinate or excite her. The case, no doubt, is much more +difficult with insects. I fear that you will find it difficult to +experiment on diurnal lepidoptera in confinement, for I have never heard +of any of these breeding in this state. (461/2. We are indebted to Mr. +Bateson for the following note: "This belief does not seem to be well +founded, for since Darwin's time several species of Rhopalocera (e.g. +Pieris, Pararge, Caenonympha) have been successfully bred in confinement +without any special difficulty; and by the use of large cages members +even of strong-flying genera, such as Vanessa, have been induced to +breed.") I was extremely pleased at hearing from Fritz Muller that he +liked my chapter on lepidoptera in the "Descent of Man" more than any +other part, excepting the chapter on morals. + + +LETTER 462. TO H. MULLER. Down [May, 1872]. + +I have now read with the greatest interest your essay, which contains +a vast amount of matter quite new to me. (462/1. "Anwendung der +Darwin'schen Lehre auf Bienen," "Verhandl. d. naturhist. Vereins fur +preuss. Rheinld. u. Westf." 1872. References to Muller's paper occur in +the second edition of the "Descent of Man.") I really have no criticisms +or suggestions to offer. The perfection of the gradation in the +character of bees, especially in such important parts as the +mouth-organs, was altogether unknown to me. You bring out all such facts +very clearly by your comparison with the corresponding organs in the +allied hymenoptera. How very curious is the case of bees and wasps +having acquired, independently of inheritance from a common source, the +habit of building hexagonal cells and of producing sterile workers! +But I have been most interested by your discussion on secondary sexual +differences; I do not suppose so full an account of such differences in +any other group of animals has ever been published. It delights me +to find that we have independently arrived at almost exactly the +same conclusion with respect to the more important points deserving +investigation in relation to sexual selection. For instance, the +relative number of the two sexes, the earlier emergence of the males, +the laws of inheritance, etc. What an admirable illustration you give of +the transference of characters acquired by one sex--namely, that of the +male of Bombus possessing the pollen-collecting apparatus. Many of +your facts about the differences between male and female bees are +surprisingly parallel with those which occur with birds. The reading +your essay has given me great confidence in the efficacy of sexual +selection, and I wanted some encouragement, as extremely few naturalists +in England seem inclined to believe in it. I am, however, glad to find +that Prof. Weismann has some faith in this principle. + +The males of Bombus follow one remarkable habit, which I think it would +interest you to investigate this coming summer, and no one could do +it better than you. (462/2. Mr. Darwin's observations on this curious +subject were sent to Hermann Muller, and after his death were translated +and published in Krause's "Gesammelte kleinere Schriften von Charles +Darwin," 1887, page 84. The male bees had certain regular lines of +flight at Down, as from the end of the kitchen garden to the corner of +the "sand-walk," and certain regular "buzzing places" where they stopped +on the wing for a moment or two. Mr. Darwin's children remember vividly +the pleasure of helping in the investigation of this habit.) I have +therefore enclosed a briefly and roughly drawn-up account of this habit. +Should you succeed in making any observations on this subject, and if +you would like to use in any way my MS. you are perfectly welcome. I +could, should you hereafter wish to make any use of the facts, give them +in rather fuller detail; but I think that I have given enough. + +I hope that you may long have health, leisure, and inclination to do +much more work as excellent as your recent essay. + + + +2.VIII.III. EXPRESSION, 1868-1874. + +LETTER 463. TO F. MULLER. Down, January 30th [1868]. + +I am very much obliged for your answers, though few in number (October +5th), about expression. I was especially glad to hear about shrugging +the shoulders. You say that an old negro woman, when expressing +astonishment, wonderfully resembled a Cebus when astonished; but are you +sure that the Cebus opened its mouth? I ask because the Chimpanzee does +not open its mouth when astonished, or when listening. (463/1. Darwin +in the "Expression of the Emotions," adheres to this statement as being +true of monkeys in general.) Please have the kindness to remember that +I am very anxious to know whether any monkey, when screaming violently, +partially or wholly closes its eyes. + + +LETTER 464. TO W. BOWMAN. + +(464/1. The late Sir W. Bowman, the well-known surgeon, supplied a good +deal of information of value to Darwin in regard to the expression of +the emotions. The gorging of the eyes with blood during screaming is +an important factor in the physiology of weeping, and indirectly in the +obliquity of the eyebrows--a characteristic expression of suffering. See +"Expression of the Emotions," pages 160 and 192.) + +Down, March 30th [1868]. + +I called at your house about three weeks since, and heard that you were +away for the whole month, which I much regretted, as I wished to +have had the pleasure of seeing you, of asking you a question, and +of thanking you for your kindness to my son George. You did not quite +understand the last note which I wrote to you--viz., about Bell's +precise statement that the conjunctiva of an infant or young child +becomes gorged with blood when the eyes are forcibly opened during +a screaming fit. (464/2. Sir C. Bell's statement in his "Anatomy +of Expression" (1844, page 106) is quoted in the "Expression of the +Emotions," page 158.) I have carefully kept your previous note, in which +you spoke doubtfully about Bell's statement. I intended in my former +note only to express a wish that if, during your professional work, you +were led to open the eyelids of a screaming child, you would specially +observe this point about the eye showing signs of becoming gorged with +blood, which interests me extremely. Could you ask any one to observe +this for me in an eye-dispensary or hospital? But I now have to beg you +kindly to consider one other question at any time when you have half an +hour's leisure. + +When a man coughs violently from choking or retches violently, even when +he yawns, and when he laughs violently, tears come into the eyes. Now, +in all these cases I observe that the orbicularis muscle is more or less +spasmodically contracted, as also in the crying of a child. So, again, +when the muscles of the abdomen contract violently in a propelling +manner, and the breath is, I think, always held, as during the +evacuation of a very costive man, and as (I hear) with a woman during +severe labour-pains, the orbicularis contracts, and tears come into +the eyes. Sir J.E. Tennant states that tears roll down the cheeks +of elephants when screaming and trumpeting at first being captured; +accordingly I went to the Zoological Gardens, and the keeper made two +elephants trumpet, and when they did this violently the orbicularis was +invariably plainly contracted. Hence I am led to conclude that there +must be some relation between the contraction of this muscle and the +secretion of tears. Can you tell me what this relation is? Does the +orbicularis press against, and so directly stimulate, the lachrymal +gland? As a slight blow on the eye causes, by reflex action, a +copious effusion of tears, can the slight spasmodic contraction of the +orbicularis act like a blow? This seems hardly possible. Does the same +nerve which runs to the orbicularis send off fibrils to the lachrymal +glands; and if so, when the order goes for the muscle to contract, +is nervous force sent sympathetically at the same time to the glands? +(464/3. See "Expression of the Emotions," page 169.) + +I should be extremely much obliged if you [would] have the kindness to +give me your opinion on this point. + + +LETTER 465. TO F.C. DONDERS. + +(465/1. Mr. Darwin was indebted to Sir W. Bowman for an introduction to +Professor Donders, whose work on Sir Charles Bell's views is quoted in +the "Expression of the Emotions," pages 160-62.) + +Down, June 3rd [1870?]. + +I do not know how to thank you enough for the very great trouble which +you have taken in writing at such length, and for your kind expressions +towards me. I am particularly obliged for the abstract with respect to +Sir C. Bell's views (465/2. See "Expression of the Emotions," pages 158 +et seq.: Sir Charles Bell's view is that adopted by Darwin--viz. that +the contraction of the muscles round the eyes counteracts the gorging of +the parts during screaming, etc. The essay of Donders is, no doubt, +"On the Action of the Eyelids in Determination of Blood from Expiratory +Effort" in Beale's "Archives of Medicine," Volume V., 1870, page 20, +which is a translation of the original in Dutch.), as I shall now +proceed with some confidence; but I am intensely curious to read your +essay in full when translated and published, as I hope, in the "Dublin +Journal," as you speak of the weak point in the case--viz., that +injuries are not known to follow from the gorging of the eye with blood. +I may mention that my son and his friend at a military academy tell me +that when they perform certain feats with their heads downwards their +faces become purple and veins distended, and that they then feel an +uncomfortable sensation in their eyes; but that as it is necessary for +them to see, they cannot protect their eyes by closing the eyelids. The +companions of one young man, who naturally has very prominent eyes, used +to laugh at him when performing such feats, and declare that some day +both eyes would start out of his head. + +Your essay on the physiological and anatomical relations between the +contraction of the orbicular muscles and the secretion of tears is +wonderfully clear, and has interested me greatly. I had not thought +about irritating substances getting into the nose during vomiting; but +my clear impression is that mere retching causes tears. I will, however, +try to get this point ascertained. When I reflect that in vomiting +(subject to the above doubt), in violent coughing from choking, in +yawning, violent laughter, in the violent downward action of the +abdominal muscle...and in your very curious case of the spasms (465/3. +In some cases a slight touch to the eye causes spasms of the orbicularis +muscle, which may continue for so long as an hour, being accompanied by +a flow of tears. See "Expression of the Emotions," page 166.)--that in +all these cases the orbicular muscles are strongly and unconsciously +contracted, and that at the same time tears often certainly flow, I must +think that there is a connection of some kind between these phenomena; +but you have clearly shown me that the nature of the relation is at +present quite obscure. + + +LETTER 466. TO A.D. BARTLETT. 6, Queen Anne Street, W., December 19th +[1870?]. + +I was with Mr. Wood this morning, and he expressed himself strongly +about your and your daughter's kindness in aiding him. He much wants +assistance on another point, and if you would aid him, you would greatly +oblige me. You know well the appearance of a dog when approaching +another dog with hostile intentions, before they come close together. +The dog walks very stiffly, with tail rigid and upright, hair on back +erected, ears pointed and eyes directed forwards. When the dog attacks +the other, down go the ears, and the canines are uncovered. Now, could +you anyhow arrange so that one of your dogs could see a strange dog from +a little distance, so that Mr. Wood could sketch the former attitude, +viz., of the stiff gesture with erected hair and erected ears. (466/1. +In Chapter II. of the "Expression of the Emotions" there are sketches +of dogs in illustration of the "Principle of Antithesis," drawn by Mr. +Riviere and by Mr. A. May (figures 5-8). Mr. T.W. Wood supplied similar +drawings of a cat (figures 9, 10), also a sketch of the head of a +snarling dog (figure 14).) And then he could afterwards sketch the same +dog, when fondled by his master and wagging his tail with drooping ears. +These two sketches I want much, and it would be a great favour to Mr. +Wood, and myself, if you could aid him. + +P.S.--When a horse is turned out into a field he trots with high, +elastic steps, and carries his tail aloft. Even when a cow frisks about +she throws up her tail. I have seen a drawing of an elephant, apparently +trotting with high steps, and with the tail erect. When the elephants in +the garden are turned out and are excited so as to move quickly, do they +carry their tails aloft? How is this with the rhinoceros? Do not trouble +yourself to answer this, but I shall be in London in a couple of months, +and then perhaps you will be able to answer this trifling question. Or, +if you write about wolves and jackals turning round, you can tell me +about the tails of elephants, or of any other animals. (466/2. In the +"Expression of the Emotions," page 44, reference is made under the head +of "Associated habitual movements in the lower animals," to dogs and +other animals turning round and round and scratching the ground with +their fore-paws when they wish to go to sleep on a carpet, or other +similar surface.) + + +LETTER 467. TO A.D. BARTLETT. Down, January 5th, [1871?] + +Many thanks about Limulus. I am going to ask another favour, but I do +not want to trouble you to answer it by letter. When the Callithrix +sciureus screams violently, does it wrinkle up the skin round the eyes +like a baby always does? (467/1. "Humboldt also asserts that the eyes +of the Callithrix sciureus 'instantly fill with tears when it is seized +with fear'; but when this pretty little monkey in the Zoological Gardens +was teased, so as to cry out loudly, this did not occur. I do not, +however, wish to throw the least doubt on the accuracy of Humboldt's +statement." ("The Expression of the Emotions in Man and Animals," +1872, page 137.) When thus screaming do the eyes become suffused with +moisture? Will you ask Sutton to observe carefully? (467/2. One of the +keepers who made many observations on monkeys for Mr. Darwin.) Could you +make it scream without hurting it much? I should be truly obliged some +time for this information, when in spring I come to the Gardens. + + +LETTER 468. TO W. OGLE. Down, March 7th [1871]. + +I wrote to Tyndall, but had no clear answer, and have now written to +him again about odours. (468/1. Dr. Ogle's work on the Sense of Smell +("Medico-Chirurgical Trans." LIII., page 268) is referred to in the +"Expression of the Emotions," page 256.) I write now to ask you to be so +kind (if there is no objection) to tell me the circumstances under which +you saw a man arrested for murder. (468/2. Given in the "Expression of +the Emotions," page 294.) I say in my notes made from your conversation: +utmost horror--extreme pallor--mouth relaxed and open--general +prostration--perspiration--muscle of face contracted--hair observed on +account of having been dyed, and apparently not erected. Secondly, may +I quote you that you have often (?) seen persons (young or old? men +or women?) who, evincing no great fear, were about to undergo severe +operation under chloroform, showing resignation by (alternately?) +folding one open hand over the other on the lower part of chest (whilst +recumbent?)--I know this expression, and think I ought to notice it. +Could you look out for an additional instance? + +I fear you will think me very troublesome, especially when I remind you +(not that I am in a hurry) about the Eustachian tube. + + +LETTER 469. TO J. JENNER WEIR. Down, June 14th [1870]. + +As usual, I am going to beg for information. Can you tell me whether +any Fringillidae or Sylviadae erect their feathers when frightened or +enraged? (469/1. See "Expression of the Emotions," page 99.) I want to +show that this expression is common to all or most of the families of +birds. I know of this only in the fowl, swan, tropic-bird, owl, ruff and +reeve, and cuckoo. I fancy that I remember having seen nestling birds +erect their feathers greatly when looking into nests, as is said to +be the case with young cuckoos. I should much like to know whether +nestlings do really thus erect their feathers. I am now at work on +expression in animals of all kinds, and birds; and if you have any hints +I should be very glad for them, and you have a rich wealth of facts of +all kinds. Any cases like the following: the sheldrake pats or dances on +the tidal sands to make the sea-worms come out; and when Mr. St. John's +tame sheldrakes came to ask for their dinners they used to pat the +ground, and this I should call an expression of hunger and impatience. +How about the Quagga case? (469/2. See Letter 235, Volume I.) + +I am working away as hard as I can on my book; but good heavens, how +slow my progress is. + + +LETTER 470. TO F.C. DONDERS. Down, March 18th, 1871. + +Very many thanks for your kind letter. I have been interested by what +you tell me about your views published in 1848, and I wish I could +read your essay. It is clear to me that you were as near as possible in +preceding me on the subject of Natural Selection. + +You will find very little that is new to you in my last book; whatever +merit it may possess consists in the grouping of the facts and in +deductions from them. I am now at work on my essay on Expression. +My last book fatigued me much, and I have had much correspondence, +otherwise I should have written to you long ago, as I often intended to +tell you in how high a degree your essay published in Beale's Archives +interested me. (470/1. Beale's "Archives of Medicine," Volume V., 1870.) +I have heard others express their admiration at the complete manner in +which you have treated the subject. Your confirmation of Sir C. Bell's +rather loose statement has been of paramount importance for my work. +(470/2. On the contraction of the muscles surrounding the eye. See +"Expression of the Emotions," page 158. See Letters 464, 465.) You told +me that I might make further enquiries from you. + +When a person is lost in meditation his eyes often appear as if fixed +on a distant object (470/3. The appearance is due to divergence of the +lines of vision produced by muscular relaxation. See "Expression of the +Emotions," Edition II., page 239.), and the lower eyelids may be seen to +contract and become wrinkled. I suppose the idea is quite fanciful, but +as you say that the eyeball advances in adaptation for vision for close +objects, would the eyeball have to be pushed backwards in adaptation for +distant objects? (470/4. Darwin seems to have misunderstood a remark of +Donders.) If so, can the wrinkling of the lower eyelids, which has often +perplexed me, act in pushing back the eyeball? + +But, as I have said, I daresay this is quite fanciful. Gratiolet says +that the pupil contracts in rage, and dilates enormously in terror. +(470/5. See "Expression of the Emotions," Edition II., page 321.) I have +not found this great anatomist quite trustworthy on such points, and am +making enquiries on this subject. But I am inclined to believe him, as +the old Scotch anatomist Munro says, that the iris of parrots contracts +and dilates under passions, independently of the amount of light. Can +you give any explanation of this statement? When the heart beats hard +and quick, and the head becomes somewhat congested with blood in any +illness, does the pupil contract? Does the pupil dilate in incipient +faintness, or in utter prostration, as when after a severe race a man +is pallid, bathed in perspiration, with all his muscles quivering? Or in +extreme prostration from any illness? + + +LETTER 471. TO W. TURNER. Down, March 28th [1871]. + +I am much obliged for your kind note, and especially for your offer of +sending me some time corrections, for which I shall be truly grateful. I +know that there are many blunders to which I am very liable. There is +a terrible one confusing the supra-condyloid foramen with another one. +(471/1. In the first edition of the "Descent of Man," I., page 28, +in quoting Mr. Busk "On the Caves of Gibraltar," Mr. Darwin confuses +together the inter-condyloid foramen in the humerus with the +supra-condyloid foramen. His attention was called to the mistake by +Sir William Turner, to whom he had been previously indebted for other +information on the anatomy of man. The error is one, as Sir William +Turner points out in a letter, "which might easily arise where the +writer is not minutely acquainted with human anatomy." In speaking of +his correspondence with Darwin, Sir William remarks on a characteristic +of Darwin's method of asking for information, namely, his care in +avoiding leading questions.) This, however, I have corrected in all the +copies struck off after the first lot of 2500. I daresay there will be +a new edition in the course of nine months or a year, and this I will +correct as well as I can. As yet the publishers have kept up type, +and grumble dreadfully if I make heavy corrections. I am very far from +surprised that "you have not committed yourself to full acceptation" of +the evolution of man. Difficulties and objections there undoubtedly are, +enough and to spare, to stagger any cautious man who has much knowledge +like yourself. + +I am now at work at my hobby-horse essay on Expression, and I have been +reading some old notes of yours. In one you say it is easy to see that +the spines of the hedgehog are moved by the voluntary panniculus. Now, +can you tell me whether each spine has likewise an oblique unstriped +or striped muscle, as figured by Lister? (472/2. "Expression of the +Emotions," page 101.) Do you know whether the tail-coverts of peacock or +tail of turkey are erected by unstriped or striped muscles, and whether +these are homologous with the panniculus or with the single oblique +unstriped muscles going to each separate hair in man and many animals? I +wrote some time ago to Kolliker to ask this question (and in relation to +quills of porcupine), and I received a long and interesting letter, but +he could not answer these questions. If I do not receive any answer (for +I know how busy you must be), I will understand you cannot aid me. + +I heard yesterday that Paget was very ill; I hope this is not true. What +a loss he would be; he is so charming a man. + +P.S.--As I am writing I will trouble you with one other question. Have +you seen anything or read of any facts which could induce you to think +that the mind being intently and long directed to any portion of +the skin (or, indeed, any organ) would influence the action of the +capillaries, causing them either to contract or dilate? Any information +on this head would be of great value to me, as bearing on blushing. + +If I remember right, Paget seems to be a great believer in the influence +of the mind in the nutrition of parts, and even in causing disease. It +is awfully audacious on my part, but I remember thinking (with respect +to the latter assertion on disease) when I read the passage that it +seemed rather fanciful, though I should like to believe in it. Sir H. +Holland alludes to this subject of the influence of the mind on local +circulation frequently, but gives no clear evidence. (472/3. Ibid., +pages 339 et seq.) + + +LETTER 472. TO W. TURNER. Down, March 29th [1871]. + +Forgive me for troubling you with one line. Since writing my P.S. I have +read the part on the influence of the nervous system on the nutrition of +parts in your last edition of Paget's "Lectures." (472/1. "Lectures on +Surgical Pathology," Edition III., revised by Professor Turner, 1870.) +I had not read before this part in this edition, and I see how foolish I +was. But still, I should be extremely grateful for any hint or +evidence of the influence of mental attention on the capillary or +local circulation of the skin, or of any part to which the mind may be +intently and long directed. For instance, if thinking intently about a +local eruption on the skin (not on the face, for shame might possibly +intervene) caused it temporarily to redden, or thinking of a tumour +caused it to throb, independently of increased heart action. + + +LETTER 473. TO HUBERT AIRY. + +(473/1. Dr. Airy had written to Mr. Darwin on April 3rd:-- + +"With regard to the loss of voluntary movement of the ears in man and +monkey, may I ask if you do not think it might have been caused, as it +is certainly compensated, by the facility and quickness in turning the +head, possessed by them in virtue of their more erect stature, and the +freedom of the atlanto-axial articulation? (in birds the same end is +gained by the length and flexibility of the neck.) The importance, in +case of danger, of bringing the eyes to help the ears would call for a +quick turn of the head whenever a new sound was heard, and so would tend +to make superfluous any special means of moving the ears, except in the +case of quadrupeds and the like, that have great trouble (comparatively +speaking) in making a horizontal turn of the head--can only do it by a +slow bend of the whole neck." (473/2. We are indebted to Dr. Airy for +furnishing us with a copy of his letter to Mr. Darwin, the original of +which had been mislaid.) + +Down, April 5th [1871]. + +I am greatly obliged for your letter. Your idea about the easy turning +of the head instead of the ears themselves strikes me as very good, and +quite new to me, and I will keep it in mind; but I fear that there are +some cases opposed to the notion. + +If I remember right the hedgehog has very human ears, but birds support +your view, though lizards are opposed to it. + +Several persons have pointed out my error about the platysma. (473/3. +The error in question occurs on page 19 of the "Descent of Man," Edition +I., where it is stated that the Platysma myoides cannot be voluntarily +brought into action. In the "Expression of the Emotions" Darwin remarks +that this muscle is sometimes said not to be under voluntary control, +and he shows that this is not universally true.) Nor can I remember how +I was misled. I find I can act on this muscle myself, now that I know +the corners of the mouth have to be drawn back. I know of the case of a +man who can act on this muscle on one side, but not on the other; yet +he asserts positively that both contract when he is startled. And this +leads me to ask you to be so kind as to observe, if any opportunity +should occur, whether the platysma contracts during extreme terror, +as before an operation; and secondly, whether it contracts during a +shivering fit. Several persons are observing for me, but I receive most +discordant results. + +I beg you to present my most respectful and kind compliments to your +honoured father [Sir G.B. Airy]. + + +LETTER 474. TO FRANCIS GALTON. + +(474/1. Mr. Galton had written on November 7th, 1872, offering to send +to various parts of Africa Darwin's printed list of questions intended +to guide observers on expression. Mr. Galton goes on: "You do not, +I think, mention in "Expression" what I thought was universal among +blubbering children (when not trying to see if harm or help was coming +out of the corner of one eye) of pressing the knuckles against the +eyeballs, thereby reinforcing the orbicularis.") + +Down, November 8th [1872]. + +Many thanks for your note and offer to send out the queries; but my +career is so nearly closed that I do not think it worth while. What +little more I can do shall be chiefly new work. I ought to have thought +of crying children rubbing their eyes with their knuckles, but I did not +think of it, and cannot explain it. As far as my memory serves, they do +not do so whilst roaring, in which case compression would be of use. I +think it is at the close of the crying fit, as if they wished to stop +their eyes crying, or possibly to relieve the irritation from the salt +tears. I wish I knew more about the knuckles and crying. + +What a tremendous stir-up your excellent article on prayer has made in +England and America! (474/2. The article entitled "Statistical Inquiries +into the Efficacy of Prayer" appeared in the "Fortnightly Review," 1872. +In Mr. Francis Galton's book on "Enquiries into Human Faculty and its +Development," London, 1883, a section (pages 277-94) is devoted to a +discussion on the "Objective Efficacy of Prayer.") + + +LETTER 475. TO F.C. DONDERS. + +(475/1. We have no means of knowing whether the observations suggested +in the following letter were made--if not, the suggestion is worthy of +record.) + +Down, December 21st, 1872. + +You will have received some little time ago my book on Expression, in +writing which I was so deeply indebted to your kindness. I want now to +beg a favour of you, if you have the means to grant it. A clergyman, the +head of an institution for the blind in England (475/2. The Rev. R.H. +Blair, Principal of the Worcester College: "Expression of the Emotions," +Edition II., page 237.), has been observing the expression of those born +blind, and he informs me that they never or very rarely frown. He kept +a record of several cases, but at last observed a frown on two of the +children who he thought never frowned; and then in a foolish manner tore +up his notes, and did not write to me until my book was published. He +may be a bad observer and altogether mistaken, but I think it would +be worth while to ascertain whether those born blind, when young, and +whilst screaming violently, contract the muscles round the eyes like +ordinary infants. And secondly, whether in after years they rarely or +never frown. If it should prove true that infants born blind do not +contract their orbicular muscles whilst screaming (though I can hardly +believe it) it would be interesting to know whether they shed tears as +copiously as other children. The nature of the affection which causes +blindness may possibly influence the contraction of the muscles, but on +all such points you will judge infinitely better than I can. Perhaps you +could get some trustworthy superintendent of an asylum for the blind to +attend to this subject. I am sure that you will forgive me asking this +favour. + + +LETTER 476. TO D. HACK TUKE. Down, December 22nd, 1872. + +I have now finished your book, and have read it with great interest. +(476/1. "Influence of the Mind upon the Body. Designed to elucidate the +Power of the Imagination." 1872.) + +Many of your cases are very striking. As I felt sure would be the case, +I have learnt much from it; and I should have modified several passages +in my book on Expression, if I had had the advantage of reading your +work before my publication. I always felt, and said so a year ago to +Professor Donders, that I had not sufficient knowledge of Physiology to +treat my subject in a proper way. + +With many thanks for the interest which I have felt in reading your +work... + + +LETTER 477. TO A.R. WALLACE. Down, January 10th [1873]. + +I have read your Review with much interest, and I thank you sincerely +for the very kind spirit in which it is written. I cannot say that I am +convinced by your criticisms. (477/1. "Quarterly Journal of Science," +January, 1873, page 116: "I can hardly believe that when a cat, lying +on a shawl or other soft material, pats or pounds it with its feet, or +sometimes sucks a piece of it, it is the persistence of the habit of +pressing the mammary glands and sucking during kittenhood." Mr. Wallace +goes on to say that infantine habits are generally completely lost in +adult life, and that it seems unlikely that they should persist in a few +isolated instances.) If you have ever actually observed a kitten sucking +and pounding, with extended toes, its mother, and then seen the same +kitten when a little older doing the same thing on a soft shawl, and +ultimately an old cat (as I have seen), and do not admit that it is +identically the same action, I am astonished. With respect to the +decapitated frog, I have always heard of Pfluger as a most trustworthy +observer. (477/2. Mr. Wallace speaks of "a readiness to accept the most +marvellous conclusions or interpretations of physiologists on what +seem very insufficient grounds," and he goes on to assert that the frog +experiment is either incorrectly recorded or else that it "demonstrates +volition, and not reflex action.") If, indeed, any one knows a frog's +habits so well as to say that it never rubs off a bit of leaf or other +object which may stick to its thigh, in the same manner as it did the +acid, your objection would be valid. Some of Flourens' experiments, in +which he removed the cerebral hemispheres from a pigeon, indicate that +acts apparently performed consciously can be done without consciousness. +I presume through the force of habit, in which case it would appear that +intellectual power is not brought into play. Several persons have made +suggestions and objections as yours about the hands being held up +in astonishment; if there was any straining of the muscles, as with +protruded arms under fright, I would agree; as it is I must keep to +my old opinion, and I dare say you will say that I am an obstinate old +blockhead. (477/3. The raising of the hands in surprise is explained +("Expression of Emotions," Edition I., page 287) on the doctrine of +antithesis as being the opposite of listlessness. Mr. Wallace's view +(given in the 2nd edition of "Expression of the Emotions," page 300) is +that the gesture is appropriate to sudden defence or to the giving of +aid to another person.) + +The book has sold wonderfully; 9,000 copies have now been printed. + + +LETTER 478. TO CHAUNCEY WRIGHT. Down, September 21st, 1874. + +I have read your long letter with the greatest interest, and it was +extremely kind of you to take such great trouble. Now that you call my +attention to the fact, I well know the appearance of persons moving +the head from side to side when critically viewing any object; and I am +almost sure that I have seen the same gesture in an affected person when +speaking in exaggerated terms of some beautiful object not present. +I should think your explanation of this gesture was the true one. But +there seems to me a rather wide difference between inclining or moving +the head laterally, and moving it in the same plane, as we do in +negation, and, as you truly add, in disapprobation. It may, however, be +that these two movements of the head have been confounded by travellers +when speaking of the Turks. Perhaps Prof. Lowell would remember whether +the movement was identically the same. Your remarks on the effects of +viewing a sunset, etc., with the head inverted are very curious. (478/1. +The letter dated September 3rd, 1874, is published in Mr. Thayer's +"Letters" of Chauncey Wright, privately printed, Cambridge, Mass., 1878. +Wright quotes Mr. Sophocles, a native of Greece, at the time Professor +of Modern and Ancient Greek at Harvard University, to the effect that +the Turks do not express affirmation by a shake of the head, but by a +bow or grave nod, negation being expressed by a backward nod. From +the striking effect produced by looking at a landscape with the head +inverted, or by looking at its reflection, Chauncey Wright was led to +the lateral movement of the head, which is characteristic of critical +inspection--eg. of a picture. He thinks that in this way a gesture of +deliberative assent arose which may have been confused with our ordinary +sign of negation. He thus attempts to account for the contradictions +between Lieber's statement that a Turk or Greek expresses "yes" by a +shake of the head, and the opposite opinion of Prof. Sophocles, and +lastly, Mr. Lowell's assertion that in Italy our negative shake of the +head is used in affirmation (see "Expression of the Emotions," Edition +II., page 289).) We have a looking-glass in the drawing-room opposite +the flower-garden, and I have often been struck how extremely pretty +and strange the flower garden and surrounding bushes appear when thus +viewed. Your letter will be very useful to me for a new edition of my +Expression book; but this will not be for a long time, if ever, as the +publisher was misled by the very large sale at first, and printed far +too many copies. + +I daresay you intend to publish your views in some essay, and I think +you ought to do so, for you might make an interesting and instructive +discussion. + +I have been half killing myself of late with microscopical work on +plants. I begin to think that they are more wonderful than animals. + +P.S., January 29th, 1875.--You will see that by a stupid mistake in +the address this letter has just been returned to me. It is by no +means worth forwarding, but I cannot bear that you should think me +so ungracious and ungrateful as not to have thanked you for your long +letter. + +As I forget whether "Cambridge" is sufficient address, I will send this +through Asa Gray. + + + +(PLATE: CHARLES LYELL. Engraved by G.I. (J). Stodart from a photograph.) + + + +CHAPTER 2.IX. GEOLOGY, 1840-1882. + +I. Vulcanicity and Earth-movements.--II. Ice-action.--III. The Parallel +Roads of Glen Roy.--IV. Coral Reefs, Fossil and Recent.--V. Cleavage +and Foliation.--VI. Age of the World.--VII. Geological Action of +Earthworms.--VIII. Miscellaneous. + + +2.IX.I. VULCANICITY AND EARTH-MOVEMENTS, 1840-1881. + + +LETTER 479. TO DAVID MILNE. 12, Upper Gower Street, Thursday [March] +20th [1840]. + +I much regret that I am unable to give you any information of the kind +you desire. You must have misunderstood Mr. Lyell concerning the object +of my paper. (479/1. "On the Connexion of certain Volcanic Phenomena, +and on the Formation of Mountain-chains and the Effects of Continental +Elevations." "Trans. Geol. Soc." Volume V., 1840, pages 601-32 [March +7th, 1838].) It is an account of the shock of February, 1835, in Chile, +which is particularly interesting, as it ties most closely together +volcanic eruptions and continental elevations. In that paper I notice a +very remarkable coincidence in volcanic eruptions in S. America at very +distant places. I have also drawn up some short tables showing, as +it appears to me, that there are periods of unusually great volcanic +activity affecting large portions of S. America. I have no record of any +coincidences between shocks there and in Europe. Humboldt, by his table +in the "Pers. Narrative" (Volume IV., page 36, English Translation), +seems to consider the elevation of Sabrina off the Azores as connected +with S. American subterranean activity: this connection appears to be +exceedingly vague. I have during the past year seen it stated that a +severe shock in the northern parts of S. America coincided with one +in Kamstchatka. Believing, then, that such coincidences are purely +accidental, I neglected to take a note of the reference; but I +believe the statement was somewhere in "L'Institut" for 1839. (479/2. +"L'Institut, Journal General des Societes et Travaux Scientifiques de la +France et de l'Etranger," Tome VIII. page 412, Paris, 1840. In a note +on some earthquakes in the province Maurienne it is stated that they +occurred during a change in the weather, and at times when a south wind +followed a north wind, etc.) I was myself anxious to see the list of the +1200 shocks alluded to by you, but I have not been able to find out that +the list has been published. With respect to any coincidences you may +discover between shocks in S. America and Europe, let me venture to +suggest to you that it is probably a quite accurate statement that +scarcely one hour in the year elapses in S. America without an +accompanying shock in some part of that large continent. There are many +regions in which earthquakes take place every three and four days; and +after the severer shocks the ground trembles almost half-hourly for +months. If, therefore, you had a list of the earthquakes of two or +three of these districts, it is almost certain that some of them would +coincide with those in Scotland, without any other connection than mere +chance. + +My paper will be published immediately in the "Geological Transactions," +and I will do myself the pleasure of sending you a copy in the course of +(as I hope) a week or ten days. A large part of it is theoretical, and +will be of little interest to you; but the account of the Concepcion +shock of 1835 will, I think, be worth your perusal. I have understood +from Mr. Lyell that you believe in some connection between the state of +the weather and earthquakes. Under the very peculiar climate of Northern +Chile, the belief of the inhabitants in such connection can hardly, in +my opinion, be founded in error. It must possibly be worth your while to +turn to pages 430-433 in my "Journal of Researches during the Voyage of +the 'Beagle'," where I have stated this circumstance. (479/3. "Journal +of Researches into the Natural History and Geology of the Countries +visited during the Voyage of H.M.S. 'Beagle' round the World." London, +1870, page 351.) On the hypothesis of the crust of the earth resting on +fluid matter, would the influence of the moon (as indexed by the tides) +affect the periods of the shocks, when the force which causes them is +just balanced by the resistance of the solid crust? The fact you mention +of the coincidence between the earthquakes of Calabria and Scotland +appears most curious. Your paper will possess a high degree of interest +to all geologists. I fancied that such uniformity of action, as seems +here indicated, was probably confined to large continents, such as the +Americas. How interesting a record of volcanic phenomena in Iceland +would be, now that you are collecting accounts of every slight trembling +in Scotland. I am astonished at their frequency in that quiet country, +as any one would have called it. I wish it had been in my power to +have contributed in any way to your researches on this most interesting +subject. + + +LETTER 480. TO L. HORNER. Down, August 29th [1844]. + +I am greatly obliged for your kind note, and much pleased with its +contents. If one-third of what you say be really true, and not the +verdict of a partial judge (as from pleasant experience I much suspect), +then should I be thoroughly well contented with my small volume which, +small as it is, cost me much time. (480/1. "Geological Observations +on the Volcanic Islands visited during the Voyage of H.M.S. 'Beagle'": +London, 1844. A French translation has been made by Professor Renard +of Ghent, and published by Reinwald of Paris in 1902.) The pleasure +of observation amply repays itself: not so that of composition; and it +requires the hope of some small degree of utility in the end to make up +for the drudgery of altering bad English into sometimes a little better +and sometimes worse. With respect to craters of elevation (480/2. +"Geological Observations," pages 93-6.), I had no sooner printed off +the few pages on that subject than I wished the whole erased. I utterly +disbelieve in Von Buch and de Beaumont's views; but on the other +hand, in the case of the Mauritius and St. Jago, I cannot, perhaps +unphilosophically, persuade myself that they are merely the basal +fragments of ordinary volcanoes; and therefore I thought I would suggest +the notion of a slow circumferential elevation, the central part +being left unelevated, owing to the force from below being spent +and [relieved?] in eruptions. On this view, I do not consider these +so-called craters of elevation as formed by the ejection of ashes, +lava, etc., etc., but by a peculiar kind of elevation acting round and +modified by a volcanic orifice. I wish I had left it all out; I trust +that there are in other parts of the volume more facts and less theory. +The more I reflect on volcanoes, the more I appreciate the importance +of E. de Beaumont's measurements (480/3. Elie de Beaumont's views are +discussed by Sir Charles Lyell both in the "Principles of Geology" +(Edition X., 1867, Volume I. pages 633 et seq.) and in the "Elements +of Geology" (Edition III., 1878, pages 495, 496). See also Darwin's +"Geological Observations," Edition II., 1876, page 107.) (even if +one does not believe them implicitly) of the natural inclination of +lava-streams, and even more the importance of his view of the dikes, +or unfilled fissures, in every volcanic mountain, being the proofs +and measures of the stretching and consequent elevation which all +such mountains must have undergone. I believe he thus unintentionally +explains most of his cases of lava-streams being inclined at a greater +angle than that at which they could have flowed. + +But excuse this lengthy note, and once more let me thank you for the +pleasure and encouragement you have given me--which, together with +Lyell's never-failing kindness, will help me on with South America, and, +as my books will not sell, I sometimes want such aid. I have been lately +reading with care A. d'Orbigny's work on South America (480/4. "Voyage +dans l'Amerique Meridionale--execute pendant les annees 1826-33": six +volumes, Paris, 1835-43.), and I cannot say how forcibly impressed I am +with the infinite superiority of the Lyellian school of Geology over +the continental. I always feel as if my books came half out of Lyell's +brain, and that I never acknowledge this sufficiently; nor do I know how +I can without saying so in so many words--for I have always thought that +the great merit of the "Principles" was that it altered the whole tone +of one's mind, and therefore that, when seeing a thing never seen by +Lyell, one yet saw it partially through his eyes--it would have been in +some respects better if I had done this less: but again excuse my long, +and perhaps you will think presumptuous, discussion. Enclosed is a note +from Emma to Mrs. Horner, to beg you, if you can, to give us the great +pleasure of seeing you here. We are necessarily dull here, and can offer +no amusements; but the weather is delightful, and if you could see how +brightly the sun now shines you would be tempted to come. Pray remember +me most kindly to all your family, and beg of them to accept our +proposal, and give us the pleasure of seeing them. + + +LETTER 481. TO C. LYELL. Down, [September, 1844]. + +I was glad to get your note, and wanted to hear about your work. I +have been looking to see it advertised; it has been a long task. I had, +before your return from Scotland, determined to come up and see you; but +as I had nothing else to do in town, my courage has gradually eased +off, more especially as I have not been very well lately. We get so many +invitations here that we are grown quite dissipated, but my stomach has +stood it so ill that we are going to have a month's holidays, and go +nowhere. + +The subject which I was most anxious to talk over with you I have +settled, and having written sixty pages of my "S. American Geology," I +am in pretty good heart, and am determined to have very little theory +and only short descriptions. The two first chapters will, I think, be +pretty good, on the great gravel terraces and plains of Patagonia and +Chili and Peru. + +I am astonished and grieved over D'Orbigny's nonsense of sudden +elevations. (481/1. D'Orbigny's views are referred to by Lyell in +chapter vii. of the "Principles," Volume I. page 131. "This mud [i.e. +the Pampean mud] contains in it recent species of shells, some of them +proper to brackish water, and is believed by Mr. Darwin to be an +estuary or delta deposit. M.A. D'Orbigny, however, has advanced an +hypothesis...that the agitation and displacement of the waters of the +ocean, caused by the elevation of the Andes, gave rise to a deluge, of +which this Pampean mud, which reaches sometimes the height of 12,000 +feet, is the result and monument.") I must give you one of his cases: +He finds an old beach 600 feet above sea. He finds STILL ATTACHED to the +rocks at 300 feet six species of truly littoral shells. He finds at 20 +to 30 feet above sea an immense accumulation of chiefly littoral shells. +He argues the whole 600 feet uplifted at one blow, because the attached +shells at 300 feet have not been displaced. Therefore when the sea +formed a beach at 600 feet the present littoral shells were attached +to rocks at 300 feet depth, and these same shells were accumulating by +thousands at 600 feet. + +Hear this, oh Forbes. Is it not monstrous for a professed conchologist? +This is a fair specimen of his reasoning. + +One of his arguments against the Pampas being a slow deposit, is that +mammifers are very seldom washed by rivers into the sea! + +Because at 12,000 feet he finds the same kind of clay with that of +the Pampas he never doubts that it is contemporaneous with the Pampas +[debacle?] which accompanied the right royal salute of every volcano +in the Cordillera. What a pity these Frenchmen do not catch hold of +a comet, and return to the good old geological dramas of Burnett and +Whiston. I shall keep out of controversy, and just give my own facts. It +is enough to disgust one with Geology; though I have been much pleased +with the frank, decided, though courteous manner with which D'Orbigny +disputes my conclusions, given, unfortunately, without facts, and +sometimes rashly, in my journal. + +Enough of S. America. I wish you would ask Mr. Horner (for I forgot to +do so, and am unwilling to trouble him again) whether he thinks there +is too much detail (quite independent of the merits of the book) in my +volcanic volume; as to know this would be of some real use to me. You +could tell me when we meet after York, when I will come to town. I had +intended being at York, but my courage has failed. I should much like +to hear your lecture, but still more to read it, as I think reading is +always better than hearing. + +I am very glad you talk of a visit to us in the autumn if you can spare +the time. I shall be truly glad to see Mrs. Lyell and yourself here; but +I have scruples in asking any one--you know how dull we are here. Young +Hooker (481/2. Sir J.D. Hooker.) talks of coming; I wish he might meet +you,--he appears to me a most engaging young man. + +I have been delighted with Prescott, of which I have read Volume I. at +your recommendation; I have just been a good deal interested with W. +Taylor's (of Norwich) "Life and Correspondence." + +On your return from York I shall expect a great supply of Geological +gossip. + + +LETTER 482. TO C. LYELL. [October 3rd, 1846.] + +I have been much interested with Ramsay, but have no particular +suggestions to offer (482/1. "On the Denudation of South Wales and the +Adjacent Counties of England." A.C. Ramsay, "Mem. Geol. Survey Great +Britain," Volume I., London, 1846.); I agree with all your remarks made +the other day. My final impression is that the only argument against +him is to tell him to read and re-read the "Principles," and if not +then convinced to send him to Pluto. Not but what he has well read the +"Principles!" and largely profited thereby. I know not how carefully you +have read this paper, but I think you did not mention to me that he does +(page 327) (482/2. Ramsay refers the great outlines of the country to +the action of the sea in Tertiary times. In speaking of the denudation +of the coast, he says: "Taking UNLIMITED time into account, we can +conceive that any extent of land might be so destroyed...If to this be +added an EXCEEDINGLY SLOW DEPRESSION of the land and sea bottom, the +wasting process would be materially assisted by this depression" (loc. +cit., page 327).) believe that the main part of his great denudation +was effected during a vast (almost gratuitously assumed) slow Tertiary +subsidence and subsequent Tertiary oscillating slow elevation. So +our high cliff argument is inapplicable. He seems to think his great +subsidence only FAVOURABLE for great denudation. I believe from +the general nature of the off-shore sea's bottoms that it is almost +necessary; do look at two pages--page 25 of my S. American volume--on +this subject. (482/3. "Geological Observations on S. America," 1846, +page 25. "When viewing the sea-worn cliffs of Patagonia, in some parts +between 800 and 900 feet in height, and formed of horizontal Tertiary +strata, which must once have extended far seaward...a difficulty often +occurred to me, namely, how the strata could possibly have been removed +by the action of the sea at a considerable depth beneath its surface." +The cliffs of St. Helena are referred to in illustration of the same +problem; speaking of these, Darwin adds: "Now, if we had any reason +to suppose that St. Helena had, during a long period, gone on slowly +subsiding, every difficulty would be removed...I am much inclined to +suspect that we shall hereafter find in all such cases that the land +with the adjoining bed of the sea has in truth subsided..." (loc. cit., +pages 25-6).) + +The foundation of his views, viz., of one great sudden upheaval, strikes +me as threefold. First, to account for the great dislocations. This +strikes me as the odder, as he admits that a little northwards there +were many and some violent dislocations at many periods during the +accumulation of the Palaeozoic series. If you argue against him, allude +to the cool assumption that petty forces are conflicting: look at +volcanoes; look at recurrent similar earthquakes at same spots; look at +repeatedly injected intrusive masses. In my paper on Volcanic Phenomena +in the "Geol. Transactions." (482/4. "On the Connection of certain +Volcanic Phenomena, and on the Formation of Mountain-chains and the +Effects of Continental Elevations." "Geol. Soc. Proc." Volume II., pages +654-60, 1838; "Trans. Geol. Soc." Volume V., pages 601-32, 1842. [Read +March 7th, 1838.]) I have argued (and Lonsdale thought well of the +argument, in favour, as he remarked, of your original doctrine) that if +Hopkins' views are correct, viz., that mountain chains are subordinate +consequences to changes of level in mass, then, as we have evidence of +such horizontal movements in mass having been slow, the foundation of +mountain chains (differing from volcanoes only in matter being injected +instead of ejected) must have been slow. + +Secondly, Ramsay has been influenced, I think, by his Alpine insects; +but he is wrong in thinking that there is any necessary connection +of tropics and large insects--videlicet--Galapagos Arch., under the +equator. Small insects swarm in all parts of tropics, though accompanied +generally with large ones. + +Thirdly, he appears influenced by the absence of newer deposits on the +old area, blinded by the supposed necessity of sediment accumulating +somewhere near (as no doubt is true) and being PRESERVED--an example, +as I think, of the common error which I wrote to you about. The +preservation of sedimentary deposits being, as I do not doubt, the +exception when they are accumulated during periods of elevation or of +stationary level, and therefore the preservation of newer deposits would +not be probable, according to your view that Ramsay's great Palaeozoic +masses were denuded, whilst slowly rising. Do pray look at end of +Chapter II., at what little I have said on this subject in my S. +American volume. (482/5. The second chapter of the "Geological +Observations" concludes with a Summary on the Recent Elevations of the +West Coast of South America, (page 53).) + +I do not think you can safely argue that the whole surface was probably +denuded at same time to the level of the lateral patches of Magnesian +conglomerate. + +The latter part of the paper strikes me as good, but obvious. + +I shall send him my S. American volume for it is curious on how many +similar points we enter, and I modestly hope it may be a half-oz. weight +towards his conversion to better views. If he would but reject his great +sudden elevations, how sound and good he would be. I doubt whether this +letter will be worth the reading. + + +LETTER 483. TO C. LYELL. Down [September 4th, 1849]. + +It was very good of you to write me so long a letter, which has +interested me much. I should have answered it sooner, but I have not +been very well for the few last days. Your letter has also flattered +me much in many points. I am very glad you have been thinking over the +relation of subsidence and the accumulation of deposits; it has to me +removed many great difficulties; please to observe that I have carefully +abstained from saying that sediment is not deposited during periods of +elevation, but only that it is not accumulated to sufficient thickness +to withstand subsequent beach action; on both coasts of S. America the +amount of sediment deposited, worn away, and redeposited, oftentimes +must have been enormous, but still there have been no wide formations +produced: just read my discussion (page 135 of my S. American book +(483/1. See Letter 556, note. The discussion referred to ("Geological +Observations on South America," 1846) deals with the causes of +the absence of recent conchiferous deposits on the coasts of South +America.)) again with this in your mind. I never thought of your +difficulty (i.e. in relation to this discussion) of where was the land +whence the three miles of S. Wales strata were derived! (483/2. In +his classical paper "On the Denudation of South Wales and the Adjacent +Counties of England" ("Mem. Geol. Survey," Volume I., page 297, 1846), +Ramsay estimates the thickness of certain Palaeozoic formations in South +Wales, and calculates the cubic contents of the strata in the area they +now occupy together with the amount removed by denudation; and he goes +on to say that it is evident that the quantity of matter employed to +form these strata was many times greater than the entire amount of solid +land they now represent above the waves. "To form, therefore, so great +a thickness, a mass of matter of nearly equal cubic contents must have +been worn by the waves and the outpourings of rivers from neighbouring +lands, of which perhaps no original trace now remains" (page 334.)) Do +you not think that it may be explained by a form of elevation which I +have always suspected to have been very common (and, indeed, had once +intended getting all facts together), viz. thus?-- + +(Figure 1. A line drawing of ocean bottom subsiding beside mountains and +continent rising.) + +The frequency of a DEEP ocean close to a rising continent bordered with +mountains, seems to indicate these opposite movements of rising and +sinking CLOSE TOGETHER; this would easily explain the S. Wales and +Eocene cases. I will only add that I should think there would be a +little more sediment produced during subsidence than during elevation, +from the resulting outline of coast, after long period of rise. There +are many points in my volume which I should like to have discussed with +you, but I will not plague you: I should like to hear whether you think +there is anything in my conjecture on Craters of Elevation (483/3. In +the "Geological Observations on Volcanic Islands," 1844, pages 93-6, +Darwin speaks of St. Helena, St. Jago and Mauritius as being bounded by +a ring of basaltic mountains which he regards as "Craters of Elevation." +While unable to accept the theory of Elie de Beaumont and attribute +their formation to a dome-shaped elevation and consequent arching of the +strata, he recognises a "very great difficulty in admitting that these +basaltic mountains are merely the basal fragments of great volcanoes, +of which the summits have been either blown off, or, more probably, +swallowed by subsidence." An explanation of the origin and structure of +these volcanic islands is suggested which would keep them in the class +of "Craters of Elevation," but which assumes a slow elevation, during +which the central hollow or platform having been formed "not by the +arching of the surface, but simply by that part having been upraised to +a less height."); I cannot possibly believe that Saint Jago or Mauritius +are the basal fragments of ordinary volcanoes; I would sooner even admit +E. de Beaumont's views than that--much as I would sooner in my own mind +in all cases follow you. Just look at page 232 in my "S. America" for a +trifling point, which, however, I remember to this day relieved my +mind of a considerable difficulty. (483/4. This probably refers to +a paragraph (page 232) "On the Eruptive Sources of the Porphyritic +Claystone and Greenstone Lavas." The opinion is put forward that "the +difficulty of tracing the streams of porphyries to their ancient and +doubtless numerous eruptive sources, may be partly explained by the very +general disturbance which the Cordillera in most parts has suffered"; +but, Darwin adds, "a more specific cause may be that 'the original +points of eruption tend to become the points of injection'...On this +view of there being a tendency in the old points of eruption to become +the points of subsequent injection and disturbance, and consequently of +denudation, it ceases to be surprising that the streams of lava in the +porphyritic claystone conglomerate formation, and in other analogous +cases, should most rarely be traceable to their actual sources." The +latter part of this letter is published in "Life and Letters," I., +pages 377, 378.) I remember being struck with your discussion on the +Mississippi beds in relation to Pampas, but I should wish to read them +over again; I have, however, re-lent your work to Mrs. Rich, who, like +all whom I have met, has been much interested by it. I will stop about +my own Geology. But I see I must mention that Scrope did suggest (and I +have alluded to him, page 118 (483/5. "Geological Observations," Edition +II., 1876. Chapter VI. opens with a discussion "On the Separation of the +Constituent Minerals of Lava, according to their Specific Gravities." +Mr. Darwin calls attention to the fact that Mr. P. Scrope had speculated +on the subject of the separation of the trachytic and basaltic series +of lavas (page 113).), but without distinct reference and I fear not +sufficiently, though I utterly forgot what he wrote) the separation of +basalt and trachyte; but he does not appear to have thought about the +crystals, which I believe to be the keystone of the phenomenon. I cannot +but think this separation of the molten elements has played a great part +in the metamorphic rocks: how else could the basaltic dykes have come in +the great granitic districts such as those of Brazil? What a wonderful +book for labour is d'Archiac!...(483/6. Possibly this refers to +d'Archiac's "Histoire des Progres de la Geologie," 1848.) + + +LETTER 484. TO LADY LYELL. Down, Wednesday night [1849?]. + +I am going to beg a very very great favour of you: it is to translate +one page (and the title) of either Danish or Swedish or some such +language. I know not to whom else to apply, and I am quite dreadfully +interested about the barnacles therein described. Does Lyell know Loven, +or his address and title? for I must write to him. If Lyell knows him I +would use his name as introduction; Loven I know by name as a first-rate +naturalist. + +Accidentally I forgot to give you the "Footsteps," which I now return, +having ordered a copy for myself. + +I sincerely hope the "Craters of Denudation" prosper; I pin my faith to +this view. (484/1. "On Craters of Denudation, with Observations on the +Structure and Growth of Volcanic Cones." "Proc. Geol. Soc." Volume VI., +1850, pages 207-34. In a letter to Bunbury (January 17th, 1850) +Lyell wrote:..."Darwin adopts my views as to Mauritius, St. Jago, and +so-called elevation craters, which he has examined, and was puzzled +with."--"Life of Sir Charles Lyell," Volume II., page 158.) + +Please tell Sir C. Lyell that outside the crater-like mountains at St. +Jago, even throughout a distance of two or three miles, there has been +much denudation of the older volcanic rocks contemporaneous with those +of the ring of mountains. (484/2. The island of St. Jago, one of the +Cape de Verde group, is fully described in the "Volcanic Islands," +Chapter 1.) + +I hope that you will not find the page troublesome, and that you will +forgive me asking you. + + +LETTER 485. TO C. LYELL. [November 6th, 1849]. + +I have been deeply interested in your letter, and so far, at least, +worthy of the time it must have cost you to write it. I have not much to +say. I look at the whole question as settled. Santorin is splendid! +it is conclusive! it is perfect! (485/1. "The Gulf of Santorin, in the +Grecian Archipelago, has been for two thousand years a scene of active +volcanic operations. The largest of the three outer islands of the +groups (to which the general name of Santorin is given) is called Thera +(or sometimes Santorin), and forms more than two-thirds of the circuit +of the Gulf" ("Principles of Geology," Volume II., Edition X., London, +1868, page 65). Lyell attributed "the moderate slope of the beds in +Thera...to their having originally descended the inclined flanks of a +large volcanic cone..."; he refuted the theory of "Elevation Craters" by +Leopold von Buch, which explained the slope of the rocks in a volcanic +mountain by assuming that the inclined beds had been originally +horizontal and subsequently tilted by an explosion.) You have read +Dufrenoy in a hurry, I think, and added to the difficulty--it is +the whole hill or "colline" which is composed of tuff with +cross-stratification; the central boss or "monticule" is simply +trachyte. Now, I have described one tuff crater at Galapagos (page 108) +(485/2. The pages refer to Darwin's "Geological Observations on the +Volcanic Islands, etc." 1844.) which has broken through a great solid +sheet of basalt: why should not an irregular mass of trachyte have +been left in the middle after the explosion and emission of mud which +produced the overlying tuff? Or, again, I see no difficulty in a mass of +trachyte being exposed by subsequent dislocations and bared or cleaned +by rain. At Ascension (page 40), subsequent to the last great aeriform +explosion, which has covered the country with fragments, there have been +dislocations and a large circular subsidence...Do not quote Banks' case +(485/3. This refers to Banks' Cove: see "Volcanic Islands," page 107.) +(for there has been some denudation there), but the "elliptic one" +(page 105), which is 1,500 yards (three-quarters of a nautical mile) +in internal diameter...and is the very one the inclination of whose +mud stream on tuff strata I measured (before I had ever heard the name +Dufrenoy) and found varying from 25 to 30 deg. Albemarle Island, instead +of being a crater of elevation, as Von Buch foolishly guessed, is formed +of four great subaerial basaltic volcanoes (page 103), of one of which +you might like to know the external diameter of the summit or crater +was above three nautical miles. There are no "craters of denudation" +at Galapagos. (485/4. See Lyell "On Craters of Denudation, with +Observations on the Structure and Growth of Volcanic Cones," "Quart. +Journ. Geol. Soc." Volume VI., 1850, page 207.) + +I hope you will allude to Mauritius. I think this is the instance on the +largest scale of any known, though imperfectly known. + +If I were you I would give up consistency (or, at most, only allude in +note to your old edition) and bring out the Craters of Denudation as +a new view, which it essentially is. You cannot, I think, give it +prominence as a novelty and yet keep to consistency and passages in old +editions. I should grudge this new view being smothered in your address, +and should like to see a separate paper. The one great channel to +Santorin and Palma, etc., etc., is just like the one main channel +being kept open in atolls and encircling barrier reefs, and on the same +principle of water being driven in through several shallow breaches. + +I of course utterly reprobate my wild notion of circular elevation; +it is a satisfaction to me to think that I perceived there was a screw +loose in the old view, and, so far, I think I was of some service to +you. + +Depend on it, you have for ever smashed, crushed, and abolished craters +of elevation. There must be craters of engulfment, and of explosion +(mere modifications of craters of eruption), but craters of denudation +are the ones which have given rise to all the discussions. + +Pray give my best thanks to Lady Lyell for her translation, which was as +clear as daylight to me, including "leglessness." + + +LETTER 486. TO C. LYELL. + +Down [November 20th, 1849]. + +I remembered the passage in E. de B. [Elie de Beaumont] and have now +re-read it. I have always and do still entirely disbelieve it; in such a +wonderful case he ought to have hammered every inch of rock up to actual +junction; he describes no details of junction, and if I were in your +place I would absolutely dispute the fact of junction (or articulation +as he oddly calls it) on such evidence. I go farther than you; I do not +believe in the world there is or has been a junction between a dike and +stream of lava of exact shape of either (1) or (2) Figure 2]. + +(Figures 2, 3 and 4.) + +If dike gave immediate origin to volcanic vent we should have craters of +[an] elliptic shape [Figure 3]. I believe that when the molten rock in a +dike comes near to the surface, some one two or three points will +always certainly chance to afford an easier passage upward to the actual +surface than along the whole line, and therefore that the dike will be +connected (if the whole were bared and dissected) with the vent by a +column or cone (see my elegant drawing) of lava [Figure 4]. I do not +doubt that the dikes are thus indirectly connected with eruptive vents. +E. de B. seems to have observed many of his T; now without he supposes +the whole line of fissure or dike to have poured out lava (which +implies, as above remarked, craters of an elliptic or almost linear +shape) on both sides, how extraordinarily improbable it is, that there +should have been in a single line of section so many intersections of +points eruption; he must, I think, make his orifices of eruption almost +linear or, if not so, astonishingly numerous. One must refer to what one +has seen oneself: do pray, when you go home, look at the section of a +minute cone of eruption at the Galapagos, page 109 (486/1. "Geological +Observations on Volcanic Islands." London, 1890, page 238.), which is +the most perfect natural dissection of a crater which I have ever heard +of, and the drawing of which you may, I assure you, trust; here the +arching over of the streams as they were poured out over the lip of +the crater was evident, and are now thus seen united to the central +irregular column. Again, at St. Jago I saw some horizontal sections of +the bases of small craters, and the sources or feeders were circular. I +really cannot entertain a doubt that E. de B. is grossly wrong, and that +you are right in your view; but without most distinct evidence I will +never admit that a dike joins on rectangularly to a stream of lava. Your +argument about the perpendicularity of the dike strikes me as good. + +The map of Etna, which I have been just looking at, looks like a sudden +falling in, does it not? I am not much surprised at the linear vent +in Santorin (this linear tendency ought to be difficult to a +circular-crater-of-elevation-believer), I think Abich (486/2. +"Geologische Beobachtungen uber die vulkanischen Erscheinungen und +Bildungen in Unter- und Mittel-Italien." Braunschweig, 1841.) describes +having seen the same actual thing forming within the crater of Vesuvius. +In such cases what outline do you give to the upper surface of the lava +in the dike connecting them? Surely it would be very irregular and would +send up irregular cones or columns as in my above splendid drawing. + +At the Royal on Friday, after more doubt and misgiving than I almost +ever felt, I voted to recommend Forbes for Royal Medal, and that view +was carried, Sedgwick taking the lead. + +I am glad to hear that all your party are pretty well. I know from +experience what you must have gone through. From old age with suffering +death must be to all a happy release. (486/3. This seems to refer to +the death of Sir Charles Lyell's father, which occurred on November 8th, +1849.) + +I saw Dan Sharpe the other day, and he told me he had been working at +the mica schist (i.e. not gneiss) in Scotland, and that he was quite +convinced my view was right. You are wrong and a heretic on this point, +I know well. + + +LETTER 487. TO C.H.L. WOODD. Down, March 4th [1850]. + +(487/1. The paper was sent in MS., and seems not to have been published. +Mr. Woodd was connected by marriage with Mr. Darwin's cousin, the late +Rev. W. Darwin Fox. It was perhaps in consequence of this that Mr. +Darwin proposed Mr. Woodd for the Geological Society.) + +I have read over your paper with attention; but first let me thank you +for your very kind expressions towards myself. I really feel hardly +competent to discuss the questions raised by your paper; I feel the +want of mathematical mechanics. All such problems strike me as awfully +complicated; we do not even know what effect great pressure has on +retarding liquefaction by heat, nor, I apprehend, on expansion. The +chief objection which strikes me is a doubt whether a mass of strata, +when heated, and therefore in some slight degree at least softened, +would bow outwards like a bar of metal. Consider of how many subordinate +layers each great mass would be composed, and the mineralogical changes +in any length of any one stratum: I should have thought that the strata +would in every case have crumpled up, and we know how commonly in +metamorphic strata, which have undergone heat, the subordinate layers +are wavy and sinuous, which has always been attributed to their +expansion whilst heated. + +Before rocks are dried and quarried, manifold facts show how extremely +flexible they are even when not at all heated. Without the bowing out +and subsequent filling in of the roof of the cavity, if I understand +you, there would be no subsidence. Of course the crumpling up of the +strata would thicken them, and I see with you that this might compress +the underlying fluidified rock, which in its turn might escape by +a volcano or raise a weaker part of the earth's crust; but I am too +ignorant to have any opinion whether force would be easily propagated +through a viscid mass like molten rock; or whether such viscid mass +would not act in some degree like sand and refuse to transmit pressure, +as in the old experiment of trying to burst a piece of paper tied +over the end of a tube with a stick, an inch or two of sand being +only interposed. I have always myself felt the greatest difficulty in +believing in waves of heat coming first to this and then to that quarter +of the world: I suspect that heat plays quite a subordinate part in the +upward and downward movements of the earth's crust; though of course +it must swell the strata where first affected. I can understand Sir +J. Herschel's manner of bringing heat to unheated strata--namely, by +covering them up by a mile or so of new strata, and then the heat would +travel into the lower ones. But who can tell what effect this mile or +two of new sedimentary strata would have from mere gravity on the level +of the supporting surface? Of course such considerations do not render +less true that the expansion of the strata by heat would have some +effect on the level of the surface; but they show us how awfully +complicated the phenomenon is. All young geologists have a great turn +for speculation; I have burned my fingers pretty sharply in that way, +and am now perhaps become over-cautious; and feel inclined to cavil at +speculation when the direct and immediate effect of a cause in question +cannot be shown. How neatly you draw your diagrams; I wish you would +turn your attention to real sections of the earth's crust, and then +speculate to your heart's content on them; I can have no doubt that +speculative men, with a curb on, make far the best observers. I +sincerely wish I could have made any remarks of more interest to you, +and more directly bearing on your paper; but the subject strikes me as +too difficult and complicated. With every good wish that you may go +on with your geological studies, speculations, and especially +observations... + + +LETTER 488. TO C. LYELL. Down, March 24th [1853]. + +I have often puzzled over Dana's case, in itself and in relation to the +trains of S. American volcanoes of different heights in action at the +same time (page 605, Volume V. "Geological Transactions." (488/1. "On +the Connection of certain Volcanic Phenomena in South America, and on +the Formation of Mountain Chains and Volcanoes, as the Effect of the +same Power by which Continents are Elevated" ("Trans. Geol. Soc." +Volume V., page 601, 1840). On page 605 Darwin records instances of the +simultaneous activity after an earthquake of several volcanoes in +the Cordillera.)) I can throw no light on the subject. I presume you +remember that Hopkins (488/2. See "Report on the Geological Theories +of Elevation and Earthquakes," by W. Hopkins, "Brit. Assoc. Rep." 1847, +page 34.) in some one (I forget which) of his papers discusses such +cases, and urgently wishes the height of the fluid lava was known in +adjoining volcanoes when in contemporaneous action; he argues vehemently +against (as far as I remember) volcanoes in action of different heights +being connected with one common source of liquefied rock. If lava was as +fluid as water, the case would indeed be hopeless; and I fancy we should +be led to look at the deep-seated rock as solid though intensely hot, +and becoming fluid as soon as a crack lessened the tension of the +super-incumbent strata. But don't you think that viscid lava might be +very slow in communicating its pressure equally in all directions? I +remember thinking strongly that Dana's case within the one crater of +Kilauea proved too much; it really seems monstrous to suppose that the +lava within the same crater is not connected at no very great depth. + +When one reflects on (and still better sees) the enormous masses of lava +apparently shot miles high up, like cannon-balls, the force seems out of +all proportion to the mere gravity of the liquefied lava; I should think +that a channel a little straightly or more open would determine the line +of explosion, like the mouth of a cannon compared to the touch-hole. +If a high-pressure boiler was cracked across, no one would think for a +moment that the quantity of water and steam expelled at different points +depended on the less or greater height of the water within the boiler +above these points, but on the size of the crack at these points; and +steam and water might be driven out both at top and bottom. May not a +volcano be likened to a protruding and cracked portion on a vast natural +high-pressure boiler, formed by the surrounding area of country? In +fact, I think my simile would be truer if the difference consisted only +in the cracked case of the boiler being much thicker in some parts than +in others, and therefore having to expel a greater thickness or depth of +water in the thicker cracks or parts--a difference of course absolutely +as nothing. + +I have seen an old boiler in action, with steam and drops of water +spurting out of some of the rivet-holes. No one would think whether the +rivet-holes passed through a greater or less thickness of iron, or were +connected with the water higher or lower within the boiler, so small +would the gravity be compared with the force of the steam. If the boiler +had been not heated, then of course there would be a great difference +whether the rivet-holes entered the water high or low, so that there +was greater or less pressure of gravity. How to close my volcanic +rivet-holes I don't know. + +I do not know whether you will understand what I am driving at, and it +will not signify much whether you do or not. I remember in old days (I +may mention the subject as we are on it) often wishing I could get +you to look at continental elevations as THE phenomenon, and volcanic +outbursts and tilting up of mountain chains as connected, but quite +secondary, phenomena. I became deeply impressed with the truth of this +view in S. America, and I do not think you hold it, or if so make it +clear: the same explanation, whatever it may be, which will account for +the whole coast of Chili rising, will and must apply to the volcanic +action of the Cordillera, though modified no doubt by the liquefied +rock coming to the surface and reaching water, and so [being] rendered +explosive. To me it appears that this ought to be borne in mind in your +present subject of discussion. I have written at too great length; and +have amused myself if I have done you no good--so farewell. + + +LETTER 489. TO C. LYELL. Down, July 5th [1856]. + +I am very much obliged for your long letter, which has interested me +much; but before coming to the volcanic cosmogony I must say that I +cannot gather your verdict as judge and jury (and not as advocate) +on the continental extensions of late authors (489/1. See "Life and +Letters," II., page 74; Letter to Lyell, June 25th, 1856: also +letters in the sections of the present work devoted to Evolution and +Geographical Distribution.), which I must grapple with, and which as yet +strikes me as quite unphilosophical, inasmuch as such extensions must be +applied to every oceanic island, if to any one, as to Madeira; and this +I cannot admit, seeing that the skeletons, at least, of our continents +are ancient, and seeing the geological nature of the oceanic islands +themselves. Do aid me with your judgment: if I could honestly admit +these great [extensions], they would do me good service. + +With respect to active volcanic areas being rising areas, which looks +so pretty on the coral maps, I have formerly felt "uncomfortable" on +exactly the same grounds with you, viz. maritime position of volcanoes; +and still more from the immense thicknesses of Silurian, etc., volcanic +strata, which thicknesses at first impress the mind with the idea of +subsidence. If this could be proved, the theory would be smashed; but +in deep oceans, though the bottom were rising, great thicknesses of +submarine lava might accumulate. But I found, after writing Coral Book, +cases in my notes of submarine vesicular lava-streams in the upper +masses of the Cordillera, formed, as I believe, during subsidence, +which staggered me greatly. With respect to the maritime position of +volcanoes, I have long been coming to the conclusion that there must +be some law causing areas of elevation (consequently of land) and of +subsidence to be parallel (as if balancing each other) and closely +approximate; I think this from the form of continents with a deep ocean +on one side, from coral map, and especially from conversations with you +on immense subsidences of the Carboniferous and [other] periods, and yet +with continued great supply of sediment. If this be so, such areas, +with opposite movements, would probably be separated by sets of parallel +cracks, and would be the seat of volcanoes and tilts, and consequently +volcanoes and mountains would be apt to be maritime; but why volcanoes +should cling to the rising edge of the cracks I cannot conjecture. That +areas with extinct volcanic archipelagoes may subside to any extent I do +not doubt. + +Your view of the bottom of Atlantic long sinking with continued volcanic +outbursts and local elevations at Madeira, Canaries, etc., grates (but +of course I do not know how complex the phenomena are which are thus +explained) against my judgment; my general ideas strongly lead me to +believe in elevatory movements being widely extended. One ought, I +think, never to forget that when a volcano is in action we have distinct +proof of an action from within outwards. Nor should we forget, as I +believe follows from Hopkins (489/2. "Researches in Physical Geology," +W. Hopkins, "Trans. Phil. Soc. Cambridge," Volume VI., 1838. See also +"Report on the Geological Theories of Elevation and Earthquakes," W. +Hopkins, "Brit. Assoc. Rep." page 33, 1847 (Oxford meeting).), and as I +have insisted in my Earthquake paper, that volcanoes and mountain chains +are mere accidents resulting from the elevation of an area, and as +mountain chains are generally long, so should I view areas of elevation +as generally large. (489/3. "On the Connexion of certain Volcanic +Phenomena in S. America, and on the Formation of Mountain Chains and +Volcanoes, as the Effect of the same Power by which Continents are +Elevated," "Trans. Geol. Soc." Volume V., page 601, 1840. "Bearing in +mind Mr. Hopkins' demonstration, if there be considerable elevation +there must be fissures, and, if fissures, almost certainly unequal +upheaval, or subsequent sinking down, the argument may be finally +thus put: mountain chains are the effects of continental elevations; +continental elevations and the eruptive force of volcanoes are due to +one great motive, now in progressive action..." (loc. cit., page 629).) + +Your old original view that great oceans must be sinking areas, from +there being causes making land and yet there being little land, has +always struck me till lately as very good. But in some degree this +starts from the assumption that within periods of which we know anything +there was either a continent in such areas, or at least a sea-bottom of +not extreme depth. + + +LETTER 490. TO C. LYELL. King's Head Hotel, Sandown, Isle of Wight, July +18th [1858]. + +I write merely to thank you for the abstract of the Etna paper. (490/1. +"On the Structure of Lavas which have Consolidated on Steep Slopes, +with Remarks on the Mode of Origin of Mount Etna and on the Theory of +'Craters of Elevation,'" by C. Lyell, "Phil. Trans. R. Soc." Volume +CXLVIII., page 703, 1859.) It seems to me a very grand contribution to +our volcanic knowledge. Certainly I never expected to see E. de B.'s +[Elie de Beaumont] theory of slopes so completely upset. He must have +picked out favourable cases for measurement. And such an array of facts +he gives! You have scotched, and will see die, I now think, the Crater +of Elevation theory. But what vitality there is in a plausible theory! +(490/2. The rest of this letter is published in "Life and Letters," II., +page 129.) + + +LETTER 491. TO C. LYELL. Down, November 25th [1860]. + +I have endeavoured to think over your discussion, but not with much +success. You will have to lay down, I think, very clearly, what +foundation you argue from--four parts (which seems to me exceedingly +moderate on your part) of Europe being now at rest, with one part +undergoing movement. How it is, that from this you can argue that the +one part which is now moving will have rested since the commencement of +the Glacial period in the proportion of four to one, I do not pretend +to see with any clearness; but does not your argument rest on the +assumption that within a given period, say two or three million years, +the whole of Europe necessarily has to undergo movement? This may +be probable or not so, but it seems to me that you must explain the +foundation of your argument from space to time, which at first, to me +was very far from obvious. I can, of course, see that if you can make +out your argument satisfactorily to yourself and others it would be most +valuable. I can imagine some one saying that it is not fair to argue +that the great plains of Europe and the mountainous districts of +Scotland and Wales have been at all subjected to the same laws of +movement. Looking to the whole world, it has been my opinion, from the +very size of the continents and oceans, and especially from the enormous +ranges of so many mountain-chains (resulting from cracks which follow +from vast areas of elevation, as Hopkins argues (491/1. See "Report +on the Geological Theories of Elevation and Earthquakes." by William +Hopkins. "Brit. Assoc. Rep." 1847, pages 33-92; also the Anniversary +Address to the Geological Society by W. Hopkins in 1852 ("Quart. Journ. +Geol. Soc." Volume VIII.); in this Address, pages lxviii et seq.) +reference is made to the theory of elevation which rests on the +supposition "of the simultaneous action of an upheaving force at every +point of the area over which the phenomena of elevation preserve a +certain character of continuity...The elevated mass...becomes stretched, +and is ultimately torn and fissured in those directions in which +the tendency thus to tear is greatest...It is thus that the complex +phenomena of elevation become referable to a general and simple +mechanical cause...")) and from other reasons, it has been my opinion +that, as a general rule, very large portions of the world have been +simultaneously affected by elevation or subsidence. I can see that this +does not apply so strongly to broken Europe, any more than to the Malay +Archipelago. Yet, had I been asked, I should have said that probably +nearly the whole of Europe was subjected during the Glacial period +to periods of elevation and of subsidence. It does not seem to me so +certain that the kinds of partial movement which we now see going on +show us the kind of movement which Europe has been subjected to since +the commencement of the Glacial period. These notions are at least +possible, and would they not vitiate your argument? Do you not rest on +the belief that, as Scandinavia and some few other parts are now rising, +and a few others sinking, and the remainder at rest, so it has been +since the commencement of the Glacial period? With my notions I +should require this to be made pretty probable before I could put much +confidence in your calculations. You have probably thought this all +over, but I give you the reflections which come across me, supposing +for the moment that you took the proportions of space at rest and in +movement as plainly applicable to time. I have no doubt that you have +sufficient evidence that, at the commencement of the Glacial period, the +land in Scotland, Wales, etc., stood as high or higher than at present, +but I forget the proofs. + +Having burnt my own fingers so consumedly with the Wealden, I am fearful +for you, but I well know how infinitely more cautious, prudent, and +far-seeing you are than I am; but for heaven's sake take care of your +fingers; to burn them severely, as I have done, is very unpleasant. + +Your 2 1/2 feet for a century of elevation seems a very handsome +allowance. can D. Forbes really show the great elevation of Chili? I am +astounded at it, and I took some pains on the point. + +I do not pretend to say that you may not be right to judge of the past +movements of Europe by those now and recently going on, yet it somehow +grates against my judgment,--perhaps only against my prejudices. + +As a change from elevation to subsidence implies some great subterranean +or cosmical change, one may surely calculate on long intervals of +rest between. Though, if the cause of the change be ever proved to be +astronomical, even this might be doubtful. + +P.S.--I do not know whether I have made clear what I think probable, or +at least possible: viz., that the greater part of Europe has at times +been elevated in some degree equably; at other times it has all subsided +equably; and at other times might all have been stationary; and at other +times it has been subjected to various unequal movements, up and down, +as at present. + + +LETTER 492. TO C. LYELL. Down, December 4th [1860]. + +It certainly seems to me safer to rely solely on the slowness of +ascertained up-and-down movement. But you could argue length of probable +time before the movement became reversed, as in your letter. And might +you not add that over the whole world it would probably be admitted that +a larger area is NOW at rest than in movement? and this I think would be +a tolerably good reason for supposing long intervals of rest. You might +even adduce Europe, only guarding yourself by saying that possibly (I +will not say probably, though my prejudices would lead me to say so) +Europe may at times have gone up and down all together. I forget whether +in a former letter you made a strong point of upward movement being +always interrupted by long periods of rest. After writing to you, out +of curiosity I glanced at the early chapters in my "Geology of South +America," and the areas of elevation on the E. and W. coasts are so +vast, and proofs of many successive periods of rest so striking, +that the evidence becomes to my mind striking. With regard to the +astronomical causes of change: in ancient days in the "Beagle" when I +reflected on the repeated great oscillations of level on the very same +area, and when I looked at the symmetry of mountain chains over such +vast spaces, I used to conclude that the day would come when the slow +change of form in the semi-fluid matter beneath the crust would be found +to be the cause of volcanic action, and of all changes of level. And the +late discussion in the "Athenaeum" (492/1. "On the Change of Climate +in Different Regions of the Earth." Letters from Sir Henry James, Col. +R.E., "Athenaeum," August 25th, 1860, page 256; September 15th, page +355; September 29th, page 415; October 13th, page 483. Also letter from +J. Beete Jukes, Local Director of the Geological Survey of Ireland, loc. +cit., September 8th, page 322; October 6th, page 451.), by Sir H. James +(though his letter seemed to me mighty poor, and what Jukes wrote good), +reminded me of this notion. In case astronomical agencies should ever +be proved or rendered probable, I imagine, as in nutation or precession, +that an upward movement or protrusion of fluidified matter below might +be immediately followed by movement of an opposite nature. This is all +that I meant. + +I have not read Jamieson, or yet got the number. (492/2. Possibly +William Jameson, "Journey from Quito to Cayambe," "Geog. Soc. Journ." +Volume XXXI., page 184, 1861.) I was very much struck with Forbes' +explanation of n[itrate] of soda beds and the saliferous crust, which +I saw and examined at Iquique. (492/3. "On the Geology of Bolivia and +Southern Peru," by D. Forbes, "Quart. Journ. Geol. Soc." Volume XVII., +page 7, 1861. Mr. Forbes attributes the formation of the saline deposits +to lagoons of salt water, the communication of which with the sea has +been cut off by the rising of the land (loc. cit., page 13).) I often +speculated on the greater rise inland of the Cordilleras, and could +never satisfy myself... + +I have not read Stur, and am awfully behindhand in many things...(492/4. +The end of this letter is published as a footnote in "Life and Letters," +II., page 352.) + + +(FIGURE 5. Map of part of South America and the Galapagos Archipelago.) + + +LETTER 493. TO C. LYELL. Down, July 18th [1867]. + +(493/1. The first part of this letter is published in "Life and +Letters," III., page 71.) + +(493/2. Tahiti (Society Islands) is coloured blue in the map showing +the distribution of the different kinds of reefs in "The Structure and +Distribution of Coral Reefs," Edition III., 1889, page 185. The blue +colour indicates the existence of barrier reefs and atolls which, on +Darwin's theory, point to subsidence.) + +Tahiti is, I believe, rightly coloured, for the reefs are so far from +the land, and the ocean so deep, that there must have been subsidence, +though not very recently. I looked carefully, and there is no evidence +of recent elevation. I quite agree with you versus Herschel on Volcanic +Islands. (493/3. Sir John Herschel suggested that the accumulation on +the sea-floor of sediment, derived from the waste of the island, +presses down the bed of the ocean, the continent being on the other hand +relieved of pressure; "this brings about a state of strain in the crust +which will crack in its weakest spot, the heavy side going down, and the +light side rising." In discussing this view Lyell writes ("Principles," +Volume II. Edition X., page 229), "This hypothesis appears to me of +very partial application, for active volcanoes, even such as are on the +borders of continents, are rarely situated where great deltas have been +forming, whether in Pliocene or post-Tertiary times. The number, also, +of active volcanoes in oceanic islands is very great, not only in +the Pacific, but equally in the Atlantic, where no load of coral +matter...can cause a partial weighting and pressing down of a supposed +flexible crust.") Would not the Atlantic and Antarctic volcanoes be the +best examples for you, as there then can be no coral mud to depress +the bottom? In my "Volcanic Islands," page 126, I just suggest that +volcanoes may occur so frequently in the oceanic areas as the surface +would be most likely to crack when first being elevated. I find one +remark, page 128 (493/4. "Volcanic Islands," page 128: "The islands, +moreover, of some of the small volcanic groups, which thus border +continents, are placed in lines related to those along which the +adjoining shores of the continents trend" [see Figure 5].), which seems +to me worth consideration--viz. the parallelism of the lines of eruption +in volcanic archipelagoes with the coast lines of the nearest continent, +for this seems to indicate a mechanical rather than a chemical +connection in both cases, i.e. the lines of disturbance and cracking. In +my "South American Geology," page 185 (493/5. "Geological Observations +on South America," London, 1846, page 185.), I allude to the remarkable +absence at present of active volcanoes on the east side of the +Cordillera in relation to the absence of the sea on this side. Yet I +must own I have long felt a little sceptical on the proximity of water +being the exciting cause. The one volcano in the interior of Asia is +said, I think, to be near great lakes; but if lakes are so important, +why are there not many other volcanoes within other continents? I have +always felt rather inclined to look at the position of volcanoes on the +borders of continents, as resulting from coast lines being the lines of +separation between areas of elevation and subsidence. But it is useless +in me troubling you with my old speculations. + + +LETTER 494. TO A.R. WALLACE. March 22nd [1869]. + +(494/1. The following extract from a letter to Mr. Wallace refers to his +"Malay Archipelago," 1869.) + +I have only one criticism of a general nature, and I am not sure that +other geologists would agree with me. You repeatedly speak as if the +pouring out of lava, etc., from volcanoes actually caused the subsidence +of an adjoining area. I quite agree that areas undergoing opposite +movements are somehow connected; but volcanic outbursts must, I think, +be looked at as mere accidents in the swelling up of a great dome or +surface of plutonic rocks, and there seems no more reason to conclude +that such swelling or elevation in mass is the cause of the subsidence, +than that the subsidence is the cause of the elevation, which latter +view is indeed held by some geologists. I have regretted to find so +little about the habits of the many animals which you have seen. + + +LETTER 495. TO C. LYELL. Down, May 20th, 1869. + +I have been much pleased to hear that you have been looking at my +S. American book (495/1. "Geological Observations on South America," +London, 1846.), which I thought was as completely dead and gone as any +pre-Cambrian fossil. You are right in supposing that my memory about +American geology has grown very hazy. I remember, however, a paper on +the Cordillera by D. Forbes (495/2. "Geology of Bolivia and South Peru," +by Forbes, "Quart. Journ. Geol. Soc." Volume XVII., pages 7-62, 1861. +Forbes admits that there is "the fullest evidence of elevation of the +Chile coast since the arrival of the Spaniards. North of Arica, if we +accept the evidence of M. d'Orbigny and others, the proof of elevation +is much more decided; and consequently it may be possible that here, +as is the case about Lima, according to Darwin, the elevation may have +taken place irregularly in places..." (loc. cit., page 11).), with +splendid sections, which I saw in MS., but whether "referred" to me or +lent to me I cannot remember. This would be well worth your looking to, +as I think he both supports and criticises my views. In Ormerod's +Index to the Journal (495/3. "Classified Index to the Transactions, +Proceedings and Quarterly Journal of the Geological Society."), which I +do not possess, you would, no doubt, find a reference; but I think the +sections would be worth borrowing from Forbes. Domeyko (495/4. Reference +is made by Forbes in his paper on Bolivia and Peru to the work of +Ignacio Domeyko on the geology of Chili. Several papers by this author +were published in the "Annales des Mines" between 1840 and 1869, also in +the "Comptes Rendus" of 1861, 1864, etc.) has published in the "Comptes +Rendus" papers on Chili, but not, as far as I can remember, on the +structure of the mountains. Forbes, however, would know. What you say +about the plications being steepest in the central and generally highest +part of the range is conclusive to my mind that there has been the chief +axis of disturbance. The lateral thrusting has always appeared to me +fearfully perplexing. I remember formerly thinking that all lateral +flexures probably occurred deep beneath the surface, and have been +brought into view by an enormous superincumbent mass having been +denuded. If a large and deep box were filled with layers of damp paper +or clay, and a blunt wedge was slowly driven up from beneath, would not +the layers above it and on both sides become greatly convoluted, whilst +those towards the top would be only slightly arched? When I spoke of +the Andes being comparatively recent, I suppose that I referred to the +absence of the older formations. In looking to my volume, which I have +not done for many years, I came upon a passage (page 232) which would be +worth your looking at, if you have ever felt perplexed, as I often was, +about the sources of volcanic rocks in mountain chains. You have stirred +up old memories, and at the risk of being a bore I should like to call +your attention to another point which formerly perplexed me much--viz. +the presence of basaltic dikes in most great granitic areas. I cannot +but think the explanation given at page 123 of my "Volcanic Islands" is +the true one. (495/5. On page 123 of the "Geological Observations on the +Volcanic Islands visited during the Voyage of H.M.S. 'Beagle,'" 1844, +Darwin quotes several instances of greenstone and basaltic dikes +intersecting granitic and allied metamorphic rocks. He suggests that +these dikes "have been formed by fissures penetrating into partially +cooled rocks of the granitic and metamorphic series, and by their more +fluid parts, consisting chiefly of hornblende oozing out, and being +sucked into such fissures.") + + +LETTER 496. TO VICTOR CARUS. Down, March 21st, 1876. + +The very kind expressions in your letter have gratified me deeply. + +I quite forget what I said about my geological works, but the papers +referred to in your letter are the right ones. I enclose a list with +those which are certainly not worth translating marked with a red line; +but whether those which are not thus marked with a red line are worth +translation you will have to decide. I think much more highly of my +book on "Volcanic Islands" since Mr. Judd, by far the best judge on the +subject in England, has, as I hear, learnt much from it. + +I think the short paper on the "formation of mould" is worth +translating, though, if I have time and strength, I hope to write +another and longer paper on the subject. + +I can assure you that the idea of any one translating my books better +than you never even momentarily crossed my mind. I am glad that you can +give a fairly good account of your health, or at least that it is not +worse. + + +LETTER 497. TO T. MELLARD READE. London, December 9th, 1880. + +I am sorry to say that I do not return home till the middle of next +week, and as I order no pamphlets to be forwarded to me by post, I +cannot return the "Geolog. Mag." until my return home, nor could my +servants pick it out of the multitude which come by the post. (497/1. +Article on "Oceanic Islands," by T. Mellard Reade, "Geol. Mag." Volume +VIII., page 75, 1881.) + +As I remarked in a letter to a friend, with whom I was discussing +Wallace's last book (497/2. Wallace's "Island Life," 1880.), the subject +to which you refer seems to me a most perplexing one. The fact which +I pointed out many years ago, that all oceanic islands are volcanic +(except St. Paul's, and now this is viewed by some as the nucleus of an +ancient volcano), seems to me a strong argument that no continent ever +occupied the great oceans. (497/3. "During my investigations on coral +reefs I had occasion to consult the works of many voyagers, and I +was invariably struck with the fact that, with rare exceptions, the +innumerable islands scattered through the Pacific, Indian, and Atlantic +Oceans were composed either of volcanic or of modern coral rocks" +("Geological Observations on Volcanic Islands, etc." Edition II., 1876, +page 140).) Then there comes the statement from the "Challenger" that +all sediment is deposited within one or two hundred miles from the +shores, though I should have thought this rather doubtful with respect +to great rivers like the Amazons. + +The chalk formerly seemed to me the best case of an ocean having +extended where a continent now stands; but it seems that some good +judges deny that the chalk is an oceanic deposit. On the whole, I lean +to the side that the continents have since Cambrian times occupied +approximately their present positions. But, as I have said, the question +seems a difficult one, and the more it is discussed the better. + + +LETTER 498. TO A. AGASSIZ. Down, January 1st, 1881. + +I must write a line or two to thank you much for having written to me so +long a letter on coral reefs at a time when you must have been so busy. +Is it not difficult to avoid believing that the wonderful elevation +in the West Indies must have been accompanied by much subsidence, +notwithstanding the state of Florida? (498/1. The Florida reefs cannot +be explained by subsidence. Alexander Agassiz, who has described these +reefs in detail ("Three Cruises of the U.S. Coast and Geodetic Survey +Steamer 'Blake,'" 2 volumes, London, 1888), shows that the southern +extremity of the peninsula "is of comparatively recent growth, +consisting of concentric barrier-reefs, which have been gradually +converted into land by the accumulation of intervening mud-flats" (see +also Appendix II., page 287, to Darwin's "Coral Reefs," by T.G. Bonney, +Edition III., 1889.)) When reflecting in old days on the configuration +of our continents, the position of mountain chains, and especially on +the long-continued supply of sediment over the same areas, I used to +think (as probably have many other persons) that areas of elevation and +subsidence must as a general rule be separated by a single great line +of fissure, or rather of several closely adjoining lines of fissure. I +mention this because, when looking within more recent times at charts +with the depths of the sea marked by different tints, there seems to be +some connection between the profound depths of the ocean and the trends +of the nearest, though distant, continents; and I have often wished +that some one like yourself, to whom the subject was familiar, would +speculate on it. + +P.S.--I do hope that you will re-urge your views about the reappearance +of old characters (498/2. See "Life and Letters," III., pages 245, +246.), for, as far as I can judge, the most important views are often +neglected unless they are urged and re-urged. + +I am greatly indebted to you for sending me very many most valuable +works published at your institution. + + +2.IX.II. ICE-ACTION, 1841-1882. + + +LETTER 499. TO C. LYELL. [1841.] + +Your extract has set me puzzling very much, and as I find I am better +at present for not going out, you must let me unload my mind on paper. +I thought everything so beautifully clear about glaciers, but now your +case and Agassiz's statement about the cavities in the rock formed by +cascades in the glaciers, shows me I don't understand their structure at +all. I wish out of pure curiosity I could make it out. (499/1. "Etudes +sur les Glaciers," by Louis Agassiz, 1840, contains a description of +cascades (page 343), and "des cavites interieures" (page 348).) + +If the glacier travelled on (and it certainly does travel on), and the +water kept cutting back over the edge of the ice, there would be a great +slit in front of the cascade; if the water did not cut back, the whole +hollow and cascade, as you say, must travel on; and do you suppose the +next season it falls down some crevice higher up? In any case, how in +the name of Heaven can it make a hollow in solid rock, which surely must +be a work of many years? I must point out another fact which Agassiz +does not, as it appears to me, leave very clear. He says all the blocks +on the surface of the glaciers are angular, and those in the moraines +rounded, yet he says the medial moraines whence the surface rocks come +and are a part [of], are only two lateral moraines united. Can he +refer to terminal moraines alone when he says fragments in moraines are +rounded? What a capital book Agassiz's is. In [reading] all the early +part I gave up entirely the Jura blocks, and was heartily ashamed of my +appendix (499/2. "M. Agassiz has lately written on the subject of the +glaciers and boulders of the Alps. He clearly proves, as it appears to +me, that the presence of the boulders on the Jura cannot be explained +by any debacle, or by the power of ancient glaciers driving before them +moraines...M. Agassiz also denies that they were transported by floating +ice." ("Voyages of the 'Adventure' and 'Beagle,'" Volume III., 1839: +"Journal and Remarks: Addenda," page 617.)) (and am so still of the +manner in which I presumptuously speak of Agassiz), but it seems by his +own confession that ordinary glaciers could not have transported the +blocks there, and if an hypothesis is to be introduced the sea is much +simpler; floating ice seems to me to account for everything as well +as, and sometimes better than the solid glaciers. The hollows, however, +formed by the ice-cascades appear to me the strongest hostile fact, +though certainly, as you said, one sees hollow round cavities on present +rock-beaches. + +I am glad to observe that Agassiz does not pretend that direction +of scratches is hostile to floating ice. By the way, how do you and +Buckland account for the "tails" of diluvium in Scotland? (499/3. Mr. +Darwin speaks of the tails of diluvium in Scotland extending from +the protected side of a hill, of which the opposite side, facing the +direction from which the ice came, is marked by grooves and striae +(loc. cit., pages 622, 623).) I thought in my appendix this made out the +strongest argument for rocks having been scratched by floating ice. + +Some facts about boulders in Chiloe will, I think, in a very small +degree elucidate some parts of Jura case. What a grand new feature all +this ice work is in Geology! How old Hutton would have stared! (499/4. +Sir Charles Lyell speaks of the Huttonian theory as being characterised +by "the exclusion of all causes not supposed to belong to the present +order of Nature" (Lyell's "Principles," Edition XII., volume I., page +76, 1875). Sir Archibald Geikie has recently edited the third volume of +Hutton's "Theory of the Earth," printed by the Geological Society, 1899. +See also "The Founders of Geology," by Sir Archibald Geikie; London, +1897.) + +I ought to be ashamed of myself for scribbling on so. Talking of shame, +I have sent a copy of my "Journal" (499/5. "Journal and Remarks," +1832-36. See note 2, page 148.) with very humble note to Agassiz, as an +apology for the tone I used, though I say, I daresay he has never seen +my appendix, or would care at all about it. + +I did not suppose my note about Glen Roy could have been of any use to +you--I merely scribbled what came uppermost. I made one great oversight, +as you would perceive. I forgot the Glacier theory: if a glacier most +gradually disappeared from mouth of Spean Valley [this] would account +for buttresses of shingle below lowest shelf. The difficulty I put about +the ice-barrier of the middle Glen Roy shelf keeping so long at exactly +same level does certainly appear to me insuperable. (499/5. For a +description of the shelves or parallel roads in Glen Roy see Darwin's +"Observations on the Parallel Roads of Glen Roy, etc." "Phil. Trans. R. +Soc." 1839, page 39; also Letter 517 et seq.) + +What a wonderful fact this breakdown of old Niagara is. How it disturbs +the calculations about lengths of time before the river would have +reached the lakes. + +I hope Mrs. Lyell will read this to you, then I shall trust for +forgiveness for having scribbled so much. I should have sent back +Agassiz sooner, but my servant has been very unwell. Emma is going on +pretty well. + +My paper on South American boulders and "till," which latter deposit +is perfectly characterised in Tierra del Fuego, is progressing rapidly. +(499/6. "On the Distribution of the Erratic Boulders and on the +Contemporaneous Unstratified Deposits of South America," "Trans. Geol. +Soc." Volume VI., page 415, 1842.) + +I much like the term post-Pliocene, and will use it in my present paper +several times. + +P.S.--I should have thought that the most obvious objection to the +marine-beach theory for Glen Roy would be the limited extension of the +shelves. Though certainly this is not a valid one, after an intermediate +one, only half a mile in length, and nowhere else appearing, even in the +valley of Glen Roy itself, has been shown to exist. + + +LETTER 500. TO C. LYELL. 1842. + +I had some talk with Murchison, who has been on a flying visit into +Wales, and he can see no traces of glaciers, but only of the trickling +of water and of the roots of the heath. It is enough to make +an extraneous man think Geology from beginning to end a work of +imagination, and not founded on observation. Lonsdale, I observe, pays +Buckland and myself the compliment of thinking Murchison not seeing as +worth nothing; but I confess I am astonished, so glaringly clear after +two or three days did the evidence appear to me. Have you seen last "New +Edin. Phil. Journ.", it is ice and glaciers almost from beginning to +end. (500/1. "The Edinburgh New Philosophical Journal," Volume XXXIII. +(April-October), 1842, contains papers by Sir G.S. Mackenzie, Prof. +H.G. Brown, Jean de Charpentier, Roderick Murchison, Louis Agassiz, all +dealing with glaciers or ice; also letters to the Editor relating to +Prof. Forbes' account of his recent observations on Glaciers, and a +paper by Charles Darwin entitled "Notes on the Effects produced by the +Ancient Glaciers of Carnarvonshire, and on the Boulders transported by +Floating Ice.") Agassiz says he saw (and has laid down) the two lowest +terraces of Glen Roy in the valley of the Spean, opposite mouth of Glen +Roy itself, where no one else has seen them. (500/2. "The Glacial Theory +and its Recent Progress," by Louis Agassiz, loc. cit., page 216. Agassiz +describes the parallel terraces on the flanks of Glen Roy and Glen Spean +(page 236), and expresses himself convinced "that the Glacial theory +alone satisfies all the exigencies of the phenomenon" of the parallel +roads.) I carefully examined that spot, owing to the sheep tracks +[being] nearly but not quite parallel to the terrace. So much, again, +for difference of observation. I do not pretend to say who is right. + + +LETTER 501. TO J.D. HOOKER. Down, October 12th, 1849. + +I was heartily glad to get your last letter; but on my life your thanks +for my very few and very dull letters quite scalded me. I have been very +indolent and selfish in not having oftener written to you and kept +my ears open for news which would have interested you; but I have not +forgotten you. Two days after receiving your letter, there was a short +leading notice about you in the "Gardeners' Chronicle" (501/1. The +"Gardeners' Chronicle," 1849, page 628.); in which it is said you +have discovered a noble crimson rose and thirty rhododendrons. I must +heartily congratulate you on these discoveries, which will interest +the public; and I have no doubt that you will have made plenty of most +interesting botanical observations. This last letter shall be put with +all your others, which are now safe together. I am very glad that +you have got minute details about the terraces in the valleys: your +description sounds curiously like the terraces in the Cordillera of +Chili; these latter, however, are single in each valley; but you will +hereafter see a description of these terraces in my "Geology of S. +America." (501/2. "Geological Observations," pages 10 et passim.) At the +end of your letter you speak about giving up Geology, but you must not +think of it; I am sure your observations will be very interesting. Your +account of the great dam in the Yangma valley is most curious, and quite +full; I find that I did not at all understand its wonderful structure in +your former letter. Your notion of glaciers pushing detritus into +deep fiords (and ice floating fragments on their channels), is in many +respects new to me; but I cannot help believing your dam is a lateral +moraine: I can hardly persuade myself that the remains of floating ice +action, at a period so immensely remote as when the Himalaya stood at +a low level in the sea, would now be distinguishable. (501/3. Hooker's +"Himalayan Journals," Volume II., page 121, 1854. In describing certain +deposits in the Lachoong valley, Hooker writes: "Glaciers might have +forced immense beds of gravel into positions that would dam up lakes +between the ice and the flanks of the valley" (page 121). In a footnote +he adds: "We are still very ignorant of many details of ice action, and +especially of the origin of many enormous deposits which are not true +moraines." Such deposits are referred to as occurring in the Yangma +valley.) Your not having found scored boulders and solid rocks is an +objection both to glaciers and floating ice; for it is certain that +both produce such. I believe no rocks escape scoring, polishing and +mammillation in the Alps, though some lose it easily when exposed. Are +you familiar with appearance of ice-action? If I understand rightly, you +object to the great dam having been produced by a glacier, owing to the +dryness of the lateral valley and general infrequency of glaciers in +Himalaya; but pray observe that we may fairly (from what we see in +Europe) assume that the climate was formerly colder in India, and when +the land stood at a lower height more snow might have fallen. Oddly +enough, I am now inclined to believe that I saw a gigantic moraine +crossing a valley, and formerly causing a lake above it in one of the +great valleys (Valle del Yeso) of the Cordillera: it is a mountain of +detritus, which has puzzled me. If you have any further opportunities, +do look for scores on steep faces of rock; and here and there remove +turf or matted parts to have a look. Again I beg, do not give up +Geology:--I wish you had Agassiz's work and plates on Glaciers. (501/4. +"Etudes sur les Glaciers." L. Agassiz, Neuchatel, 1840.) I am extremely +sorry that the Rajah, ill luck to him, has prevented your crossing +to Thibet; but you seem to have seen most interesting country: one is +astonished to hear of Fuegian climate in India. I heard from the Sabines +that you were thinking of giving up Borneo; I hope that this report may +prove true. + + +LETTER 502. TO C. LYELL. Down, May 8th [1855]. + +The notion you refer to was published in the "Geological Journal" +(502/1. "on the Transportal of Erratic Boulders from a lower to a higher +Level." By C. Darwin.), Volume IV. (1848), page 315, with reference to +all the cases which I could collect of boulders apparently higher than +the parent rock. + +The argument of probable proportion of rock dropped by sea ice compared +to land glaciers is new to me. I have often thought of the idea of the +viscosity and enormous momentum of great icebergs, and still think that +the notion I pointed out in appendix to Ramsay's paper is probable, and +can hardly help being applicable in some cases. (502/2. The paper by +Ramsay has no appendix; probably, therefore Mr. Darwin's notes were +published separately as a paper in the "Phil. Mag.") I wonder whether +the "Phil. Journal [Magazine?.]" would publish it, if I could get it +from Ramsay or the Geological Society. (502/3. "On the Power of Icebergs +to make rectilinear, uniformly-directed grooves across a Submarine +Undulatory Surface." By C. Darwin, "Phil. Mag." Volume X., page 96, +1855.) If you chance to meet Ramsay will you ask him whether he has it? +I think it would perhaps be worth while just to call the N. American +geologists' attention to the idea; but it is not worth any trouble. I am +tremendously busy with all sorts of experiments. By the way, Hopkins at +the Geological Society seemed to admit some truth in the idea of scoring +by (viscid) icebergs. If the Geological Society takes so much [time] to +judge of truth of notions, as you were telling me in regard to Ramsay's +Permian glaciers (502/4. "On the Occurrence of angular, sub-angular, +polished, and striated Fragments and Boulders in the Permian Breccia +of Shropshire, Worcestershire, etc.; and on the Probable Existence of +Glaciers and Icebergs in the Permian Epoch." By A.C. Ramsay, "Quart. +Journ. Geol. Soc." Volume XI., page 185, 1855.), it will be as injurious +to progress as the French Institut. + + +LETTER 503. TO J.D. HOOKER. Cliff Cottage, Bournemouth, [September] 21st +[1862]. + +I am especially obliged to you for sending me Haast's communications. +(503/1. "Quart. Journ. Geol. Soc." Volume XXI., pages 130, 133, 1865; +Volume XXIII., page 342, 1867.) They are very interesting and grand +about glacial and drift or marine glacial. I see he alludes to the +whole southern hemisphere. I wonder whether he has read the "Origin." +Considering your facts on the Alpine plants of New Zealand and remarks, +I am particularly glad to hear of the geological evidence of glacial +action. I presume he is sure to collect and send over the mountain rat +of which he speaks. I long to know what it is. A frog and rat together +would, to my mind, prove former connection of New Zealand to some +continent; for I can hardly suppose that the Polynesians introduced the +rat as game, though so esteemed in the Friendly Islands. Ramsay sent +me his paper (503/2. "On the Glacial Origin of certain Lakes in +Switzerland, etc." "Quart. Journ. Geol. Soc." Volume XVIII., page 185, +1862.) and asked my opinion on it. I agree with you and think highly of +it. I cannot doubt that it is to a large extent true; my only doubt +is, that in a much disturbed country, I should have thought that some +depressions, and consequently lakes, would almost certainly have been +left. I suggested a careful consideration of mountainous tropical +countries such as Brazil, peninsula of India, etc.; if lakes are there, +[they are] very rare. I should fully subscribe to Ramsay's views. + +What presumption, as it seems to me, in the Council of Geological +Society that it hesitated to publish the paper. + +We return home on the 30th. I have made up [my] mind, if I can keep up +my courage, to start on the Saturday for Cambridge, and stay the last +few days of the [British] Association there. I do so hope that you may +be there then. + + +LETTER 504. TO J.D. HOOKER. November 3rd [1864]. + +When I wrote to you I had not read Ramsay. (504/1. "On the Erosion +of Valleys and Lakes: a Reply to Sir Roderick Murchison's Anniversary +Address to the Geographical Society." "Phil. Mag." Volume XXVIII., page +293, 1864) How capitally it is written! It seems that there is nothing +for style like a man's dander being put up. I think I agree largely with +you about denudation--but the rocky-lake-basin theory is the part +which interests me at present. It seems impossible to know how much to +attribute to ice, running water, and sea. I did not suppose that Ramsay +would deny that mountains had been thrown up irregularly, and that the +depressions would become valleys. The grandest valleys I ever saw were +at Tahiti, and here I do not believe ice has done anything; anyhow there +were no erratics. I said in my S. American Geology (504/2. "Finally, the +conclusion at which I have arrived with respect to the relative powers +of rain, and sea-water on the land is, that the latter is by far the +most efficient agent, and that its chief tendency is to widen the +valleys, whilst torrents and rivers tend to deepen them and to remove +the wreck of the sea's destroying action" ("Geol. Observations," pages +66, 67).) that rivers deepen and the sea widens valleys, and I am +inclined largely to stick to this, adding ice to water. I am sorry to +hear that Tyndall has grown dogmatic. H. Wedgwood was saying the +other day that T.'s writings and speaking gave him the idea of intense +conceit. I hope it is not so, for he is a grand man of science. + +...I have had a prospectus and letter from Andrew Murray (504/3. See +Volume II., Letters 379, 384, etc.) asking me for suggestions. I think +this almost shows he is not fit for the subject, as he gives me no idea +what his book will be, excepting that the printed paper shows that all +animals and all plants of all groups are to be treated of. Do you know +anything of his knowledge? + +In about a fortnight I shall have finished, except concluding chapter, +my book on "Variation under Domestication"; (504/4. Published in 1868.) +but then I have got to go over the whole again, and this will take me +very many months. I am able to work about two hours daily. + + +LETTER 505. TO J.D. HOOKER. Down [July, 1865]. + +I was glad to read your article on Glaciers, etc., in Yorkshire. You +seem to have been struck with what most deeply impressed me at Glen Roy +(wrong as I was on the whole subject)--viz. the marvellous manner in +which every detail of surface of land had been preserved for an enormous +period. This makes me a little sceptical whether Ramsay, Jukes, etc., +are not a little overdoing sub-aerial denudation. + +In the same "Reader" (505/1. Sir J.D. Hooker wrote to Darwin, July +13th, 1865, from High Force Inn, Middleton, Teesdale: "I am studying the +moraines all day long with as much enthusiasm as I am capable of after +lying in bed till nine, eating heavy breakfasts, and looking forward to +dinner as the summum bonum of existence." The result of his work, under +the title "Moraines of the Tees Valley," appeared in the "Reader" +(July 15th, 1865, page 71), of which Huxley was one of the managers +or committee-men, and Norman Lockyer was scientific editor ("Life and +Letters of T.H. Huxley," I., page 211). Hooker describes the moraines +and other evidence of glacial action in the upper part of the Tees +valley, and speaks of the effect of glaciers in determining the present +physical features of the country.) there was a striking article +on English and Foreign Men of Science (505/2. "British and Foreign +Science," "The Reader," loc. cit., page 61. The writer of the article +asserts the inferiority of English scientific workers.), and I think +unjust to England except in pure Physiology; in biology Owen and R. +Brown ought to save us, and in Geology we are most rich. + +It is curious how we are reading the same books. We intend to read Lecky +and certainly to re-read Buckle--which latter I admired greatly before. +I am heartily glad you like Lubbock's book so much. It made me grieve +his taking to politics, and though I grieve that he has lost his +election, yet I suppose, now that he is once bitten, he will never give +up politics, and science is done for. Many men can make fair M.P.'s; and +how few can work in science like him! + +I have been reading a pamphlet by Verlot on "Variation of Flowers," +which seems to me very good; but I doubt whether it would be worth your +reading. it was published originally in the "Journal d'Hort.," and +so perhaps you have seen it. It is a very good plan this republishing +separately for sake of foreigners buying, and I wish I had tried to get +permission of Linn. Soc. for my Climbing paper, but it is now too late. + +Do not forget that you have my paper on hybridism, by Max Wichura. +(505/3. Wichura, M.E., "L'Hybridisation dans le regne vegetal etudiee +sur les Saules," "Arch. Sci. Phys. Nat." XXIII., page 129, 1865.) + +I hope you are returned to your work, refreshed like a giant by your +huge breakfasts. How unlucky you are about contagious complaints with +your children! + +I keep very weak, and had much sickness yesterday, but am stronger this +morning. + +Can you remember how we ever first met? (505/4. See "Life and Letters," +II., page 19.) It was in Park Street; but what brought us together? I +have been re-reading a few old letters of yours, and my heart is very +warm towards you. + + +LETTER 506. TO C. LYELL. Down, March 8th [1866]. + +(506/1. In a letter from Sir Joseph Hooker to Mr. Darwin on February +21st, 1866, the following passage occurs: "I wish I could explain to you +my crude notions as to the Glacial period and your position towards it. +I suppose I hold this doctrine: that there was a Glacial period, but +that it was not one of universal cold, because I think that the +existing distribution of glaciers is sufficiently demonstrative of the +proposition that by comparatively slight redispositions of sea and +land, and perhaps axis of globe, you may account for all the leading +palaeontological phenomena." This letter was sent by Mr. Darwin to Sir +Charles Lyell, and the latter, writing on March 1st, 1866, expresses +his belief that "the whole globe must at times have been superficially +cooler. Still," he adds, "during extreme excentricity the sun would make +great efforts to compensate in perihelion for the chill of a long winter +in aphelion in one hemisphere, and a cool summer in the other. I +think you will turn out to be right in regard to meridional lines of +mountain-chains by which the migrations across the equator took place +while there was contemporaneous tropical heat of certain lowlands, where +plants requiring heat and moisture were saved from extinction by the +heat of the earth's surface, which was stored up in perihelion, being +prevented from radiating off freely into space by a blanket of aqueous +vapour caused by the melting of ice and snow. But though I am inclined +to profit by Croll's maximum excentricity for the glacial period, I +consider it quite subordinate to geographical causes or the relative +position of land and sea and the abnormal excess of land in polar +regions." In another letter (March 5th, 1866) Lyell writes: "In the +beginning of Hooker's letter to you he speaks hypothetically of a change +in the earth's axis as having possibly co-operated with redistribution +of land and sea in causing the cold of the Glacial period. Now, when we +consider how extremely modern, zoologically and botanically, the Glacial +period is proved to be, I am shocked at any one introducing, with what I +may call so much levity, so organic a change as a deviation in the axis +of the planet...' (see Lyell's "Principles," 1875, Chapter XIII.; also a +letter to Sir Joseph Hooker printed in the "Life of Sir Charles Lyell," +Volume II., page 410.)) + +Many thanks for your interesting letter. From the serene elevation of +my old age I look down with amazement at your youth, vigour, and +indomitable energy. With respect to Hooker and the axis of the earth, I +suspect he is too much overworked to consider now any subject properly. +His mind is so acute and critical that I always expect to hear a torrent +of objections to anything proposed; but he is so candid that he often +comes round in a year or two. I have never thought on the causes of the +Glacial period, for I feel that the subject is beyond me; but though I +hope you will own that I have generally been a good and docile pupil +to you, yet I must confess that I cannot believe in change of land and +water, being more than a subsidiary agent. (506/2. In Chapter XI. of the +"Origin," Edition V., 1869, page 451, Darwin discusses Croll's theory, +and is clearly inclined to trust in Croll's conclusion that "whenever +the northern hemisphere passes through a cold period the temperature of +the southern hemisphere is actually raised..." In Edition VI., page 336, +he expresses his faith even more strongly. Mr. Darwin apparently sent +his MS. on the climate question, which was no doubt prepared for a +new edition of the "Origin," to Sir Charles. The arrival of the MS. is +acknowledged in a letter from Lyell on March 10th, 1866 ("Life of Sir +Charles Lyell," II., page 408), in which the writer says that he is +"more than ever convinced that geographical changes...are the principal +and not the subsidiary causes.") I have come to this conclusion from +reflecting on the geographical distribution of the inhabitants of the +sea on the opposite sides of our continents and of the inhabitants of +the continents themselves. + + +LETTER 507. TO C. LYELL. Down, September 8th [1866]. + +Many thanks for the pamphlet, which was returned this morning. I was +very glad to read it, though chiefly as a psychological curiosity. I +quite follow you in thinking Agassiz glacier-mad. (507/1. Agassiz's +pamphlet, ("Geology of the Amazons") is referred to by Lyell in a letter +written to Bunbury in September, 1866 ("Life of Sir Charles Lyell," II., +page 409): "Agassiz has written an interesting paper on the 'Geology of +the Amazons,' but, I regret to say, he has gone wild about glaciers, and +has actually announced his opinion that the whole of the great valley, +down to its mouth in latitude 0 deg., was filled by ice..." Agassiz +published a paper, "Observations Geologiques faites dans la Vallee de +l'Amazone," in the "Comptes Rendus," Volume LXIV., page 1269, 1867. See +also a letter addressed to M. Marcou, published in the "Bull. Soc. Geol. +France," Volume XXIV., page 109, 1866.) His evidence reduces itself to +supposed moraines, which would be difficult to trace in a forest-clad +country; and with respect to boulders, these are not said to be angular, +and their source cannot be known in a country so imperfectly explored. +When I was at Rio, I was continually astonished at the depth (sometimes +100 feet) to which the granitic rocks were decomposed in situ, and this +soft matter would easily give rise to great alluvial accumulations; I +well remember finding it difficult to draw a line between the alluvial +matter and the softened rock in situ. What a splendid imagination +Agassiz has, and how energetic he is! What capital work he would have +done, if he had sucked in your "Principles" with his mother's milk. It +is wonderful that he should have written such wild nonsense about the +valley of the Amazon; yet not so wonderful when one remembers that he +once maintained before the British Association that the chalk was all +deposited at once. + +With respect to the insects of Chili, I knew only from Bates that the +species of Carabus showed no special affinity to northern species; +from the great difference of climate and vegetation I should not have +expected that many insects would have shown such affinity. It is more +remarkable that the birds on the broad and lofty Cordillera of Tropical +S. America show no affinity with European species. The little power of +diffusion with birds has often struck me as a most singular fact--even +more singular than the great power of diffusion with plants. Remember +that we hope to see you in the autumn. + +P.S.--There is a capital paper in the September number of "Annals +and Magazine," translated from Pictet and Humbert, on Fossil Fish of +Lebanon, but you will, I daresay, have received the original. (507/2. +"Recent Researches on the Fossil Fishes of Mount Lebanon," "Ann. Mag. +Nat. Hist." Volume XVIII., page 237, 1866.) It is capital in relation to +modification of species; I would not wish for more confirmatory facts, +though there is no direct allusion to the modification of species. +Hooker, by the way, gave an admirable lecture at Nottingham; I read it +in MS., or rather, heard it. I am glad it will be published, for it was +capital. (507/3. Sir Joseph Hooker delivered a lecture at the Nottingham +meeting of the British Association (1866) on "Insular Floras," published +in the "Gardeners' Chronicle," 1867. See Letters 366-377, etc.) + +Sunday morning. + +P.S.--I have just received a letter from Asa Gray with the following +passage, so that, according to this, I am the chief cause of Agassiz's +absurd views:-- + +"Agassiz is back (I have not seen him), and he went at once down to the +National Academy of Sciences, from which I sedulously keep away, and, I +hear, proved to them that the Glacial period covered the whole continent +of America with unbroken ice, and closed with a significant gesture and +the remark: 'So here is the end of the Darwin theory.' How do you like +that? + +"I said last winter that Agassiz was bent on covering the whole +continent with ice, and that the motive of the discovery he was sure +to make was to make sure that there should be no coming down of any +terrestrial life from Tertiary or post-Tertiary period to ours. You +cannot deny that he has done his work effectually in a truly imperial +way." + + +LETTER 508. TO C. LYELL. Down, July 14th, 1868. + +Mr. Agassiz's book has been read aloud to me, and I am wonderfully +perplexed what to think about his precise statements of the existence of +glaciers in the Ceara Mountains, and about the drift formation near Rio. +(508/1. "Sur la Geologie de l'Amazone," by MM. Agassiz and Continho, +"Bull. Soc. Geol. France," Volume XXV., page 685, 1868. See also "A +Journey in Brazil," by Professor and Mrs. Louis Agassiz, Boston, 1868.) +There is a sad want of details. Thus he never mentions whether any of +the blocks are angular, nor whether the embedded rounded boulders, which +cannot all be disintegrated, are scored. Yet how can so experienced an +observer as A. be deceived about lateral and terminal moraines? If there +really were glaciers in the Ceara Mountains, it seems to me one of the +most important facts in the history of the inorganic and organic world +ever observed. Whether true or not, it will be widely believed, and +until finally decided will greatly interfere with future progress +on many points. I have made these remarks in the hope that you will +coincide. If so, do you think it would be possible to persuade some +known man, such as Ramsay, or, what would be far better, some two men, +to go out for a summer trip, which would be in many respects delightful, +for the sole object of observing these phenomena in the Ceara Mountains, +and if possible also near Rio? I would gladly put my name down for 50 +pounds in aid of the expense of travelling. Do turn this over in your +mind. I am so very sorry not to have seen you this summer, but for the +last three weeks I have been good for nothing, and have had to stop +almost all work. I hope we may meet in the autumn. + + +LETTER 509. TO JAMES CROLL. Down, November 24th, 1868. + +I have read with the greatest interest the last paper which you have +kindly sent me. (509/1. Croll discussed the power of icebergs as +grinding and striating agents in the latter part of a paper ("On +Geological Time, and the probable Dates of the Glacial and the Upper +Miocene Period") published in the "Philosophical Magazine," Volume +XXXV., page 363, 1868, Volume XXXVI., pages 141, 362, 1868. His +conclusion was that the advocates of the Iceberg theory had formed "too +extravagant notions regarding the potency of floating ice as a striating +agent.") If we are to admit that all the scored rocks throughout the +more level parts of the United States result from true glacier action, +it is a most wonderful conclusion, and you certainly make out a very +strong case; so I suppose I must give up one more cherished belief. But +my object in writing is to trespass on your kindness and ask a question, +which I daresay I could answer for myself by reading more carefully, +as I hope hereafter to do, all your papers; but I shall feel much more +confidence in a brief reply from you. Am I right in supposing that you +believe that the glacial periods have always occurred alternately in the +northern and southern hemispheres, so that the erratic deposits which I +have described in the southern parts of America, and the glacial work in +New Zealand, could not have been simultaneous with our Glacial period? +From the glacial deposits occurring all round the northern hemisphere, +and from such deposits appearing in S. America to be as recent as in the +north, and lastly, from there being some evidence of the former lower +descent of glaciers all along the Cordilleras, I inferred that the whole +world was at this period cooler. It did not appear to me justifiable +without distinct evidence to suppose that the N. and S. glacial deposits +belonged to distinct epochs, though it would have been an immense +relief to my mind if I could have assumed that this had been the +case. Secondly, do you believe that during the Glacial period in one +hemisphere the opposite hemisphere actually becomes warmer, or does +it merely retain the same temperature as before? I do not ask these +questions out of mere curiosity; but I have to prepare a new edition +of my "Origin of Species," and am anxious to say a few words on this +subject on your authority. I hope that you will excuse my troubling you. + + +LETTER 510. TO J. CROLL. Down, January 31st, 1869. + +To-morrow I will return registered your book, which I have kept so long. +I am most sincerely obliged for its loan, and especially for the MS., +without which I should have been afraid of making mistakes. If you +require it, the MS. shall be returned. Your results have been of more +use to me than, I think, any other set of papers which I can remember. +Sir C. Lyell, who is staying here, is very unwilling to admit the +greater warmth of the S. hemisphere during the Glacial period in the N.; +but, as I have told him, this conclusion which you have arrived at from +physical considerations, explains so well whole classes of facts in +distribution, that I must joyfully accept it; indeed, I go so far as to +think that your conclusion is strengthened by the facts in distribution. +Your discussion on the flowing of the great ice-cap southward is +most interesting. I suppose that you have read Mr. Moseley's recent +discussion on the force of gravity being quite insufficient to account +for the downward movement of glaciers (510/1. Canon Henry Moseley, "On +the Mechanical Impossibility of the Descent of Glaciers by their Weight +only." "Proc. R. Soc." Volume XVII., page 202, 1869; "Phil. Mag." Volume +XXXVII., page 229, 1869.): if he is right, do you not think that the +unknown force may make more intelligible the extension of the great +northern ice-cap? Notwithstanding your excellent remarks on the work +which can be effected within the million years (510/2. In his paper +"On Geological Time, and the probable Date of the Glacial and the Upper +Miocene Period" ("Phil. Mag." Volume XXXV., page 363, 1868), Croll +endeavours to convey to the mind some idea of what a million years +really is: "Take a narrow strip of paper, an inch broad or more, and 83 +feet 4 inches in length, and stretch it along the wall of a large hall, +or round the walls of an apartment somewhat over 20 feet square. +Recall to memory the days of your boyhood, so as to get some adequate +conception of what a period of a hundred years is. Then mark off from +one of the ends of the strip one-tenth of an inch. The one-tenth of an +inch will then represent a hundred years, and the entire length of the +strip a million of years" (loc. cit., page 375).), I am greatly troubled +at the short duration of the world according to Sir W. Thomson (510/3. +In a paper communicated to the Royal Society of Edinburgh, Lord Kelvin +(then Sir William Thomson) stated his belief that the age of our planet +must be more than twenty millions of years, but not more than four +hundred millions of years ("Trans. R. Soc. Edinb." Volume XXIII., page +157, 1861, "On the Secular Cooling of the Earth."). This subject has +been recently dealt with by Sir Archibald Geikie in his address as +President of the Geological Section of the British Association, 1899 +("Brit. Assoc. Report," Dover Meeting, 1899, page 718).), for I +require for my theoretical views a very long period BEFORE the Cambrian +formation. If it would not trouble you, I should like to hear what you +think of Lyell's remark on the magnetic force which comes from the sun +to the earth: might not this penetrate the crust of the earth and then +be converted into heat? This would give a somewhat longer time during +which the crust might have been solid; and this is the argument on which +Sir W. Thomson seems chiefly to rest. You seem to argue chiefly on +the expenditure of energy of all kinds by the sun, and in this respect +Lyell's remark would have no bearing. + +My new edition of the "Origin" (510/4. Fifth edition, May, 1869.) will +be published, I suppose, in about two months, and for the chance of your +liking to have a copy I will send one. + +P.S.--I wish that you would turn your astronomical knowledge to the +consideration whether the form of the globe does not become periodically +slightly changed, so as to account for the many repeated ups and downs +of the surface in all parts of the world. I have always thought that +some cosmical cause would some day be discovered. + + +LETTER 511. TO C. LYELL. Down, July 12th [1872]. + +I have been glad to see the enclosed and return it. It seems to me +very cool in Agassiz to doubt the recent upheaval of Patagonia, without +having visited any part; and he entirely misrepresents me in saying that +I infer upheaval from the form of the land, as I trusted entirely to +shells embedded and on the surface. It is simply monstrous to suppose +that the terraces stretching on a dead level for leagues along the +coast, and miles in breadth, and covered with beds of stratified gravel, +10 to 30 feet in thickness, are due to subaerial denudation. + +As for the pond of salt-water twice or thrice the density of sea-water, +and nearly dry, containing sea-shells in the same relative proportions +as on the adjoining coast, it almost passes my belief. Could there have +been a lively midshipman on board, who in the morning stocked the pool +from the adjoining coast? + +As for glaciation, I will not venture to express any opinion, for when +in S. America I knew nothing about glaciers, and perhaps attributed much +to icebergs which ought to be attributed to glaciers. On the other hand, +Agassiz seems to me mad about glaciers, and apparently never thinks of +drift ice. + +I did see one clear case of former great extension of a glacier in T. +del Fuego. + + +LETTER 512. TO J. GEIKIE. + +(512/1. The following letter was in reply to a request from Prof. James +Geikie for permission to publish Mr. Darwin's views, communicated in a +previous letter (November 1876), on the vertical position of stones in +gravelly drift near Southampton. Prof. Geikie wrote (July 15th, 1880): +"You may remember that you attributed the peculiar position of those +stones to differential movements in the drift itself arising from the +slow melting of beds of frozen snow interstratified into the gravels...I +have found this explanation of great service even in Scotland, and +from what I have seen of the drift-gravels in various parts of southern +England and northern France, I am inclined to think that it has a wide +application.") + +Down, July 19th, 1880. + +Your letter has pleased me very much, and I truly feel it an honour that +anything which I wrote on the drift, etc., should have been of the least +use or interest to you. Pray make any use of my letter (512/2. Professor +James Geikie quotes the letter in "Prehistoric Europe," London, 1881 +(page 141). Practically the whole of it is given in the "Life and +Letters," III., page 213.): I forget whether it was written carefully or +clearly, so pray touch up any passages that you may think fit to quote. + +All that I have seen since near Southampton and elsewhere has +strengthened my notion. Here I live on a chalk platform gently sloping +down from the edge of the escarptment to the south (512/3. Id est, +sloping down from the escarpment which is to the south.) (which is +about 800 feet in height) to beneath the Tertiary beds to the north. The +(512/4. From here to the end of the paragraph is quoted by Prof. Geikie, +loc. cit., page 142.) beds of the large and broad valleys (and only of +these) are covered with an immense mass of closely packed broken and +angular flints; in which mass the skull of the musk-ox [musk-sheep] +and woolly elephant have been found. This great accumulation of unworn +flints must therefore have been made when the climate was cold, and I +believe it can be accounted for by the larger valleys having been filled +up to a great depth during a large part of the year with drifted frozen +snow, over which rubbish from the upper parts of the platforms was +washed by the summer rains, sometimes along one line and sometimes along +another, or in channels cut through the snow all along the main course +of the broad valleys. + +I suppose that I formerly mentioned to you the frequent upright position +of elongated flints in the red clayey residue over the chalk, which +residue gradually subsides into the troughs and pipes corroded in the +solid chalk. This letter is very untidy, but I am tired. + +P.S. Several palaeolithic celts have recently been found in the great +angular gravel-bed near Southampton in several places. + + +LETTER 513. TO D. MACKINTOSH. Down, November 13th, 1880. + +Your discovery is a very interesting one, and I congratulate you on +it. (513/1. "On the Precise Mode of Accumulation and Derivation of the +Moel-Tryfan Shelly Deposits; on the Discovery of Similar High-level +Deposits along the Eastern Slopes of the Welsh Mountains; and on the +Existence of Drift-Zones, showing probable Variations in the Rate +of Submergence." By D. Mackintosh, "Quart. Journ. Geol. Soc." Volume +XXXVII., pages 351-69, 1881. [Read April 27th, 1881.]) I failed to find +shells on Moel Tryfan, but was interested by finding ("Philosoph. Mag." +3rd series, Volume XXI., page 184) shattered rocks (513/2. In reviewing +the work by previous writers on the Moel-Tryfan deposits, Mackintosh +refers to Darwin's "very suggestive description of the Moel-Tryfan +deposits...Under the drift he saw that the surface of the slate, TO +A DEPTH OF SEVERAL FEET, HAD BEEN SHATTERED AND CONTORTED IN A VERY +PECULIAR MANNER." The contortion of the slate, which Mackintosh +regarded as "the most interesting of the Moel-Tryfan phenomena," had not +previously been regarded as "sufficiently striking to arrest attention" +by any geologist except Darwin. The Pleistocene gravel and sand +containing marine shells on Moel-Tryfan, about five miles south-east of +Caernarvon, have been the subject of considerable controversy. By some +geologists the drift deposits have been regarded as evidence of a great +submergence in post-Pliocene times, while others have explained their +occurrence at a height of 1300 feet by assuming that the gravel and sand +had been thrust uphill by an advancing ice-sheet. (See H.B. Woodward, +"Geology of England and Wales," Edition II., 1887, pages 491, 492.) +Darwin attributed the shattering and contorting of the slates below the +drift to "icebergs grating over the surface.") and far-distant rounded +boulders, which I attributed to the violent impact of icebergs or +coast-ice. I can offer no opinion on whether the more recent changes of +level in England were or were not accompanied by earthquakes. It does +not seem to me a correct expression (which you use probably from +haste in your note) to speak of elevations or depressions as caused +by earthquakes: I suppose that every one admits that an earthquake +is merely the vibration from the fractured crust when it yields to an +upward or downward force. I must confess that of late years I have often +begun to suspect (especially when I think of the step-like plains of +Patagonia, the heights of which were measured by me) that many of the +changes of level in the land are due to changes of level in the sea. +(513/3. This view is an agreement with the theory recently put forward +by Suess in his "Antlitz der Erde" (Prag and Leipzig, 1885). Suess +believes that "the local invasions and transgressions of the continental +areas by the sea" are due to "secular movements of the hydrosphere +itself." (See J. Geikie, F.R.S., Presidential Address before Section E +at the Edinburgh Meeting of the British Association, "Annual Report," +page 794.) I suppose that there can be no doubt that when there was much +ice piled up in the Arctic regions the sea would be attracted to them, +and the land on the temperate regions would thus appear to have risen. +There would also be some lowering of the sea by evaporation and the +fixing of the water as ice near the Pole. + +I shall read your paper with much interest when published. + + +LETTER 514. TO J. GEIKIE. Down, December 13th, 1880. + +You must allow me the pleasure of thanking you for the great interest +with which I have read your "Prehistoric Europe." (514/1. "Prehistoric +Europe: a Geological Sketch," London, 1881.) Nothing has struck me more +than the accumulated evidence of interglacial periods, and assuredly +the establishment of such periods is of paramount importance for +understanding all the later changes of the earth's surface. Reading +your book has brought vividly before my mind the state of knowledge, or +rather ignorance, half a century ago, when all superficial matter was +classed as diluvium, and not considered worthy of the attention of a +geologist. If you can spare the time (though I ask out of mere idle +curiosity) I should like to hear what you think of Mr. Mackintosh's +paper, illustrated by a little map with lines showing the courses or +sources of the erratic boulders over the midland counties of England. +(514/2. "Results of a Systematic Survey, in 1878, of the Directions and +Limits of Dispersion, Mode of Occurrence, and Relation to Drift-Deposits +of the Erratic Blocks or Boulders of the West of England and East of +Wales, including a Revision of Many Years' Previous Observations," D. +Mackintosh, "Quart. Journ. Geol. Soc." Volume XXXV., page 425, 1879.) It +is a little suspicious their ending rather abruptly near Wolverhampton, +yet I must think that they were transported by floating ice. Fifty years +ago I knew Shropshire well, and cannot remember anything like till, but +abundance of gravel and sand beds, with recent marine shells. A great +boulder (514/3. Mackintosh alludes (loc. cit., page 442) to felstone +boulders around Ashley Heath, the highest ground between the Pennine and +Welsh Hills north of the Wrekin; also to a boulder on the summit of the +eminence (774 feet above sea-level), "probably the same as that noticed +many years ago by Mr. Darwin." In a later paper, "On the Correlation +of the Drift-Deposits of the North-West of England with those of the +Midland and Eastern Counties" ("Quart. Journ. Geol. Soc." Volume XXXVI., +page 178, 1880) Mackintosh mentions a letter received from Darwin, "who +was the first to elucidate the boulder-transporting agency of floating +ice," containing an account of the great Ashley Heath boulder, which +he was the first to discover and expose,...so as to find that the block +rested on fragments of New Red Sandstone, one of which was split into +two and deeply scored...The facts mentioned in the letter from Mr. +Darwin would seem to show that the boulder must have fallen through +water from floating ice with a force sufficient to split the underlying +lump of sandstone, but not sufficient to crush it.") which I had +undermined on the summit of Ashley Heath, 720 (?) feet above the sea, +rested on clean blocks of the underlying red sandstone. I was also +greatly interested by your long discussion on the Loss (514/4. For an +account of the Loss of German geologists--"a fine-grained, more or less +homogeneous, consistent, non-plastic loam, consisting of an intimate +admixture of clay and carbonate of lime," see J. Geikie, loc. cit., page +144 et seq.); but I do not feel satisfied that all has been made +out about it. I saw much brick-earth near Southampton in some manner +connected with the angular gravel, but had not strength enough to +make out relations. It might be worth your while to bear in mind the +possibility of fine sediment washed over and interstratified with thick +beds of frozen snow, and therefore ultimately dropped irrespective of +the present contour of the country. + +I remember as a boy that it was said that the floods of the Severn were +more muddy when the floods were caused by melting snow than from the +heaviest rains; but why this should be I cannot see. + +Another subject has interested me much--viz. the sliding and travelling +of angular debris. Ever since seeing the "streams of stones" at the +Falkland Islands (514/5. "Geological Observations on South America" +(1846), page 19 et seq.), I have felt uneasy in my mind on this subject. +I wish Mr. Kerr's notion could be fully elucidated about frozen snow. +Some one ought to observe the movements of the fields of snow which +supply the glaciers in Switzerland. + +Yours is a grand book, and I thank you heartily for the instruction and +pleasure which it has given me. + +For heaven's sake forgive the untidiness of this whole note. + + +LETTER 515. TO JOHN LUBBOCK [Lord Avebury]. Down, November 6th, 1881. + +If I had written your Address (515/1. Address delivered by Lord Avebury +as President of the British Association at York in 1881. Dr. Hicks +is mentioned as having classed the pre-Cambrian strata in "four great +groups of immense thickness and implying a great lapse of time" and +giving no evidence of life. Hicks' third formation was named by him the +Arvonian ("Quart. Journ. Geol. Soc." Volume XXXVII., 1881, Proc., page +55.) (but this requires a fearful stretch of imagination on my part) I +should not alter what I had said about Hicks. You have the support of +the President [of the] Geological Society (515/2. Robert Etheridge.), +and I think that Hicks is more likely to be right than X. The latter +seems to me to belong to the class of objectors general. If Hicks should +be hereafter proved to be wrong about this third formation, it would +signify very little to you. + +I forget whether you go as far as to support Ramsay about lakes as large +as the Italian ones: if so, I would myself modify the passage a little, +for these great lakes have always made me tremble for Ramsay, yet +some of the American geologists support him about the still larger N. +American lakes. I have always believed in the main in Ramsay's views +from the date of publication, and argued the point with Lyell, and am +convinced that it is a very interesting step in Geology, and that you +were quite right to allude to it. (515/3. "Glacial Origin of Lakes in +Switzerland, Black Forest, etc." ("Quart. Journ. Geol. Soc." Volume +XVIII., pages 185-204, 1862). Sir John Lubbock (Lord Avebury) gives +a brief statement of Ramsay's views concerning the origin of lakes +(Presidential Address, Brit. Assoc. 1881, page 22): "Prof. Ramsay +divides lakes into three classes: (1) Those which are due to irregular +accumulations of drift, and which are generally quite shallow; (2) those +which are formed by moraines; and (3) those which occupy true basins +scooped by glaciers out of the solid rocks. To the latter class belong, +in his opinion, most of the great Swiss and Italian lakes...Professor +Ramsay's theory seems, therefore, to account for a large number of +interesting facts." Sir Archibald Geikie has given a good summary of +Ramsay's theory in his "Memoir of Sir Andrew Crombie Ramsay," page 361, +London, 1895.) + + +LETTER 516. TO D. MACKINTOSH. Down, February 28th, 1882. + +I have read professor Geikie's essay, and it certainly appears to +me that he underrated the importance of floating ice. (516/1. "The +Intercrossing of Erratics in Glacial Deposits," by James Geikie, +"Scottish Naturalist," 1881.) Memory extending back for half a century +is worth a little, but I can remember nothing in Shropshire like till +or ground moraine, yet I can distinctly remember the appearance of many +sand and gravel beds--in some of which I found marine shells. I think it +would be well worth your while to insist (but perhaps you have done so) +on the absence of till, if absent in the Western Counties, where you +find many erratic boulders. + +I was pleased to read the last sentence in Geikie's essay about the +value of your work. (516/2. The concluding paragraph reads as follows: +"I cannot conclude this paper without expressing my admiration for the +long-continued and successful labours of the well-known geologist whose +views I have been controverting. Although I entered my protest against +his iceberg hypothesis, and have freely criticised his theoretical +opinions, I most willingly admit that the results of his unwearied +devotion to the study of those interesting phenomena with which he is +so familiar have laid all his fellow-workers under a debt of gratitude." +Mr. Darwin used to speak with admiration of Mackintosh's work, carried +on as it was under considerable difficulties.) + +With respect to the main purport of your note, I hardly know what to +say. Though no evidence worth anything has as yet, in my opinion, been +advanced in favour of a living being, being developed from inorganic +matter, yet I cannot avoid believing the possibility of this will be +proved some day in accordance with the law of continuity. I remember the +time, above fifty years ago, when it was said that no substance found +in a living plant or animal could be produced without the aid of vital +forces. As far as external form is concerned, Eozoon shows how difficult +it is to distinguish between organised and inorganised bodies. If it is +ever found that life can originate on this world, the vital phenomena +will come under some general law of nature. Whether the existence of a +conscious God can be proved from the existence of the so-called laws +of nature (i.e., fixed sequence of events) is a perplexing subject, on +which I have often thought, but cannot see my way clearly. If you have +not read W. Graham's "Creed of Science," (516/3. "The Creed of Science: +Religious, Moral, and Social," London, 1881.), it would, I think, +interest you, and he supports the view which you are inclined to uphold. + + +2.IX.III. THE PARALLEL ROADS OF GLEN ROY, 1841-1880. + +(517/1. In the bare hilly country of Lochaber, in the Scotch Highlands, +the slopes of the mountains overlooking the vale of Glen Roy are marked +by narrow terraces or parallel roads, which sweep round the shoulders of +the hills with "undeviating horizontality." These roads are described +by Sir Archibald Geikie as having long been "a subject of wonderment and +legendary story among the Highlanders, and for so many years a source +of sore perplexity among men of science." (517/2. "The Scenery of +Scotland," 1887, page 266.) In Glen Roy itself there are three distinct +shelves or terraces, and the mountain sides of the valley of the Spean +and other glens bear traces of these horizontal "roads." + +The first important papers dealing with the origin of this striking +physical feature were those of MacCulloch (517/3. "Trans. Geol. Soc." +Volume IV., page 314, 1817.) and Sir Thomas Lauder Dick (517/4. "Trans. +R. Soc. Edinb." Volume IX., page 1, 1823.), in which the writers +concluded that the roads were the shore-lines of lakes which once filled +the Lochaber valleys. Towards the end of June 1838 Mr. Darwin devoted +"eight good days" (517/5. "Life and Letters," I., page 290.) to the +examination of the Lochaber district, and in the following year he +communicated a paper to the Royal Society of London, in which he +attributed their origin to the action of the sea, and regarded them +as old sea beaches which had been raised to their present level by a +gradual elevation of the Lochaber district. + +In 1840 Louis Agassiz and Buckland (517/6. "Edinb. New Phil. Journal," +Volume XXXIII., page 236, 1842.) proposed the glacier-ice theory; they +described the valleys as having been filled with lakes dammed back by +glaciers which formed bars across the valleys of Glen Roy, Glen +Spean, and the other glens in which the hill-sides bear traces of old +lake-margins. Agassiz wrote in 1842: "When I visited the parallel roads +of Glen Roy with Dr. Buckland we were convinced that the glacial theory +alone satisfied all the exigencies of the phenomenon." (517/7. Ibid., +page 236.) + +Mr. David Milne (afterwards Milne-Home) (517/8. "Trans. R. Soc. Edinb." +Volume XVI., page 395, 1847.) in 1847 upheld the view that the ledges +represent the shore-lines of lakes which were imprisoned in the valleys +by dams of detrital material left in the glens during a submergence +of 3,000 feet, at the close of the Glacial period. Chambers, in his +"Ancient Sea Margins" (1848), expressed himself in agreement with Mr. +Darwin's marine theory. The Agassiz-Buckland theory was supported by +Mr. Jamieson (517/9. "Quart. Journ. Geol. Soc." Volume XIX., page 235, +1863.), who brought forward additional evidence in favour of the glacial +barriers. Sir Charles Lyell at first (517/10. "Elements of Geology," +Edition II., 1841.) accepted the explanation given by Mr. Darwin, but +afterwards (517/11. "Antiquity of Man," 1863, pages 252 et seq.) came to +the conclusion that the terrace-lines represent the beaches of glacial +lakes. In a paper published in 1878 (517/12. "Phil. Trans. R. Soc." +1879, page 663.), Prof. Prestwich stated his acceptance of the lake +theory of MacCulloch and Sir T. Lauder Dick and of the glacial theory +of Agassiz, but differed from these authors in respect of the age of the +lakes and the manner of formation of the roads. + +The view that has now gained general acceptance is that the parallel +roads of Glen Roy represent the shores of a lake "that came into being +with the growth of the glaciers and vanished as these melted away." +(517/13. Sir Archibald Geikie, loc. cit., page 269.) + +Mr. Darwin became a convert to the glacier theory after the publication +of Mr. Jamieson's paper. He speaks of his own paper as "a great +failure"; he argued in favour of sea action as the cause of the terraces +"because no other explanation was possible under our then state of +knowledge." Convinced of his mistake, Darwin looked upon his error as +"a good lesson never to trust in science to the principle of exclusion." +(517/14. "Life and Letters," I., page 69.) + + +LETTER 517. TO C. LYELL. [March 9th, 1841.] + +I have just received your note. It is the greatest pleasure to me to +write or talk Geology with you... + +I think I have thought over the whole case without prejudice, and +remain firmly convinced they [the parallel roads] are marine beaches. My +principal reason for doing so is what I have urged in my paper (517/15. +"Observations on the Parallel Roads of Glen Roy, and of other parts of +Lochaber in Scotland, with an attempt to prove that they are of Marine +Origin." "Phil. Trans. R. Soc." 1839, page 39.), the buttress-like +accumulations of stratified shingle on sides of valley, especially those +just below the lowest shelf in Spean Valley. + +2nd. I can hardly conceive the extension of the glaciers in front of the +valley of Kilfinnin, where I found a new road--where the sides of Great +Glen are not very lofty. + +3rd. The flat watersheds which I describe in places where there are +no roads, as well as those connected with "roads." These remain +unexplained. + +I might continue to add many other such reasons, all of which, however, +I daresay would appear trifling to any one who had not visited the +district. With respect to equable elevation, it cannot be a valid +objection to any one who thinks of Scandinavia or the Pampas. With +respect to the glacier theory, the greatest objection appears to me the +following, though possibly not a sound one. The water has beyond doubt +remained very long at the levels of each shelf--this is unequivocally +shown by the depth of the notch or beach formed in many places in +the hard mica-slate, and the large accumulations or buttresses of +well-rounded pebbles at certain spots on the level of old beaches. (The +time must have been immense, if formed by lakes without tides.) During +the existence of the lakes their drainage must have been at the head of +the valleys, and has given the flat appearance of the watersheds. All +this is very clear for four of the shelves (viz., upper and lower in +Glen Roy, the 800-foot one in Glen Spean, and the one in Kilfinnin), and +explains the coincidence of "roads" with the watersheds more simply than +my view, and as simply as the common lake theory. But how was the Glen +Roy lake drained when the water stood at level of the middle "road"? It +must (for there is no other exit whatever) have been drained over the +glacier. Now this shelf is full as narrow in a vertical line and +as deeply worn horizontally into the mountain side and with a large +accumulation of shingle (I can give cases) as the other shelves. We +must, therefore, on the glacier theory, suppose that the surface of +the ice remained at exactly the same level, not being worn down by the +running water, or the glacier moved by its own movement during the very +long period absolutely necessary for a quiet lake to form such a beach +as this shelf presents in its whole course. I do not know whether I have +explained myself clearly. I should like to know what you think of this +difficulty. I shall much like to talk over the Jura case with you. I am +tired, so goodbye. + + +LETTER 518. TO L. HORNER. Down [1846]. + +(518/1. It was agreed at the British Association meeting held at +Southampton in 1846 "That application be made to Her Majesty's +Government to direct that during the progress of the Ordnance +Trigonometrical Surveys in the North of Scotland, the so-called Parallel +Roads of Glen Roy and the adjoining country be accurately surveyed, with +the view of determining whether they are truly parallel and horizontal, +the intervening distances, and their elevations above the present +sea-level" ("British Association Report," 1846, page xix). The survey +was undertaken by the Government Ordnance Survey Office under Col. Sir +Henry James, who published the results in 1874 ("Notes on the Parallel +Roads of Glen Roy"); the map on which the details are given is sheet 63 +(one-inch scale).) + +In following your suggestion in drawing out something about Glen Roy for +the Geological Committee, I have been completely puzzled how to do it. +I have written down what I should say if I had to meet the head of the +Survey and wished to persuade him to undertake the task; but as I have +written it, it is too long, ill expressed, seems as if it came from +nobody and was going to nobody, and therefore I send it to you in +despair, and beg you to turn the subject in your mind. I feel a +conviction if it goes through the Geological part of Ordnance Survey it +will be swamped, and as it is a case for mere accurate measurements it +might, I think without offence, go to the head of the real Surveyors. + +If Agassiz or Buckland are on the Committee they will sneer at the whole +thing and declare the beaches are those of a glacier-lake, than which I +am sure I could convince you that there never was a more futile theory. + +I look forward to Southampton (518/2. The British Association meeting +(1846).) with much interest, and hope to hear to-morrow that the +lodgings are secured to us. You cannot think how thoroughly I enjoyed +our geological talks, and the pleasure of seeing Mrs. Horner and +yourself here. (518/3. This letter is published in the privately printed +"Memoir of Leonard Horner," II., page 103.) + +[Here follows Darwin's Memorandum.] + +The Parallel Roads of Glen Roy, in Scotland, have been the object of +repeated examination, but they have never hitherto been levelled with +sufficient accuracy. Sir T. Lauder Dick (518/4. "On the Parallel Roads +of Lochaber" (with map and plates), by Sir Thomas Lauder Dick, "Trans. +R. Soc. Edinb." Volume IX., page 1, 1823.) procured the assistance of an +engineer for this purpose, but owing to the want of a true ground-plan +it was impossible to ascertain their exact curvature, which, as far as +could be estimated, appeared equal to that of the surface of the sea. +Considering how very rarely the sea has left narrow and well-defined +marks of its action at any considerable height on the land, and more +especially considering the remarkable observations by M. Bravais (518/5. +"On the Lines of Ancient Level of the Sea in Finmark," by M. A. Bravais, +translated from "Voyages de la Commission Scientifique du Nord, etc."; +"Quart. Journ. Geol. Soc." Volume I., page 534, 1845.) on the ancient +sea-beaches of Scandinavia, showing the they are not strictly parallel +to each other, and that the movement has been greater nearer the +mountains than on the coast, it appears highly desirable that the roads +of Glen Roy should be examined with the utmost care during the execution +of the Ordnance Survey of Scotland. The best instruments and the most +accurate measurements being necessary for this end almost precludes the +hope of its being ever undertaken by private individuals; but by the +means at the disposal of the Ordnance, measurements would be easily made +even more accurate than those of M. Bravais. It would be desirable to +take two lines of the greatest possible length in the district, and at +nearly right angles to each other, and to level from the beach at one +extremity to that at the other, so that it might be ascertained whether +the curvature does exactly correspond with that of the globe, or, if +not, what is the direction of the line of greatest elevation. Much +attention would be requisite in fixing on either the upper or lower edge +of the ancient beaches as the standard of measurement, and in rendering +this line conspicuous. The heights of the three roads, one above +the other and above the level of the sea, ought to be accurately +ascertained. Mr. Darwin observed one short beach-line north of Glen Roy, +and he has indicated, on the authority of Sir David Brewster, others +in the valley of the Spey. If these could be accurately connected, by +careful measurements of their absolute heights or by levelling, with +those of Glen Roy, it would make a most valuable addition to our +knowledge on this subject. Although the observations here specified +would probably be laborious, yet, considering how rarely such evidence +is afforded in any quarter of the world, it cannot be doubted that one +of the most important problems in Geology--namely, the exact manner in +which the crust of the earth rises in mass--would be much elucidated, +and a great service done to geological science. + + +LETTER 519. R. CHAMBERS TO D. MILNE-HOME. St. Andrews, September 7th, +1847. + +I have had a letter to-day from Mr. Charles Darwin, beseeching me to +obtain for him a copy of your paper on Glen Roy. (519/1. No doubt Mr. +Milne's paper "On the Parallel Roads of Lochaber," "Trans. R. Soc. +Edinb." Volume XVI., page 395, 1849. [Read March 1st and April 5th, +1847.]) I am sure you will have pleasure in sending him one; his +address is "Down, Farnborough, Kent." I have again read over your paper +carefully, and feel assured that the careful collection and statement of +facts which are found in it must redound to your credit with all candid +persons. The suspicions, however, which I obtained some time ago as to +land-straits and heights of country being connected with sea-margins and +their ordinary memorials still possesses me, and I am looking forward to +some means of further testing the Glen Roy mystery. If my suspicion turn +out true, I shall at once be regretful on your account, and shall feel +it as a great check and admonition to myself not to be too confident +about anything in science till it has been proved over and over again. +The ground hereabouts is now getting clear of the crops; perhaps when I +am in town a few days hence we may be able to make some appointment for +an examination of the beaches of the district, my list of which has been +greatly enlarged during the last two months. + + +LETTER 520. TO R. CHAMBERS. September 11th, 1847. + +I hope you will read the first part of my paper before you go [to Glen +Roy], and attend to the manner in which the lines end in Glen Collarig. +I wish Mr. Milne had read it more carefully. He misunderstands me in +several respects, but [I] suppose it is my own fault, for my paper is +most tediously written. Mr. Milne fights me very pleasantly, and I plead +guilty to his rebuke about "demonstration." (520/1. See Letter 521, +note.) I do not know what you think; but Mr. Milne will think me as +obstinate as a pig when I say that I think any barriers of detritus at +the mouth of Glen Roy, Collarig and Glaster more utterly impossible +than words can express. I abide by all that I have written on that head. +Conceive such a mass of detritus having been removed, without great +projections being left on each side, in the very close proximity to +every little delta preserved on the lines of the shelves, even on the +shelf 4, which now crosses with uniform breadth the spot where the +barrier stood, with the shelves dying gradually out, etc. To my mind it +is monstrous. Oddly enough, Mr. Milne's description of the mouth of Loch +Treig (I do not believe that valley has been well examined in its upper +end) leaves hardly a doubt that a glacier descended from it, and, if the +roads were formed by a lake of any kind, I believe it must have been +an ice-lake. I have given in detail to Lyell my several reasons for +not thinking ice-lakes probable (520/2. Mr. Darwin gives some arguments +against the glacier theory in the letter (517) to Sir Charles Lyell; +but the letter alluded to is no doubt the one written to Lyell on +"Wednesday, 8th" (Letter 522), in which the reasons are fully stated.); +but to my mind they are incomparably more probable than detritus of +rock-barriers. Have you ever attended to glacier action? After having +seen N. Wales, I can no more doubt the former existence of gigantic +glaciers than I can the sun in the heaven. I could distinguish in N. +Wales to a certain extent icebergs from glacier action (Lyell has shown +that icebergs at the present day score rocks), and I suspect that in +Lochaber the two actions are united, and that the scored rock on the +watersheds, when tideways, were rubbed and bumped by half-stranded +icebergs. You will, no doubt, attend to Glen Glaster. Mr. Milne, I +think, does not mention whether shelf 4 enters it, which I should like +to know, and especially he does not state whether rocks worn on their +upper faces are found on the whole 212 [feet] vertical course of this +Glen down to near L. Loggan, or whether only in the upper part; nor does +he state whether these rocks are scored, or polished, or moutonnees, or +whether there are any "perched" boulders there or elsewhere. I suspect +it would be difficult to distinguish between a river-bed and tidal +channel. Mr. Milne's description of the Pass of Mukkul, expanding to a +width of several hundred yards 21 feet deep in the shoalest part, and +with a worn islet in the middle, sounds to me much more like a tidal +channel than a river-bed. There must have been, on the latter view, +plenty of fresh water in those days. With respect to the coincidence +of the shelves with the now watersheds, Mr. Milne only gives half of my +explanation. Please read page 65 of my paper. (520/3. "Observations +on the Parallel Roads of Glen Roy, and of other Parts of Lochaber in +Scotland, with an Attempt to Prove that they are of Marine Origin." +"Phil. Trans. R. Soc." 1839, page 39. [Read February 7th, 1839.]) I +allude only to the head of Glen Roy and Kilfinnin as silted up. I did +not know Mukkul Pass; and Glen Roy was so much covered up that I did not +search it well, as I was not able to walk very well. It has been an old +conjectural belief of mine that a rising surface becomes stationary, +not suddenly, but by the movement becoming very slow. Now, this would +greatly aid the tidal currents cutting down the passes between the +mountains just before, and to the level of, the stationary periods. +The currents in the fiords in T. del Fuego in a narrow crooked part are +often most violent; in other parts they seem to silt up. + +Shall you do any levelling? I believe all the levelling has been +[done] in Glen Roy, nearly parallel to the Great Glen of Scotland. For +inequalities of elevation, the valley of the Spean, at right angles to +the apparent axes of elevation, would be the one to examine. If you go +to the head of Glen Roy, attend to the apparent shelf above the highest +one in Glen Roy, lying on the south side of Loch Spey, and therefore +beyond the watershed of Glen Roy. It would be a crucial case. I was +too unwell on that day to examine it carefully, and I had no levelling +instruments. Do these fragments coincide in level with Glen Gluoy shelf? + +MacCulloch talks of one in Glen Turret above the shelf. I could not see +it. These would be important discoveries. But I will write no more, and +pray your forgiveness for this long, ill-written outpouring. I am very +glad you keep to your subject of the terraces. I have lately observed +that you have one great authority (C. Prevost), [not] that authority +signifies a [farthing?] on your side respecting your heretical and +damnable doctrine of the ocean falling. You see I am orthodox to the +burning pitch. + + +LETTER 521. TO D. MILNE-HOME. Down, [September] 20th, [1847]. + +I am much obliged by your note. I returned from London on Saturday, and +I found then your memoir (521/1. "On the Parallel Roads of Lochaber, +with Remarks on the Change of Relative Levels of Sea and Land in +Scotland, and on the Detrital Deposits in that Country," "Trans. R. +Soc. Edinb." Volume XVI., page 395, 1849. [Read March 1st and April 5th, +1847.]), which I had not then received, owing to the porter having been +out when I last sent to the Geological Society. I have read your paper +with the greatest interest, and have been much struck with the novelty +and importance of many of your facts. I beg to thank you for the +courteous manner in which you combat me, and I plead quite guilty to +your rebuke about demonstration. (521/2. Mr. Milne quotes a passage from +Mr. Darwin's paper ("Phil. Trans. R. Soc." 1839, page 56), in which the +latter speaks of the marine origin of the parallel roads of Lochaber as +appearing to him as having been demonstrated. Mr. Milne adds: "I regret +that Mr. Darwin should have expressed himself in these very decided and +confident terms, especially as his survey was incomplete; for I venture +to think that it can be satisfactorily established that the parallel +roads of Lochaber were formed by fresh-water lakes" (Milne, loc. cit., +page 400).) You have misunderstood my paper on a few points, but I do +not doubt that is owing to its being badly and tediously written. You +will, I fear, think me very obstinate when I say that I am not in the +least convinced about the barriers (521/3. Mr. Milne believed that the +lower parts of the valleys were filled with detritus, which constituted +barriers and thus dammed up the waters into lakes.): they remain to me +as improbable as ever. But the oddest result of your paper on me (and I +assure you, as far as I know myself, it is not perversity) is that I +am very much staggered in favour of the ice-lake theory of Agassiz and +Buckland (521/4. Agassiz and Buckland believed that the lakes which +formed the "roads" were confined by glaciers or moraines. See "The +Glacial Theory and its Recent Progress," by Louis Agassiz, "Edinb. New +Phil. Journ." Volume XXXIII., page 217, 1842 (with map).): until I read +your important discovery of the outlet in Glen Glaster I never thought +this theory at all tenable. (521/5. Mr. Milne discovered that the middle +shelf of Glen Roy, which Mr. Darwin stated was "not on a level with +any watershed" (Darwin, loc. cit., page 43), exactly coincided with a +watershed at the head of Glen Glaster (Milne, loc. cit., page 398).) Now +it appears to me that a very good case can be made in its favour. I am +not, however, as yet a believer in the ice-lake theory, but I tremble +for the result. I have had a good deal of talk with Mr. Lyell on +the subject, and from his advice I am going to send a letter to the +"Scotsman," in which I give briefly my present impression (though there +is not space to argue with you on such points as I think I could argue), +and indicate what points strike me as requiring further investigation +with respect, chiefly, to the ice-lake theory, so that you will not care +about it... + +P.S.--Some facts mentioned in my "Geology of S. America," page 24 +(521/6. The creeks which penetrate the western shores of Tierra del +Fuego are described as "almost invariably much shallower close to +the open sea at their mouths than inland...This shoalness of the +sea-channels near their entrances probably results from the quantity of +sediment formed by the wear and tear of the outer rocks exposed to +the full force of the open sea. I have no doubt that many lakes--for +instance, in Scotland--which are very deep within, and are separated +from the sea apparently only by a tract of detritus, were originally +sea-channels, with banks of this nature near their mouths, which have +since been upheaved" ("Geol. Obs. S. America," page 24, footnote.), with +regard to the shoaling of the deep fiords of T. del Fuego near their +mouths, and which I have remarked would tend, with a little elevation, +to convert such fiords into lakes with a great mound-like barrier of +detritus at their mouths, might, possibly, have been of use to you with +regard to the lakes of Glen Roy. + + +LETTER 522. TO C. LYELL. Down, Wednesday, 8th. + +Many thanks for your paper. (522/1. "On the Ancient Glaciers of +Forfarshire." "Proc. Geol. Soc." Volume III., page 337, 1840.) I do +admire your zeal on a subject on which you are not immediately at work. +I will give my opinion as briefly as I can, and I have endeavoured my +best to be honest. Poor Mrs. Lyell will have, I foresee, a long letter +to read aloud, but I will try to write better than usual. Imprimis, it +is provoking that Mr. Milne (522/2. "On the Parallel Roads of Lochaber, +etc." "Trans. R. Soc. Edinb." Volume XVI., page 395, 1849. [Read March +1st and April 5th, 1847.]) has read my paper (522/3. "Observations on +the Parallel Roads of Glen Roy, etc." "Phil. Trans. R. Soc." 1839, page +39. [Read February 7th, 1839.].) with little attention, for he makes +me say several things which I do not believe--as, that the water sunk +suddenly! (page 10), that the Valley of Glen Roy, page 13, and Spean was +filled up with detritus to level of the lower shelf, against which there +is, I conceive, good evidence, etc., but I suppose it is the consequence +of my paper being most tediously written. He gives me a just snub for +talking of demonstration, and he fights me in a very pleasant manner. +Now for business. I utterly disbelieve in the barriers (522/4. See note, +Letter 521.) for his lakes, and think he has left that point exactly +where it was in the time of MacCulloch (522/5. "On the Parallel Roads of +Glen Roy." "Geol. Trans." Volume IV., page 314, 1817 (with several maps +and sections).) and Dick. (522/6. "On the Parallel Roads of Lochaber." +"Trans. R. Soc. Edinb." Volume IX., page 1, 1823.) Indeed, in showing +that there is a passage at Glen Glaster at the level of the intermediate +shelf, he makes the difficulty to my mind greater. (522/7. See Letter +521, note.) When I think of the gradual manner in which the two upper +terraces die out at Glen Collarig and at the mouth of Glen Roy, the +smooth rounded form of the hills there, and the lower shelf retaining +its usual width where the immense barrier stood, I can deliberately +repeat "that more convincing proofs of the non-existence of the +imaginary Loch Roy could scarcely have been invented with full play +given to the imagination," etc.: but I do not adhere to this remark +with such strength when applied to the glacier-lake theory. Oddly, I was +never at all staggered by this theory until now, having read Mr. Milne's +argument against it. I now can hardly doubt that a great glacier did +emerge from Loch Treig, and this by the ice itself (not moraine) might +have blocked up the three outlets from Glen Roy. I do not, however, yet +believe in the glacier theory, for reasons which I will presently give. + +There are three chief hostile considerations in Mr. Milne's paper. +First, the Glen [shelf?], not coinciding in height with the upper one +[outlet?], from observations giving 12 feet, 15 feet, 29 feet, 23 feet: +if the latter are correct the terrace must be quite independent, and the +case is hostile; but Mr. Milne shows that there is one in Glen Roy 14 +feet below the upper one, and a second one again (which I observed) +beneath this, and then we come to the proper second shelf. Hence there +is no great improbability in an independent shelf having been found in +Glen Gluoy. + +This leads me to Mr. Milne's second class of facts (obvious to every +one), namely the non-extension of the three shelves beyond Glen Roy; but +I abide by what I have written on that point, and repeat that if in Glen +Roy, where circumstances have been so favourable for the preservation +or formation of the terraces, a terrace could be formed quite plain for +three-quarters of a mile with hardly a trace elsewhere, we cannot argue, +from the non-existence of shelves, that water did not stand at the same +levels in other valleys. Feeling absolutely convinced that there was no +barrier of detritus at the mouth of Glen Roy, and pretty well convinced +that there was none of ice, the manner in which the terraces die out +when entering Glen Spean, which must have been a tideway, shows on +what small circumstances the formation of these shelves depended. With +respect to the non-existence of shelves in other parts of Scotland, Mr. +Milne shows that many others do exist, and their heights above the sea +have not yet been carefully measured, nor have even those of Glen +Roy, which I suspect are all 100 feet too high. Moreover, according to +Bravais (522/8. "On the Lines of Ancient Level of the Sea in Finmark." +By A. Bravais, Member of the Scientific Commission of the North. "Quart. +Journ. Geol. Soc." Volume I., page 534, 1845 (a translation).), we +must not feel sure that either the absolute height or the intermediate +heights between the terraces would be at all the same at distant points. +In levelling the terraces in Lochaber, all, I believe, have been taken +in Glen Roy, nearly N. and S. There should be levels taken at right +angles to this line and to the Great Glen of Scotland or chief line of +elevation. + +Thirdly, the nature of the outlets from the supposed lakes. This appears +to me the best and newest part of the paper. If Sir James Clark would +like to attend to any particular points, direct his attention to this: +especially to follow Glen Glaster from Glen Roy to L. Laggan. Mr. Milne +describes this as an old and great river-course with a fall of 212 feet. +He states that the rocks are smooth on upper face and rough on lower, +but he does not mention whether this character prevails throughout the +whole 212 vertical feet--a most important consideration; nor does he +state whether these rocks are polished or scratched, as might have +happened even to a considerable depth beneath the water (Mem. great +icebergs in narrow fiords of T. del Fuego (522/9. In the "Voyage of the +'Beagle'" a description is given of the falling of great masses of ice +from the icy cliffs of the glaciers with a crash that "reverberates +like the broadside of a man-of-war, through the lonely channels" which +intersect the coast-line of Tierra del Fuego. Loc. cit., page 246.)) +by the action of icebergs, for that icebergs transported boulders on to +terraces, I have no doubt. Mr. Milne's description of the outlets of +his lake sound to me more like tidal channels, nor does he give any +arguments how such are to be distinguished from old river-courses. +I cannot believe in the body of fresh water which must, on the lake +theory, have flowed out of them. At the Pass of Mukkul he states that +the outlet is 70 feet wide and the rocky bottom 21 feet below the level +of the shelf, and that the gorge expands to the eastwards into a broad +channel of several hundred yards in width, divided in the middle by what +has formerly been a rocky islet, against which the waters of this large +river had chafed in issuing from the pass. We know the size of the river +at the present day which would flow out through this pass, and it seems +to me (and in the other given cases) to be as inadequate; the whole +seems to me far easier explained by a tideway than by a formerly more +humid climate. + +With respect to the very remarkable coincidence between the shelves and +the outlets (rendered more remarkable by Mr. Milne's discovery of the +outlet to the intermediate shelf at Glen Glaster (522/10. See Letter +521, note.)), Mr. Milne gives only half of my explanation; he alludes +to (and disputes) the smoothing and silting-up action, which I still +believe in. I state: If we consider what must take place during +the gradual rise of a group of islands, we shall have the currents +endeavouring to cut down and deepen some shallow parts in the channels +as they are successively brought near the surface, but tending from the +opposition of tides to choke up others with littoral deposits. During +a long interval of rest, from the length of time allowed to the above +processes, the tendency would often prove effective, both in forming, by +accumulation of matter, isthmuses, and in keeping open channels. Hence +such isthmuses and channels just kept open would oftener be formed at +the level which the waters held at the interval of rest, than at any +other (page 65). I look at the Pass of Mukkul (21 feet deep, Milne) as a +channel just kept open, and the head of Glen Roy (where there is a +great bay silted up) and of Kilfinnin (at both which places there are +level-topped mounds of detritus above the level of the terraces) as +instances of channels filled up at the stationary levels. I have long +thought it a probable conjecture that when a rising surface becomes +stationary it becomes so, not at once, but by the movements first +becoming very slow; this would greatly favour the cutting down many gaps +in the mountains to the level of the stationary periods. + +GLACIER THEORY. + +If a glacialist admitted that the sea, before the formation of the +terraces, covered the country (which would account for land-straits +above level of terraces), and that the land gradually emerged, and if +he supposed his lakes were banked by ice alone, he would make out, in my +opinion, the best case against the marine origin of the terraces. From +the scattered boulders and till, you and I must look at it as certain +that the sea did cover the whole country, and I abide quite by my +arguments from the buttresses, etc., that water of some kind receded +slowly from the valleys of Lochaber (I presume Mr. Milne admits this). +Now, I do not believe in the ice-lake theory, from the following weak +but accumulating reasons: because, 1st, the receding water must have +been that of a lake in Glen Spean, and of the sea in the other valleys +of Scotland, where I saw similar buttresses at many levels; 2nd, because +the outlets of the supposed lakes as already stated seem, from Mr. +Milne's statements, too much worn and too large; 3rd, when the lake +stood at the three-quarters of a mile shelf the water from it must have +flowed over ice itself for a very long time, and kept at the same exact +level: certainly this shelf required a long time for its formation; 4th, +I cannot believe a glacier would have blocked up the short, very wide +valley of Kilfinnin, the Great Glen of Scotland also being very low +there; 5th, the country at some places where Mr. Milne has described +terraces is not mountainous, and the number of ice-lakes appears to me +very improbable; 6th, I do not believe any lake could scoop the rocks +so much as they are at the entrance to Loch Treig or cut them off at the +head of Upper Glen Roy; 7th, the very gradual dying away of the terraces +at the mouth of Glen Roy does not look like a barrier of any kind; 8th, +I should have expected great terminal moraines across the mouth of Glen +Roy, Glen Collarig, and Glaster, at least at the bottom of the valleys. +Such, I feel pretty sure, do not exist. + +I fear I must have wearied you with the length of this letter, which +I have not had time to arrange properly. I could argue at great length +against Mr. Milne's theory of barriers of detritus, though I could help +him in one way--viz., by the soundings which occur at the entrances of +the deepest fiords in T. del Fuego. I do not think he gives the smallest +satisfaction with respect to the successive and comparatively sudden +breakage of his many lakes. + +Well, I enjoyed my trip to Glen Roy very much, but it was time thrown +away. I heartily wish you would go there; it should be some one who +knows glacier and iceberg action, and sea action well. I wish the Queen +would command you. I had intended being in London to-morrow, but one of +my principal plagues will, I believe, stop me; if I do I will assuredly +call on you. I have not yet read Mr. Milne on Elevation (522/11. "On +a Remarkable Oscillation of the Sea, observed at Various Places on the +Coasts of Great Britain in the First Week of July, 1843." "Trans. R. +Soc. Edinb." Volume XV., page 609, 1844.), so will keep his paper for a +day or two. + +P.S.--As you cannot want this letter, I wish you would return it to me, +as it will serve as a memorandum for me. Possibly I shall write to Mr. +Chambers, though I do not know whether he will care about what I think +on the subject. This letter is too long and ill-written for Sir J. +Clark. + + +LETTER 523. TO LADY LYELL. [October 4th, 1847.] + +I enclose a letter from Chambers, which has pleased me very much (which +please return), but I cannot feel quite so sure as he does. If the +Lochaber and Tweed roads really turn out exactly on a level, the sea +theory is proved. What a magnificent proof of equality of elevation, +which does not surprise me much; but I fear I see cause of doubt, for +as far as I remember there are numerous terraces, near Galashiels, with +small intervals of height, so that the coincidence of height might be +cooked. Chambers does not seem aware of one very striking coincidence, +viz., that I made by careful measurement my Kilfinnin terrace 1202 feet +above sea, and now Glen Gluoy is 1203 feet, according to the recent more +careful measurements. Even Agassiz (523/1. "On the Glacial Theory," by +Louis Agassiz, "Edinb. New Phil. Journ." Volume XXXIII., page 217, 1842. +The parallel terraces are dealt with by Agassiz, pages 236 et seq.) +would be puzzled to block up Glen Gluoy and Kilfinnin by the same +glacier, and then, moreover, the lake would have two outlets. With +respect to the middle terrace of Glen Roy--seen by Chambers in the Spean +(figured by Agassiz, and seen by myself but not noticed, as I thought +it might have been a sheep track)--it might yet have been formed on the +ice-lake theory by two independent glaciers going across the Spean, but +it is very improbable that two such immense ones should not have been +united into one. Chambers, unfortunately, does not seem to have visited +the head of the Spey, and I have written to propose joining funds and +sending some young surveyor there. If my letter is published in the +"Scotsman," how Buckland (523/2. Professor Buckland may be described as +joint author, with Agassiz, of the Glacier theory.), as I have foreseen, +will crow over me: he will tell me he always knew that I was wrong, but +now I shall have rather ridiculously to say, "but I am all right again." + +I have been a good deal interested in Miller (523/3. Hugh Miller's +"First Impressions of England and its People," London, 1847.), but I +find it not quick reading, and Emma has hardly begun it yet. I rather +wish the scenic descriptions were shorter, and that there was a little +less geologic eloquence. + +Lyell's picture now hangs over my chimneypiece, and uncommonly glad I am +to have it, and thank you for it. + + +LETTER 524. TO C. LYELL. Down, September 6th [1861]. + +I think the enclosed is worth your reading. I am smashed to atoms about +Glen Roy. My paper was one long gigantic blunder from beginning to end. +Eheu! Eheu! (524/1. See "Life and Letters," I., pages 68, 69, also pages +290, 291.) + + +LETTER 525. TO C. LYELL. Down, September 22nd [1861]. + +I have read Mr. Jamieson's last letter, like the former ones, with very +great interest. (525/1. Mr. Jamieson visited Glen Roy in August 1861 and +in July 1862. His paper "On the Parallel Roads of Glen Roy, and their +Place in the History of the Glacial Period," was published in the +"Quarterly Journal of the Geological Society" in 1863, Volume XIX., +page 235. His latest contribution to this subject was published in the +"Quarterly Journal," Volume XLVIII., page 5, 1892.) What a problem you +have in hand! It beats manufacturing new species all to bits. It would +be a great personal consolation to me if Mr. J. can admit the sloping +Spean terrace to be marine, and would remove one of my greatest +difficulties--viz. the vast contrast of Welsh and Lochaber valleys. But +then, as far as I dare trust my observations, the sloping terraces ran +far up the Roy valley, so as to reach not far below the lower shelf. If +the sloping fringes are marine and the shelves lacustrine, all I can +say is that nature has laid a shameful trap to catch an unwary wretch. I +suppose that I have underrated the power of lakes in producing pebbles; +this, I think, ought to be well looked to. I was much struck in Wales +on carefully comparing the glacial scratches under a lake (formed by a +moraine and which must have existed since the Glacial epoch) and above +water, and I could perceive NO difference. I believe I saw many such +beds of good pebbles on level of lower shelf, which at the time I could +not believe could have been found on shores of lake. The land-straits +and little cliffs above them, to which I referred, were quite above the +highest shelf; they may be of much more ancient date than the shelves. +Some terrace-like fringes at head of the Spey strike me as very +suspicious. Mr. J. refers to absence of pebbles at considerable heights: +he must remember that every storm, every deer, every hare which runs +tends to roll pebbles down hill, and not one ever goes up again. I +may mention that I particularly alluded to this on S. Ventanao (525/2. +"Geolog. Obs. on South America," page 79. "On the flanks of the +mountains, at a height of 300 or 400 feet above the plain, there were +a few small patches of conglomerate and breccia, firmly cemented by +ferruginous matter to the abrupt and battered face of the quartz--traces +being thus exhibited of ancient sea-action.") in N. Patagonia, a great +isolated rugged quartz-mountain 3,000 feet high, and I could find not +one pebble except on one very small spot, where a ferruginous spring had +firmly cemented a few to the face of mountain. If the Lochaber lakes had +been formed by an ice-period posterior to the (marine?) sloping terraces +in the Spean, would not Mr. J. have noticed gigantic moraines across the +valley opposite the opening of Lake Treig? I go so far as not to like +making the elevation of the land in Wales and Scotland considerably +different with respect to the ice-period, and still more do I dislike +it with respect to E. and W. Scotland. But I may be prejudiced by having +been so long accustomed to the plains of Patagonia. But the equality of +level (barring denudation) of even the Secondary formations in Britain, +after so many ups and downs, always impresses my mind, that, except when +the crust-cracks and mountains are formed, movements of elevation and +subsidence are generally very equable. + +But it is folly my scribbling thus. You have a grand problem, and heaven +help you and Mr. Jamieson through it. It is out of my line nowadays, and +above and beyond me. + + +LETTER 526. TO J.D. HOOKER. Down, September 28th [1861]. + +It is, I believe, true that Glen Roy shelves (I remember your Indian +letter) were formed by glacial lakes. I persuaded Mr. Jamieson, an +excellent observer, to go and observe them; and this is his result. +There are some great difficulties to be explained, but I presume this +will ultimately be proved the truth... + + +LETTER 527. TO C. LYELL. Down, October 1st [1861]. + +Thank you for the most interesting correspondence. What a wonderful case +that of Bedford. (527/1. No doubt this refers to the discovery of flint +implements in the Valley of the Ouse, near Bedford, in 1861 (see Lyell's +"Antiquity of Man," pages 163 et seq., 1863.) I thought the problem +sufficiently perplexing before, but now it beats anything I ever heard +of. Far from being able to give any hypothesis for any part, I cannot +get the facts into my mind. What a capital observer and reasoner Mr. +Jamieson is. The only way that I can reconcile my memory of Lochaber +with the state of the Welsh valleys is by imagining a great barrier, +formed by a terminal moraine, at the mouth of the Spean, which the +river had to cut slowly through, as it drained the lowest lake after +the Glacial period. This would, I can suppose, account for the sloping +terraces along the Spean. I further presume that sharp transverse +moraines would not be formed under the waters of the lake, where the +glacier came out of L. Treig and abutted against the opposite side of +the valley. A nice mess I made of Glen Roy! I have no spare copy of +my Welsh paper (527/2. "Notes on the Effects produced by the Ancient +Glaciers of Caernarvonshire, and on the Boulders transported by Floating +Ice," "Edinb. New Phil. Journ." Volume XXXIII., page 352, 1842.); it +would do you no good to lend it. I suppose I thought that there must +have been floating ice on Moel Tryfan. I think it cannot be disputed +that the last event in N. Wales was land-glaciers. I could not decide +where the action of land-glaciers ceased and marine glacial action +commenced at the mouths of the valleys. + +What a wonderful case the Bedford case. Does not the N. American view of +warmer or more equable period, after great Glacial period, become much +more probable in Europe? + +But I am very poorly to-day, and very stupid, and hate everybody and +everything. One lives only to make blunders. I am going to write a +little book for Murray on Orchids (527/3. "On the Various Contrivances +by which Orchids are Fertilised by Insects," London, 1862.), and to-day +I hate them worse than everything. So farewell, in a sweet frame of +mind. + + +LETTER 528. TO C. LYELL. Down, October 14th [1861]. + +I return Jamieson's capital letter. I have no comments, except to say +that he has removed all my difficulties, and that now and for evermore I +give up and abominate Glen Roy and all its belongings. It certainly is +a splendid case, and wonderful monument of the old Ice-period. You ought +to give a woodcut. How many have blundered over those horrid shelves! + +That was a capital paper by Jamieson in the last "Geol. Journal." +(528/1. "On the Drift and Rolled Gravel of the North of Scotland," +"Quart. Journ. Geol. Soc." Volume XVI., page 347, 1860.) I was never +before fully convinced of the land glacialisation of Scotland before, +though Chambers tried hard to convince me. + +I must say I differ rather about Ramsay's paper; perhaps he pushes it +too far. (528/2. "On the Glacial Origin of Certain Lakes, etc." "Quart. +Journ. Geol. Soc." Volume XVIII., page 185. See Letter 503.) It struck +me the more from remembering some years ago marvelling what could be +the meaning of such a multitude of lakes in Friesland and other northern +districts. Ramsay wrote to me, and I suggested that he ought to compare +mountainous tropical regions with northern regions. I could not remember +many lakes in any mountainous tropical country. When Tyndall talks of +every valley in Switzerland being formed by glaciers, he seems to forget +there are valleys in the tropics; and it is monstrous, in my opinion, +the accounting for the Glacial period in the Alps by greater height +of mountains, and their lessened height, if I understand, by glacial +erosion. "Ne sutor ultra crepidam," I think, applies in this case to +him. I am hard at work on "Variation under Domestication." (528/3. +Published 1868.) + +P.S.--I am rather overwhelmed with letters at present, and it has just +occurred to me that perhaps you will forward my note to Mr. Jamieson; as +it will show that I entirely yield. I do believe every word in my Glen +Roy paper is false. + + +LETTER 529. TO C. LYELL. Down, October 20th [1861]. + +Notwithstanding the orchids, I have been very glad to see Jamieson's +letter; no doubt, as he says, certainty will soon be reached. + +With respect to the minor points of Glen Roy, I cannot feel easy with +a mere barrier of ice; there is so much sloping, stratified detritus in +the valleys. I remember that you somewhere have stated that a running +stream soon cuts deeply into a glacier. I have been hunting up all old +references and pamphlets, etc., on shelves in Scotland, and will +send them off to Mr. J., as they possibly may be of use to him if he +continues the subject. The Eildon Hills ought to be specially examined. +Amongst MS. I came across a very old letter from me to you, in which I +say: "If a glacialist admitted that the sea, before the formation of the +shelves, covered the country (which would account for the land-straits +above the level of the shelves), and if he admitted that the land +gradually emerged, and if he supposed that his lakes were banked up by +ice alone, he would make out, in my opinion, the best case against the +marine origin of the shelves." (529/1. See Letter 522.) This seems very +much what you and Mr. J. have come to. + +The whole glacial theory is really a magnificent subject. + + +LETTER 530. TO C. LYELL. Down, April 1st [1862]. + +I am not quite sure that I understand your difficulty, so I must give +what seems to me the explanation of the glacial lake theory at some +little length. You know that there is a rocky outlet at the level of +all the shelves. Please look at my map. (530/1. The map accompanying +Mr. Darwin's paper in the "Phil. Trans. R. Soc." 1839.) I suppose whole +valley of Glen Spean filled with ice; then water would escape from +an outlet at Loch Spey, and the highest shelf would be first formed. +Secondly, ice began to retreat, and water will flow for short time over +its surface; but as soon as it retreated from behind the hill marked +Craig Dhu, where the outlet on level of second shelf was discovered by +Milne (530/2. See note, Letter 521.), the water would flow from it and +the second shelf would be formed. This supposes that a vast barrier +of ice still remains under Ben Nevis, along all the lower part of the +Spean. Lastly, I suppose the ice disappeared everywhere along L. Loggan, +L. Treig, and Glen Spean, except close under Ben Nevis, where it still +formed a barrier, the water flowing out at level of lowest shelf by the +Pass of Mukkul at head of L. Loggan. This seems to me to account for +everything. It presupposes that the shelves were formed towards the +close of the Glacial period. I come up to London to read on Thursday a +short paper at the Linnean Society. Shall I call on Friday morning at +9.30 and sit half an hour with you? Pray have no scruple to send a line +to Queen Anne Street to say "No" if it will take anything out of you. If +I do not hear, I will come. + + +LETTER 531. TO J. PRESTWICH. Down, January 3rd, 1880. + +You are perfectly right. (531/1. Prof. Prestwich's paper on Glen Roy was +published in the "Phil. Trans. R. Soc." for 1879, page 663.) As soon as +I read Mr. Jamieson's article on the parallel roads, I gave up the ghost +with more sighs and groans than on almost any other occasion in my life. + + + +2.IX.IV. CORAL REEFS, FOSSIL AND RECENT, 1841-1881. + + +LETTER 532. TO C. LYELL. Shrewsbury, Tuesday, 6th [July, 1841]. + +Your letter was forwarded me here. I was the more glad to receive it, as +I never dreamed of your being able to find time to write, now that you +must be so very busy; and I had nothing to tell you about myself, else I +should have written. I am pleased to hear how extensive and successful +a trip you appear to have made. You must have worked hard, and got your +Silurian subject well in your head, to have profited by so short an +excursion. How I should have enjoyed to have followed you about the +coral-limestone. I once was close to Wenlock (532/1. The Wenlock +limestone (Silurian) contains an abundance of corals. "The rock seems +indeed to have been formed in part by massive sheets and bunches of +coral" (Geikie, "Text-book of Geology," 1882, page 678.), something such +as you describe, and made a rough drawing, I remember, of the masses of +coral. But the degree in which the whole mass was regularly stratified, +and the quantity of mud, made me think that the reefs could never have +been like those in the Pacific, but that they most resembled those on +the east coast of Africa, which seem (from charts and descriptions) +to confine extensive flats and mangrove swamps with mud, or like some +imperfect ones about the West India Islands, within the reefs of which +there are large swamps. All the reefs I have myself seen could be +associated only with nearly pure calcareous rocks. I have received a +description of a reef lying some way off the coast near Belize (terra +firma), where a thick bed of mud seems to have invaded and covered a +coral reef, leaving but very few islets yet free from it. But I can +give you no precise information without my notes (even if then) on these +heads... + +Bermuda differs much from any other island I am acquainted with. At +first sight of a chart it resembles an atoll; but it differs from this +structure essentially in the gently shelving bottom of the sea all round +to some distance; in the absence of the defined circular reefs, and, as +a consequence, of the defined central pool or lagoon; and lastly, in +the height of the land. Bermuda seems to be an irregular, circular, flat +bank, encrusted with knolls and reefs of coral, with land formed on one +side. This land seems once to have been more extensive, as on some parts +of the bank farthest removed from the island there are little pinnacles +of rock of the same nature as that of the high larger islands. I cannot +pretend to form any precise notion how the foundation of so anomalous an +island has been produced, but its whole history must be very different +from that of the atolls of the Indian and Pacific oceans--though, as +I have said, at first glance of the charts there is a considerable +resemblance. + + +LETTER 533. TO C. LYELL. [1842.] + +Considering the probability of subsidence in the middle of the great +oceans being very slow; considering in how many spaces, both large ones +and small ones (within areas favourable to the growth of corals), reefs +are absent, which shows that their presence is determined by peculiar +conditions; considering the possible chance of subsidence being more +rapid than the upward growth of the reefs; considering that reefs not +very rarely perish (as I cannot doubt) on part, or round the whole, of +some encircled islands and atolls: considering these things, I admit as +very improbable that the polypifers should continue living on and +above the same reef during a subsidence of very many thousand feet; and +therefore that they should form masses of enormous thickness, say at +most above 5,000 feet. (533/1. "...As we know that some inorganic causes +are highly injurious to the growth of coral, it cannot be expected that +during the round of change to which earth, air, and water are exposed, +the reef-building polypifers should keep alive for perpetuity in any +one place; and still less can this be expected during the progressive +subsidences...to which by our theory these reefs and islands have been +subjected, and are liable" ("The Structure and Distribution of Coral +Reefs," page 107: London, 1842).) This admission, I believe, is in no +way fatal to the theory, though it is so to certain few passages in my +book. + +In the areas where the large groups of atolls stand, and where likewise +a few scattered atolls stand between such groups, I always imagined that +there must have been great tracts of land, and that on such large tracts +there must have been mountains of immense altitudes. But not, it appears +to me, that one is only justified in supposing that groups of islands +stood there. There are (as I believe) many considerable islands and +groups of islands (Galapagos Islands, Great Britain, Falkland Islands, +Marianas, and, I believe, Viti groups), and likewise the majority of +single scattered islands, all of which a subsidence between 4,000 +and 5,000 feet would entirely submerge or would leave only one or two +summits above water, and hence they would produce either groups of +nothing but atolls, or of atolls with one or two encircled islands. I +am far from wishing to say that the islands of the great oceans have not +subsided, or may not continue to subside, any number of feet, but if the +average duration (from all causes of destruction) of reefs on the same +spot is limited, then after this limit has elapsed the reefs would +perish, and if the subsidence continued they would be carried down; and +if the group consisted only of atolls, only open ocean would be left; if +it consisted partly or wholly of encircled islands, these would be left +naked and reefless, but should the area again become favourable for +growth of reefs, new barrier-reefs might be formed round them. As an +illustration of this notion of a certain average duration of reefs on +the same spot, compared with the average rate of subsidence, we may take +the case of Tahiti, an island of 7,000 feet high. Now here the present +barrier-reefs would never be continued upwards into an atoll, although, +should the subsidence continue at a period long after the death of the +present reefs, new ones might be formed high up round its sides and +ultimately over it. The case resolves itself into: what is the ordinary +height of groups of islands, of the size of existing groups of atolls +(excepting as many of the highest islands as there now ordinarily occur +encircling barrier-reefs in the existing groups of atolls)? and likewise +what is the height of the single scattered islands standing between such +groups of islands? Subsidence sufficient to bury all these islands (with +the exception of as many of the highest as there are encircled islands +in the present groups of atolls) my theory absolutely requires, but no +more. To say what amount of subsidence would be required for this end, +one ought to know the height of all existing islands, both single ones +and those in groups, on the face of the globe--and, indeed, of half a +dozen worlds like ours. The reefs may be of much greater [thickness] +than that just sufficient on an average to bury groups of islands; and +the probability of the thickness being greater seems to resolve itself +into the average rate of subsidence allowing upward growth, and average +duration of reefs on the same spot. Who will say what this rate and +what this duration is? but till both are known, we cannot, I think, tell +whether we ought to look for upraised coral formations (putting on one +side denudation) above the unknown limit, say between 3,000 and 5,000 +feet, necessary to submerge groups of common islands. How wretchedly +involved do these speculations become. + + +LETTER 534. TO E. VON MOJSISOVICS. Down, January 29th, 1879. + +I thank you cordially for the continuation of your fine work on the +Tyrolese Dolomites (534/1. "Dolomitriffe Sudtirols und Venetiens": +Wien, 1878.), with its striking engravings and the maps, which are quite +wonderful from the amount of labour which they exhibit, and its extreme +difficulty. I well remember more than forty years ago examining a +section of Silurian limestone containing many corals, and thinking to +myself that it would be for ever impossible to discover whether the +ancient corals had formed atolls or barrier reefs; so you may well +believe that your work will interest me greatly as soon as I can find +time to read it. I am much obliged for your photograph, and from its +appearance rejoice to see that much more good work may be expected from +you. + +I enclose my own photograph, in case you should like to possess a copy. + + +LETTER 535. TO A. AGASSIZ. + +(535/1. Part of this letter is published in "Life and Letters," III., +pages 183, 184.) + +Down, May 5th, 1881. + +It was very good of you to write to me from Tortugas, as I always feel +much interested in hearing what you are about, and in reading your +many discoveries. It is a surprising fact that the peninsula of Florida +should have remained at the same level for the immense period requisite +for the accumulation of so vast a pile of debris. (535/2. Alexander +Agassiz published a paper on "The Tortugas and Florida Reefs" in the +"Mem. Amer. Acad. Arts and Sci." XI., page 107, 1885. See also his +"Three Cruises of the 'Blake,'" Volume I., 1888.) + +You will have seen Mr. Murray's views on the formation of atolls and +barrier reefs. (535/3. "On the Structure and Origin of Coral Reefs and +Islands," "Proc. R. Soc. Edin." Volume X., page 505, 1880. Prof. Bonney +has given a summary of Sir John Murray's views in Appendix II. of the +third edition of Darwin's "Coral Reefs," 1889.) Before publishing my +book, I thought long over the same view, but only as far as ordinary +marine organisms are concerned, for at that time little was known of the +multitude of minute oceanic organisms. I rejected this view, as from +the few dredgings made in the 'Beagle' in the S. Temperate regions, I +concluded that shells, the smaller corals, etc., etc., decayed and were +dissolved when not protected by the deposition of sediment; and sediment +could not accumulate in the open ocean. Certainly shells, etc., were +in several cases completely rotten, and crumbled into mud between my +fingers; but you will know well whether this is in any degree common. I +have expressly said that a bank at the proper depth would give rise +to an atoll, which could not be distinguished from one formed during +subsidence. I can, however, hardly believe, in the former presence of as +many banks (there having been no subsidence) as there are atolls in +the great oceans, within a reasonable depth, on which minute oceanic +organisms could have accumulated to the thickness of many hundred feet. +I think that it has been shown that the oscillations from great waves +extend down to a considerable depth, and if so the oscillating water +would tend to lift up (according to an old doctrine propounded by +Playfair) minute particles lying at the bottom, and allow them to be +slowly drifted away from the submarine bank by the slightest current. +Lastly, I cannot understand Mr. Murray, who admits that small calcareous +organisms are dissolved by the carbonic acid in the water at great +depths, and that coral reefs, etc., etc., are likewise dissolved near +the surface, but that this does not occur at intermediate depths, where +he believes that the minute oceanic calcareous organisms accumulate +until the bank reaches within the reef-building depth. But I suppose +that I must have misunderstood him. + +Pray forgive me for troubling you at such a length, but it has occurred +to me that you might be disposed to give, after your wide experience, +your judgment. If I am wrong, the sooner I am knocked on the head and +annihilated so much the better. It still seems to me a marvellous thing +that there should not have been much and long-continued subsidence in +the beds of the great oceans. I wish that some doubly rich millionaire +would take it into his head to have borings made in some of the Pacific +and Indian atolls, and bring home cores for slicing from a depth of 500 +or 600 feet. (535/4. In 1891 a Committee of the British Association was +formed for the investigation of an atoll by means of boring. The Royal +Society took up the scheme, and an expedition was sent to Funafuti, with +Prof. Sollas as leader. Another expedition left Sydney in 1897 under the +direction of Prof. Edgeworth David, and a deeper boring was made. The +Reports will be published in the "Philosophical Transactions," and will +contain Prof. David's notes upon the boring and the island generally, +Dr. Hinde's description of the microscopic structure of the cores and +other examinations of them, carried on at the Royal College of Science, +South Kensington. The boring reached a depth of 1114 feet; the cores +were found to consist entirely of reef-forming corals in situ and in +fragments, with foraminifera and calcareous algae; at the bottom there +were no traces of any other kind of rock. It seems, therefore, to us, +that unless it can be proved that reef-building corals began their work +at depths of at least 180 fathoms--far below that hitherto assigned--the +result gives the strongest support to Darwin's theory of subsidence; the +test which Darwin wished to be applied has been fairly tried, and the +verdict is entirely in his favour.) + + +2.IX.V. CLEAVAGE AND FOLIATION, 1846-1856. + + +LETTER 536. TO D. SHARPE. + +(536/1. The following eight letters were written at a time when the +subjects of cleavage and foliation were already occupying the minds of +several geologists, including Sharpe, Sorby, Rogers, Haughton, Phillips, +and Tyndall. The paper by Sharpe referred to was published in 1847 +("Quart. Journ. Geol. Soc." Volume III.), and his ideas were amplified +in two later papers (ibid., Volume V., 1849, and "Phil. Trans." 1852). +Darwin's own views, based on his observations during the "Beagle" +expedition, had appeared in Chapter XIII. of "South America" (1846) and +in the "Manual of Scientific Enquiry" (1849), but are perhaps nowhere +so clearly expressed as in this correspondence. His most important +contribution to the question was in establishing the fact that foliation +is often a part of the same process as cleavage, and is in nowise +necessarily connected with planes of stratification. Herein he was +opposed to Lyell and the other geologists of the day, but time has +made good his position. The postscript to Letter 542 is especially +interesting. We are indebted to Mr. Harker, of St. John's College, for +this note.) + +Down, August 23rd [1846?]. + +I must just send one line to thank you for your note, and to say +how heartily glad I am that you stick to the cleavage and foliation +question. Nothing will ever convince me that it is not a noble subject +of investigation, which will lead some day to great views. I think it +quite extraordinary how little the subject seems to interest British +geologists. You will, I think live to see the importance of your paper +recognised. (536/2. Probably the paper "On Slaty Cleavage." "Quart. +Journ. Geol. Soc." Volume III., page 74, 1847.) I had always thought +that Studer was one of the few geologists who had taken a correct and +enlarged view on the subject. + + +LETTER 537. TO D. SHARPE. Down [November 1846]. + +I have been much interested with your letter, and am delighted that +you have thought my few remarks worth attention. My observations on +foliation are more deserving confidence than those on cleavage; for +during my first year in clay-slate countries, I was quite unaware of +there being any marked difference between cleavage and stratification; I +well remember my astonishment at coming to the conclusion that they +were totally different actions, and my delight at subsequently reading +Sedgwick's views (537/1. "Remarks on the Structure of Large Mineral +Masses, and especially on the Chemical Changes produced in the +Aggregation of Stratified Rocks during different periods after their +Deposition." "Trans. Geol. Soc." Volume III., page 461, 1835. In the +section of this paper dealing with cleavage (page 469) Prof. Sedgwick +lays stress on the fact that "the cleavage is in no instance parallel +to the true beds."); hence at that time I was only just getting out of +a mist with respect to cleavage-laminae dipping inwards on mountain +flanks. I have certainly often observed it--so often that I thought +myself justified in propounding it as usual. I might perhaps have been +in some degree prejudiced by Von Buch's remarks, for which in those +days I had a somewhat greater deference than I now have. The Mount at +M. Video (page 146 of my book (537/2. "Geol. Obs. S. America." page 146. +The mount is described as consisting of hornblendic slate; "the laminae +of the slate on the north and south side near the summit dip inwards.")) +is certainly an instance of the cleavage-laminae of a hornblendic schist +dipping inwards on both sides, for I examined this hill carefully +with compass in hand and notebook. I entirely admit, however, that a +conclusion drawn from striking a rough balance in one's mind is worth +nothing compared with the evidence drawn from one continuous line of +section. I read Studer's paper carefully, and drew the conclusion stated +from it; but I may very likely be in an error. I only state that I have +frequently seen cleavage-laminae dipping inwards on mountain sides; +that I cannot give up, but I daresay a general extension of the rule (as +might justly be inferred from the manner of my statement) would be quite +erroneous. Von Buch's statement is in his "Travels in Norway" (537/3. +"Travels through Norway and Lapland during the years 1806-8": London, +1813.); I have unfortunately lost the reference, and it is a high crime, +I confess, even to refer to an opinion without a precise reference. If +you never read these travels they might be worth skimming, chiefly as an +amusement; and if you like and will send me a line by the general +post of Monday or Tuesday, I will either send it up with Hopkins on +Wednesday, or bring it myself to the Geological Society. I am very glad +you are going to read Hopkins (537/4. "Researches in Physical Geology," +by W. Hopkins. "Phil. Trans. R. Soc." 1839, page 381; ibid, 1842, page +43, etc.); his views appear to me eminently worth well comprehending; +false views and language appear to me to be almost universally held by +geologists on the formation of fissures, dikes and mountain chains. If +you would have the patience, I should be glad if you would read in my +"Volcanic Islands" from page 65, or even pages 54 to 72--viz., on +the lamination of volcanic rocks; I may add that I sent the series +of specimens there described to Professor Forbes of Edinburgh, and he +thought they bore out my views. + +There is a short extract from Prof. Rogers (537/5. "On Cleavage of +Slate-strata." "Edinburgh New Phil. Journ." Volume XLI., page 422, +1846.) in the last "Edinburgh New Phil. Journal," well worth your +attention, on the cleavage of the Appalachian chain, and which seems far +more uniform in the direction of dip than in any case which I have met +with; the Rogers doctrine of the ridge being thrown up by great waves +I believe is monstrous; but the manner in which the ridges have been +thrown over (as if by a lateral force acting on one side on a higher +level than on the other) is very curious, and he now states that the +cleavage is parallel to the axis-planes of these thrown-over ridges. +Your case of the limestone beds to my mind is the greatest difficulty +on any mechanical doctrine; though I did not expect ever to find +actual displacement, as seems to be proved by your shell evidence. I am +extremely glad you have taken up this most interesting subject in such +a philosophical spirit; I have no doubt you will do much in it; Sedgwick +let a fine opportunity slip away. I hope you will get out another +section like that in your letter; these are the real things wanted. + + +LETTER 538. TO D. SHARPE. Down, [January 1847]. + +I am very much obliged for the MS., which I return. I do not quite +understand from your note whether you have struck out all on this point +in your paper: I much hope not; if you have, allow me to urge on you to +append a note, briefly stating the facts, and that you omitted them in +your paper from the observations not being finished. + +I am strongly tempted to suspect that the cleavage planes will be proved +by you to have slided a little over each other, and to have been planes +of incipient tearing, to use Forbes' expression in ice; it will in that +case be beautifully analogical with my laminated lavas, and these in +composition are intimately connected with the metamorphic schists. + +The beds without cleavage between those with cleavage do not weigh quite +so heavily on me as on you. You remember, of course, Sedgwick's facts +of limestone, and mine of sandstone, breaking in the line of cleavage, +transversely to the planes of deposition. If you look at cleavage as +I do, as the result of chemical action or crystalline forces, +super-induced in certain places by their mechanical state of tension, +then it is not surprising that some rocks should yield more or less +readily to the crystalline forces. + +I think I shall write to Prof. Forbes (538/1. Prof. D. Forbes.) of +Edinburgh, with whom I corresponded on my laminated volcanic rocks, to +call his early attention to your paper. + + +LETTER 539. TO D. SHARPE. Down, October 16th [1851]. + +I am very much obliged to you for telling me the results of your +foliaceous tour, and I am glad you are drawing up an account for the +Royal Society. (539/1. "On the Arrangement of the Foliation and Cleavage +of the Rocks of the North of Scotland." "Phil. Trans. R. Soc." 1852, +page 445, with Plates XXIII. and XXIV.) I hope you will have a good +illustration or map of the waving line of junction of the slate and +schist with uniformly directed cleavage and foliation. It strikes me as +crucial. I remember longing for an opportunity to observe this point. +All that I say is that when slate and the metamorphic schists occur in +the same neighbourhood, the cleavage and foliation are uniform: of +this I have seen many cases, but I have never observed slate overlying +mica-slate. I have, however, observed many cases of glossy clay-slate +included within mica-schist and gneiss. All your other observations on +the order, etc., seem very interesting. From conversations with Lyell, +etc., I recommend you to describe in a little detail the nature of the +metamorphic schists; especially whether there are quasi-substrata of +different varieties of mica-slate or gneiss, etc.; and whether you +traced such quasi beds into the cleavage slate. I have not the least +doubt of such facts occurring, from what I have seen (and described at +M. Video) of portions of fine chloritic schists being entangled in the +midst of a gneiss district. Have you had any opportunity of tracing a +bed of marble? This, I think, from reasons given at page 166 of my +"S. America," would be very interesting. (539/2. "I have never had an +opportunity of tracing, for any distance, along the line both of strike +and dip, the so-called beds in the metamorphic schists, but I strongly +suspect that they would not be found to extend, with the same character, +very far in the line either of their dip or strike. Hence I am led to +believe that most of the so-called beds are of the nature of complex +folia, and have not been separately deposited. Of course, this view +cannot be extended to THICK masses included in the metamorphic series, +which are of totally different composition from the adjoining schists, +and which are far-extended, as is sometimes the case with quartz +and marble; these must generally be of the nature of true strata" +("Geological Observations," page 166).) A suspicion has sometimes +occurred to me (I remember more especially when tracing the clay-slate +at the Cape of Good Hope turning into true gneiss) that possibly all the +metamorphic schists necessarily once existed as clay-slate, and that +the foliation did not arise or take its direction in the metamorphic +schists, but resulted simply from the pre-existing cleavage. The +so-called beds in the metamorphic schists, so unlike common cleavage +laminae, seems the best, or at least one argument against such a +suspicion. Yet I think it is a point deserving your notice. Have you +thought at all over Rogers' Law, as he reiterates it, of cleavage being +parallel to his axes-planes of elevation? + +If you know beforehand, will you tell me when your paper is read, for +the chance of my being able to attend? I very seldom leave home, as I +find perfect quietude suits my health best. + + +(PLATE: CHARLES DARWIN, Cir. 1854. Maull & Fox, photo. Walker & +Cockerell, ph. sc.) + + +LETTER 540. TO C. LYELL. Down, January 10th, 1855. + +I received your letter yesterday, but was unable to answer it, as I had +to go out at once on business of importance. I am very glad that you +are reconsidering the subject of foliation; I have just read over what +I have written on the subject, and admire it very much, and abide by it +all. (540/1. "Geological Observations on South America," Chapter VI., +1846.) You will not readily believe how closely I attended to the +subject, and in how many and wide areas I verified my remarks. I see I +have put pretty strongly the mechanical view of origin; but I might even +then, but was afraid, have put my belief stronger. Unfortunately I have +not D. Sharpe's paper here to look over, but I think his chief points +[are] (1) the foliation forming great symmetrical curves, and (2) +the proof from effects of form of shell (540/2. This refers to the +distortion of shells in cleaved rocks.) of the mechanical action in +cleaved rocks. The great curvature would be, I think, a grand discovery +of Sharpe's, but I confess there is some want of minuteness in the +statement of Sharpe which makes me wish to see his facts confirmed. That +the foliation and cleavage are parts of curves I am quite prepared, +from what I have seen, to believe; but the simplicity and grandeur of +Sharpe's curves rather stagger me. I feel deeply convinced that when +(and I and Sharpe have seen several most striking and obvious examples) +great neighbouring or alternating regions of true metamorphic schists +and clay-slate have their foliations and cleavage parallel, there is +no way of escaping the conclusion, that the layers of pure quartz, +feldspar, mica, chlorite, etc., etc., are due not to original +deposition, but to segregation; and this is I consider the point which I +have established. This is very odd, but I suspect that great metamorphic +areas are generally derived from the metamorphosis of clay-slate, and +not from alternating layers of ordinary sedimentary matter. I think you +have exactly put the chief difficulty in its strongest light--viz. what +would be the result of pure or nearly pure layers of very different +mineralogical composition being metamorphosed? I believe even such might +be converted into an ordinary varying mass of metamorphic schists. I am +certain of the correctness of my account of patches of chlorite schists +enclosed in other schist, and of enormous quartzose veins of segregation +being absolutely continuous and contemporaneous with the folia of +quartz, and such, I think, might be the result of the folia crossing +a true stratum of quartz. I think my description of the wonderful and +beautiful laminated volcanic rocks at Ascension would be worth your +looking at. (540/3. "Geological Observations on S. America," pages 166, +167; also "Geological Observations on the Volcanic Islands," Chapter +III. (Ascension), 1844.) + + +LETTER 541. TO C. LYELL. Down, January 14th [1855]. + +We were yesterday and the day before house-hunting, so I could not +answer your letter. I hope we have succeeded in a house, after infinite +trouble, but am not sure, in York Place, Baker Street. + +I do not doubt that I either read or heard from Sharpe about the +Grampians; otherwise from my own old suspicion I should not have +inserted the passage in the manual. + +The laminated rocks at Ascension are described at page 54. (541/1. +"Volcanic Islands," page 54. "Singular laminated beds alternating with +and passing into obsidian.") + +As far as my experience has gone, I should speak only of clay-slate +being associated with mica-slate, for when near the metamorphic schists +I have found stratification so gone that I should not dare to speak of +them as overlying them. With respect to the difficulty of beds of quartz +and marble, this has for years startled me, and I have longed (since I +have felt its force) to have some opportunity of testing this point, +for without you are sure that the beds of quartz dip, as well as strike, +parallel to the foliation, the case is only just like true strata of +sandstone included in clay-slate and striking parallel to the cleavage +of the clay-slate, but of course with different dip (excepting in those +rare cases when cleavage and stratification are parallel). Having this +difficulty before my eyes, I was much struck with MacCulloch's statement +(page 166 of my "S. America") about marble in the metamorphic series not +forming true strata. + +(FIGURE 6.) + +Your expectation of the metamorphic schists sending veins into +neighbouring rocks is quite new to me; but I much doubt whether you have +any right to assume fluidity from almost any amount of molecular +change. I have seen in fine volcanic sandstone clear evidence of all +the calcareous matter travelling at least 4 1/2 feet in distance to +concretions on either hand (page 113 of "S. America") (541/2. "Some +of these concretions (flattened spherical concretions composed of hard +calcareous sandstone, containing a few shells, occurring in a bed of +sandstone) were 4 feet in diameter, and in a horizontal line 9 feet +apart, showing that the calcareous matter must have been drawn to the +centres of attraction from a distance of four feet and a half on both +sides" ("Geological Observations on S. America," page 113).) I have not +examined carefully, from not soon enough seeing all the difficulties; +but I believe, from what I have seen, that the folia in the metamorphic +schists (I do not here refer to the so-called beds) are not of great +length, but thin out, and are succeeded by others; and the notion I have +of the molecular movements is shown in the indistinct sketch herewith +sent [Figure 6]. The quartz of the strata might here move into the +position of the folia without much more movement of molecules than in +the formation of concretions. I further suspect in such cases as this, +when there is a great original abundance of quartz, that great branching +contemporaneous veins of segregation (as sometimes called) of quartz +would be formed. I can only thus understand the relation which exists +between the distorted foliation (not appearing due to injection) and the +presence of such great veins. + +I believe some gneiss, as the gneiss-granite of Humboldt, has been as +fluid as granite, but I do not believe that this is usually the case, +from the frequent alternations of glossy clay and chlorite slates, which +we cannot suppose to have been melted. + +I am far from wishing to doubt that true sedimentary strata have been +converted into metamorphic schists: all I can say is, that in the three +or four great regions, where I could ascertain the relations of the +metamorphic schists to the neighbouring cleaved rocks, it was impossible +(as it appeared to me) to admit that the foliation was due to aqueous +deposition. Now that you intend agitating the subject, it will soon be +cleared up. + + +LETTER 542. TO C. LYELL. 27, York Place, Baker Street [1855]. + +I have received your letter from Down, and I have been studying my S. +American book. + +I ought to have stated [it] more clearly, but undoubtedly in W. Tierra +del Fuego, where clay-slate passes by alternation into a grand district +of mica-schist, and in the Chonos Islands and La Plata, where glossy +slates occur within the metamorphic schists, the foliation is parallel +to the cleavage--i.e. parallel in strike and dip; but here comes, I am +sorry and ashamed to say, a great hiatus in my reasoning. I have assumed +that the cleavage in these neighbouring or intercalated beds was (as in +more distant parts) distinct from stratification. If you choose to +say that here the cleavage was or might be parallel to true bedding, +I cannot gainsay it, but can only appeal to apparent similarity to +the great areas of uniformity of strike and high angle--all certainly +unlike, as far as my experience goes, to true stratification. I have +long known how easily I overlook flaws in my own reasoning, and this is +a flagrant case. I have been amused to find, for I had quite forgotten, +how distinctly I give a suspicion (top of page 155) to the idea, before +Sharpe, of cleavage (not foliation) being due to the laminae forming +parts of great curves. (542/1. "I suspect that the varying and opposite +dips (of the cleavage-planes) may possibly be accounted for by the +cleavage-laminae...being parts of large abrupt curves, with their +summits cut off and worn down" ("Geological Observations on S. America," +page 155). I well remember the fine section at the end of a region where +the cleavage (certainly cleavage) had been most uniform in strike and +most variable in dip. + +I made with really great care (and in MS. in detail) observations on +a case which I believe is new, and bears on your view of metamorphosis +(page 149, at bottom). (Ibid., page 149.) + +(FIGURE 7.) + +In a clay-slate porphyry region, where certain thin sedimentary layers +of tuff had by self-attraction shortened themselves into little curling +pieces, and then again into crystals of feldspar of large size, and +which consequently were all strictly parallel, the series was perfect +and beautiful. Apparently also the rounded grains of quartz had in other +parts aggregated themselves into crystalline nodules of quartz. [Figure +7.] + +I have not been able to get Sorby yet, but shall not probably have +anything to write on it. I am delighted you have taken up the subject, +even if I am utterly floored. + +P.S.--I have a presentiment it will turn out that when clay-slate has +been metamorphosed the foliation in the resultant schist has been due +generally (if not, as I think, always) to the cleavage, and this to a +certain degree will "save my bacon" (please look at my saving clause, +page 167) (542/2. "As in some cases it appears that where a fissile rock +has been exposed to partial metamorphic action (for instance, from +the irruption of granite) the foliation has supervened on the already +existing cleavage-planes; so, perhaps in some instances, the foliation +of a rock may have been determined by the original planes of deposition +or of oblique current laminae. I have, however, myself never seen such +a case, and I must maintain that in most extensive metamorphic areas the +foliation is the extreme result of that process, of which cleavage is +the first effect" (Ibid., page 167).), but [with] other rocks than that, +stratification has been the ruling agent, the strike, but not the dip, +being in such cases parallel to any adjoining clay-slate. If this be +so, pre-existing planes of division, we must suppose on my view of the +cause, determining the lines of crystallisation and segregation, and +not planes of division produced for the first time during the act of +crystallisation, as in volcanic rocks. If this should ever be proved, I +shall not look back with utter shame at my work. + + +LETTER 543. TO J.D. HOOKER. Down, September 8th [1856]. + +I got your letter of the 1st this morning, and a real good man you have +been to write. Of all the things I ever heard, Mrs. Hooker's pedestrian +feats beat them. My brother is quite right in his comparison of "as +strong as a woman," as a type of strength. Your letter, after what +you have seen in the Himalayas, etc., gives me a wonderful idea of the +beauty of the Alps. How I wish I was one-half or one-quarter as strong +as Mrs. Hooker: but that is a vain hope. You must have had some very +interesting work with glaciers, etc. When will the glacier structure +and motion ever be settled! When reading Tyndall's paper it seemed to me +that movement in the particles must come into play in his own doctrine +of pressure; for he expressly states that if there be pressure on all +sides, there is no lamination. I suppose I cannot have understood him, +for I should have inferred from this that there must have been movement +parallel to planes of pressure. (543/1. Prof. Tyndall had published +papers "On Glaciers," and "On some Physical Properties of Ice" ("Proc. +R. Inst." 1854-58) before the date of this letter. In 1856 he wrote +a paper entitled "Observations on 'The Theory of the Origin of Slaty +Cleavage,' by H.C. Sorby." "Phil. Mag." XII., 1856, page 129.) + +Sorby read a paper to the Brit. Assoc., and he comes to the conclusion +that gneiss, etc., may be metamorphosed cleavage or strata; and I +think he admits much chemical segregation along the planes of division. +(543/2. "On the Microscopical Structure of Mica-schist:" "Brit. Ass. +Rep." 1856, page 78. See also Letters 540-542.) I quite subscribe to +this view, and should have been sorry to have been so utterly wrong, as +I should have been if foliation was identical with stratification. + +I have been nowhere and seen no one, and really have no news of any kind +to tell you. I have been working away as usual, floating plants in salt +water inter alia, and confound them, they all sink pretty soon, but at +very different rates. Working hard at pigeons, etc., etc. By the way, +I have been astonished at the differences in the skeletons of domestic +rabbits. I showed some of the points to Waterhouse, and asked him +whether he could pretend that they were not as great as between species, +and he answered, "They are a great deal more." How very odd that no +zoologist should ever have thought it worth while to look to the real +structure of varieties... + + +2.IX.VI. AGE OF THE WORLD, 1868-1877. + + +LETTER 544. TO J. CROLL. Down, September 19th, 1868. + +I hope that you will allow me to thank you for sending me your papers +in the "Phil. Magazine." (544/1. Croll published several papers in +the "Philosophical Magazine" between 1864 and the date of this letter +(1868).) I have never, I think, in my life been so deeply interested +by any geological discussion. I now first begin to see what a million +means, and I feel quite ashamed of myself at the silly way in which I +have spoken of millions of years. I was formerly a great believer in the +power of the sea in denudation, and this was perhaps natural, as most of +my geological work was done near sea-coasts and on islands. But it is a +consolation to me to reflect that as soon as I read Mr. Whitaker's paper +(544/2. "On Subaerial Denudation," and "On Cliffs and Escarpments of +the Chalk and Lower Tertiary Beds," "Geol. Mag." Volume IV., page 447, +1867.) on the escarpments of England, and Ramsay (544/3. "Quart. Journ. +Geol. Soc." Volume XVIII., page 185, 1862. "On the Glacial Origin of +certain Lakes in Switzerland, the Black Forest, Great Britain, Sweden, +North America, and elsewhere.') and Jukes' papers (544/4. "Quart. Journ. +Geol. Soc." Volume XVIII., page 378, 1862. "On the Mode of Formation of +some River-Valleys in the South of Ireland."), I gave up in my own mind +the case; but I never fully realised the truth until reading your papers +just received. How often I have speculated in vain on the origin of the +valleys in the chalk platform round this place, but now all is clear. I +thank you cordially for having cleared so much mist from before my eyes. + + +LETTER 545. TO T. MELLARD READE. Down, February 9th, 1877. + +I am much obliged for your kind note, and the present of your essay. +I have read it with great interest, and the results are certainly most +surprising. (545/1. Presidential Address delivered by T. Mellard Reade +before the Liverpool Geological Society ("Proc. Liverpool Geol. Soc." +Volume III., pt. iii., page 211, 1877). See also "Examination of a +Calculation of the Age of the Earth, based upon the hypothesis of the +Permanence of Oceans and Continents." "Geol. Mag." Volume X., page 309, +1883.) It appears to me almost monstrous that Professor Tait should +say that the duration of the world has not exceeded ten million years. +(545/2. "Lecture on Some Recent Advances in Physical Science," by P.G. +Tait, London, 1876.) The argument which seems the most weighty in favour +of the belief that no great number of millions of years have elapsed +since the world was inhabited by living creatures is the rate at which +the temperature of the crust increases, and I wish that I could see this +argument answered. + + +LETTER 546. TO J. CROLL. Down, August 9th, 1877. + +I am much obliged for your essay, which I have read with the greatest +interest. With respect to the geological part, I have long wished to see +the evidence collected on the time required for denudation, and you have +done it admirably. (546/1. In a paper "On the Tidal Retardation Argument +for the Age of the Earth" ("Brit. Assoc. Report," 1876, page 88), Croll +reverts to the influence of subaerial denudation in altering the form of +the earth as an objection to the argument from tidal retardation. He had +previously dealt with this subject in "Climate and Time," Chapter +XX., London, 1875.) I wish some one would in a like spirit compare +the thickness of sedimentary rocks with the quickest estimated rate of +deposition by a large river, and other such evidence. Your main argument +with respect to the sun seems to me very striking. + +My son George desires me to thank you for his copy, and to say how much +he has been interested by it. + + +2.IX.VII. GEOLOGICAL ACTION OF EARTHWORMS, 1880-1882. + +"My whole soul is absorbed with worms just at present." (From a letter +to Sir W. Thistleton-Dyer, November 26th, 1880.) + + +LETTER 547. TO T.H. FARRER (Lord Farrer). + +(547/1. The five following letters, written shortly before and after the +publication of "The Formation of Vegetable Mould through the Action of +Worms," 1881, deal with questions connected with Mr. Darwin's work on +the habits and geological action of earthworms.) + +Down, October 20th, 1880. + +What a man you are to do thoroughly whatever you undertake to do! The +supply of specimens has been magnificent, and I have worked at them for +a day and a half. I find a very few well-rounded grains of brick in +the castings from over the gravel walk, and plenty over the hole in the +field, and over the Roman floor. (547/2. See "The Formation of Vegetable +Mould," 1881, pages 178 et seq. The Roman remains formed part of a villa +discovered at Abinger, Surrey. Excavations were carried out, under Lord +Farrer's direction, in a field adjoining the ground in which the Roman +villa was first found, and extended observations were made by Lord +Farrer, which led Mr. Darwin to conclude that a large part of the fine +vegetable mould covering the floor of the villa had been brought up +from below by worms.) You have done me the greatest possible service +by making me more cautious than I should otherwise have been--viz., by +sending me the rubbish from the road itself; in this rubbish I find +very many particles, rounded (I suppose) by having been crushed, angles +knocked off, and somewhat rolled about. But not a few of the particles +may have passed through the bodies of worms during the years since the +road was laid down. I still think that the fragments are ground in the +gizzards of worms, which always contain bits of stone; but I must try +and get more evidence. I have to-day started a pot with worms in very +fine soil, with sharp fragments of hard tiles laid on the surface, and +hope to see in the course of time whether any of those become rounded. I +do not think that more specimens from Abinger would aid me... + + +LETTER 548. TO G.J. ROMANES. Down, March 7th. + +I was quite mistaken about the "Gardeners' Chronicle;" in my index there +are only the few enclosed and quite insignificant references having any +relation to the minds of animals. When I returned to my work, I found +that I had nearly completed my statement of facts about worms plugging +up their burrows with leaves (548/1. Chapter II., of "The Formation +of Vegetable Mould through the Action of Worms," 1881, contains a +discussion on the intelligence shown by worms in the manner of plugging +up their burrows with leaves (pages 78 et seq.).), etc., etc., so I +waited until I had naturally to draw up a few concluding remarks. I hope +that it will not bore you to read the few accompanying pages, and in the +middle you will find a few sentences with a sort of definition of, or +rather discussion on, intelligence. I am altogether dissatisfied with +it. I tried to observe what passed in my own mind when I did the work +of a worm. If I come across a professed metaphysician, I will ask him +to give me a more technical definition, with a few big words about the +abstract, the concrete, the absolute, and the infinite; but seriously, I +should be grateful for any suggestions, for it will hardly do to assume +that every fool knows what "intelligent" means. (548/2. "Mr. Romanes, +who has specially studied the minds of animals, believes that we can +safely infer intelligence only when we see an individual profiting +by its own experience...Now, if worms try to drag objects into their +burrows, first in one way and then in another, until they at last +succeed, they profit, at least in each particular instance, by +experience" ("The Formation of Vegetable Mould," 1881, page 95).) You +will understand that the MS. is only the first rough copy, and will need +much correction. Please return it, for I have no other copy--only a few +memoranda. When I think how it has bothered me to know what I mean by +"intelligent," I am sorry for you in your great work on the minds of +animals. + +I daresay that I shall have to alter wholly the MS. + + +LETTER 549. TO FRANCIS GALTON. Down, March 8th [1881]. + +Very many thanks for your note. I have been observing the [worm] tracks +on my walks for several months, and they occur (or can be seen) only +after heavy rain. As I know that worms which are going to die (generally +from the parasitic larva of a fly) always come out of their burrows, +I have looked out during these months, and have usually found in the +morning only from one to three or four along the whole length of my +walks. On the other hand, I remember having in former years seen scores +or hundreds of dead worms after heavy rain. (549/1. "After heavy +rain succeeding dry weather, an astonishing number of dead worms may +sometimes be seen lying on the ground. Mr. Galton informs me that on +one occasion (March, 1881), the dead worms averaged one for every +two-and-a-half paces in length on a walk in Hyde Park, four paces in +width" (loc. cit., page 14).) I cannot possibly believe that worms are +drowned in the course of even three or four days' immersion; and I am +inclined to conclude that the death of sickly (probably with parasites) +worms is thus hastened. I will add a few words to what I have said about +these tracks. Occasionally worms suffer from epidemics (of what nature I +know not) and die by the million on the surface of the ground. Your ruby +paper answers capitally, but I suspect that it is only for dimming the +light, and I know not how to illuminate worms by the same intensity of +light, and yet of a colour which permits the actinic rays to pass. I +have tried drawing triangles of damp paper through a small cylindrical +hole, as you suggested, and I can discover no source of error. (549/2. +Triangles of paper were used in experiments to test the intelligence of +worms (loc. cit., page 83).) Nevertheless, I am becoming more doubtful +about the intelligence of worms. The worst job is that they will do +their work in a slovenly manner when kept in pots (549/3. Loc. cit., +page 75.), and I am beyond measure perplexed to judge how far such +observations are trustworthy. + + +LETTER 550. TO E. RAY LANKESTER. + +(550/1. Mr. Lankester had written October 11th, 1881, to thank Mr. +Darwin for the present of the Earthworm book. He asks whether Darwin +knows of "any experiments on the influence of sea-water on earthworms. +I have assumed that it is fatal to them. But there is a littoral species +(Pontodrilus of Perrier) found at Marseilles." Lankester adds, "It is +a great pleasure and source of pride to me to see my drawing of the +earthworm's alimentary canal figuring in your pages." + +Down, October 13th [1881]. + +I have been much pleased and interested by your note. I never actually +tried sea-water, but I was very fond of angling when a boy, and as I +could not bear to see the worms wriggling on the hook, I dipped them +always first in salt water, and this killed them very quickly. I +remember, though not very distinctly, seeing several earthworms dead on +the beach close to where a little brook entered, and I assumed that they +had been brought down by the brook, killed by the sea-water, and cast +on shore. With your skill and great knowledge, I have no doubt that you +will make out much new about the anatomy of worms, whenever you take up +the subject again. + + +LETTER 551. TO J.H. GILBERT. Down, January, 12th, 1882. + +I have been much interested by your letter, for which I thank you +heartily. There was not the least cause for you to apologise for not +having written sooner, for I attributed it to the right cause, i.e. your +hands being full of work. + +Your statement about the quantity of nitrogen in the collected castings +is most curious, and much exceeds what I should have expected. In lately +reading one of your and Mr. Lawes' great papers in the "Philosophical +Transactions" (551/1. The first Report on "Agricultural, Botanical, +and Chemical Results of Experiments on the Mixed Herbage of Permanent +Grassland, conducted for many years in succession on the same land," was +published in the "Philosophical Transactions of the Royal Society" in +1880, the second paper appeared in the "Phil. Trans." for 1882, and the +third in the "Phil. Trans." of 1900, Volume 192, page 139.) (the value +and importance of which cannot, in my opinion, be exaggerated) I +was struck with the similarity of your soil with that near here; and +anything observed here would apply to your land. Unfortunately I have +never made deep sections in this neighbourhood, so as to see how deep +the worms burrow, except in one spot, and here there had been left on +the surface of the chalk a little very fine ferruginous sand, probably +of Tertiary age; into this the worms had burrowed to a depth of 55 and +61 inches. I have never seen here red castings on the surface, but it +seems possible (from what I have observed with reddish sand) that much +of the red colour of the underlying clay would be discharged in passing +through the intestinal canal. + +Worms usually work near the surface, but I have noticed that at certain +seasons pale-coloured earth is brought up from beneath the outlying +blackish mould on my lawn; but from what depth I cannot say. That some +must be brought up from a depth of four or five or six feet is certain, +as the worms retire to this depth during very dry and very cold weather. +As worms devour greedily raw flesh and dead worms, they could devour +dead larvae, eggs, etc., etc., in the soil, and thus they might locally +add to the amount of nitrogen in the soil, though not of course if the +whole country is considered. I saw in your paper something about +the difference in the amount of nitrogen at different depths in the +superficial mould, and here worms may have played a part. I wish that +the problem had been before me when observing, as possibly I might have +thrown some little light on it, which would have pleased me greatly. + + +2.IX.VIII. MISCELLANEOUS, 1846-1878. + +(552/1. The following four letters refer to questions connected with the +origin of coal.) + + +LETTER 552. TO J.D. HOOKER. Down, May [1846]. + +I am delighted that you are in the field, geologising or +palaeontologising. I beg you to read the two Rogers' account of the +Coal-fields of N. America; in my opinion they are eminently instructive +and suggestive. (552/1. "On the Physical Structure of the Appalachian +Chain," by W.B. and H.D. Rogers. Boston, 1843. See also "Geology of +Pennsylvania," by H.D. Rogers. 4 volumes. London and Philadelphia, +1843.) I can lend you their resume of their own labours, and, indeed, I +do not know that their work is yet published in full. L. Horner gives +a capital balance of difficulties on the Coal-theory in his last +Anniversary Address, which, if you have not read, will, I think, +interest you. (552/2. "Quart. Journ. Geol. Soc." Volume II., 1846, page +170.) In a paper just read an author (552/3. "On the Remarkable Fossil +Trees lately discovered near St. Helen's." By E.W. Binney. "Phil. +Mag." Volume XXIV., page 165, 1844. On page 173 the author writes: "The +Stigmaria or Sigillaria, whichever name is to be retained... was a +tree that undoubtedly grew in water.") throws out the idea that the +Sigillaria was an aquatic plant (552/4. See "Life and Letters," I., +pages 356 et seq.)--I suppose a Cycad-Conifer with the habits of the +mangrove. From simple geological reasoning I have for some time been led +to suspect that the great (and great and difficult it is) problem of +the Coal would be solved on the theory of the upright plants having been +aquatic. But even on such, I presume improbable notion, there are, as it +strikes me, immense difficulties, and none greater than the width of the +coal-fields. On what kind of coast or land could the plants have lived? +It is a grand problem, and I trust you will grapple with it. I shall +like much to have some discussion with you. When will you come here +again? I am very sorry to infer from your letter that your sister has +been ill. + + +LETTER 553. TO J.D. HOOKER. [June 2nd, 1847.] + +I received your letter the other day, full of curious facts, almost all +new to me, on the coal-question. (553/1. Sir Joseph Hooker deals with +the formation of coal in his classical paper "On the Vegetation of the +Carboniferous Period, as compared with that of the Present Day." "Mem. +Geol. Surv. Great Britain," Volume II., pt. ii., 1848.) I will bring +your note to Oxford (553/2. The British Association met at Oxford in +1847.), and then we will talk it over. I feel pretty sure that some of +your purely geological difficulties are easily solvable, and I can, I +think, throw a very little light on the shell difficulty. Pray put +no stress in your mind about the alternate, neatly divided, strata of +sandstone and shale, etc. I feel the same sort of interest in the coal +question as a man does watching two good players at play, he knowing +little or nothing of the game. I confess your last letter (and this +you will think very strange) has almost raised Binney's notion (an old, +growing hobby-horse of mine) to the dignity of an hypothesis (553/3. +Binney suggested that the Coal-plants grew in salt water. (See Letters +102, 552.) Recent investigations have shown that several of the plants +of the Coal period possessed certain anatomical peculiarities, which +indicate xerophytic characteristics, and lend support to the view that +some at least of the plants grew in seashore swamps.), though very far +yet below the promotion of being properly called a theory. + +I will bring the remainder of my species-sketch to Oxford to go over +your remarks. I have lately been getting a good many rich facts. I saw +the poor old Dean of Manchester (553/4. Dean Herbert.) on Friday, and +he received me very kindly. He looked dreadfully ill, and about an hour +afterwards died! I am most sincerely sorry for it. + + +LETTER 554. TO J.D. HOOKER. [May 12th, 1847.] + +I cannot resist thanking you for your most kind note. Pray do not +think that I was annoyed by your letter. I perceived that you had been +thinking with animation, and accordingly expressed yourself strongly, +and so I understood it. Forefend me from a man who weighs every +expression with Scotch prudence. I heartily wish you all success in your +noble problem, and I shall be very curious to have some talk with you +and hear your ultimatum. (554/1. The above paragraph was published in +"Life and Letters," I., page 359.) I do really think, after Binney's +pamphlet (554/2. "On the Origin of Coal," "Mem. Lit. Phil. Soc." +Manchester Volume VIII., page 148, 1848.), it will be worth your while +to array your facts and ideas against an aquatic origin of the coal, +though I do not know whether you object to freshwater. I am sure I have +read somewhere of the cones of Lepidodendron being found round the +stump of a tree, or am I confusing something else? How interesting all +rooted--better, it seems from what you say, than upright--specimens +become. + +I wish Ehrenberg would undertake a microscopical hunt for infusoria in +the underclay and shales; it might reveal something. Would a comparison +of the ashes of terrestrial peat and coal give any clue? (554/3. In an +article by M. F. Rigaud on "La Formation de la Houille," published in +the "Revue Scientifique," Volume II., page 385, 1894, the author lays +stress on the absence of certain elements in the ash of coals, which +ought to be present, on the assumption that the carbon has been derived +from plant tissues. If coal consists of altered vegetable debris, we +ought to find a certain amount of alkalies and phosphoric acid in +its ash. Had such substances ever been present, it is difficult to +understand how they could all have been removed by the solvent action of +water. (Rigaud's views are given at greater length in an article on the +"Structure and Formation of Coal," "Science Progress," Volume II., pages +355 and 431, 1895.)) Peat ashes are good manure, and coal ashes, except +mechanically, I believe are of little use. Does this indicate that the +soluble salts have been washed out? i.e., if they are NOT present. I go +up to Geological Council to-day--so farewell. + +(554/4. In a letter to Sir Joseph Hooker, October 6th, 1847, Mr. Darwin, +in referring to the origin of Coal, wrote: "...I sometimes think it +could not have been formed at all. Old Sir Anthony Carlisle once said to +me gravely that he supposed Megatherium and such cattle were just sent +down from heaven to see whether the earth would support them, and I +suppose the coal was rained down to puzzle mortals. You must work the +coal well in India.") + + +LETTER 555. TO J.D. HOOKER. Down, May 22nd, 1860. + +Lyell tells me that Binney has published in Proceedings of Manchester +Society a paper trying to show that Coal plants must have grown in very +marine marshes. (555/1. "On the Origin of Coal," by E.W. Binney, "Mem. +Lit. Phil. Soc. Manchester," Volume VIII., 1848, page 148. Binney +examines the evidence on which dry land has been inferred to exist +during the formation of the Coal Measures, and comes to the conclusion +that the land was covered by water, confirming Brongniart's opinion that +Sigillaria was an aquatic plant. He believes the Sigillaria "grew in +water, on the deposits where it is now discovered, and that it is the +plant which in a great measure contributed to the formation of our +valuable beds of coal." (Loc. cit., page 193.)) Do you remember how +savage you were long years ago at my broaching such a conjecture? + + +LETTER 556. TO L. HORNER. Down [1846?]. + +I am truly pleased at your approval of my book (556/1. "Geological +Observations on South America," London, 1846.): it was very kind of +you taking the trouble to tell me so. I long hesitated whether I +would publish it or not, and now that I have done so at a good cost of +trouble, it is indeed highly satisfactory to think that my labour has +not been quite thrown away. + +I entirely acquiesce in your criticism on my calling the Pampean +formation "recent" (556/2. "We must, therefore, conclude that the +Pampean formation belongs, in the ordinary geological sense of the word, +to the Recent Period." ("Geol. Obs." page 101).); Pleistocene would have +been far better. I object, however, altogether on principle (whether I +have always followed my principle is another question) to designate any +epoch after man. It breaks through all principles of classification +to take one mammifer as an epoch. And this is presupposing we know +something of the introduction of man: how few years ago all beds earlier +than the Pleistocene were characterised as being before the monkey +epoch. It appears to me that it may often be convenient to speak of an +Historical or Human deposit in the same way as we speak of an Elephant +bed, but that to apply it to an epoch is unsound. + +I have expressed myself very ill, and I am not very sure that my notions +are very clear on this subject, except that I know that I have often +been made wroth (even by Lyell) at the confidence with which people +speak of the introduction of man, as if they had seen him walk on the +stage, and as if, in a geological chronological sense, it was more +important than the entry of any other mammifer. + +You ask me to do a most puzzling thing, to point out what is newest in +my volume, and I found myself incapable of doing almost the same for +Lyell. My mind goes from point to point without deciding: what has +interested oneself or given most trouble is, perhaps quite falsely, +thought newest. The elevation of the land is perhaps more carefully +treated than any other subject, but it cannot, of course, be called new. +I have made out a sort of index, which will not take you a couple of +minutes to skim over, and then you will perhaps judge what seems newest. +The summary at the end of the book would also serve same purpose. + +I do not know where E. de B. [Elie de Beaumont] has lately put forth +on the recent elevation of the Cordillera. He "rapported" favourably +on d'Orbigny, who in late times fires off a most Royal salute; every +volcano bursting forth in the Andes at the same time with their +elevation, the debacle thus caused depositing all the Pampean mud and +all the Patagonian shingle! Is not this making Geology nice and simple +for beginners? + +We have been very sorry to hear of Bunbury's severe illness; I believe +the measles are often dangerous to grown-up people. I am very glad that +your last account was so much better. + +I am astonished that you should have had the courage to go right through +my book. It is quite obvious that most geologists find it far easier to +write than to read a book. + +Chapter I. and II.--Elevation of the land: equability on E. coast as +shown by terraces, page 19; length on W. coast, page 53; height at +Valparaiso, page 32; number of periods of rest at Coquimbo, page 49; +elevation within Human period near Lima greater than elsewhere observed; +the discussion (page 41) on non-horizontality of terraces perhaps one of +newest features--on formation of terraces rather newish. + +Chapter III., page 65.--Argument of horizontal elevation of Cordillera +I believe new. I think the connection (page 54) between earthquake +[shocks] and insensible rising important. + +Chapter IV.--The strangeness of the (Eocene) mammifers, co-existing with +recent shells. + +Chapter V.--Curious pumiceous infusorial mudstone (page 118) of +Patagonia; climate of old Tertiary period, page 134. The subject which +has been most fertile in my mind is the discussion from page 135 to end +of chapter on the accumulation of fossiliferous deposits. (556/3. The +last section of Chapter V. treats of "the Absence of extensive modern +Conchiferous Deposits in South America; and on the contemporaneousness +of the older Tertiary Deposits at distant points being due to +contemporaneous movements of subsidence." Darwin expresses the view that +"the earth's surface oscillates up and down; and...during the elevatory +movements there is but a small chance of durable fossiliferous deposits +accumulating" (loc. cit., page 139).) + +Chapter VI.--Perhaps some facts on metamorphism, but chiefly on the +layers in mica-slate, etc., being analogous to cleavage. + +Chapter VII.--The grand up-and-down movements (and vertical silicified +trees) in the Cordillera: see summary, page 204 and page 240. Origin of +the Claystone porphyry formation, page 170. + +Chapter VIII., page 224.--Mixture of Cretaceous and Oolitic forms (page +226)--great subsidence. I think (page 232) there is some novelty in +discussion on axes of eruption and injection. (page 247) Continuous +volcanic action in the Cordillera. I think the concluding summary (page +237) would show what are the most salient features in the book. + + +LETTER 557. TO C. LYELL. Shrewsbury [August 10th, 1846]. + +I was delighted to receive your letter, which was forwarded here to +me. I am very glad to hear about the new edition of the "Principles," +(557/1. The seventh edition of the "Principles of Geology" was published +in 1847.), and I most heartily hope you may live to bring out half a +dozen more editions. There would not have been such books as d'Orbigny's +S. American Geology (557/2. "Voyage dans l'Amerique meridionale execute +pendant les Annees 1826-37." 6 volumes, Paris, 1835-43.) published, if +there had been seven editions of the "Principles" distributed in France. +I am rather sorry about the small type; but the first edition, my old +true love, which I never deserted for the later editions, was also in +small type. I much fear I shall not be able to give any assistance to +Book III. (557/3. This refers to Book III. of the "Principles"--"Changes +of the Organic World now in Progress.") I think I formerly gave my +few criticisms, but I will read it over again very soon (though I +am striving to finish my S. American Geology (557/4. "Geological +Observations on South America" was published in 1846.)) and see whether +I can give you any references. I have been thinking over the subject, +and can remember no one book of consequence, as all my materials (which +are in an absolute chaos on separate bits of paper) have been picked out +of books not directly treating of the subjects you have discussed, and +which I hope some day to attempt; thus Hooker's "Antarctic Flora" I have +found eminently useful (557/5. "Botany of the Antarctic Voyage of H.M.S. +'Erebus' and 'Terror' in the Years 1839-43." I., "Flora Antarctica." 2 +volumes, London, 1844-47.), and yet I declare I do not know what +precise facts I could refer you to. Bronn's "Geschichte" (557/6. +"Naturgeschichte der drei Reiche." H.E. Bronn, Stuttgart, 1834-49.) +which you once borrowed) is the only systematic book I have met with on +such subjects; and there are no general views in such parts as I have +read, but an immense accumulation of references, very useful to follow +up, but not credible in themselves: thus he gives hybrids from ducks and +fowls just as readily as between fowls and pheasants! You can have it +again if you like. I have no doubt Forbes' essay, which is, I suppose, +now fairly out, will be very good under geographical head. (557/7. "On +the Connection between the Distribution of the existing Fauna and Flora +of the British Isles, and the Geological Changes which have affected +their Area, especially during the Epoch of the Northern Drift," by E. +Forbes. "Memoirs of Geological Survey," Volume I., page 336, 1846.) +Kolreuter's German book is excellent on hybrids, but it will cost you a +good deal of time to work out any conclusion from his numerous details. +(557/8. Joseph Gottlieb Kolreuter's "Vorlaufige Nachricht von eininigen +das Geschlecht der Pflanzen betreffenden Versuchen und Beobachtungen." +Leipzig, 1761.) With respect to variation I have found nothing--but +minute details scattered over scores of volumes. But I will look over +Book III. again. What a quantity of work you have in hand! I almost wish +you could have finished America, and thus have allowed yourself rather +more time for the old "Principles"; and I am quite surprised that you +could possibly have worked your own new matter in within six weeks. Your +intention of being in Southampton will much strengthen mine, and I shall +be very glad to hear some of your American Geology news. + + +LETTER 558. TO L. HORNER. Down, Sunday [January 1847]. + +Your most agreeable praise of my book is enough to turn my head; I am +really surprised at it, but shall swallow it with very much gusto... +(558/1. "Geological Observations in S. America," London, 1846.) + +E. de Beaumont measured the inclination with a sextant and artificial +horizon, just as you take the height of the sun for latitude. + +With respect to my Journal, I think the sketches in the second edition +(558/2. "Journal of Researches into the Natural History and Geology of +the Countries visited during the Voyage of H.M.S. 'Beagle.'" Edition II. +London, 1845.) are pretty accurate; but in the first they are not so, +for I foolishly trusted to my memory, and was much annoyed to find how +hasty and inaccurate many of my remarks were, when I went over my huge +pile of descriptions of each locality. + +If ever you meet anyone circumstanced as I was, advise him not, on any +account, to give any sketches until his materials are fully worked out. + +What labour you must be undergoing now; I have wondered at your patience +in having written to me two such long notes. How glad Mrs. Horner will +be when your address is completed. (558/3. Anniversary Address of the +President ("Quart. Journ. Geol. Soc." Volume III., page xxii, 1847).) I +must say that I am much pleased that you will notice my volume in your +address, for former Presidents took no notice of my two former volumes. + +I am exceedingly glad that Bunbury is going on well. + + +LETTER 559. TO C. LYELL. Down, July 3rd [1849]. + +I don't know when I have read a book so interesting (559/1. "A Second +Visit to the United States of North America." 2 volumes, London, 1849.); +some of your stories are very rich. You ought to be made Minister of +Public Education--not but what I should think even that beneath the +author of the old "Principles." Your book must, I should think, do +a great deal of good and set people thinking. I quite agree with the +"Athenaeum" that you have shown how a man of science can bring his +powers of observation to social subjects. (559/2. "Sir Charles Lyell, +besides the feelings of a gentleman, seems to carry with him the best +habits of scientific observation into other strata than those of clay, +into other 'formations' than those of rock or river-margin." "The +Athenaeum," June 23rd, 1849, page 640.) You have made H. Wedgwood, heart +and soul, an American; he wishes the States would annex us, and was all +day marvelling how anyone who could pay his passage money was so foolish +as to remain here. + + +LETTER 560. TO C. LYELL. Down, [December, 1849]. + +(560/1. In this letter Darwin criticises Dana's statements in his volume +on "Geology," forming Volume X. of the "Wilkes Exploring Expedition," +1849.) + +...Dana is dreadfully hypothetical in many parts, and often as "d--d +cocked sure" as Macaulay. He writes however so lucidly that he is very +persuasive. I am more struck with his remarks on denudation than you +seem to be. I came to exactly the same conclusion in Tahiti, that the +wonderful valleys there (on the opposite extreme of the scale of wonder +[to] the valleys of New South Wales) were formed exclusively by fresh +water. He underrates the power of sea, no doubt, but read his remarks +on valleys in the Sandwich group. I came to the conclusion in S. America +(page 67) that the main effect of fresh water is to deepen valleys, and +sea to widen them; I now rather doubt whether in a valley or fiord...the +sea would deepen the rock at its head during the elevation of the land. +I should like to tour on the W. coast of Scotland, and attend to this. +I forget how far generally the shores of fiords (not straits) are +cliff-formed. It is a most interesting subject. + +I return once again to Coral. I find he does not differ so much in +detail with me regarding areas of subsidence; his map is coloured on +some quite unintelligible principle, and he deduces subsidence from the +vaguest grounds, such as that the N. Marianne Islands must have subsided +because they are small, though long in volcanic action: and that the +Marquesas subsided because they are penetrated by deep bays, etc., etc. +I utterly disbelieve his statements that most of the atolls have +been lately raised a foot or two. He does not condescend to notice +my explanation for such appearances. He misrepresents me also when he +states that I deduce, without restriction, elevation from all fringing +reefs, and even from islands without any reefs! If his facts are true, +it is very curious that the atolls decrease in size in approaching the +vast open ocean S. of the Sandwich Islands. Dana puts me in a passion +several times by disputing my conclusions without condescending to +allude to my reasons; thus, regarding S. Lorenzo elevation, he is +pleased to speak of my "characteristic accuracy" (560/2. Dana's +"Geology" (Wilkes expedition), page 590.), and then gives difficulties +(as if his own) when they are stated by me, and I believe explained +by me--whereas he only alludes to a few of the facts. So in Australian +valleys, he does not allude to my several reasons. But I am forgetting +myself and running on about what can only interest myself. He strikes me +as a very clever fellow; I wish he was not quite so grand a generaliser. +I see little of interest except on volcanic action and denudation, and +here and there scattered remarks; some of the later chapters are very +bald. + + +LETTER 561. TO J.D. DANA. Down, December 5th, 1849. + +I have not for some years been so much pleased as I have just been +by reading your most able discussion on coral reefs. I thank you most +sincerely for the very honourable mention you make of me. (561/1. +"United States Exploring Expedition during the Years 1839-42 under the +Command of Charles Wilkes, U.S.N." Volume X., "Geology," by J.D. Dana, +1849.) This day I heard that the atlas has arrived, and this completes +your munificent present to me. I have not yet come to the chapter +on subsidence, and in that I fancy we shall disagree, but in the +descriptive part our agreement has been eminently satisfactory to me, +and far more than I ever ventured to anticipate. I consider that now +the subsidence theory is established. I have read about half through +the descriptive part of the "Volcanic Geology" (561/2. Part of Dana's +"Geology" is devoted to volcanic action.) (last night I ascended the +peaks of Tahiti with you, and what I saw in my short excursion was most +vividly brought before me by your descriptions), and have been most +deeply interested by it. Your observations on the Sandwich craters +strike me as the most important and original of any that I have read +for a long time. Now that I have read yours, I believe I saw at the +Galapagos, at a distance, instances of those most curious fissures of +eruption. There are many points of resemblance between the Galapagos and +Sandwich Islands (even to the shape of the mound-like hills)--viz., in +the liquidity of the lavas, absence of scoriae, and tuff-craters. Many +of your scattered remarks on denudation have particularly interested me; +but I see that you attribute less to sea and more to running water than +I have been accustomed to do. After your remarks in your last very kind +letter I could not help skipping on to the Australian valleys (561/3. +Ibid., pages 526 et seq.: "The Formation of Valleys, etc., in New South +Wales."), on which your remarks strike me as exceedingly ingenious and +novel, but they have not converted me. I cannot conceive how the great +lateral bays could have been scooped out, and their sides rendered +precipitous by running water. I shall go on and read every word of your +excellent volume. + +If you look over my "Geological Instructions" you will be amused to +see that I urge attention to several points which you have elaborately +discussed. (561/4. "A Manual of Scientific Enquiry, prepared for the use +of Her Majesty's Navy, and adapted for Travellers in General." Edited by +Sir John F.W. Herschel, Bart. London, 1849 (Section VI., "Geology." By +Charles Darwin).) I lately read a paper of yours on Chambers' book, and +was interested by it. I really believe the facts of the order described +by Chambers, in S. America, which I have described in my Geolog. volume. +This leads me to ask you (as I cannot doubt that you will have much +geological weight in N. America) to look to a discussion at page 135 +in that volume on the importance of subsidence to the formation of +deposits, which are to last to a distant age. This view strikes me as of +some importance. + +When I meet a very good-natured man I have that degree of badness of +disposition in me that I always endeavour to take advantage of him; +therefore I am going to mention some desiderata, which if you can supply +I shall be very grateful, but if not no answer will be required. + +Thank you for your "Conspectus Crust.," but I am sorry to say I am not +worthy of it, though I have always thought the Crustacea a beautiful +subject. (561/5. "Conspectus Crustaceorum in orbis terrarum +circumnavigatione, C. Wilkes duce, collectorum." Cambridge (U.S.A.), +1847.) + + +LETTER 562. TO C. LYELL. [Down, March 9th, 1850.] + +I am uncommonly much obliged to you for your address, which I had not +expected to see so soon, and which I have read with great interest. +(562/1. Anniversary Address of the President, "Quart. Journ. Geol. Soc." +Volume VI., page 32, 1850.) I do not know whether you spent much time +over it, but it strikes me as extra well arranged and written--done +in the most artistic manner, to use an expression which I particularly +hate. Though I am necessarily pretty well familiar with your ideas from +your conversation and books, yet the whole had an original freshness +to me. I am glad that you broke through the routine of the President's +addresses, but I should be sorry if others did. Your criticisms on +Murchison were to me, and I think would be to many, particularly +acceptable. (562/2. In a paper "On the Geological Structure of the Alps, +etc." ("Quart. Journ. Geol. Soc." Volume V., page 157, 1849) Murchison +expressed his belief that the apparent inversion of certain Tertiary +strata along the flanks of the Alps afforded "a clear demonstration of +a sudden operation or catastrophe." It is this view of paroxysmal energy +that Lyell criticises in the address.) Capital, that metaphor of the +clock. (562/3. "In a word, the movement of the inorganic world is +obvious and palpable, and might be likened to the minute-hand of +a clock, the progress of which can be seen and heard, whereas the +fluctuations of the living creation are nearly invisible, and resemble +the motion of the hour-hand of a timepiece" (loc. cit., page xlvi).) I +shall next February be much interested by seeing your hour-hand of the +organic world going. + +Many thanks for your kindness in taking the trouble to tell me of the +anniversary dinner. What a compliment that was which Lord Mahon paid me! +I never had so great a one. He must be as charming a man as his wife is +a woman, though I was formerly blind to his merit. Bunsen's speech must +have been very interesting and very useful, if any orthodox clergyman +were present. Your metaphor of the pebbles of pre-existing languages +reminds me that I heard Sir J. Herschel at the Cape say how he wished +some one would treat language as you had Geology, and study the existing +causes of change, and apply the deduction to old languages. + +We are all pretty flourishing here, though I have been retrograding a +little, and I think I stand excitement and fatigue hardly better than in +old days, and this keeps me from coming to London. My cirripedial task +is an eternal one; I make no perceptible progress. I am sure that they +belong to the hour-hand, and I groan under my task. + + +LETTER 563. C. LYELL TO CHARLES DARWIN. April 23rd, 1855. + +I have seen a good deal of French geologists and palaeontologists +lately, and there are many whom I should like to put on the R.S. Foreign +List, such as D'Archiac, Prevost, and others. But the man who has made +the greatest sacrifices and produced the greatest results, who has, in +fact, added a new period to the calendar, is Barrande. + +The importance of his discoveries as they stand before the public fully +justify your choice of him; but what is unpublished, and which I +have seen, is, if possible, still more surprising. Thirty genera of +gasteropods (150 species) and 150 species of lamellibranchiate bivalves +in the Silurian! All obtained by quarries opened solely by him for +fossils. A man of very moderate fortune spending nearly all his capital +on geology, and with success. + +E. Forbes' polarity doctrines are nearly overturned by the unpublished +discoveries of Barrande. (563/1. See note, Letter 41, Volume I.) + +I have called Barrande's new period Cambrian (see "Manual," 5th +edition), and you will see why. I could not name it Protozoic, but had +Barrande called it Bohemian, I must have adopted that name. All the +French will rejoice if you confer an honour on Barrande. Dana is well +worthy of being a foreign member. + +Should you succeed in making Barrande F.R.S., send me word. + + +LETTER 564. TO J.D. HOOKER. June 5th [1857]. + +(564/1. The following, which bears on the subject of medals, forms part +of the long letter printed in the "Life and Letters," II., page 100.) + +I do not quite agree with your estimate of Richardson's merits. Do, I +beg you (whenever you quietly see), talk with Lyell on Prestwich: if +he agrees with Hopkins, I am silenced; but as yet I must look at the +correlation of the Tertiaries as one of the highest and most frightfully +difficult tasks a man could set himself, and excellent work, as I +believe, P. has done. (564/2. Prof. Prestwich had published numerous +papers dealing with Tertiary Geology before 1857. The contributions +referred to are probably those "On the Correlation of the Lower +Tertiaries of England with those of France and Belgium," "Quart. Journ. +Geol. Soc." Volume X., 1854, page 454; and "On the Correlation of the +Middle Eocene Tertiaries of England, France, and Belgium," ibid., XII., +1856, page 390.) I confess I do not value Hopkins' opinion on such a +point. I confess I have never thought, as you show ought to be done, on +the future. I quite agree, under all circumstances, with the propriety +of Lindley. How strange no new geologists are coming forward! Are there +not lots of good young chemists and astronomers or physicists? Fitton +is the only old geologist left who has done good work, except Sedgwick. +Have you thought of him? He would be a brilliant companion for Lindley. +Only it would never do to give Lyell a Copley and Sedgwick a Royal in +the same year. It seems wrong that there should be three Natural Science +medals in the same year. Lindley, Sedgwick, and Bunsen sounds well, +and Lyell next year for the Copley. (564/3. In 1857 a Royal medal was +awarded to John Lindley; Lyell received the Copley in 1858, and Bunsen +in 1860.) You will see that I am speculating as a mere idle amateur. + + +LETTER 565. TO S.P. WOODWARD. Down, May 27th [1856]. + +I am very much obliged to you for having taken the trouble to answer +my query so fully. I can now be at rest, for from what you say and from +what little I remember Forbes said, my point is unanswerable. The case +of Terebratula is to the point as far as it goes, and is negative. +I have already attempted to get a solution through geographical +distribution by Dr. Hooker's means, and he finds that the same genera +which have very variable species in Europe have other very variable +species elsewhere. This seems the general rule, but with some few +exceptions. I see from the several reasons which you assign, that there +is no hope of comparing the same genus at two different periods, and +seeing whether the tendency to vary is greater at one period in such +genus than at another period. The variability of certain genera or +groups of species strikes me as a very odd fact. (565/1. The late Dr. +Neumayr has dealt, to some extent, with this subject in "Die Stamme des +Thierreichs," Volume I., Wien, 1889.) + +I shall have no points, as far as I can remember, to suggest for your +reconsideration, but only some on which I shall have to beg for a little +further information. However, I feel inclined very much to dispute your +doctrine of islands being generally ancient in comparison, I presume, +with continents. I imagine you think that islands are generally remnants +of old continents, a doctrine which I feel strongly disposed to doubt. I +believe them generally rising points; you, it seems, think them sinking +points. + + +LETTER 566. TO T.H. HUXLEY. Down, April 14th [1860]. + +Many thanks for your kind and pleasant letter. I have been much +interested by "Deep-sea Soundings,", and will return it by this post, or +as soon as I have copied a few sentences. (566/1. Specimens of the mud +dredged by H.M.S. "Cyclops" were sent to Huxley for examination, who +gave a brief account of them in Appendix A of Capt. Dayman's Report, +1858, under the title "Deep-sea Soundings in the North Atlantic.") +I think you said that some one was investigating the soundings. I +earnestly hope that you will ask the some one to carefully observe +whether any considerable number of the calcareous organisms are more or +less friable, or corroded, or scaling; so that one might form some crude +notion whether the deposition is so rapid that the foraminifera are +preserved from decay and thus are forming strata at this profound depth. +This is a subject which seems to me to have been much neglected in +examining soundings. + +Bronn has sent me two copies of his Morphologische Studien uber die +Gestaltungsgesetze." (H.G. Bronn, "Morphologische Studien uber die +Gestaltungsgesetze der Naturkorper uberhaupt und der organischen +insbesondere": Leipzig, 1858.) It looks elementary. If you will write +you shall have the copy; if not I will give it to the Linnean Library. + +I quite agree with the letter from Lyell that your extinguished +theologians lying about the cradle of each new science, etc., etc., is +splendid. (566/2. "Darwiniana, Collected Essays," Volume II., page 52.) + + +LETTER 567. TO T.H. HUXLEY. May 10th [1862 or later]. + +I have been in London, which has prevented my writing sooner. I am very +sorry to hear that you have been ill: if influenza, I can believe in any +degree of prostration of strength; if from over-work, for God's sake do +not be rash and foolish. You ask for criticisms; I have none to give, +only impressions. I fully agree with your "skimming-of-pot theory," and +very well you have put it. With respect [to] contemporaneity I nearly +agree with you, and if you will look to the d--d book, 3rd edition, page +349 you will find nearly similar remarks. (567/1. "When the marine forms +are spoken of as having changed simultaneously throughout the world, it +must not be supposed that this expression relates to the same year, or +to the same century, or even that it has a very strict geological sense; +for if all the marine animals now living in Europe, and all those that +lived in Europe during the Pleistocene period (a very remote period as +measured by years, including the whole Glacial epoch), were compared +with those now existing in South America or in Australia, the most +skilful naturalist would hardly be able to say whether the present or +the Pleistocene inhabitants of Europe resembled most closely those of +the Southern hemisphere." "Origin," Edition VI., page 298. The passage +in Edition III., page 350, is substantially the same.) But at page 22 +of your Address, in my opinion you put your ideas too far. (567/2. +Anniversary Address to the Geological Society of London ("Quart. Journ. +Geol. Soc." Volume XVIII., page xl, 1862). As an illustration of the +misleading use of the term "contemporaneous" as employed by geologists, +Huxley gives the following illustration: "Now suppose that, a million +or two of years hence, when Britain has made another dip beneath the sea +and has come up again, some geologist applies this doctrine [i.e., +the doctrine of the Contemporaneity of the European and of the North +American Silurians: proof of contemporaneity is considered to be +established by the occurrence of 60 per cent. of species in common], in +comparing the strata laid bare by the upheaval of the bottom, say, of +St. George's Channel with what may then remain of the Suffolk Crag. +Reasoning in the same way, he will at once decide the Suffolk Crag and +the St. George's Channel beds to be contemporaneous; although we happen +to know that a vast period...of time...separates the two" (loc. cit., +page xlv). This address is republished in the "Collected Essays," Volume +VIII.; the above passage is at page 284.) I cannot think that +future geologists would rank the Suffolk and St. George's strata as +contemporaneous, but as successive sub-stages; they rank N. America +and British stages as contemporaneous, notwithstanding a percentage +of different species (which they, I presume, would account for by +geographical difference) owing to the parallel succession of the forms +in both countries. For terrestrial productions I grant that great errors +may creep in (567/3. Darwin supposes that terrestrial productions have +probably not changed to the same extent as marine organisms. "If the +Megatherium, Mylodon...had been brought to Europe from La Plata, without +any information in regard to their geological position, no one would +have suspected that they had co-existed with sea shells all still +living" ("Origin," Edition VI., page 298).); but I should require +strong evidence before believing that, in countries at all well-known, +so-called Silurian, Devonian, and Carboniferous strata could +be contemporaneous. You seem to me on the third point, viz., on +non-advancement of organisation, to have made a very strong case. I have +not knowledge or presumption enough to criticise what you say. I have +said what I could at page 363 of "Origin." It seems to me that the whole +case may be looked at from several points of view. I can add only +one miserable little special case of advancement in cirripedes. The +suspicion crosses me that if you endeavoured your best you would say +more on the other side. Do you know well Bronn in his last Entwickelung +(or some such word) on this subject? it seemed to me very well done. +(567/4. Probably "Untersuchungen uber die Entwickelungsgesetze der +organischen Welt wahrend der Bildungszeit unserer Erdoberflache," +Stuttgart, 1858. Translated by W.S. Dallas in the "Ann. and Mag. Nat. +Hist." Volume IV., page 81.) I hope before you publish again you will +read him again, to consider the case as if you were a judge in a court +of appeal; it is a very important subject. I can say nothing against +your side, but I have an "inner consciousness" (a highly philosophical +style of arguing!) that something could be said against you; for I +cannot help hoping that you are not quite as right as you seem to be. +Finally, I cannot tell why, but when I finished your Address I felt +convinced that many would infer that you were dead against change of +species, but I clearly saw that you were not. I am not very well, so +good-night, and excuse this horrid letter. + + +LETTER 568. TO J.D. HOOKER. Down, June 30th [1866]. + +I have heard from Sulivan (who, poor fellow, gives a very bad account +of his own health) about the fossils (568/1. In a letter to Huxley (June +4th, 1866) Darwin wrote: "Admiral Sulivan several years ago discovered +an astonishingly rich accumulation of fossil bones not far from the +Straits [of Magellan]...During many years it has seemed to me extremely +desirable that these should be collected; and here is an excellent +opportunity.")... The place is Gallegos, on the S. coast of Patagonia. +Sulivan says that in the course of two or three days all the boats in +the ship could be filled twice over; but to get good specimens out of +the hardish rock two or three weeks would be requisite. It would be a +grand haul for Palaeontology. I have been thinking over your lecture. +(568/2. A lecture on "Insular Floras" given at the British Association +meeting at Nottingham, August 27th, 1866, published in the "Gard. +Chron." 1867.) Will it not be possible to give enlarged drawings of +some leading forms of trees? You will, of course, have a large map, and +George tells me that he saw at Sir H. James', at Southampton, a map of +the world on a new principle, as seen from within, so that almost 4/5ths +of the globe was shown at once on a large scale. Would it not be worth +while to borrow one of these from Sir H. James as a curiosity to hang +up? + +Remember you are to come here before Nottingham. I have almost finished +the last number of H. Spencer, and am astonished at its prodigality of +original thought. But the reflection constantly recurred to me that each +suggestion, to be of real value to science, would require years of work. +It is also very unsatisfactory, the impossibility of conjecturing where +direct action of external circumstances begins and ends--as he candidly +owns in discussing the production of woody tissue in the trunks of trees +on the one hand, and on the other in spines and the shells of nuts. I +shall like to hear what you think of this number when we meet. + + +LETTER 569. TO A. GAUDRY. Down, November 17th, 1868. + +On my return home after a short absence I found your note of Nov. 9th, +and your magnificent work on the fossil animals of Attica. (569/1. The +"Geologie de l'Attique," 2 volumes 4to, 1862-7, is the only work of +Gaudry's of this date in Mr. Darwin's library.) I assure you that I feel +very grateful for your generosity, and for the honour which you have +thus conferred on me. I know well, from what I have already read of +extracts, that I shall find your work a perfect mine of wealth. One long +passage which Sir C. Lyell quotes from you in the 10th and last edition +of the "Principles of Geology" is one of the most striking which I +have ever read on the affiliation of species. (569/2. The quotation +in Lyell's "Principles," Edition X., Volume II., page 484, is from M. +Gaudry's "Animaux Fossiles de Pikermi," 1866, page 34:-- + +"In how different a light does the question of the nature of species now +present itself to us from that in which it appeared only twenty years +ago, before we had studied the fossil remains of Greece and the allied +forms of other countries. How clearly do these fossil relics point to +the idea that species, genera, families, and orders now so distinct have +had common ancestors. The more we advance and fill up the gaps, the more +we feel persuaded that the remaining voids exist rather in our knowledge +than in nature. A few blows of the pickaxe at the foot of the Pyrenees, +of the Himalaya, of Mount Pentelicus in Greece, a few diggings in the +sandpits of Eppelsheim, or in the Mauvaises Terres of Nebraska, have +revealed to us the closest connecting links between forms which seemed +before so widely separated. How much closer will these links be drawn +when Palaeontology shall have escaped from its cradle!") + + +LETTER 570. A. SEDGWICK TO CHARLES DARWIN. + +(570/1. In May, 1870, Darwin "went to the Bull Hotel, Cambridge, to see +the boys, and for a little rest and enjoyment." (570/2. See "Life and +Letters," III., 125.) The following letter was received after his return +to Down.) + +Trinity College, Cambridge, May 30th, 1870. + +My dear Darwin, + +Your very kind letter surprised me. Not that I was surprised at the +pleasant and very welcome feeling with which it was written. But I could +not make out what I had done to deserve the praise of "extraordinary +kindness to yourself and family." I would most willingly have done +my best to promote the objects of your visit, but you gave me no +opportunity of doing so. I was truly grieved to find that my joy at +seeing you again was almost too robust for your state of nerves, and +that my society, after a little while, became oppressive to you. But I +do trust that your Cambridge visit has done you no constitutional harm; +nay, rather that it has done you some good. I only speak honest truth +when I say that I was overflowing with joy when I saw you, and saw you +in the midst of a dear family party, and solaced at every turn by +the loving care of a dear wife and daughters. How different from my +position--that of a very old man, living in cheerless solitude! May god +help and cheer you all with the comfort of hopeful hearts--you and your +wife, and your sons and daughters! + +You were talking about my style of writing,--I send you my last +specimen, and it will probably continue to be my last. It is the +continuation of a former pamphlet of which I have not one spare copy. +I do not ask you to read it. It is addressed to the old people in my +native Dale of Dent, on the outskirts of Westmorland. While standing +at the door of the old vicarage, I can see down the valley the Lake +mountains--Hill Bell at the head of Windermere, about twenty miles off. +On Thursday next (D.V.) I am to start for Dent, which I have not visited +for full two years. Two years ago I could walk three or four miles with +comfort. Now, alas! I can only hobble about on my stick. + +I remain your true-hearted old friend A. Sedgwick. + + +LETTER 571. TO C. LYELL. Down, September 3rd [1874]. + +Many thanks for your very kind and interesting letter. I was glad to +hear at Southampton from Miss Heathcote a good account of your health +and strength. + +With respect to the great subject to which you refer in your P.S., +I always try to banish it from my mind as insoluble; but if I were +circumstanced as you are, no doubt it would recur in the dead of the +night with painful force. Many persons seem to make themselves quite +easy about immortality (571/1. See "Life and Letters," I., page 312.) +and the existence of a personal God, by intuition; and I suppose that I +must differ from such persons, for I do not feel any innate conviction +on any such points. + +We returned home about ten days ago from Southampton, and I enjoyed +my holiday, which did me much good. But already I am much fatigued by +microscope and experimental work with insect-eating plants. + +When at Southampton I was greatly interested by looking at the odd +gravel deposits near at hand, and speculating about their formation. You +once told me something about them, but I forget what; and I think that +Prestwich has written on the superficial deposits on the south coasts, +and I must find out his paper and read it. (571/2. Prof. Prestwich +contributed several papers to the Geological Society on the Superficial +Deposits of the South of England.) + +From what I have seen of Mr. Judd's papers I have thought that he would +rank amongst the few leading British geologists. + + +LETTER 572. TO J.D. HOOKER. + +(572/1. The following letter was written before Mr. Darwin knew that Sir +Charles Lyell was to be buried in Westminster Abbey, a memorial which +thoroughly satisfied him. See "Life and Letters," III., 197.) + +Down, February 23rd, 1875. + +I have just heard from Miss Buckley of Lyell's death. I have long felt +opposed to the present rage for testimonials; but when I think how +Lyell revolutionised Geology, and aided in the progress of so many other +branches of science, I wish that something could be done in his honour. +On the other hand it seems to me that a poor testimonial would be worse +than none; and testimonials seem to succeed only when a man has been +known and loved by many persons, as in the case of Falconer and Forbes. +Now, I doubt whether of late years any large number of scientific men +did feel much attachment towards Lyell; but on this head I am very ill +fitted to judge. I should like to hear some time what you think, and if +anything is proposed I should particularly wish to join in it. We have +both lost as good and as true a friend as ever lived. + + +LETTER 573. TO J.D. HOOKER. + +(573/1. This letter shows the difficulty which the inscription for Sir +Charles Lyell's memorial gave his friends. The existing inscription is, +"Charles Lyell...Author of 'The Principles of Geology'...Throughout +a long and laborious life he sought the means of deciphering the +fragmentary records of the Earth's history in the patient investigation +of the present order of Nature, enlarging the boundaries of knowledge, +and leaving on Scientific thought an enduring influence..." + +Down, June 21st [1876]. + +I am sorry for you about the inscription, which has almost burst me. We +think there are too many plurals in yours, and when read aloud it hisses +like a goose. I think the omission of some words makes it much stronger. +"World" (573/2. The suggested sentence runs: "he gave to the world the +results of his labour, etc.") is much stronger and truer than "public." +As Lyell wrote various other books and memoirs, I have some little +doubt about the "Principles of Geology." People here do not like your +"enduring value": it sounds almost an anticlimax. They do not much like +my "last (or endure) as long as science lasts." If one reads a sentence +often enough, it always becomes odious. + +God help you. + + +LETTER 574. TO OSWALD HEER. Down, March 8th [1875]. + +I thank you for your very kind and deeply interesting letter of March +1st, received yesterday, and for the present of your work, which no +doubt I shall soon receive from Dr. Hooker. (574/1. "Flora Fossilis +Arctica," Volume III., 1874, sent by Prof. Heer through Sir Joseph +Hooker.) The sudden appearance of so many Dicotyledons in the Upper +Chalk appears to me a most perplexing phenomenon to all who believe +in any form of evolution, especially to those who believe in extremely +gradual evolution, to which view I know that you are strongly opposed. +(574/2. The volume referred to contains a paper on the Cretaceous +Flora of the Arctic Zone (Spitzbergen and Greenland), in which several +dicotyledonous plants are described. In a letter written by Heer to +Darwin the author speaks of a species of poplar which he describes as +the oldest Dicotyledon so far recorded.) The presence of even one true +Angiosperm in the Lower Chalk makes me inclined to conjecture that +plants of this great division must have been largely developed in +some isolated area, whence owing to geographical changes, they at last +succeeded in escaping, and spread quickly over the world. (574/3. No +satisfactory evidence has so far been brought forward of the occurrence +of fossil Angiosperms in pre-Cretaceous rocks. The origin of the +Monocotyledons and Dicotyledons remains one of the most difficult and +attractive problems of Palaeobotany.) (574/4. See Letters 395, 398.) But +I fully admit that this case is a great difficulty in the views which I +hold. Many as have been the wonderful discoveries in Geology during the +last half-century, I think none have exceeded in interest your results +with respect to the plants which formerly existed in the Arctic regions. +How I wish that similar collections could be made in the Southern +hemisphere, for instance in Kerguelen's Land. + +The death of Sir C. Lyell is a great loss to science, but I do not think +to himself, for it was scarcely possible that he could have retained his +mental powers, and he would have suffered dreadfully from their loss. +The last time I saw him he was speaking with the most lively interest +about his last visit to you, and I was grieved to hear from him a very +poor account of your health. I have been working for some time on a +special subject, namely insectivorous plants. I do not know whether the +subject will interest you, but when my book is published I will have the +pleasure of sending you a copy. + +I am very much obliged for your photograph, and enclose one of myself. + + +LETTER 574*. TO S.B.J. SKERTCHLY. March 2nd, 1878. + +It is the greatest possible satisfaction to a man nearly at the close +of his career to believe that he has aided or stimulated an able and +energetic fellow-worker in the noble cause of science. Therefore your +letter has deeply gratified me. I am writing this away from home, as my +health failed, and I was forced to rest; and this will account for the +delay in answering your letter. No doubt on my return home I shall find +the memoir which you have kindly sent me. I shall read it with much +interest, as I have heard something of your work from Prof. Geikie, and +have read his admirable "Ice Age." (574/5. "The Great Ice Age and its +Relation to the Antiquity of Man": London, 1874. By James Geikie.) I +have noticed the criticisms on your work, but such opposition must +be expected by every one who draws fine grand conclusions, and such +assuredly are yours as abstracted in your letter. (574/6. Mr. S.B.J. +Skertchly recorded "the discovery of palaeolithic flint implements, +mammalian bones, and fresh-water shells in brick-earths below the +Boulder-clay of East Anglia," in a letter published in the "Geol. Mag." +Volume III., page 476, 1876. (See also "The Fenland, Past and Present." +S.H. Miller and S.B.J. Skertchly, London, 1878.) The conclusions of Mr. +Skertchly as to the pre-Glacial age of the flint implements were not +accepted by some authorities. (See correspondence in "Nature," Volume +XV., 1877, pages 141, 142.) We are indebted to Mr. Marr for calling +our attention to Mr. Skertchly's discovery.) What magnificent progress +Geology has made within my lifetime! + +I shall have very great pleasure in sending you any of my books with my +autograph, but I really do not know which to send. It will cost you only +the trouble of a postcard to tell me which you would like, and it shall +soon be sent. Forgive this untidy note, as it is rather an effort to +write. + +With all good wishes for your continued success in science and for your +happiness... + + + +CHAPTER 2.X.--BOTANY, 1843-1871. + +2.X.I. Miscellaneous.--2.X.II. Melastomaceae.--2.X.III. Correspondence +with John Scott. + + +2.X.I. MISCELLANEOUS, 1843-1862. + +(PLATE: SIR JOSEPH HOOKER, 1897. From a Photograph by W.J. Hawker +Wimborne. Walker & Cockerell, ph. sc.) + + +LETTER 575. TO WILLIAM JACKSON HOOKER. Down, March 12th [1843]. + +...When you next write to your son, will you please remember me kindly +to him and give him my best thanks for his note? I had the pleasure +yesterday of reading a letter from him to Mr. Lyell of Kinnordy, full of +the most interesting details and descriptions, and written (if I may be +permitted to make such a criticism) in a particularly agreeable style. +It leads me anxiously to hope, even more than I did before, that he will +publish some separate natural history journal, and not allow (if it can +be avoided) his materials to be merged in another work. I am very glad +to hear you talk of inducing your son to publish an Antarctic Flora. +I have long felt much curiosity for some discussion on the general +character of the flora of Tierra del Fuego, that part of the globe +farthest removed in latitude from us. How interesting will be a strict +comparison between the plants of these regions and of Scotland and +Shetland. I am sure I may speak on the part of Prof. Henslow that all +my collection (which gives a fair representation of the Alpine flora of +Tierra del Fuego and of Southern Patagonia) will be joyfully laid at his +disposal. + + +LETTER 576. TO JOHN LINDLEY. Down, Saturday [April 8th, 1843]. + +I take the liberty, at the suggestion of Dr. Royle, of forwarding to you +a few seeds, which have been found under very singular circumstances. +They have been sent to me by Mr. W. Kemp, of Galashiels, a (partially +educated) man, of whose acuteness and accuracy of observation, from +several communications on geological subjects, I have a VERY HIGH +opinion. He found them in a layer under twenty-five feet thickness of +white sand, which seems to have been deposited on the margins of an +anciently existing lake. These seeds are not known to the provincial +botanists of the district. He states that some of them germinated in +eight days after being planted, and are now alive. Knowing the interest +you took in some raspberry seeds, mentioned, I remember, in one of your +works, I hope you will not think me troublesome in asking you to have +these seeds carefully planted, and in begging you so far to oblige me as +to take the trouble to inform me of the result. Dr. Daubeny has started +for Spain, otherwise I would have sent him some. Mr. Kemp is anxious to +publish an account of his discovery himself, so perhaps you will be so +kind as to communicate the result to me, and not to any periodical. The +chance, though appearing so impossible, of recovering a plant lost to +any country if not to the world, appears to me so very interesting, that +I hope you will think it worth while to have these seeds planted, and +not returned to me. + + +LETTER 577. TO C. LYELL. [September, 1843.] + +An interesting fact has lately, as it were, passed through my hands. A +Mr. Kemp (almost a working man), who has written on "parallel roads," +and has corresponded with me (577/1. In a letter to Henslow, Darwin +wrote: "If he [Mr. Kemp] had not shown himself a most careful and +ingenious observer, I should have thought nothing of the case."), sent +me in the spring some seeds, with an account of the spot where they +were found, namely, in a layer at the bottom of a deep sand pit, near +Melrose, above the level of the river, and which sand pit he thinks must +have been accumulated in a lake, when the whole features of the valleys +were different, ages ago; since which whole barriers of rock, it +appears, must have been worn down. These seeds germinated freely, and +I sent some to the Horticultural Society, and Lindley writes to me that +they turn out to be a common Rumex and a species of Atriplex, which +neither he nor Henslow (as I have since heard) have ever seen, and +certainly not a British plant! Does this not look like a vivification of +a fossil seed? It is not surprising, I think, that seeds should last ten +or twenty thousand [years], as they have lasted two or three [thousand +years] in the Druidical mounds, and have germinated. + +When not building, I have been working at my volume on the volcanic +islands which we visited; it is almost ready for press...I hope you will +read my volume, for, if you don't, I cannot think of anyone else who +will! We have at last got our house and place tolerably comfortable, and +I am well satisfied with our anchorage for life. What an autumn we have +had: completely Chilian; here we have had not a drop of rain or a cloudy +day for a month. I am positively tired of the fine weather, and long for +the sight of mud almost as much as I did when in Peru. + +(577/2. The vitality of seeds was a subject in which Darwin continued to +take an interest. In July, 1855 ("Life and Letters," II., page 65), +he wrote to Hooker: "A man told me the other day of, as I thought, a +splendid instance--and splendid it was, for according to his evidence +the seed came up alive out of the lower part of the London Clay! I +disgusted him by telling him that palms ought to have come up." + +In the "Gardeners' Chronicle," 1855, page 758, appeared a notice (half +a column in length) by Darwin on the "Vitality of Seeds." The facts +related refer to the "Sand-walk" at Down; the wood was planted in 1846 +on a piece of pasture land laid down as grass in 1840. In 1855, on the +soil being dug in several places, Charlock (Brassica sinapistrum) sprang +up freely. The subject continued to interest him, and we find a note +dated July 2nd, 1874, in which Darwin recorded that forty-six plants +of Charlock sprang up in that year over a space (14 x 7 feet) which had +been dug to a considerable depth. In the course of the article in the +"Gardeners' Chronicle," Darwin remarks: "The power in seeds of retaining +their vitality when buried in damp soil may well be an element in +preserving the species, and therefore seeds may be specially endowed +with this capacity; whereas the power of retaining vitality in a dry +artificial condition must be an indirect, and in one sense accidental, +quality in seeds of little or no use to the species." + +The point of view expressed in the letter to Lyell above given is of +interest in connection with the research of Horace Brown and F. Escombe +(577/3. "Proc. Roy. Soc." Volume LXII., page 160.) on the remarkable +power possessed by dry seeds of resistance to the temperature of liquid +air. The point of the experiment is that life continues at a temperature +"below that at which ordinary chemical reactions take place." A still +more striking demonstration of the fact has been made by Thiselton-Dyer +and Dewar who employed liquid hydrogen as a refrigerant. (577/4. Read +before the British Association (Dover), 1899, and published in the +"Comptes rendus," 1899, and in the "Proc. R. Soc." LXV., page 361, +1899.) The connection between these facts and the dormancy of buried +seeds is only indirect; but inasmuch as the experiment proves the +possibility of life surviving a period in which no ordinary chemical +change occurs, it is clear that they help one to believe in greatly +prolonged dormancy in conditions which tend to check metabolism. For a +discussion of the bearing of their results on the life-problem, and for +the literature of the subject, reference should be made to the paper by +Brown and Escombe. See also C. de Candolle "On Latent Life in Seeds," +"Brit. Assoc. Report," 1896, page 1023 and F. Escombe, "Science +Progress," Volume I., N.S., page 585, 1897.) + + +LETTER 578. TO J.S. HENSLOW. Down, Saturday [November 5th, 1843]. + +I sent that weariful Atriplex to Babington, as I said I would, and +he tells me that he has reared a facsimile by sowing the seeds of A. +angustifolia in rich soil. He says he knows the A. hastata, and that it +is very different. Until your last note I had not heard that Mr. Kemp's +seeds had produced two Polygonums. He informs me he saw each plant bring +up the husk of the individual seed which he planted. I believe myself in +his accuracy, but I have written to advise him not to publish, for as +he collected only two kinds of seeds--and from them two Polygomuns, two +species or varieties of Atriplex and a Rumex have come up, any one would +say (as you suggested) that more probably all the seeds were in the +soil, than that seeds, which must have been buried for tens of thousands +of years, should retain their vitality. If the Atriplex had turned out +new, the evidence would indeed have been good. I regret this result of +poor Mr. Kemp's seeds, especially as I believed, from his statements and +the appearance of the seeds, that they did germinate, and I further have +no doubt that their antiquity must be immense. I am sorry also for the +trouble you have had. I heard the other day through a circuitous course +how you are astonishing all the clodhoppers in your whole part of the +county: and [what is] far more wonderful, as it was remarked to me, that +you had not, in doing this, aroused the envy of all the good surrounding +sleeping parsons. What good you must do to the present and all +succeeding generations. (578/1. For an account of Professor Henslow's +management of his parish of Hitcham see "Memoir of the Rev. John Stevens +Henslow, M.A." by the Rev. Leonard Jenyns: 8vo, London, 1862.) + + +LETTER 579. TO J.D. HOOKER. Down, November 14th [1855]. + +You well know how credulous I am, and therefore you will not be +surprised at my believing the Raspberry story (579/1. This probably +refers to Lindley's story of the germination of raspberry seeds taken +from a barrow 1600 years old.): a very similar case is on record in +Germany--viz., seeds from a barrow; I have hardly zeal to translate it +for the "Gardeners' Chronicle." (579/2. "Vitality of Seeds," "Gardeners' +Chronicle," November 17th, 1855, page 758.) I do not go the whole +hog--viz., that sixty and two thousand years are all the same, for I +should imagine that some slight chemical change was always going on in a +seed. Is this not so? The discussions have stirred me up to send my very +small case of the charlock; but as it required some space to give all +details, perhaps Lindley will not insert; and if he does, you, you worse +than an unbelieving dog, will not, I know, believe. The reason I do +not care to try Mr. Bentham's plan is that I think it would be very +troublesome, and it would not, if I did not find seed, convince me +myself that none were in the earth, for I have found in my salting +experiments that the earth clings to the seeds, and the seeds are very +difficult to find. Whether washing would do I know not; a gold-washer +would succeed, I daresay. + + +LETTER 580. TO W.J. HOOKER. + +Testimonial from Charles Darwin, Esq., M.A., F.R.S. and G.S., late +Naturalist to Captain Fitz-Roy's Voyage. + +Down House, Farnborough, August 25th, 1845. + +I have heard with much interest that your son, Dr. Hooker, is a +candidate for the Botanical Chair at Edinburgh. From my former +attendance at that University, I am aware how important a post it is for +the advancement of science, and I am therefore the more anxious for your +son's success, from my firm belief that no one will fulfil its duties +with greater zeal or ability. Since his return from the famous Antarctic +expedition, I have had, as you are aware, much communication with him, +with respect to the collections brought home by myself, and on other +scientific subjects; and I cannot express too strongly my admiration +at the accuracy of his varied knowledge, and at his powers of +generalisation. From Dr. Hooker's disposition, no one, in my opinion, +is more fitted to communicate to beginners a strong taste for those +pursuits to which he is himself so ardently devoted. For the sake of +the advancement of Botany in all its branches, your son has my warmest +wishes for his success. + + +LETTER 581. TO J.D. HOOKER. Down, Thursday [June 11th, 1847]. + +Many thanks for your kindness about the lodgings--it will be of great +use to me. (581/1. The British Association met at Oxford in 1847.) +Please let me know the address if Mr. Jacobson succeeds, for I think I +shall go on the 22nd and write previously to my lodgings. I have since +had a tempting invitation from Daubeny to meet Henslow, etc., but upon +the whole, I believe, lodgings will answer best, for then I shall have a +secure solitary retreat to rest in. + +I am extremely glad I sent the Laburnum (581/2. This refers to the +celebrated form known as Cytisus Adami, of which a full account is given +in "Variation of Animals and Plants," Volume I., Edition II., page 413. +It has been supposed to be a seminal hybrid or graft-hybrid between C. +laburnum and C. purpureus. It is remarkable for bearing "on the same +tree tufts of dingy red, bright yellow, and purple flowers, borne on +branches having widely different leaves and manner of growth." In a +paper by Camuzet in the "Annales de la Societe d'Horticulture de Paris, +XIII., 1833, page 196, the author tries to show that Cytisus Adami is +a seminal hybrid between C. alpinus and C. laburnum. Fuchs ("Sitz. k. +Akad. Wien," Bd. 107) and Beijerinck ("K. Akad. Amsterdam," 1900) have +spoken on Cytisus Adami, but throw no light on the origin of the hybrid. +See letters to Jenner Weir in the present volume.): the raceme grew in +centre of tree, and had a most minute tuft of leaves, which presented +no unusual appearance: there is now on one raceme a terminal bilateral +[i.e., half yellow, half purple] flower, and on other raceme a single +terminal pure yellow and one adjoining bilateral flower. If you would +like them I will send them; otherwise I would keep them to see whether +the bilateral flowers will seed, for Herbert (581/3. Dean Herbert.) says +the yellow ones will. Herbert is wrong in thinking there are no somewhat +analogous facts: I can tell you some, when we meet. I know not whether +botanists consider each petal and stamen an individual; if so, there +seems to me no especial difficulty in the case, but if a flower-bud is a +unit, are not their flowers very strange? + +I have seen Dillwyn in the "Gardeners' Chronicle," and was disgusted +at it, for I thought my bilateral flowers would have been a novelty for +you. + +(581/4. In a letter to Hooker, dated June 2nd, 1847, Darwin makes a bold +suggestion as to floral symmetry:--) + +I send you a tuft of the quasi-hybrid Laburnum, with two kinds of +flowers on same stalk, and with what strikes [me] as very curious +(though I know it has been observed before), namely, a flower +bilaterally different: one other, I observe, has half its calyx purple. +Is this not very curious, and opposed to the morphological idea that a +flower is a condensed continuous spire of leaves? Does it not look as +if flowers were normally bilateral; just in the same way as we now know +that the radiating star-fish, etc., are bilateral? The case reminds me +of those insects with exactly half having secondary male characters and +the other half female. + +(581/5. It is interesting to note his change of view in later years. +In an undated letter written to Mr. Spencer, probably in 1873, he +says: "With respect to asymmetry in the flowers themselves, I remain +contented, from all that I have seen, with adaptation to visits of +insects. There is, however, another factor which it is likely enough may +have come into play--viz., the protection of the anthers and pollen +from the injurious effects of rain. I think so because several flowers +inhabiting rainy countries, as A. Kerner has lately shown, bend their +heads down in rainy weather.") + + +LETTER 582. TO J.D. HOOKER. June [1855]. + +(582/1. This is an early example of Darwin's interest in the movements +of plants. Sleeping plants, as is well-known, may acquire a rhythmic +movement differing from their natural period, but the precise experiment +here described has not, as far as known, been carried out. See Pfeffer, +"Periodische Bewegungen," 1875, page 32.) + +I thank you much for Hedysarum: I do hope it is not very precious, +for, as I told you, it is for probably a most foolish purpose. I read +somewhere that no plant closes its leaves so promptly in darkness, and I +want to cover it up daily for half an hour, and see if I can TEACH IT to +close by itself, or more easily than at first in darkness. I am rather +puzzled about its transmission, from not knowing how tender it is... + + +LETTER 583. TO J.D. HOOKER. Down, July 19th, 1856. + +I thank you warmly for the very kind manner with which you have taken my +request. It will, in truth, be a most important service to me; for it is +absolutely necessary that I should discuss single and double creations, +as a very crucial point on the general origin of species, and I must +confess, with the aid of all sorts of visionary hypotheses, a very +hostile one. I am delighted that you will take up possibility of +crossing, no botanist has done so, which I have long regretted, and I am +glad to see that it was one of A. De Candolle's desiderata. By the way, +he is curiously contradictory on subject. I am far from expecting that +no cases of apparent impossibility will be found; but certainly I expect +that ultimately they will disappear; for instance, Campanulaceae seems +a strong case, but now it is pretty clear that they must be liable to +crossing. Sweet-peas (583/1. In Lathyrus odoratus the absence of the +proper insect has been supposed to prevent crossing. See "Variation +under Domestication," Edition II., Volume II., page 68; but the +explanation there given for Pisum may probably apply to Lathyrus.), +bee-orchis, and perhaps hollyhocks are, at present, my greatest +difficulties; and I find I cannot experimentise by castrating +sweet-peas, without doing fatal injury. Formerly I felt most interest +on this point as one chief means of eliminating varieties; but I feel +interest now in other ways. One general fact [that] makes me believe in +my doctrine (583/2. The doctrine which has been epitomised as "Nature +abhors perpetual self-fertilisation," and is generally known as +Knight's Law or the Knight-Darwin Law, is discussed by Francis Darwin in +"Nature," 1898. References are there given to the chief passages in +the "Origin of Species," etc., bearing on the question. See Letter 19, +Volume I.), is that NO terrestrial animal in which semen is liquid is +hermaphrodite except with mutual copulation; in terrestrial plants in +which the semen is dry there are many hermaphrodites. Indeed, I do wish +I lived at Kew, or at least so that I could see you oftener. To return +again to subject of crossing: I have been inclined to speculate so far, +as to think (my!?) notion (I say MY notion, but I think others have put +forward nearly or quite similar ideas) perhaps explains the frequent +separation of the sexes in trees, which I think I have heard remarked +(and in looking over the mono- and dioecious Linnean classes in Persoon +seems true) are very apt to have sexes separated; for [in] a tree having +a vast number of flowers on the same individual, or at least the same +stock, each flower, if only hermaphrodite on the common plan, would +generally get its own pollen or only pollen from another flower on +same stock,--whereas if the sexes were separate there would be a better +chance of occasional pollen from another distinct stock. I have thought +of testing this in your New Zealand Flora, but I have no standard of +comparison, and I found myself bothered by bushes. I should propound +that some unknown causes had favoured development of trees and bushes +in New Zealand, and consequent on this there had been a development +of separation of sexes to prevent too much intermarriage. I do not, of +course, suppose the prevention of too much intermarriage the only good +of separation of sexes. But such wild notions are not worth troubling +you with the reading of. + + +LETTER 584. TO J.D. HOOKER. Moor Park [May 2nd, 1857]. + +The most striking case, which I have stumbled on, on apparent, but +false relation of structure of plants to climate, seems to be Meyer +and Doege's remark that there is not one single, even moderately-sized, +family at the Cape of Good Hope which has not one or several species +with heath-like foliage; and when we consider this together with the +number of true heaths, any one would have been justified, had it not +been for our own British heaths (584/1. It is well known that plants +with xerophytic characteristics are not confined to dry climates; it +is only necessary to mention halophytes, alpine plants and certain +epiphytes. The heaths of Northern Europe are placed among the xerophytes +by Warming ("Lehrbuch der okologischen Pflanzengeographie," page 234, +Berlin, 1896).), in saying that heath-like foliage must stand in direct +relation to a dry and moderately warm climate. Does this not strike you +as a good case of false relation? I am so pleased with this place and +the people here, that I am greatly tempted to bring Etty here, for she +has not, on the whole, derived any benefit from Hastings. With thanks +for your never failing assistance to me... + +I remember that you were surprised at number of seeds germinating in +pond mud. I tried a fourth pond, and took about as much mud (rather +more than in former case) as would fill a very large breakfast cup, and +before I had left home 118 plants had come up; how many more will be up +on my return I know not. This bears on chance of birds by their muddy +feet transporting fresh-water plants. + +This would not be a bad dodge for a collector in country when plants +were not in seed, to collect and dry mud from ponds. + + +LETTER 585. TO ASA GRAY. Down [1857]. + +I am very glad to hear that you think of discussing the relative ranges +of the identical and allied U. States and European species, when +you have time. Now this leads me to make a very audacious remark in +opposition to what I imagine Hooker has been writing (585/1. See Letter +338, Volume I.), and to your own scientific conscience. I presume he +has been urging you to finish your great "Flora" before you do anything +else. Now I would say it is your duty to generalise as far as you safely +can from your as yet completed work. Undoubtedly careful discrimination +of species is the foundation of all good work; but I must look at such +papers as yours in Silliman as the fruit. As careful observation is far +harder work than generalisation, and still harder than speculation, do +you not think it very possible that it may be overvalued? It ought never +to be forgotten that the observer can generalise his own observations +incomparably better than any one else. How many astronomers have +laboured their whole lives on observations, and have not drawn a single +conclusion; I think it is Herschel who has remarked how much better it +would be if they had paused in their devoted work and seen what they +could have deduced from their work. So do pray look at this side of the +question, and let us have another paper or two like the last admirable +ones. There, am I not an audacious dog! + +You ask about my doctrine which led me to expect that trees would tend +to have separate sexes. I am inclined to believe that no organic being +exists which perpetually self-fertilises itself. This will appear very +wild, but I can venture to say that if you were to read my observations +on this subject you would agree it is not so wild as it will at first +appear to you, from flowers said to be always fertilised in bud, etc. It +is a long subject, which I have attended to for eighteen years. Now, it +occurred to me that in a large tree with hermaphrodite flowers, we will +say it would be ten to one that it would be fertilised by the pollen of +its own flower, and a thousand or ten thousand to one that if crossed +it would be crossed only with pollen from another flower of same tree, +which would be opposed to my doctrine. Therefore, on the great principle +of "Nature not lying," I fully expected that trees would be apt to be +dioecious or monoecious (which, as pollen has to be carried from flower +to flower every time, would favour a cross from another individual of +the same species), and so it seems to be in Britain and New Zealand. Nor +can the fact be explained by certain families having this structure +and chancing to be trees, for the rule seems to hold both in genera and +families, as well as in species. + +I give you full permission to laugh your fill at this wild speculation; +and I do not pretend but what it may be chance which, in this case, has +led me apparently right. But I repeat that I feel sure that my doctrine +has more probability than at first it appears to have. If you had not +asked, I should not have written at such length, though I cannot give +any of my reasons. + +The Leguminosae are my greatest opposers: yet if I were to trust to +observations on insects made during many years, I should fully expect +crosses to take place in them; but I cannot find that our garden +varieties ever cross each other. I do NOT ask you to take any trouble +about it, but if you should by chance come across any intelligent +nurseryman, I wish you would enquire whether they take any pains +in raising the varieties of papilionaceous plants apart to prevent +crossing. (I have seen a statement of naturally formed crossed Phaseoli +near N. York.) The worst is that nurserymen are apt to attribute all +varieties to crossing. + +Finally I incline to believe that every living being requires an +occasional cross with a distinct individual; and as trees from the mere +multitude of flowers offer an obstacle to this, I suspect this obstacle +is counteracted by tendency to have sexes separated. But I have +forgotten to say that my maximum difficulty is trees having +papilionaceous flowers: some of them, I know, have their keel-petals +expanded when ready for fertilisation; but Bentham does not believe +that this is general: nevertheless, on principle of nature not lying, I +suspect that this will turn out so, or that they are eminently sought by +bees dusted with pollen. Again I do NOT ask you to take trouble, but if +strolling under your Robinias when in full flower, just look at stamens +and pistils whether protruded and whether bees visit them. I must just +mention a fact mentioned to me the other day by Sir W. Macarthur, a +clever Australian gardener: viz., how odd it was that his Erythrinas in +N.S. Wales would not set a seed, without he imitated the movements of +the petals which bees cause. Well, as long as you live, you will never, +after this fearfully long note, ask me why I believe this or that. + + +LETTER 586. TO ASA GRAY. June 18th [1857]. + +It has been extremely kind of you telling me about the trees: now with +your facts, and those from Britain, N. Zealand, and Tasmania I shall +have fair materials for judging. I am writing this away from home, but +I think your fraction of 95/132 is as large as in other cases, and is at +least a striking coincidence. + +I thank you much for your remarks about my crossing notions, to which, +I may add, I was led by exactly the same idea as yours, viz., that +crossing must be one means of eliminating variation, and then I wished +to make out how far in animals and vegetables this was possible. +Papilionaceous flowers are almost dead floorers to me, and I cannot +experimentise, as castration alone often produces sterility. I am +surprised at what you say about Compositae and Gramineae. From what I +have seen of latter they seemed to me (and I have watched wheat, +owing to what L. de Longchamps has said on their fertilisation in bud) +favourable for crossing; and from Cassini's observations and Kolreuter's +on the adhesive pollen, and C.C. Sprengel's, I had concluded that the +Compositae were eminently likely (I am aware of the pistil brushing +out pollen) to be crossed. (586/1. This is an instance of the curious +ignorance of the essential principles of floral mechanism which was to +be found even among learned and accomplished botanists such as Gray, +before the publication of the "Fertilisation of Orchids." Even in 1863 +we find Darwin explaining the meaning of dichogamy in a letter to Gray.) +If in some months' time you can find time to tell me whether you have +made any observations on the early fertilisation of plants in these two +orders, I should be very glad to hear, as it would save me from great +blunder. In several published remarks on this subject in various genera +it has seemed to me that the early fertilisation has been inferred +from the early shedding of the pollen, which I think is clearly a false +inference. Another cause, I should think, of the belief of fertilisation +in the bud, is the not-rare, abnormal, early maturity of the pistil as +described by Gartner. I have hitherto failed in meeting with detailed +accounts of regular and normal impregnation in the bud. Podostemon and +Subularia under water (and Leguminosae) seem and are strongest cases +against me, as far as I as yet know. I am so sorry that you are so +overwhelmed with work; it makes your VERY GREAT kindness to me the more +striking. + +It is really pretty to see how effectual insects are. A short time ago +I found a female holly sixty measured yards from any other holly, and +I cut off some twigs and took by chance twenty stigmas, cut off their +tops, and put them under the microscope: there was pollen on every one, +and in profusion on most! weather cloudy and stormy and unfavourable, +wind in wrong direction to have brought any. + + +LETTER 587. TO J.D. HOOKER. Down, January 12th [1858]. + +I want to ask a question which will take you only few words to answer. +It bears on my former belief (and Asa Gray strongly expressed opinion) +that Papilionaceous flowers were fatal to my notion of there being no +eternal hermaphrodites. First let me say how evidence goes. You will +remember my facts going to show that kidney-beans require visits of bees +to be fertilised. This has been positively stated to be the case with +Lathyrus grandiflorus, and has been very partially verified by me. +Sir W. Macarthur tells me that Erythrina will hardly seed in Australia +without the petals are moved as if by bee. I have just met the statement +that, with common bean, when the humble-bees bite holes at the base +of the flower, and therefore cease visiting the mouth of the corolla, +"hardly a bean will set." But now comes a much more curious statement, +that [in] 1842-43, "since bees were established at Wellington (New +Zealand), clover seeds all over the settlement, WHICH IT DID NOT +BEFORE." (587/1. See Letter 362, Volume I.) The writer evidently has no +idea what the connection can be. Now I cannot help at once connecting +this statement (and all the foregoing statements in some degree support +each other, as all have been advanced without any sort of theory) with +the remarkable absence of Papilionaceous plants in N. Zealand. I see in +your list Clianthus, Carmichaelia (four species), a new genus, a shrub, +and Edwardsia (is latter Papilionaceous?). Now what I want to know is +whether any of these have flowers as small as clover; for if they +have large flowers they may be visited by humble-bees, which I think I +remember do exist in New Zealand; and which humble-bees would not visit +the smaller clover. Even the very minute little yellow clover in England +has every flower visited and revisited by hive-bees, as I know by +experience. Would it not be a curious case of correlation if it could be +shown to be probable that herbaceous and small Leguminosae do not exist +because when [their] seeds [are] washed ashore (!!!) no small bees exist +there. Though this latter fact must be ascertained. I may not prove +anything, but does it not seem odd that so many quite independent facts, +or rather statements, should point all in one direction, viz., that bees +are necessary to the fertilisation of Papilionaceous flowers? + + +LETTER 588. TO JOHN LUBBOCK (Lord Avebury). Sunday [1859]. + +Do you remember calling my attention to certain flowers in the truss +of Pelargoniums not being true, or not having the dark shade on the two +upper petals? I believe it was Lady Lubbock's observation. I find, as +I expected, it is always the central or sub-central flower; but what is +far more curious, the nectary, which is blended with the peduncle of +the flowers, gradually lessens and quite disappears (588/1. This fact +is mentioned in Maxwell Masters' "Vegetable Teratology" (Ray Society's +Publications), 1869, page 221.), as the dark shade on the two upper +petals disappears. Compare the stalk in the two enclosed parcels, in +each of which there is a perfect flower. + +Now, if your gardener will not be outrageous, do look over your +geraniums and send me a few trusses, if you can find any, having the +flowers without the marks, sending me some perfect flowers on same +truss. The case seems to me rather a pretty one of correlation of +growth; for the calyx also becomes slightly modified in the flowers +without marks. + + +LETTER 589. TO MAXWELL MASTERS. Down, April 7th [1860]. + +I hope that you will excuse the liberty which I take in writing to you +and begging a favour. I have been very much interested by the abstract +(too brief) of your lecture at the Royal Institution. Many of the facts +alluded to are full of interest for me. But on one point I should be +infinitely obliged if you could procure me any information: namely, with +respect to sweet-peas. I am a great believer in the natural crossing of +individuals of the same species. But I have been assured by Mr. Cattell +(589/1. The nurseryman he generally dealt with.), of Westerham, that the +several varieties of sweet-pea can be raised close together for a number +of years without intercrossing. But on the other hand he stated that +they go over the beds, and pull up any false plant, which they very +naturally attribute to wrong seeds getting mixed in the lot. After many +failures, I succeeded in artificially crossing two varieties, and the +offspring out of the same pod, instead of being intermediate, was very +nearly like the two pure parents; yet in one, there was a trace of the +cross, and these crossed peas in the next generation showed still more +plainly their mongrel origin. Now, what I want to know is, whether there +is much variation in sweet-peas which might be owing to natural crosses. +What I should expect would be that they would keep true for many years, +but that occasionally, perhaps at long intervals, there would be a +considerable amount of crossing of the varieties grown close together. +Can you give, or obtain from your father, any information on this head, +and allow me to quote your authority? It would really be a very great +favour and kindness. + + +LETTER 590. TO J.D. HOOKER. + +(590/1. The genera Scaevola and Leschenaultia, to which the following +letter refers, belong to the Goodeniaceae (Goodenovieae, Bentham & +Hooker), an order allied to the Lobeliaceae, although the mechanism +of fertilisation resembles rather more nearly that of Campanula. The +characteristic feature of the flower in this order is the indusium, or, +as Delpino (590/2. Delpino's observations on Dichogamy, summarised by +Hildebrand in "Bot. Zeitung," 1870, page 634.) calls it, the "collecting +cup": this cuplike organ is a development of the style, and serves the +same function as the hairs on the style of Campanula, namely, that of +taking the pollen from the anthers and presenting it to the visiting +insect. During this stage the immature stigma is at the bottom of the +cup, and though surrounded by pollen is incapable of being pollinated. +In most genera of the order the pollen is pushed out of the indusium by +the growth of the style or stigma, very much as occurs in Lobelia or +the Compositae. Finally the style emerges from the indusium (590/3. +According to Hamilton ("Proc. Linn. Soc. N. S. Wales," X., 1895, page +361) the stigma rarely grows beyond the indusium in Dampiera. In the +same journal (1885-6, page 157, and IX., 1894, page 201) Hamilton +has given a number of interesting observations on Goodenia, Scaevola, +Selliera, Brunonia. There seem to be mechanisms for cross- and also +for self-fertilisation.), the stigmas open out and are pollinated from +younger flowers. The mechanism of fertilisation has been described by +F. Muller (590/4. In a letter to Hildebrand published in the "Bot. +Zeitung," 1868, page 113.), and more completely by Delpino (loc. cit.). + +Mr. Bentham wrote a paper (590/5. "Linn. Soc. Journal," 1869, page 203.) +on the style and stigma in the Goodenovieae, where he speaks of Mr. +Darwin's belief that fertilisation takes place outside the indusium. +This statement, which we imagine Mr. Bentham must have had from an +unpublished source, was incomprehensible to him as long as he confined +his work to such genera as Goodenia, Scaevola, Velleia, Coelogyne, +in which the mechanism is much as above described; but on examining +Leschenaultia the meaning became clear. Bentham writes of this +genus:--"The indusium is usually described as broadly two-lipped, +without any distinct stigma. The fact appears to be that the upper less +prominent lip is stigmatic all over, inside and out, with a transverse +band of short glandular hairs at its base outside, while the lower more +prominent lip is smooth and glabrous, or with a tuft of rigid hairs. +Perhaps this lower lip and the upper band of hairs are all that +correspond to the indusium of other genera; and the so-called upper lip, +outside of which impregnation may well take place, as observed by Mr. +Darwin, must be regarded as the true stigma." + +Darwin's interest in the Goodeniaceae was due to the mechanism being +apparently fitted for self-fertilisation. In 1871 a writer signing +himself F.W.B. made a communication to the "Gardeners' Chronicle" +(590/6. 1871, page 1103.), in which he expresses himself as "agreeably +surprised" to find Leschenaultia adapted for self-fertilisation, or at +least for self-pollinisation. This led Darwin to publish a short note in +the same journal, in which he describes the penetration of pollen-tubes +into the viscid surface on the outside of the indusium. (590/7. 1871, +page 1166. He had previously written in the "Journal of Horticulture and +Cottage Gardener," May 28th, 1861, page 151:--"Leschenaultia formosa has +apparently the most effective contrivance to prevent the stigma of one +flower ever receiving a grain of pollen from another flower; for the +pollen is shed in the early bud, and is there shut up round the stigma +within a cup or indusium. But some observations led me to suspect that +nevertheless insect agency here comes into play; for I found by holding +a camel-hair pencil parallel to the pistil, and moving it as if it were +a bee going to suck the nectar, the straggling hairs of the brush opened +the lip of the indusium, entered it, stirred up the pollen, and brought +out some grains. I did this to five flowers, and marked them. These +five flowers all set pods; whereas only two other pods set on the whole +plant, though covered with innumerable flowers...I wrote to Mr. James +Drummond, at Swan River in Australia,...and he soon wrote to me that he +had seen a bee cleverly opening the indusium and extracting pollen.") +He also describes how a brush, pushed into the flower in imitation of +an insect, presses "against the slightly projecting lower lip of the +indusium, opens it, and some of the hairs enter and become smeared +with pollen." The yield of pollen is therefore differently arranged in +Leschenaultia; for in the more typical genera it depends on the growth +of the style inside the indusium. Delpino, however (see Hildebrand's +version, loc. cit.), describes a similar opening of the cup produced by +pressure on the hairs in some genera of the order.) + +Down, June 7th [1860]. + +Best and most beloved of men, I supplicate and entreat you to observe +one point for me. Remember that the Goodeniaceae have weighed like an +incubus for years on my soul. It relates to Scaevola microcarpa. I +find that in bud the indusium collects all the pollen splendidly, but, +differently from Leschenaultia, cannot be afterwards easily opened. +Further, I find that at an early stage, when the flower first opens, a +boat-shaped stigma lies at the bottom of the indusium, and further +that this stigma, after the flower has some time expanded, grows very +rapidly, when the plant is kept hot, and pushes out of the indusium a +mass of pollen; and at same time two horns project at the corners of the +indusium. Now the appearance of these horns makes me suppose that these +are the stigmatic surfaces. Will you look to this? for if they be by the +relative position of the parts (with indusium and stigma bent at right +angles to style) [I am led to think] that an insect entering a flower +could not fail to have [its] whole back (at the period when, as I have +seen, a whole mass of pollen is pushed out) covered with pollen, which +would almost certainly get rubbed on the two horns. Indeed, I doubt +whether, without this aid, pollen would get on to the horns. What +interests me in the case is the analogy in result with the Lobelia, but +by very different means. In Lobelia the stigma, before it is mature, +pushes by its circular brush of hairs the pollen out of the conjoined +anthers; here the indusium collects pollen, and then the growth of the +stigma pushes it out. In the course of about 1 1/2 hour, I found an +indusium with hairs on the outer edge perfectly clogged with pollen, and +horns protruded, which before the 1 1/2 hour had not one grain of pollen +outside the indusium, and no trace of protruding horns. So you will see +how I wish to know whether the horns are the true stigmatic surfaces. I +would try the case experimentally by putting pollen on the horns, but my +greenhouse is so cold, and my plant so small, and in such a little pot, +that I suppose it would not seed... + +The little length of stigmatic horns at the moment when pollen is forced +out of the indusium, compared to what they ultimately attain, makes me +fancy that they are not then mature or ready, and if so, as in Lobelia, +each flower must be fertilised by pollen from another and earlier +flower. + +How curious that the indusium should first so cleverly collect pollen +and then afterwards push it out! Yet how closely analogous to Campanula +brushing pollen out of the anther and retaining it on hairs till the +stigma is ready. I am going to try whether Campanula sets seed without +insect agency. + + +LETTER 591. TO J.D. HOOKER. + +(591/1. The following letters are given here rather than in +chronological order, as bearing on the Leschenaultia problem. The latter +part of Letter 591 refers to the cleistogamic flowers of Viola.) + +Down, May 1st [1862]. + +If you can screw out time, do look at the stigma of the blue +Leschenaultia biloba. I have just examined a large bud with the indusium +not yet closed, and it seems to me certain that there is no stigma +within. The case would be very important for me, and I do not like to +trust solely to myself. I have been impregnating flowers, but it is +rather difficult... + +I have just looked again at Viola canina. The case is odder: only 2 +stamens which embrace the stigma have pollen; the 3 other stamens have +no anther-cells and no pollen. These 2 fertile anthers are of different +shape from the 3 sterile others, and the scale representing the +lower lip is larger and differently shaped from the 4 other scales +representing 4 other petals. + +In V. odorata (single flower) all five stamens produce pollen. But I +daresay all this is known. + + +LETTER 592. TO J.D. HOOKER. November 3rd [1862]. + +Do you remember the scarlet Leschenaultia formosa with the sticky margin +outside the indusium? Well, this is the stigma--at least, I find the +pollen-tubes here penetrate and nowhere else. What a joke it would be if +the stigma is always exterior, and this by far the greatest difficulty +in my crossing notions should turn out a case eminently requiring insect +aid, and consequently almost inevitably ensuring crossing. By the +way, have you any other Goodeniaceae which you could lend me, besides +Leschenaultia and Scaevola, of which I have seen enough? + +I had a long letter the other day from Crocker of Chichester; he has the +real spirit of an experimentalist, but has not done much this summer. + + +LETTER 593. TO F. MULLER. Down, April 9th and 15th [1866]. + +I am very much obliged by your letter of February 13th, abounding with +so many highly interesting facts. Your account of the Rubiaceous plant +is one of the most extraordinary that I have ever read, and I am glad +you are going to publish it. I have long wished some one to observe the +fertilisation of Scaevola, and you must permit me to tell you what I +have observed. First, for the allied genus of Leschenaultia: utterly +disbelieving that it fertilises itself, I introduced a camel-hair brush +into the flower in the same way as a bee would enter, and I found that +the flowers were thus fertilised, which never otherwise happens; I then +searched for the stigma, and found it outside the indusium with the +pollen-tubes penetrating it; and I convinced Dr. Hooker that botanists +were quite wrong in supposing that the stigma lay inside the indusium. +In Scaevola microcarpa the structure is very different, for the immature +stigma lies at the base within the indusium, and as the stigma grows it +pushes the pollen out of the indusium, and it then clings to the hairs +which fringe the tips of the indusium; and when an insect enters the +flower, the pollen (as I have seen) is swept from these long hairs on to +the insect's back. The stigma continues to grow, but is not apparently +ready for impregnation until it is developed into two long protruding +horns, at which period all the pollen has been pushed out of the +indusium. But my observations are here at fault, for I did not observe +the penetration of the pollen-tubes. The case is almost parallel with +that of Lobelia. Now, I hope you will get two plants of Scaevola, and +protect one from insects, leaving the other uncovered, and observe the +results, both in the number of capsules produced, and in the average +number of seeds in each. It would be well to fertilise half a dozen +flowers under the net, to prove that the cover is not injurious to +fertility. + +With respect to your case of Aristolochia, I think further observation +would convince you that it is not fertilised only by larvae, for in a +nearly parallel case of an Arum and a Aristolochia, I found that insects +flew from flower to flower. I would suggest to you to observe any cases +of flowers which catch insects by their probosces, as occurs with +some of the Apocyneae (593/1. Probably Asclepiadeae. See H. Muller, +"Fertilisation of Flowers," page 396.); I have never been able to +conceive for what purpose (if any) this is effected; at the same time, +if I tempt you to neglect your zoological work for these miscellaneous +observations I shall be guilty of a great crime. + +To return for a moment to the indusium: how curious it is that the +pollen should be thus collected in a special receptacle, afterwards to +be swept out by insects' agency! + +I am surprised at what you tell me about the fewness of the flowers of +your native orchids which produce seed-capsules. What a contrast with +our temperate European species, with the exception of some species of +Ophrys!--I now know of three or four cases of self-fertilising orchids, +but all these are provided with means for an occasional cross. + +I am sorry to say Dr. Cruger is dead from a fever. + +I received yesterday your paper in the "Botanische Zeitung" on the wood +of climbing plants. (593/2. Fritz Muller, "Ueber das Holz einiger um +Desterro wachsenden Kletterpflanzen." "Botanische Zeitung," 1866, pages +57, 65.) I have read as yet only your very interesting and curious +remarks on the subject as bearing on the change of species; you have +pleased me by the very high compliments which you pay to my paper. I +have been at work since March 1st on a new English edition (593/3. The +4th Edition.) of my "Origin," of which when published I will send you a +copy. I have much regretted the time it has cost me, as it has stopped +my other work. On the other hand, it will be useful for a new third +German edition, which is now wanted. I have corrected it largely, and +added some discussions, but not nearly so much as I wished to do, for, +being able to work only two hours daily, I feared I should never get it +finished. I have taken some facts and views from your work "Fur Darwin"; +but not one quarter of what I should like to have quoted. + + +LETTER 594. TO A.G. MORE. Down, June 24th, 1860. + +I hope that you will forgive the liberty which I take in writing to you +and requesting a favour. Mr. H.C. Watson has given me your address, and +has told me that he thought that you would be willing to oblige me. Will +you please to read the enclosed, and then you will understand what I +wish observed with respect to the bee-orchis. (594/1. Ophrys apifera.) +What I especially wish, from information which I have received since +publishing the enclosed, is that the state of the pollen-masses should +be noted in flowers just beginning to wither, in a district where the +bee-orchis is extremely common. I have been assured that in parts of +Isle of Wight, viz., Freshwater Gate, numbers occur almost crowded +together: whether anything of this kind occurs in your vicinity I know +not; but, if in your power, I should be infinitely obliged for any +information. As I am writing, I will venture to mention another wish +which I have: namely, to examine fresh flowers and buds of the Aceras, +Spiranthes, marsh Epipactis, and any other rare orchis. The point which +I wish to examine is really very curious, but it would take too long +space to explain. Could you oblige me by taking the great trouble to +send me in an old tin canister any of these orchids, permitting me, of +course, to repay postage? It would be a great kindness, but perhaps I am +unreasonable to make such a request. If you will inform me whether you +have leisure so far to oblige me, I would tell you my movements, for on +account of my own health and that of my daughter, I shall be on the move +for the next two or three weeks. + +I am sure I have much cause to apologise for the liberty which I have +taken... + + +LETTER 595. TO A.G. MORE. Down, August 3rd, 1860. + +I thank you most sincerely for sending me the Epipactis [palustris]. You +can hardly imagine what an interesting morning's work you have given me, +as the rostellum exhibited a quite new modification of structure. It has +been extremely kind of you to take so very much trouble for me. Have you +looked at the pollen-masses of the bee-Ophrys? I do not know whether the +Epipactis grows near to your house: if it does, and any object takes you +to the place (pray do not for a moment think me so very unreasonable +as to ask you to go on purpose), would you be so kind [as] to watch +the flowers for a quarter of an hour, and mark whether any insects (and +what?) visit these flowers. + +I should suppose they would crawl in by depressing the terminal portion +of the labellum; and that when within the flower this terminal portion +would resume its former position; and lastly, that the insect in +crawling out would not depress the labellum, but would crawl out at back +of flower. (595/1. The observations of Mr. William Darwin on Epipactis +palustris given in the "Fertilisation of Orchids," Edition II., 1877, +page 99, bear on this point. The chief fertilisers are hive-bees, which +are too big to crawl into the flower. They cling to the labellum, and +by depressing it open up the entrance to the flower. Owing to the +elasticity of the labellum and its consequent tendency to spring up +when released, the bees, "as they left the flower, seemed to fly rather +upwards." This agrees with Darwin's conception of the mechanism of the +flower as given in the first edition of the Orchid book, 1862, page 100, +although at that time he imagined that the fertilising insect crawled +into the flower. The extreme flexibility and elasticity of the labellum +was first observed by Mr. More (see first edition, page 99). The +description of the flower given in the above letter to Mr. More is not +quite clear; the reader is referred to the "Fertilisation of Orchids," +loc. cit.) An insect crawling out of a recently opened flower would, +I believe, have parts of the pollen-masses adhering to the back or +shoulder. I have seen this in Listera. How I should like to watch the +Epipactis. + +If you can it any time send me Spiranthes or Aceras or O. ustulata, you +would complete your work of kindness. + +P.S.--If you should visit the Epipactis again, would you gather a few of +the lower flowers which have been opened for some time and have begun +to wither a little, and observe whether pollen is well cleared out of +anther-case. I have been struck with surprise that in nearly all the +lower flowers sent by you, though much of the pollen has been removed, +yet a good deal of pollen is left wasted within the anthers. I observed +something of this kind in Cephalanthera grandiflora. But I fear that you +will think me an intolerable bore. + + +LETTER 596. TO A.G. MORE. Down, August 5th, 1860. + +I am infinitely obliged for your most clearly stated observations on +the bee-orchis. It is now perfectly clear that something removes the +pollen-masses far more with you than in this neighbourhood. But I am +utterly puzzled about the foot-stalk being so often cut through. I +should suspect snails. I yesterday found thirty-nine flowers, and of +them only one pollen-mass in three flowers had been removed, and as +these were extremely much-withered flowers I am not quite sure of +the truth of this. The wind again is a new element of doubt. Your +observations will aid me extremely in coming to some conclusion. (596/1. +Mr. More's observations on the percentage of flowers in which the +pollinia were absent are quoted in "Fertilisation of Orchids," Edition +I., page 68.) I hope in a day or two to receive some day-moths, on the +probosces of which I am assured the pollen-masses of the bee-orchis +still adhere (596/2. He was doomed to disappointment. On July 17th, +1861, he wrote to Mr. More:--"I found the other day a lot of bee-Ophrys +with the glands of the pollinia all in their pouches. All facts point +clearly to eternal self-fertilisation in this species; yet I cannot +swallow the bitter pill. Have you looked at any this year?")... + +I wrote yesterday to thank you for the Epipactis. For the chance of your +liking to look at what I have found: take a recently opened flower, drag +gently up the stigmatic surface almost any object (the side of a hooked +needle), and you will find the cap of the hemispherical rostellum comes +off with a touch, and being viscid on under-surface, clings to needle, +and as pollen-masses are already attached to the back of rostellum, the +needle drags out much pollen. But to do this, the curiously projecting +and fleshy summits of anther-cases must at some time be pushed back +slightly. Now when an insect's head gets into the flower, when the flap +of the labellum has closed by its elasticity, the insect would naturally +creep out by the back-side of the flower. And mark when the insect flies +to another flower with the pollen-masses adhering to it, if the flap of +labellum did not easily open and allow free ingress to the insect, it +would surely rub off the pollen on the upper petals, and so not leave +it on stigma. It is to know whether I have rightly interpreted the +structure of this whole flower that I am so curious to see how insects +act. Small insects, I daresay, would crawl in and out and do nothing. I +hope that I shall not have wearied you with these details. + +If you would like to see a pretty and curious little sight, look +to Orchis pyramidalis, and you will see that the sticky glands are +congenitally united into a saddle-shaped organ. Remove this under +microscope by pincers applied to foot-stalk of pollen-mass, and look +quickly at the spontaneous movement of the saddle-shaped organs and see +how beautifully adapted to seize proboscis of moth. + + +LETTER 597. TO J.D. HOOKER December 4th [1860]. + +Many thanks about Apocynum and Meyen. + +The latter I want about some strange movements in cells of Drosera, +which Meyen alone seems to have observed. (597/1. No observations of +Meyen are mentioned in "Insectivorous Plants.") It is very curious, but +Trecul disbelieves that Drosera really clasps flies! I should very much +wish to talk over Drosera with you. I did chloroform it, and the leaves +which were already expanded did not recover thirty seconds of exposure +for three days. I used the expression weight for the bit of hair which +caused movement and weighed 1/78000 of a grain; but I do not believe it +is weight, and what it is, I cannot after many experiments conjecture. +(597/2. The doubt here expressed as to whether the result is due to +actual weight is interesting in connection with Pfeffer's remarkable +discovery that a smooth object in contact with the gland produces no +effect if the plant is protected from all vibration; on an ordinary +table the slight shaking which reaches the plant is sufficient to make +the body resting on the gland tremble, and thus produce a series of +varying pressures--under these circumstances the gland is irritated, and +the tentacle moves. See Pfeffer, "Untersuchungen aus d. bot. Institut +zu Tubingen," Volume I., 1885, page 483; also "Insectivorous Plants," +Edition II., page 22.) The movement in this case does not depend on +the chemical nature of substance. Latterly I have tried experiments on +single glands, and a microscopical atom of raw meat causes such rapid +movement that I could see it move like hand of clock. In this case it +is the nature of the object. It is wonderful the rapidity of the +absorption: in ten seconds weak solution of carbonate of ammonia changes +not the colour, but the state of contents within the glands. In two +minutes thirty seconds juice of meat has been absorbed by gland and +passed from cell to cell all down the pedicel (or hair) of the gland, +and caused the sap to pass from the cells on the upper side of the +pedicel to the lower side, and this causes the curvature of the pedicel. +I shall work away next summer when Drosera opens again, for I am much +interested in subject. After the glandular hairs have curved, the oddest +changes take place--viz., a segregation of the homogeneous pink fluid +and necessary slow movements in the thicker matter. By Jove, I sometimes +think Drosera is a disguised animal! You know that I always so like +telling you what I do, that you must forgive me scribbling on my beloved +Drosera. Farewell. I am so very glad that you are going to reform your +ways; I am sure that you would have injured your health seriously. There +is poor Dana has done actually nothing--cannot even write a letter--for +a year, and it is hoped that in another YEAR he may quite recover. + +After this homily, good night, my dear friend. Good heavens, I ought +not to scold you, but thank you, for writing so long and interesting a +letter. + + +LETTER 598. TO E. CRESY. Down, December 12th [1860?]. + +After writing out the greater part of my paper on Drosera, I thought of +so many points to try, and I wished to re-test the basis of one large +set of experiments, namely, to feel still more sure than I am, that a +drop of plain water never produces any effect, that I have resolved +to publish nothing this year. For I found in the record of my daily +experiments one suspicious case. I must wait till next summer. It will +be difficult to try any solid substances containing nitrogen, such +as ivory; for two quite distinct causes excite the movement, namely, +mechanical irritation and presence of nitrogen. When a solid substance +is placed on leaf it becomes clasped, but is released sooner than when a +nitrogenous solid is clasped; yet it is difficult (except with raw meat +and flies) to be sure of the result, owing to differences in vigour of +different plants. The last experiments which I tried before my +plants became too languid are very curious, and were tried by putting +microscopical atoms on the gland itself of single hairs; and it is +perfectly evident that an atom of human hair, 1/76000 of a grain (as +ascertained by weighing a length of hair) in weight, causes conspicuous +movement. I do not believe (for atoms of cotton thread acted) it is the +chemical nature; and some reasons make me doubt whether it is +actual weight; it is not the shadow; and I am at present, after many +experiments, confounded to know what the cause is. That these atoms did +really act and alter the state of the contents of all the cells in the +glandular hair, which moved, was perfectly clear. But I hope next summer +to make out a good deal more... + + +LETTER 599. TO J.D. HOOKER. Down, May 14th [1861]. + +I have been putting off writing from day to day, as I did not wish to +trouble you, till my wish for a little news will not let me rest... + +I have no news to tell you, for I have had no interesting letters for +some time, and have not seen a soul. I have been going through the +"Cottage Gardener" of last year, on account chiefly of Beaton's articles +(599/1. Beaton was a regular contributor to the "Cottage Gardener," and +wrote various articles on cross breeding, etc., in 1861. One of these +was in reply to a letter published in the "Cottage Gardener," May +14th, 1861, page 112, in which Darwin asked for information as to the +Compositae and the hollyhock being crossed by insect visitors. In the +number for June 8th, 1861, page 211, Darwin wrote on the variability of +the central flower of the carrot and the peloria of the central flower +in Pelargonium. An extract from a letter by Darwin on Leschenaultia, +"Cottage Gardener," May 28th, 1861, page 151, is given in Letter 590, +note.); he strikes me as a clever but d--d cock-sure man (as Lord +Melbourne said), and I have some doubts whether to be much trusted. I +suspect he has never recorded his experiment at the time with care. He +has made me indignant by the way he speaks of Gartner, evidently +knowing nothing of his work. I mean to try and pump him in the +"Cottage Gardener," and shall perhaps defend Gartner. He alludes to me +occasionally, and I cannot tell with what spirit. He speaks of "this Mr. +Darwin" in one place as if I were a very noxious animal. + +Let me have a line about poor Henslow pretty soon. + +(599/2. In a letter of May 18th, 1861, Darwin wrote again:--) + +By the way, thanks about Beaton. I have now read more of his writings, +and one answer to me in "Cottage Gardener." I can plainly see that he is +not to be trusted. He does not well know his own subject of crossing. + + +LETTER 600. TO J.D. HOOKER. + +(600/1. Part of this letter has been published in "Life and Letters," +III., page 265.) + +2, Hesketh Crescent, Torquay [1861]. + +...The beauty of the adaptation of parts seems to me unparalleled. I +should think or guess [that] waxy pollen was most differentiated. In +Cypripedium, which seems least modified, and a much exterminated group, +the grains are single. In all others, as far as I have seen, they are in +packets of four; and these packets cohere into many wedge-formed masses +in Orchis, into eight, four, and finally two. It seems curious that +a flower should exist which could, at most, fertilise only two other +flowers, seeing how abundant pollen generally is; this fact I look at +as explaining the perfection of the contrivance by which the pollen, +so important from its fewness, is carried from flower to flower. By the +way, Cephalanthera has single pollen-grains, but this seems to be a case +of degradation, for the rostellum is utterly aborted. Oddly, the +columns of pollen are here kept in place by very early penetration of +pollen-tubes into the edge of the stigma; nevertheless, it receives more +pollen by insect agency. Epithecia [Dichaea] has done me one good little +turn. I often speculated how the caudicle of Orchis had been formed. +(600/2. The gradation here suggested is thoroughly worked out in the +"Fertilisation of Orchids," Edition I., page 323, Edition II., page +257.) I had noticed slight clouds in the substance half way down; I +have now dissected them out, and I find they are pollen-grains fairly +embedded and useless. If you suppose the pollen-grains to abort in +the lower half of the pollinia of Epipactis, but the parallel elastic +threads to remain and cohere, you have the caudicle of Orchis, and can +understand the few embedded and functionless pollen-grains. I must not +look at any more exotic orchids: hearty thanks for your offer. But if +you would make one single observation for me on Cypripedium, I should +be glad. Asa Gray writes to me that the outside of the pollen-masses +is sticky in this genus; I find that the whole mass consists of +pollen-grains immersed in a sticky brownish thick fluid. You could tell +by a mere lens and penknife. If it is, as I find it, pollen could not +get on the stigma without insect aid. Cypripedium confounds me much. +I conjecture that drops of nectar are secreted by the surface of the +labellum beneath the anthers and in front of the stigma, and that the +shield over the anthers and the form of labellum is to compel insects +to insert their proboscis all round both organs. (600/3. This view was +afterwards given up.) It would be troublesome for you to look at this, +as it is always bothersome to catch the nectar secreting, and the cup of +the labellum gets filled with water by gardener's watering. + +I have examined Listera ovata, cordata, and Neottia nidus avis: the +pollen is uniform; I suspect you must have seen some observation founded +on a mistake from the penetration and hardening of sticky fluid from the +rostellum, which does penetrate the pollen a little. + +It is mere virtue which makes me not wish to examine more orchids; for +I like it far better than writing about varieties of cocks and hens and +ducks. Nevertheless, I have just been looking at Lindley's list in +the "Vegetable Kingdom," and I cannot resist one or two of his great +division of Arethuseae, which includes Vanilla. And as I know so well +the Ophreae, I should like (God forgive me) any one of the Satyriadae, +Disidae and Corycidae. + +I fear my long lucubrations will have wearied you, but it has amused me +to write, so forgive me. + + +LETTER 601. TO J.D. HOOKER. + +(601/1. Part of the following letter is published in the "Life and +Letters," the remainder, with the omission of part bearing on the +Glen Roy problem, is now given as an example of the varied botanical +assistance Darwin received from Sir Joseph Hooker. For the part relating +to Verbascum see the "Variation of Animals and Plants," Edition II., +1875, Volume II., page 83. The point is that the white and yellow +flowered plants which occur in two species of Verbascum are undoubted +varieties, yet "the sterility which results from the crossing of the +differently coloured varieties of the same species is fully as great as +that which occurs in many cases when distinct species are crossed." + +The sterility of the long-styled form (B) of Linum grandiflorum, with +its own pollen is described in "Forms of Flowers," Edition II., page 87: +his conclusions on the short-styled form (A) differ from those in the +present letter.) + +September 28th [1861]. + +I am going to beg for help, and I will explain why I want it. + +You offer Cypripedium; I should be very glad of a specimen, and of any +good-sized Vandeae, or indeed any orchids, for this reason: I never +thought of publishing separately, and therefore did not keep specimens +in spirits, and now I should be very glad of a few woodcuts to +illustrate my few remarks on exotic orchids. If you can send me any, +send them by post in a tin canister on middle of day of Saturday, +October 5th, for Sowerby will be here. + +Secondly: Have you any white and yellow varieties of Verbascum which +you could give me, or propagate for me, or LEND me for a year? I have +resolved to try Gartner's wonderful and repeated statement, that pollen +of white and yellow varieties, whether used on the varieties or on +DISTINCT species, has different potency. I do not think any experiment +can be more important on the origin of species; for if he is correct we +certainly have what Huxley calls new physiological species arising. I +should require several species of Verbascum besides the white and yellow +varieties of the same species. It will be tiresome work, but if I can +anyhow get the plants, it shall be tried. + +Thirdly: Can you give me seeds of any Rubiaceae of the sub-order +Cinchoneae, as Spermacoce, Diodia, Mitchella, Oldenlandia? Asa Gray says +they present two forms like Primula. I am sure that this subject is +well worth working out. I have just almost proved a very curious case +in Linum grandiflorum which presents two forms, A and B. Pollen of A is +perfectly fertile on stigma of A. But pollen of B is absolutely barren +on its own stigma; you might as well put so much flour on it. It +astounded me to see the stigmas of B purple with its own pollen; and +then put a few grains of similar-looking pollen of A on them, and the +germen immediately and always swelled; those not thus treated never +swelling. + +Fourthly: Can you give me any very hairy Saxifraga (for their functions) +[i.e. the functions of the hairs]? + +I send you a resume of my requests, to save you trouble. Nor would I ask +for so much aid if I did not think all these points well worth trying to +investigate. + +My dear old friend, a letter from you always does me a world of good. +And, the Lord have mercy on me, what a return I make. + + +LETTER 602. TO J.D. HOOKER. Down, October 4th [1861]. + +Will you have the kindness to read the enclosed, and look at the +diagram. Six words will answer my question. It is not an important +point, but there is to me an irresistible charm in trying to make out +homologies. (602/1. In 1880 he wrote to Mr. Bentham: "It was very kind +of you to write to me about the Orchideae, for it has pleased me to an +extreme degree that I could have been of the least use to you about the +nature of the parts."--"Life and Letters," III., page 264.) You know +the membranous cup or clinandrum, in many orchids, behind the stigma and +rostellum: it is formed of a membrane which unites the filament of the +normal dorsal anther with the edges of the pistil. The clinandrum is +largely developed in Malaxis, and is of considerable importance in +retaining the pollinia, which as soon as the flower opens are quite +loose. + +The appearance and similarity of the tissues, etc., at once gives +suspicion that the lateral membranes of the clinandrum are the two other +and rudimentary anthers, which in Orchis and Cephalanthera, etc., exist +as mere papillae, here developed and utilised. + +Now for my question. Exactly in the middle of the filament of the +normal anther, and exactly in the middle of the lateral membrane of the +clinandrum, and running up to the same height, are quite similar bundles +of spiral vessels; ending upwards almost suddenly. Now is not this +structure a good argument that I interpret the homologies of the sides +of clinandrum rightly? (602/2. Though Robert Brown made use of the +spiral vessels of orchids, yet according to Eichler, "Bluthendiagramme," +1875, Volume I., page 184, Darwin was the first to make substantial +additions to the conclusions deducible from the course of the vessels in +relation to the problem of the morphology of these plants. Eichler +gives Darwin's diagram side by side with that of Van Tieghem without +attempting to decide between the differences in detail by which they are +characterised.) + +I find that the great Bauer does not draw very correctly! (602/3. F. +Bauer, whom Pritzel calls "der grosste Pflanzenmaler." The reference is +to his "Illustrations of Orchidaceous Plants, with Notes and Prefatory +Remarks by John Lindley," London, 1830-38, Folio. See "Fertilisation +of Orchids," Edition II., page 82.) And, good Heavens, what a jumble he +makes on functions. + + +LETTER 603. TO J.D. HOOKER. Down, October 22nd. [1861]. + +Acropera is a beast,--stigma does not open, everything seems contrived +that it shall NOT be anyhow fertilised. There is something very odd +about it, which could only be made out by incessant watching on several +individual plants. + +I never saw the very curious flower of Canna; I should say the pollen +was deposited where it is to prevent inevitable self-fertilisation. +You have no time to try the smallest experiment, else it would be worth +while to put pollen on some stigmas (supposing that it does not seed +freely with you). Anyhow, insects would probably carry pollen from +flower to flower, for Kurr states the tube formed by pistil, stamen and +"nectarblatt" secretes (I presume internally) much nectar. Thanks for +sending me the curious flower. + +Now I want much some wisdom; though I must write at considerable length, +your answer may be very brief. + +(FIGURE 8.--FLORAL DIAGRAM OF AN ORCHID. The "missing bundle" could not +be found in some species.) + +In R. Brown's admirable paper in the "Linnean Transacts." (603/4. Volume +XVI., page 685.) he suggests (and Lindley cautiously agrees) that the +flower of orchids consists of five whorls, the inner whorl of the two +whorls of anthers being all rudimentary, and when the labellum presents +ridges, two or three of the anthers of both whorls [are] combined with +it. In the ovarium there are six bundles of vessels: R. Brown judged by +transverse sections. It occurred to me, after what you said, to trace +the vessels longitudinally, and I have succeeded well. Look at my +diagram [Figure 8] (which please return, for I am transported with +admiration at it), which shows the vessels which I have traced, one +bundle to each of fifteen theoretical organs, and no more. You will see +the result is nothing new, but it seems to confirm strongly R. Brown, +for I have succeeded (perhaps he did, but he does not say so) in tracing +the vessels belonging to each organ in front of each other to the same +bundle in the ovarium: thus the vessels going to the lower sepal, to +the side of the labellum, and to one stigma (when there are two) all +distinctly branch from one ovarian bundle. So in other cases, but I have +not completely traced (only seen) that going to the rostellum. But here +comes my only point of novelty: in all orchids as yet looked at (even +one with so simple a labellum as Gymnadenia and Malaxis) the vessels on +the two sides of the labellum are derived from the bundle which goes to +the lower sepal, as in the diagram. This leads me to conclude that the +labellum is always a compound organ. Now I want to know whether it +is conceivable that the vessels coming from one main bundle should +penetrate an organ (the labellum) which receives its vessels from +another main bundle? Does it not imply that all that part of the +labellum which is supplied by vessels coming from a lateral bundle must +be part of a primordially distinct organ, however closely the two may +have become united? It is curious in Gymnadenia to trace the middle +anterior bundle in the ovarium: when it comes to the orifice of the +nectary it turns and runs right down it, then comes up the opposite side +and runs to the apex of the labellum, whence each side of the nectary +is supplied by vessels from the bundles, coming from the lower sepals. +Hence even the thin nectary is essentially, I infer, tripartite; hence +its tendency to bifurcation at its top. This view of the labellum always +consisting of three organs (I believe four when thick, as in Mormodes, +at base) seems to me to explain its great size and tripartite form, +compared with the other petals. Certainly, if I may trust the vessels, +the simple labellum of Gymnadenia consists of three organs soldered +together. Forgive me for writing at such length; a very brief answer +will suffice. I am desperately interested in the subject: the destiny +of the whole human race is as nothing to the course of vessels of +orchids... + +What plant has the most complex single stigma and pistil? The most +complex I, in my ignorance, can think of is in Iris. I want to know +whether anything beats in modification the rostellum of Catasetum. +To-morrow I mean to be at Catasetum. Hurrah! What species is it? It +is wonderfully different from that which Veitch sent me, which was C. +saccatum. + +According to the vessels, an orchid flower consists of three sepals and +two petals free; and of a compound organ (its labellum), consisting +of one petal and of two (or three) modified anthers; and of a second +compound body consisting of three pistils, one normal anther, and two +modified anthers often forming the sides of the clinandrum. + + +LETTER 604. TO JOHN LINDLEY. + +(604/1. It was in the autumn of 1861 that Darwin made up his mind to +publish his Orchid work as a book, rather than as a paper in the Linnean +Society's "Journal." (604/2. See "Life and Letters," III., page 266.) +The following letter shows that the new arrangement served as an +incitement to fresh work.) + +Down, October 25th [1861?] + +Mr. James Veitch has been most generous. I did not know that you had +spoken to him. If you see him pray say I am truly grateful; I dare not +write to a live Bishop or a Lady, but if I knew the address of "Rucker"? +and might use your name as introduction, I might write. I am half mad on +the subject. Hooker has sent me many exotics, but I stopped him, for I +thought I should make a fool of myself; but since I have determined to +publish I much regret it. + + +(FIGURE 9.--HABENARIA CHLORANTHA (Longitudinal course of bundles).) + +(605/1. The three upper curved outlines, two of which passing through +the words "upper sepal," "upper petal," "lower sepal," were in red in +the original; for explanation see text.) + + +LETTER 605. TO J.D. HOOKER. + +(605/2. The following letter is of interest because it relates to one of +the two chief difficulties Darwin met with in working out the morphology +of the orchid flower. In the orchid book (605/3. Edition I., page 303.) +he wrote, "This anomaly [in Habenaria] is so far of importance, as it +throws some doubt on the view which I have taken of the labellum being +always an organ compounded of one petal and two petaloid stamens." That +is to say, it leaves it open for a critic to assert that the vessels +which enter the sides of the labellum are lateral vessels of the petal +and do not necessarily represent petaloid stamens. In the sequel he +gives a satisfactory answer to the supposed objector.) + +Down, November 10th, [1861]. + +For the love of God help me. I believe all my work (about a +fortnight) is useless. Look at this accursed diagram (Figure 9) of the +butterfly-orchis [Habenaria], which I examined after writing to you +yesterday, when I thought all my work done. Some of the ducts of the +upper sepal (605/4. These would be described by modern morphologists as +lower, not upper, sepals, etc. Darwin was aware that he used these terms +incorrectly.) and upper petal run to the wrong bundles on the column. I +have seen no such case. + +This case apparently shows that not the least reliance can be placed on +the course of ducts. I am sure of my facts. + +There is great adhesion and extreme displacement of parts where the +organs spring from the top of the ovarium. Asa Gray says ducts are very +early developed, and it seems to me wonderful that they should pursue +this course. It may be said that the lateral ducts in the labellum +running into the antero-lateral ovarian bundle is no argument that the +labellum consists of three organs blended together. + +In desperation (and from the curious way the base of upper petals are +soldered at basal edges) I fancied the real form of upper sepal, upper +petal and lower sepal might be as represented by red lines, and that +there had been an incredible amount of splitting of sepals and petals +and subsequent fusion. + +This seems a monstrous notion, but I have just looked at Bauer's drawing +of allied Bonatea, and there is a degree of lobing of petals and sepals +which would account for anything. + +Now could you spare me a dry flower out of your Herbarium of Bonatea +speciosa (605/5. See "Fertilisation of Orchids," Edition I., page 304 +(note), where the resemblances between the anomalous vessels of Bonatea +and Habenaria are described. On November 14th, 1861, he wrote to Sir +Joseph: "You are a true friend in need. I can hardly bear to let the +Bonatea soak long enough."), that I might soak and look for ducts. If +I cannot explain the case of Habenaria all my work is smashed. I was a +fool ever to touch orchids. + + +LETTER 606. TO J.D. HOOKER. Down, November 17th [1861]. + +What two very interesting and useful letters you have sent me. You +rather astound me with respect to value of grounds of generalisation +in the morphology of plants. It reminds me that years ago I sent you +a grass to name, and your answer was, "It is certainly Festuca +(so-and-so), but it agrees as badly with the description as most +plants do." I have often laughed over this answer of a great +botanist...Lindley, from whom I asked for an orchid with a simple +labellum, has most kindly sent me a lot of what he marks "rare" and +"rarissima" of peloric orchids, etc., but as they are dried I know not +whether they will be of use. He has been most kind, and has suggested +my writing to Lady D. Nevill, who has responded in a wonderfully kind +manner, and has sent a lot of treasures. But I must stop; otherwise, +by Jove, I shall be transformed into a botanist. I wish I had been one; +this morphology is surprisingly interesting. Looking to your note, I +may add that certainly the fifteen alternating bundles of spiral vessels +(mingled with odd beadlike vessels in some cases) are present in many +orchids. The inner whorl of anther ducts are oftenest aborted. I must +keep clear of Apostasia, though I have cast many a longing look at it in +Bauer. (606/1. Apostasia has two fertile anthers like Cypripedium. It +is placed by Engler and Prantl in the Apostasieae or Apostasiinae, among +the Orchideae, by others in a distinct but closely allied group.) + +I hope I may be well enough to read my own paper on Thursday, but I +have been very seedy lately. (606/2. "On the two Forms, or Dimorphic +Condition, in the Species of the Genus Primula," "Linn. Soc. Journ." +1862. He did read the paper, but it cost him the next day in bed. "Life +and Letters," III., page 299.) I see there is a paper at the Royal on +the same night, which will more concern you, on fossil plants of Bovey +(606/3. Oswald Heer, "The Fossil Flora of Bovey Tracey," "Phil. Trans. +R. Soc." 1862, page 1039.), so that I suppose I shall not have you; but +you must read my paper when published, as I shall very much like to hear +what you think. It seems to me a large field for experiment. I shall +make use of my Orchid little volume in illustrating modification of +species doctrine, but I keep very, very doubtful whether I am not doing +a foolish action in publishing. How I wish you would keep to your old +intention and write a book on plants. (606/4. Possibly a book similar to +that described in Letter 696.) + + +LETTER 607. TO G. BENTHAM. Down, November 26th [1861]. + +Our notes have crossed on the road. I know it is an honour to have a +paper in the "Transactions," and I am much obliged to you for proposing +it, but I should greatly prefer to publish in the "Journal." Nor does +this apply exclusively to myself, for in old days at the Geological +Society I always protested against an abstract appearing when the paper +itself might appear. I abominate also the waste of time (and it would +take me a day) in making an abstract. If the referee on my paper should +recommend it to appear in the "Transactions," will you be so kind as to +lay my earnest request before the Council that it may be permitted to +appear in the "Journal?" + +You must be very busy with your change of residence; but when you are +settled and have some leisure, perhaps you will be so kind as to give me +some cases of dimorphism, like that of Primula. Should you object to my +adding them to those given me by A. Gray? By the way, I heard from A. +Gray this morning, and he gives me two very curious cases in Boragineae. + + +LETTER 608. TO JOHN LINDLEY. + +(608/1. In the following fragment occurs the earliest mention of +Darwin's work on the three sexual forms of Catasetum tridentatum. Sir +R. Schomburgk (608/2. "Trans. Linn. Soc." XVII., page 522.) described +Catasetum tridentatum, Monacanthus viridis and Myanthus barbatus +occurring on a single plant, but it remained for Darwin to make out that +they are the male, female and hermaphrodite forms of a single species. +(608/3. "Fertilisation of Orchids," Edition I., page 236; Edition II., +page 196.) + +With regard to the species of Acropera (Gongora) (608/4. Acropera +Loddigesii = Gongora galeata: A. luteola = G. fusca ("Index Kewensis").) +he was wrong in his surmise. The apparent sterility seems to be +explicable by Hildebrand's discovery (608/5. "Bot. Zeitung," 1863 +and 1865.) that in some orchids the ovules are not developed until +pollinisation has occurred. (608/6. "Fertilisation of Orchids," Edition +II., page 172. See Letter 633.)) + +Down, December 15th [1861]. + +I am so nearly ready for press that I will not ask for anything more; +unless, indeed, you stumbled on Mormodes in flower. As I am writing I +will just mention that I am convinced from the rudimentary state of +the ovules, and from the state of the stigma, that the whole plant of +Acropera luteola (and I believe A. Loddigesii) is male. Have you ever +seen any form from the same countries which could be the females? Of +course no answer is expected unless you have ever observed anything to +bear on this. I may add [judging from the] state of the ovules and of +the pollen [that]:-- + +Catasetum tridentatum is male (and never seeds, according to Schomburgk, +whom you have accidentally misquoted in the "Vegetable Kingdom"). +Monacanthus viridis is female. Myanthus barbatus is the hermaphrodite +form of same species. + + +LETTER 609. TO J.D. HOOKER. Down, December 18th [1861]. + +Thanks for your note. I have not written for a long time, for I always +fancy, busy as you are, that my letters must be a bore; though I like +writing, and always enjoy your notes. I can sympathise with you about +fear of scarlet fever: to the day of my death I shall never forget all +the sickening fear about the other children, after our poor little baby +died of it. The "Genera Plantarum" must be a tremendous work, and no +doubt very valuable (such a book, odd as it may appear, would be very +useful even to me), but I cannot help being rather sorry at the length +of time it must take, because I cannot enter on and understand your +work. Will you not be puzzled when you come to the orchids? It seems to +me orchids alone would be work for a man's lifetime; I cannot somehow +feel satisfied with Lindley's classification; the Malaxeae and +Epidendreae seem to me very artificially separated. (609/1. Pfitzer (in +the "Pflanzenfamilien") places Epidendrum in the Laeliinae-Cattleyeae, +Malaxis in the Liparidinae. He states that Bentham united the Malaxideae +and Epidendreae.) Not that I have seen enough to form an opinion worth +anything. + +Your African plant seems to be a vegetable Ornithorhynchus, and indeed +much more than that. (609/2. See Sir J.D. Hooker, "On Welwitschia, a new +genus of Gnetaceae." "Linn. Soc. Trans." XXIV., 1862-3.) The more I read +about plants the more I get to feel that all phanerogams seem comparable +with one class, as lepidoptera, rather than with one kingdom, as the +whole insecta. (609/3. He wrote to Hooker (December 28th, 1861): "I +wrote carelessly about the value of phanerogams; what I was thinking of +was that the sub-groups seemed to blend so much more one into another +than with most classes of animals. I suspect crustacea would show more +difference in the extreme forms than phanerogams, but, as you say, it is +wild speculation. Yet it is very strange what difficulty botanists seem +to find in grouping the families together into masses.") + +Thanks for your comforting sentence about the accursed ducts (accursed +though they be, I should like nothing better than to work at them in the +allied orders, if I had time). I shall be ready for press in three +or four weeks, and have got all my woodcuts drawn. I fear much that +publishing separately will prove a foolish job, but I do not care much, +and the work has greatly amused me. The Catasetum has not flowered yet! + +In writing to Lindley about an orchid which he sent me, I told him a +little about Acropera, and in answer he suggests that Gongora may be its +female. He seems dreadfully busy, and I feel that I have more right to +kill you than to kill him; so can you send me one or at most two dried +flowers of Gongora? if you know the habitat of Acropera luteola, a +Gongora from the same country would be the best, but any true Gongora +would do; if its pollen should prove as rudimentary as that of +Monacanthus relatively to Catasetum, I think I could easily perceive it +even in dried specimens when well soaked. + +I have picked a little out of Lecoq, but it is awful tedious hunting. + +Bates is getting on with his natural history travels in one volume. +(609/4. H.W. Bates, the "Naturalist on the Amazons," 1863. See Volume +I., Letters 123, 148, also "Life and Letters," Volume II., page 381.) I +have read the first chapter in MS., and I think it will be an excellent +book and very well written; he argues, in a good and new way to me, +that tropical climate has very little direct relation to the gorgeous +colouring of insects (though of course he admits the tropics have a far +greater number of beautiful insects) by taking all the few genera common +to Britain and Amazonia, and he finds that the species proper to the +latter are not at all more beautiful. I wonder how this is in species of +the same restricted genera of plants. + +If you can remember it, thank Bentham for getting my Primula paper +printed so quickly. I do enjoy getting a subject off one's hands +completely. + +I have now got dimorphism in structure in eight natural orders just like +Primula. Asa Gray sent me dried flowers of a capital case in Amsinkia +spectabilis, one of the Boragineae. I suppose you do not chance to have +the plant alive at Kew. + + +LETTER 610. TO A.G. MORE. Down, June 7th, 1862. + +If you are well and have leisure, will you kindly give me one bit of +information: Does Ophrys arachnites occur in the Isle of Wight? or do +the intermediate forms, which are said to connect abroad this species +and the bee-orchis, ever there occur? + +Some facts have led me to suspect that it might just be possible, though +improbable in the highest degree, that the bee [orchis] might be the +self-fertilising form of O. arachnites, which requires insects' aid, +something [in the same way] as we have self-fertilising flowers of +the violet and others requiring insects. I know the case is widely +different, as the bee is borne on a separate plant and is incomparably +commoner. This would remove the great anomaly of the bee being a +perpetual self-fertiliser. Certain Malpighiaceae for years produce only +one of the two forms. What has set my head going on this is receiving +to-day a bee having one alone of the best marked characters of O. +arachnites. (610/1. Ophrys arachnites is probably more nearly allied to +O. aranifera than to O. apifera. For a case somewhat analogous to +that suggested see the description of O. scolopax in "Fertilisation of +Orchids," Edition II., page 52.) Pray forgive me troubling you. + + +LETTER 611. TO G. BENTHAM. Down, June 22nd [1862?]. + +Here is a piece of presumption! I must think that you are mistaken in +ranking Hab[enaria] chlorantha (611/1. In Hooker's "Students' Flora," +1884, page 395, H. chlorantha is given as a subspecies of H. bifolia. +Sir J.D. Hooker adds that they are "according to Darwin, distinct, and +require different species of moths to fertilise them. They vary in the +position and distances of their anther-cells, but intermediates occur." +See "Fertilisation of Orchids," Edition II., page 73.) as a variety of +H. bifolia; the pollen-masses and stigma differ more than in most of the +best species of Orchis. When I first examined them I remember telling +Hooker that moths would, I felt sure, fertilise them in a different +manner; and I have just had proof of this in a moth sent me with the +pollinia (which can be easily recognised) of H. chlorantha attached to +its proboscis, instead of to the sides of its face, as an H. bifolia. + +Forgive me scribbling this way; but when a man gets on his hobby-horse +he always is run away with. Anyhow, nothing here requires any answer. + + +LETTER 612. TO J.D. HOOKER. Down, [September] 14th [1862]. + +Your letter is a mine of wealth, but first I must scold you: I cannot +abide to hear you abuse yourself, even in joke, and call yourself a +stupid dog. You, in fact, thus abuse me, because for long years I have +looked up to you as the man whose opinion I have valued more on any +scientific subject than any one else in the world. I continually +marvel at what you know, and at what you do. I have been looking at the +"Genera" (612/1. "Genera Plantarum," by Bentham and Hooker, Volume I., +Part I., 1862.), and of course cannot judge at all of its real value, +but I can judge of the amount of condensed facts under each family and +genus. + +I am glad you know my feeling of not being able to judge about one's own +work; but I suspect that you have been overworking. I should think you +could not give too much time to Wellwitchia (I spell it different every +time I write it) (612/2. "On Welwitschia," "Linn. Soc. Trans." [1862], +XXIV., 1863.); at least I am sure in the animal kingdom monographs +cannot be too long on the osculant groups. + +Hereafter I shall be excessively glad to read a paper about Aldrovanda +(612/3. See "Insectivorous Plants," page 321.), and am very much obliged +for reference. It is pretty to see how the caught flies support Drosera; +nothing else can live. + +Thanks about plants with two kinds of anthers. I presume (if an included +flower was a Cassia) (612/4. Todd has described a species of Cassia with +an arrangement of stamens like the Melastomads. See Chapter 2.X.II.) +that Cassia is like lupines, but with some stamens still more +rudimentary. If I hear I will return the three Melastomads; I do not +want them, and, indeed, have cuttings. I am very low about them, and +have wasted enormous labour over them, and cannot yet get a glimpse of +the meaning of the parts. I wish I knew any botanical collector to whom +I could apply for seeds in their native land of any Heterocentron or +Monochoetum; I have raised plenty of seedlings from your plants, but +I find in other cases that from a homomorphic union one generally gets +solely the parent form. Do you chance to know of any botanical collector +in Mexico or Peru? I must not now indulge myself with looking after +vessels and homologies. Some future time I will indulge myself. By the +way, some time I want to talk over the alternation of organs in flowers +with you, for I think I must have quite misunderstood you that it was +not explicable. + +I found out the Verbascum case by pure accident, having transplanted +one for experiment, and finding it to my astonishment utterly sterile. +I formerly thought with you about rarity of natural hybrids, but I am +beginning to change: viz., oxlips (not quite proven), Verbascum, Cistus +(not quite proven), Aegilops triticoides (beautifully shown by Godron), +Weddell's and your orchids (612/5. For Verbascum see "Animals and +Plants," Edition II., Volume I., page 356; for Cistus, Ibid., Edition +II., Volume I., page 356, Volume II., page 122; for Aegilops, Ibid., +Edition II., Volume I., page 330, note.), and I daresay many others +recorded. Your letters are one of my greatest pleasures in life, but I +earnestly beg you never to write unless you feel somewhat inclined, for +I know how hard you work, as I work only in the morning it is different +with me, and is only a pleasant relaxation. You will never know how much +I owe to you for your constant kindness and encouragement. + + +LETTER 613. TO JOHN LUBBOCK (Lord Avebury). Cliff Cottage, Bournemouth, +Hants, September 2nd [1862]. + +Hearty thanks for your note. I am so glad that your tour answered so +splendidly. My poor patients (613/1. Mrs. Darwin and one of her sons, +both recovering from scarlet fever.) got here yesterday, and are doing +well, and we have a second house for the well ones. I write now in great +haste to beg you to look (though I know how busy you are, but I cannot +think of any other naturalist who would be careful) at any field of +common red clover (if such a field is near you) and watch the hive-bees: +probably (if not too late) you will see some sucking at the mouth of the +little flowers and some few sucking at the base of the flowers, at holes +bitten through the corollas. All that you will see is that the bees put +their heads deep into the [flower] head and rout about. Now, if you see +this, do for Heaven's sake catch me some of each and put in spirits and +keep them separate. I am almost certain that they belong to two castes, +with long and short proboscids. This is so curious a point that it seems +worth making out. I cannot hear of a clover field near here. + + +LETTER 614. TO JOHN LUBBOCK (Lord Avebury). Cliff Cottage, Bournemouth, +Wednesday, September 3rd [1862]. + +I beg a million pardons. Abuse me to any degree, but forgive me: it +is all an illusion (but almost excusable) about the bees. (614/1. +H. Muller, "Fertilisation of Flowers," page 186, describes hive-bees +visiting Trifolium pratense for the sake of the pollen. Darwin may +perhaps have supposed that these were the variety of bees whose +proboscis was long enough to reach the nectar. In "Cross and Self +Fertilisation," page 361, Darwin describes hive-bees apparently +searching for a secretion on the calyx. In the same passage in "Cross +and Self Fertilisation" he quotes Muller as stating that hive-bees +obtain nectar from red clover by breaking apart the petals. This seems +to us a misinterpretation of the "Befruchtung der Blumen," page 224.) I +do so hope that you have not wasted any time from my stupid blunder. I +hate myself, I hate clover, and I hate bees. + + +(FIGURE 10.--DIAGRAM OF CRUCIFEROUS FLOWER. + +FIGURE 11.--DISSECTION OF CRUCIFEROUS FLOWER. + +Laid flat open, showing by dotted lines the course of spiral vessels +in all the organs; sepals and petals shown on one side alone, with the +stamens on one side above with course of vessels indicated, but not +prolonged. Near side of pistil with one spiral vessel cut away.) + + +LETTER 615. TO J.D. HOOKER. Cliff Cottage, Bournemouth, September 11th, +1862. + +You once told me that Cruciferous flowers were anomalous in alternation +of parts, and had given rise to some theory of dedoublement. + +Having nothing on earth to do here, I have dissected all the spiral +vessels in a flower, and instead of burning my diagrams [Figures 10 and +11], I send them to you, you miserable man. But mind, I do not want you +to send me a discussion, but just some time to say whether my notions +are rubbish, and then burn the diagrams. It seems to me that all parts +alternate beautifully by fours, on the hypothesis that two short +stamens of outer whorl are aborted (615/1. The view given by Darwin is +(according to Eichler) that previously held by Knuth, Wydler, Chatin, +and others. Eichler himself believes that the flower is dimerous, the +four longer stamens being produced by the doubling or splitting of the +upper (i.e. antero-posterior) pair of stamens. If this view is correct, +and there are good reasons for it, it throws much suspicion on the +evidence afforded by the course of vessels, for there is no trace of the +common origin of the longer stamens in the diagram (Figure 11). Again, +if Eichler is right, the four vessels shown in the section of the ovary +are misleading. Darwin afterwards gave a doubtful explanation of this, +and concluded that the ovary is dimerous. See Letter 616.); and this +view is perhaps supported by their being so few, only two sub-bundles +in the two lateral main bundles, where I imagine two short stamens +have aborted, but I suppose there is some valid objection against this +notion. The course of the side vessels in the sepals is curious, just +like my difficulty in Habenaria. (615/2. See Letter 605.) I am surprised +at the four vessels in the ovarium. Can this indicate four confluent +pistils? anyhow, they are in the right alternating position. The nectary +within the base of the shorter stamens seems to cause the end sepals +apparently, but not really, to arise beneath the lateral sepals. + +I think you will understand my diagrams in five minutes, so forgive me +for bothering you. My writing this to you reminds me of a letter which I +received yesterday from Claparede, who helped the French translatress +of the "Origin" (615/3. The late Mlle. Royer.), and he tells me he had +difficulty in preventing her (who never looked at a bee's cell) from +altering my whole description, because she affirmed that an hexagonal +prism must have an hexagonal base! Almost everywhere in the "Origin," +when I express great doubt, she appends a note explaining the +difficulty, or saying that there is none whatever!! (615/4. See +"Life and Letters," II., page 387.) It is really curious to know what +conceited people there are in the world (people, for instance, after +looking at one Cruciferous flower, explain their homologies). + +This is a nice, but most barren country, and I can find nothing to +look at. Even the brooks and ponds produce nothing. The country is like +Patagonia. my wife is almost well, thank God, and Leonard is wonderfully +improved ...Good God, what an illness scarlet fever is! The doctor +feared rheumatic fever for my wife, but she does not know her risk. It +is now all over. + + +(FIGURE 12.) + + +LETTER 616. TO J.D. HOOKER. Cliff Cottage, Bournemouth, Thursday Evening +[September 18th, 1862]. + +Thanks for your pleasant note, which told me much news, and upon the +whole good, of yourselves. You will be awfully busy for a time, but I +write now to say that if you think it really worth while to send me a +few Dielytra, or other Fumariaceous plant (which I have already tried +in vain to find here) in a little tin box, I will try and trace the +vessels; but please observe, I do not know that I shall have time, for I +have just become wonderfully interested in experimenting on Drosera with +poisons, etc. If you send any Fumariaceous plant, send if you can, also +two or three single balsams. After writing to you, I looked at vessels +of ovary of a sweet-pea, and from this and other cases I believe that in +the ovary the midrib vessel alone gives homologies, and that the vessels +on the edge of the carpel leaf often run into the wrong bundle, just +like those on the sides of the sepals. Hence I [suppose] in Crucifers +that the ovarium consists of two pistils; AA [Figure 12] being the +midrib vessels, and BB being those formed of the vessels on edges of the +two carpels, run together, and going to wrong bundles. I came to this +conclusion before receiving your letter. + +I wonder why Asa Gray will not believe in the quaternary arrangement; +I had fancied that you saw some great difficulty in the case, and that +made me think that my notion must be wrong. + + +LETTER 617. TO J.D. HOOKER. Down, September 27th [1862]. + +Masdevallia turns out nothing wonderful (617/1. This may refer to the +homologies of the parts. He was unable to understand the mechanism of +the flower.--"Fertilisation of Orchids," Edition II., page 136.); I was +merely stupid about it; I am not the less obliged for its loan, for if +I had lived till 100 years old I should have been uneasy about it. It +shall be returned the first day I send to Bromley. I have steamed the +other plants, and made the sensitive plant very sensitive, and +shall soon try some experiments on it. But after all it will only be +amusement. Nevertheless, if not causing too much trouble, I should be +very glad of a few young plants of this and Hedysarum in summer (617/2. +Hedysarum or Desmodium gyrans, the telegraph-plant.), for this kind +of work takes no time and amuses me much. Have you seeds of Oxalis +sensitiva, which I see mentioned in books? By the way, what a fault it +is in Henslow's "Botany" that he gives hardly any references; he alludes +to great series of experiments on absorption of poison by roots, but +where to find them I cannot guess. Possibly the all-knowing Oliver may +know. I can plainly see that the glands of Drosera, from rapid power +(almost instantaneous) of absorption and power of movement, give +enormous advantage for such experiments. And some day I will enjoy +myself with a good set to work; but it will be a great advantage if I +can get some preliminary notion on other sensitive plants and on roots. + +Oliver said he would speak about some seeds of Lythrum hyssopifolium +being preserved for me. By the way, I am rather disgusted to find +I cannot publish this year on Lythrum salicaria; I must make 126 +additional crosses. All that I expected is true, but I have plain +indication of much higher complexity. There are three pistils of +different structure and functional power, and I strongly suspect +altogether five kinds of pollen all different in this one species! +(617/3. See "Forms of Flowers," Edition II., page 138.) + +By any chance have you at Kew any odd varieties of the common potato? I +want to grow a few plants of every variety, to compare flowers, leaves, +fruit, etc., as I have done with peas, etc. (617/4. "Animals and +Plants," Edition II., Volume I., page 346. Compare also the similar +facts with regard to cabbages, loc. cit., page 342. Some of the original +specimens are in the Botanical Museum at Cambridge.) + + +LETTER 618. J.D. HOOKER TO CHARLES DARWIN. + +(618/1. The following is part of Letter 144, Volume I. It refers to +reviews of "Fertilisation of Orchids" in the "Gardeners' Chronicle," +1862, pages 789, 863, 910, and in the "Natural History Review," October, +1862, page 371.) + +November 7th, 1862. + +Dear old Darwin, + +I assure you it was not my fault! I worried Lindley over and over again +to notice your orchid book in the "Chronicle" by the very broadest hints +man could give. (618/2. See "Life and Letters," III., page 273.) At +last he said, "really I cannot, you must do it for me," and so I +did--volontiers. Lindley felt that he ought to have done it himself, and +my main effort was to write it "a la Lindley," and in this alone I have +succeeded--that people all think it is exactly Lindley's style!!! which +diverts me vastly. The fact is, between ourselves, I fear that poor L. +is breaking up--he said that he could not fix his mind on your book. He +works himself beyond his mental or physical powers. + +And now, my dear Darwin, I may as well make a clean breast of it, and +tell you that I wrote the "Nat. Hist. Review" notice too--to me a very +difficult task, and one I fancied I failed in, comparatively. Of this +you are no judge, and can be none; you told me to tell Oliver it pleased +you, and so I am content and happy. + + +LETTER 619. TO W.E. DARWIN. Down, 4th [about 1862-3?] + +I have been looking at the fertilisation of wheat, and I think possibly +you might find something curious. I observed in almost every one of +the pollen-grains, which had become empty and adhered to (I suppose the +viscid) branching hairs of the stigma, that the pollen-tube was always +(?) emitted on opposite side of grain to that in contact with the branch +of the stigma. This seems very odd. The branches of the stigma are +very thin, formed apparently of three rows of cells of hardly greater +diameter than pollen-tube. I am astonished that the tubes should be able +to penetrate the walls. The specimens examined (not carefully by me) +had pollen only during few hours on stigma; and the mere SUSPICION has +crossed me that the pollen-tubes crawl down these branches to the base +and then penetrate the stigmatic tissue. (619/1. See Strasburger's "Neue +Untersuchungen uber den Befruchtungsvorgang bei den Phanerogamen," 1884. +In Alopecurus pratensis he describes the pollen as adhering to the end +of a projection from the stigma where it germinates; the tube crawls +along or spirally round this projection until it reaches the angle where +the stigmatic branch is given off; here it makes an entrance and travels +in the middle lamella between two cells.) The paleae open for a +short period for stigma to be dusted, and then close again, and such +travelling down would take place under protection. High powers and good +adjustment are necessary. Ears expel anthers when kept in water in room; +but the paleae apparently do not open and expose stigma; but the stigma +could easily be artificially impregnated. + +If I were you I would keep memoranda of points worth attending to. + + +2.X.II. MELASTOMACEAE, 1862-1881. + +(620/1. The following series of letters (620-630) refers to the +Melastomaceae and certain other flowers of analogous form. In 1862 +Darwin attempted to explain the existence of two very different sets of +stamens in these plants as a case of dimorphism, somewhat analogous to +the state of things in Primula. In this view he was probably wrong, +but this does not diminish the interest of the crossing experiments +described in the letters. The persistence of his interest in this part +of the subject is shown in the following passage from his Preface to the +English translation of H. Muller's "Befruchtung der Blumen"; the passage +is dated February, 1882, but was not published until the following year. + +"There exist also some few plants the flowers of which include two sets +of stamens, differing in the shape of the anthers and in the colour of +the pollen; and at present no one knows whether this difference has +any functional significance, and this is a point which ought to be +determined." + +It is not obvious why he spoke of the problem as if no light had been +thrown on it, since in 1881 Fritz Muller had privately (see Letter 629) +offered an explanation which Darwin was strongly inclined to accept. +(620/2. H. Muller published ("Nature," August 4th, 1881) a letter +from his brother Fritz giving the theory in question for Heeria. Todd +("American Naturalist," April 1882), described a similar state of things +in Solanum rostratum and in Cassia: and H.O. Forbes ("Nature," August +1882, page 386) has done the same for Melastoma. In Rhexia virginica Mr. +W.H. Leggett ("Bulletin Torrey Bot. Club, New York," VIII., 1881, page +102) describes the curious structure of the anther, which consists of +two inflated portions and a tubular part connecting the two. By pressing +with a blunt instrument on one of the ends, the pollen is forced out +in a jet through a fine pore in the other inflated end. Mr. Leggett has +seen bees treading on the anthers, but could not get near enough to +see the pollen expelled. In the same journal, Volume IX., page 11, +Mr. Bailey describes how in Heterocentron roseum, "upon pressing the +bellows-like anther with a blunt pencil, the pollen was ejected to +a full inch in distance." On Lagerstroemia as comparable with the +Melastomads see Letter 689.) Fritz Muller's theory with regard to +the Melastomads and a number of analogous cases in other genera are +discussed in H. Muller's article in "Kosmos" (620/3. "Kosmos," XIII., +1883, page 241.), where the literature is given. F. Muller's theory is +that in Heeria the yellow anthers serve merely as a means of attracting +pollen-collecting bees, while the longer stamens with purple or crimson +anthers supply pollen for fertilising purposes. If Muller is right the +pollen from the yellow anthers would not normally reach the stigma. The +increased vigour observed in the seedlings from the yellow anthers +would seem to resemble the good effect of a cross between different +individuals of the same species as worked out in "Cross and Self +Fertilisation," for it is difficult to believe that the pollen of the +purple anthers has become, by adaptation, less effective than that +of the yellow anthers. In the letters here given there is some +contradiction between the statements as to the position of the two +sets of stamens in relation to the sepals. According to Eichler +("Bluthendiagramme, II., page 482) the longer stamens may be either +epipetalous or episepalous in this family. + +The work on the Melastomads is of such intrinsic importance that we have +thought it right to give the correspondence in considerable detail; we +have done so in spite of the fact that Darwin arrived at no +definite conclusion, and in spite of an element of confusion and +unsatisfactoriness in the series of letters. This applies also to Letter +629, written after Darwin had learned Fritz Muller's theory, which is +obscured by some errors or slips of the pen.) + + +LETTER 620. TO G. BENTHAM. Down, February 3rd [1862?] + +As you so kindly helped me before on dimorphism, will you forgive me +begging for a little further information, if in your power to give it? +The case is that of the Melastomads with eight stamens, on which I have +been experimenting. I am perplexed by opposed statements: Lindley says +the stamens which face the petals are sterile; Wallich says in Oxyspora +paniculata that the stamens which face the sepals are destitute of +pollen; I find plenty of apparently good pollen in both sets of stamens +in Heterocentron [Heeria], Monochoetum, and Centradenia. Can you throw +any light on this? But there is another point on which I am more anxious +for information. Please look at the enclosed miserable diagram. I find +that the pollen of the yellow petal-facing stamens produce more than +twice as much seed as the pollen of the purple sepal-facing stamens. +This is exactly opposed to Lindley's statement--viz., that the +petal-facing stamens are sterile. But I cannot at present believe that +the case has any relation to abortion; it is hardly possible to believe +that the longer and very curious stamens, which face the sepals in +this Heterocentron, are tending to be rudimentary, though their +pollen applied to their own flowers produces so much less seed. It is +conformable with what we see in Primula that the [purple] sepal-facing +anthers, which in the plant seen by me stood quite close on each side +of the stigma, should have been rendered less fitted to fertilise the +stigma than the stamens on the opposite side of the flower. Hence the +suspicion has crossed me that if many plants of the Heterocentron roseum +were examined, half would be found with the pistil nearly upright, +instead of being rectangularly bent down, as shown in the diagram +(620/4. According to Willis, "Flowering Plants and Ferns," 1897, Volume +II., page 252, the style in Monochoetum, "at first bent downwards, moves +slowly up till horizontal."); or, if the position of pistil is fixed, +that in half the plants the petal-facing stamens would bend down, and in +the other half of the plants the sepal-facing stamens would bend down as +in the diagram. I suspect the former case, as in Centradenia I find the +pistil nearly straight. Can you tell me? (620/5. No reply by Mr. +Bentham to this or the following queries has been found.) Can the name +Heterocentron have any reference to such diversity? Would it be +asking too great a favour to ask you to look at dried specimens of +Heterocentron roseum (which would be best), or of Monochoetum, or any +eight-stamened Melastomad, of which you have specimens from several +localities (as this would ensure specimens having been taken from +distinct plants), and observe whether the pistil bends differently or +stamens differently in different plants? You will at once see that, if +such were the fact, it would be a new form of dimorphism, and would open +up a large field of inquiry with respect to the potency of the pollen in +all plants which have two sets of stamens--viz., longer and shorter. Can +you forgive me for troubling you at such unreasonable length? But it is +such waste of time to experiment without some guiding light. I do not +know whether you have attended particularly to Melastoma; if you +have not, perhaps Hooker or Oliver may have done so. I should be very +grateful for any information, as it will guide future experiments. + +P.S.--Do you happen to know, when there are only four stamens, whether +it is the petal or sepal-facers which are preserved? and whether in the +four-stamened forms the pistil is rectangularly bent or is straight? + + +LETTER 621. TO ASA GRAY. Down, February 16th [1862?]. + +I have been trying a few experiments on Melastomads; and they seem to +indicate that the pollen of the two curious sets of anthers (i.e. the +petal-facers and the sepal-facers) have very different powers; and it +does not seem that the difference is connected with any tendency to +abortion in the one set. Now I think I can understand the structure of +the flower and means of fertilisation, if there be two forms,--one with +the pistil bent rectangularly out of the flower, and the other with it +nearly straight. + +Our hot-house and green-house plants have probably all descended by +cuttings from a single plant of each species; so I can make out nothing +from them. I applied in vain to Bentham and Hooker; but Oliver picked +out some sentences from Naudin, which seem to indicate differences in +the position of the pistil. + +I see that Rhexia grows in Massachusetts; and I suppose has two +different sets of stamens. Now, if in your power, would you observe the +position of the pistil in different plants, in lately opened flowers +of the same age? (I specify this because in Monochaetum I find great +changes of position in the pistils and stamens, as flower gets old). +Supposing that my prophecy should turn out right, please observe whether +in both forms the passage into the flower is not [on] the upper side +of the pistil, owing to the basal part of the pistil lying close to the +ring of filaments on the under side of the flower. Also I should like to +know the colour of the two sets of anthers. This would take you only a +few minutes, and is the only way I see that I can find out whether these +plants are dimorphic in this peculiar way--i.e., only in the position +of the pistil (621/1. In Exacum and in Saintpaulia the flowers are +dimorphic in this sense: the style projects to either the right or the +left side of the corolla, from which it follows that a right-handed +flower would fertilise a left-handed one, and vice versa. See Willis, +"Flowering Plants and Ferns," 1897, Volume I., page 73.) and in its +relation to the two kinds of pollen. I am anxious about this, because if +it should prove so, it will show that all plants with longer and shorter +or otherwise different anthers will have to be examined for dimorphism. + + +LETTER 622. TO ASA GRAY. March 15th [1862]. + +...I wrote some little time ago about Rhexia; since then I have been +carefully watching and experimenting on another genus, Monochaetum; and +I find that the pistil is first bent rectangularly (as in the sketch +sent), and then in a few days becomes straight: the stamens also move. +If there be not two forms of Rhexia, will you compare the position of +the part in young and old flowers? I have a suspicion (perhaps it will +be proved wrong when the seed-capsules are ripe) that one set of anthers +are adapted to the pistil in early state, and the other set for it +in its later state. If bees visit the Rhexia, for Heaven's sake watch +exactly how the anther and stigma strike them, both in old and young +flowers, and give me a sketch. + +Again I say, do not hate me. + + +LETTER 623. TO J.D. HOOKER. Leith Hill Place, Dorking, Thursday, 15th +[May 1862]. + +You stated at the Linnean Society that different sets of seedling +Cinchona (623/1. Cinchona is apparently heterostyled: see "Forms of +Flowers," Edition II., page 134.) grew at very different rate, and from +my Primula case you attributed it probably to two sorts of pollen. I +confess I thought you rash, but I now believe you were quite right. +I find the yellow and crimson anthers of the same flower in the +Melastomatous Heterocentron roseum have different powers; the yellow +producing on the same plant thrice as many seeds as the crimson anthers. +I got my neighbour's most skilful gardener to sow both kinds of seeds, +and yesterday he came to me and said it is a most extraordinary thing +that though both lots have been treated exactly alike, one lot all +remain dwarfs and the other lot are all rising high up. The dwarfs were +produced by the pollen of the crimson anthers. In Monochaetum ensiferum +the facts are more complex and still more strange; as the age and +position of the pistils comes into play, in relation to the two kinds of +pollen. These facts seem to me so curious that I do not scruple to ask +you to see whether you can lend me any Melastomad just before flowering, +with a not very small flower, and which will endure for a short time a +greenhouse or sitting-room; when fertilised and watered I could send it +to Mr. Turnbull's to a cool stove to mature seed. I fully believe the +case is worth investigation. + +P.S.--You will not have time at present to read my orchid book; I never +before felt half so doubtful about anything which I published. When you +read it, do not fear "punishing" me if I deserve it. + +Adios. I am come here to rest, which I much want. + +Whenever you have occasion to write, pray tell me whether you have +Rhododendron Boothii from Bhootan, with a smallish yellow flower, +and pistil bent the wrong way; if so, I would ask Oliver to look for +nectary, for it is an abominable error of Nature that must be corrected. +I could hardly believe my eyes when I saw the pistil. + + +LETTER 624. TO ASA GRAY. January 19th [1863]. + +I have been at those confounded Melastomads again; throwing good money +(i.e. time) after bad. Do you remember telling me you could see no +nectar in your Rhexia? well, I can find none in Monochaetum, and Bates +tells me that the flowers are in the most marked manner neglected by +bees and lepidoptera in Amazonia. Now the curious projections or horns +to the stamens of Monochaetum are full of fluid, and the suspicion +occurs to me that diptera or small hymenoptera may puncture these horns +like they puncture (proved since my orchid book was published) the dry +nectaries of true Orchis. I forget whether Rhexia is common; but I very +much wish you would next summer watch on a warm day a group of flowers, +and see whether they are visited by small insects, and what they do. + + +LETTER 625. TO I.A. HENRY. Down, January 20th [1863]. + +...You must kindly permit me to mention any point on which I want +information. If you are so inclined, I am curious to know from +systematic experiments whether Mr. D. Beaton's statement that the pollen +of two shortest anthers of scarlet Pelargonium produce dwarf plants +(625/1. See "Animals and Plants," Edition II., Volume II., page 150, for +a brief account of Darwin's experiments on this genus. Also loc. cit., +page 338 (note), for a suggested experiment.), in comparison with plants +produced from the same mother-plant by the pollen of longer stamens from +the same flower. It would aid me much in some laborious experiments on +Melastomads. I confess I feel a little doubtful; at least, I feel pretty +nearly sure that I know the meaning of short stamens in most plants. +This summer (for another object) I crossed Queen of Scarlet Pelargonium +with pollen of long and short stamens of multiflora alba, and it so +turns out that plants from short stamens are the tallest; but I believe +this to have been mere chance. My few crosses in Pelargonium were made +to get seed from the central peloric or regular flower (I have got one +from peloric flower by pollen of peloric), and this leads me to suggest +that it would be very interesting to test fertility of peloric flowers +in three ways,--own peloric pollen on peloric stigma, common pollen +on peloric stigma, peloric pollen on common stigma of same species. My +object is to discover whether with change of structure of flower there +is any change in fertility of pollen or of female organs. This might +also be tested by trying peloric and common pollen on stigma of a +distinct species, and conversely. I believe there is a peloric and +common variety of Tropaeolum, and a peloric or upright and common +variation of some species of Gloxinia, and the medial peloric flowers of +Pelargonium, and probably others unknown to me. + + +LETTER 626. TO I.A. HENRY. Hartfield, May 2nd [1863]. + +In scarlet dwarf Pelargonium, you will find occasionally an additional +and abnormal stamen on opposite and lower side of flower. Now the pollen +of this one occasional short stamen, I think, very likely would produce +dwarf plants. If you experiment on Pelargonium I would suggest your +looking out for this single stamen. + +I observed fluctuations in length of pistil in Phloxes, but thought it +was mere variability. + +If you could raise a bed of seedling Phloxes of any species except +P. Drummondii, it would be highly desirable to see if two forms are +presented, and I should be very grateful for information and flowers for +inspection. I cannot remember, but I know that I had some reason to look +after Phloxes. (626/1. See "Forms of Flowers," Edition II., page 119, +where the conjecture is hazarded that Phlox subulata shows traces of a +former heterostyled condition.) + +I do not know whether you have used microscopes much yet. It adds +immensely to interest of all such work as ours, and is indeed +indispensable for much work. Experience, however, has fully convinced me +that the use of the compound without the simple microscope is absolutely +injurious to progress of N[atural] History (excepting, of course, with +Infusoria). I have, as yet, found no exception to the rule, that when a +man has told me he works with the compound alone his work is valueless. + + +LETTER 627. TO ASA GRAY. March 20th [1863]. + +I wrote to him [Dr. H. Cruger, of Trinidad] to ask him to observe what +the insects did in the flowers of Melastomaceae: he says not proper +season yet, but that on one species a small bee seemed busy about the +horn-like appendages to the anthers. It will be too good luck if +my study of the flowers in the greenhouse has led me to right +interpretation of these appendages. + + +LETTER 628. TO J.D. HOOKER. Down, November 28th [1871]. + +If you had come here on Sunday I should have asked you whether you could +give me seed or seedlings of any Melastomad which would flower soon to +experiment on! I wrote also to J. Scott to ask if he could give me seed. + +Several years ago I raised a lot of seedlings of a Melastomad greenhouse +bush (Monochaetus or some such name) (628/1. Monochaetum.) from stigmas +fertilised separately by the two kinds of pollen, and the seedlings +differed remarkably in size, and whilst young, in appearance; and I +never knew what to think of the case (so you must not use it), and +have always wished to try again, but they are troublesome beasts to +fertilise. + +On the other hand I could detect no difference in the product from +the two coloured anthers of Clarkia. (628/2. Clarkia has eight stamens +divided into two groups which differ in the colour of the anthers.) If +you want to know further particulars of my experiments on Monochaetum +(?) and Clarkia, I will hunt for my notes. You ask about difference in +pollen in the same species. All dimorphic and trimorphic plants present +such difference in function and in size. Lythrum and the trimorphic +Oxalis are the most wonderful cases. The pollen of the closed imperfect +cleistogamic flowers differ in the transparency of the integument, and +I think in size. The latter point I could ascertain from my notes. The +pollen or female organs must differ in almost every individual in some +manner; otherwise the pollen of varieties and even distinct individuals +of same varieties would not be so prepotent over the individual plant's +own pollen. Here follows a case of individual differences in function of +pollen or ovules or both. Some few individuals of Reseda odorata and R. +lutea cannot be fertilised, or only very rarely, by pollen of the same +plant, but can by pollen of any other individual. I chanced to have two +plants of R. odorata in this state; so I crossed them and raised five +seedlings, all of which were self sterile and all perfectly fertile +with pollen of any other individual mignonette. So I made a self sterile +race! I do not know whether these are the kinds of facts which you +require. + +Think whether you can help me to seed or better seedlings (not cuttings) +of any Melastomad. + + +LETTER 629. TO F. MULLER. Down, March 20th, 1881. + +I have received the seeds and your most interesting letter of February +7th. The seeds shall be sown, and I shall like to see the plants +sleeping; but I doubt whether I shall make any more detailed +observations on this subject, as, now that I feel very old, I require +the stimulus of some novelty to make me work. This stimulus you +have amply given me in your remarkable view of the meaning of the +two-coloured stamens in many flowers. I was so much struck with this +fact with Lythrum, that I began experimenting on some Melastomaceae, +which have two sets of extremely differently coloured anthers. After +reading your letter I turned to my notes (made 20 years ago!) to see +whether they would support or contradict your suggestion. I cannot tell +yet, but I have come across one very remarkable result, that seedlings +from the crimson anthers were not 11/20ths of the size of seedlings from +the yellow anthers of the same flowers. Fewer good seeds were produced +by the crimson pollen. I concluded that the shorter stamens were +aborting, and that the pollen was not good. (629/1. "Shorter stamens" +seems to be a slip of the pen for "longer,"--unless the observations +were made on some genus in which the structure is unusual.) The mature +pollen is incoherent, and must be [word illegible] against the visiting +insect's body. I remembered this, and I find it said in my EARLY +notes that bees would never visit the flowers for pollen. This made +me afterwards write to the late Dr. Cruger in the West Indies, and he +observed for me the flowers, and saw bees pressing the anthers with +their mandibles from the base upwards, and this forced a worm-like +thread of pollen from the terminal pore, and this pollen the bees +collected with their hind legs. So that the Melastomads are not opposed +to your views. + +I am now working on the habits of worms, and it tires me much to change +my subject; so I will lay on one side your letter and my notes, until I +have a week's leisure, and will then see whether my facts bear on your +views. I will then send a letter to "Nature" or to the Linn. Soc., with +the extract of your letter (and this ought to appear in any case), with +my own observations, if they appear worth publishing. The subject had +gone out of my mind, but I now remember thinking that the imperfect +action of the crimson stamens might throw light on hybridism. If this +pollen is developed, according to your view, for the sake of attracting +insects, it might act imperfectly, as well as if the stamens were +becoming rudimentary. (629/2. As far as it is possible to understand the +earlier letters it seems that the pollen of the shorter stamens, which +are adapted for attracting insects, is the most effective.) I do not +know whether I have made myself intelligible. + + +LETTER 630. TO W. THISELTON-DYER. Down, March 21st [1881]. + +I have had a letter from Fritz Muller suggesting a novel and very +curious explanation of certain plants producing two sets of anthers +of different colour. This has set me on fire to renew the laborious +experiments which I made on this subject, now 20 years ago. Now, will +you be so kind as to turn in your much worked and much holding head, +whether you can think of any plants, especially annuals, producing +2 such sets of anthers. I believe that this is the case with Clarkia +elegans, and I have just written to Thompson for seeds. The Lythraceae +must be excluded, as these are heterostyled. + +I have got seeds from Dr. King of some Melastomaceae, and will write +to Veitch to see if I can get the Melastomaceous genera Monochaetum and +Heterocentron or some such name, on which I before experimented. Now, +if you can aid me, I know that you will; but if you cannot, do not write +and trouble yourself. + + +2.X.III. CORRESPONDENCE WITH JOHN SCOTT, 1862-1871. + +"If he had leisure he would make a wonderful observer, to my judgment; +I have come across no one like him."--Letter to J.D. Hooker, May 29th +[1863]. + + +(631/1. The following group of letters to John Scott, of whom some +account is given elsewhere (Volume I., Letters 150 and 151, and Index.) +deal chiefly with experimental work in the fertilisation of flowers. In +addition to their scientific importance, several of the letters are +of special interest as illustrating the encouragement and friendly +assistance which Darwin gave to his correspondent.) + + +LETTER 631. JOHN SCOTT TO CHARLES DARWIN. Edinburgh Botanic Gardens, +November 11th, 1862. + +I take the liberty of addressing you for the purpose of directing your +attention to an error in one of your ingenious explanations of the +structural adaptations of the Orchidaceae in your late work. This occurs +in the genus Acropera, two species of which you assume to be unisexual, +and so far as known represented by male individuals only. Theoretically +you have no doubt assigned good grounds for this view; nevertheless, +experimental observations that I am now making have already convinced me +of its fallacy. And I thus hurriedly, and as you may think prematurely, +direct your attention to it, before I have seen the final result of my +own experiment, that you might have the longer time for reconsidering +the structure of this genus for another edition of your interesting +book, if indeed it be not already called for. I am furthermore induced +to communicate the results of my yet imperfect experiments in the belief +that the actuating principle of your late work is the elicitation of +truth, and that you will gladly avail yourself of this even at the +sacrifice of much ingenious theoretical argumentation. + +Since I have had an opportunity of perusing your work on orchid +fertilisation, my attention has been particularly directed to the +curiously constructed floral organs of Acropera. I unfortunately have +as yet had only a few flowers for experimental enquiry, otherwise my +remarks might have been clearer and more satisfactory. Such as they are, +however, I respectfully lay [them] before you, with a full assurance +of their veracity, and I sincerely trust that as such you will receive +them. + +Your observations seem to have been chiefly directed to the A. luteola, +mine to the A. Loddigesii, which, however, as you remark, is in a very +similar constructural condition with the former; having the same narrow +stigmatic chamber, abnormally developed placenta, etc. In regard to the +former point--contraction of stigmatic chamber--I may remark that +it does not appear to be absolutely necessary that the pollen-masses +penetrate this chamber for effecting fecundation. Thus a raceme was +produced upon a plant of A. Loddigesii in the Botanic Gardens here +lately; upon this I left only six flowers. These I attempted to +fertilise, but with two only of the six have I been successful: I +succeeded in forcing a single pollen-mass into the stigmatic chamber +of one of the latter, but I failed to do this on the other; however, by +inserting a portion of a pedicel with a pollinium attached, I caused +the latter to adhere, with a gentle press, to the mouth of the stigmatic +chamber. Both of these, as I have already remarked, are nevertheless +fertilised; one of them I have cut off for examination, and its +condition I will presently describe; the other is still upon the plant, +and promises fair to attain maturity. In regard to the other four +flowers, I may remark that though similarly fertilised--part having +pollinia inserted, others merely attached--they all withered and dropped +off without the least swelling of the ovary. Can it be, then, that this +is really an [andro-monoecious] species?--part of the flowers male, +others truly hermaphrodite. + +In making longitudinal sections of the fertilised ovary before +mentioned, I found the basal portion entirely destitute of ovules, their +place being substituted by transparent cellular ramification of the +placentae. As I traced the placentae upwards, the ovules appeared, +becoming gradually more abundant towards its apex. A transverse section +near the apex of the ovary, however, still exhibited a more than +ordinary placental development--i.e. [congenitally?] considered--each +end giving off two branches, which meet each other in the centre of the +ovary, the ovules being irregularly and sparingly disposed upon their +surfaces. + +In regard to the mere question of fertilisation, then, I am perfectly +satisfied, but there are other points which require further elucidation. +Among these I may particularly refer to the contracted stigmatic +chamber, and the slight viscidity of its disk. The latter, however, +may be a consequence of uncongenial conditions--as you do not mention +particularly its examination by any author in its natural habitat. If +such be the case, the contracted stigmatic chamber will offer no real +difficulty, should the viscous exudations be only sufficient to render +the mouth adhesive. For, as I have already shown, the pollen-tubes may +be emitted in this condition, and effect fecundation without being in +actual contact with the stigmatic surface, as occurs pretty regularly in +the fertilisation of the Stapelias, for example. But, indeed, your +own discovery of the independent germinative capabilities of the +pollen-grains of certain Orchidaceae is sufficiently illustrative of +this. + +I may also refer to the peculiar abnormal condition that many at least +of the ovaries present in a comparative examination of the placentae, +and of which I beg to suggest the following explanation, though it is as +yet founded on limited observations. In examining certain young ovaries +of A. Loddigesii, I found some of them filled with the transparent +membranous fringes of more or less distinctly cellular matter, which, +from your description of the ovaries of luteola, appears to differ +simply in the greater development in the former species. Again, in +others I found small mammillary bodies, which appeared to be true +ovules, though I could not perfectly satisfy myself as to the existence +of the micropyle or nucleus. I unfortunately neglected to apply any +chemical test. The fact, however, that in certain of the examined +ovaries few or none of the latter bodies occurred--the placenta alone +being developed in an irregular membranous form, taken in conjunction +with the results of my experiments--before alluded to--on their +fertilisation, leads me to infer that two sexual conditions are +presented by the flowers of this plant. In short, that many of the +ovaries are now normally abortive, though Nature occasionally makes +futile efforts for their perfect development, in the production of +ovuloid bodies; these then I regard as the male flowers. The others that +are still capable of fertilisation, and likewise possessing male +organs, are hermaphrodite, and must, I think, from the results of your +comparative examinations, present a somewhat different condition; as it +can scarcely be supposed that ovules in the condition you describe could +ever be fertilised. + +This is at least the most plausible explanation I can offer for the +different results in my experiments on the fertilisation of apparently +similar morphologically constructed flowers; others may, however, occur +to you. Here there is not, as in the Catasetum, any external change +visible in the respective unisexual and bisexual flowers. And yet it +would appear from your researches that the ovules of Acropera are in a +more highly atrophied condition than occurs in Catasetum, though, as +you likewise remark, M. Neumann has never succeeded in fertilising C. +tridentatum. If there be not, then, an arrangement of the reproductive +structures, such as I have indicated, how can the different results in +M. Neumann's experiments and mine be accounted for? However, as you +have examined many flowers of both A. luteola and Loddigesii, such a +difference in the ovulary or placental structures could scarcely +have escaped your observation. But, be this as it may, the--to me at +least--demonstrated fact still remains, that certain flowers of A. +Loddigesii are capable of fertilisation, and that, though there are good +grounds for supposing that important physiological changes are going on +in the sexual phenomena of this species, there is no evidence whatever +for supposing that external morphological changes have so masked certain +individuals as to prevent their recognition. + +I would now, sir, in conclusion beg you to excuse me for this +infringement upon your valuable time, as I have been induced to +write you in the belief that you have had negative results from +other experimenters, before you ventured to propose your theoretical +explanation, and consequently that you have been unknowingly led into +error. I will continue, as opportunities present themselves, to examine +the many peculiarities you have pointed out in this as well as others of +the Orchid family; and at present I am looking forward with anxiety for +the maturation of the ovary of A. Loddigesii, which will bear testimony +to the veracity of the remarks I have ventured to lay before you. + + +LETTER 632. TO J.D. HOOKER. Down, 18th [November 1862]. + +Strange to say, I have only one little bother for you to-day, and that +is to let me know about what month flowers appear in Acropera Loddigesii +and luteola; for I want extremely to beg a few more flowers, and if I +knew the time I would keep a memorandum to remind you. Why I want these +flowers is (and I am much alarmed) that Mr. J. Scott, of Bot. Garden of +Edinburgh (do you know anything of him?) has written me a very long and +clever letter, in which he confirms most of my observations; but tells +me that with much difficulty he managed to get pollen into orifice, or +as far as mouth of orifice, of six flowers of A. Loddigesii (the ovarium +of which I did not examine), and two pods set; one he gathered, and saw +a very few ovules, as he thinks, on the large and mostly rudimentary +placenta. I shall be most curious to hear whether the other pod produces +a good lot of seed. He says he regrets that he did not test the ovules +with chemical agents: does he mean tincture of iodine? He suggests that +in a state of nature the viscid matter may come to the very surface of +stigmatic chamber, and so pollen-masses need not be inserted. This is +possible, but I should think improbable. Altogether the case is very +odd, and I am very uneasy, for I cannot hope that A. Loddigesii is +hermaphrodite and A. luteola the male of the same species. Whenever I +can get Acropera would be a very good time for me to look at Vanda in +spirits, which you so kindly preserved for me. + + +LETTER 633. TO J. SCOTT. + +(633/1. The following is Darwin's reply to the above letter from Scott. +In the first edition of "Fertilisation of Orchids" (page 209) he assumed +that the sexes in Acropera, as in Catasetum, were separate. In the +second edition (page 172) he writes: "I was, however, soon convinced +of my error by Mr. Scott, who succeeded in artificially fertilising +the flowers with their own pollen. A remarkable discovery by Hildebrand +(633/2. "Bot. Zeitung," 1863 and 1865.), namely, that in many orchids +the ovules are not developed unless the stigma is penetrated by the +pollen-tubes...explains the state of the ovarium in Acropera, as +observed by me." In regard to this subject see Letter 608.) + +Down, November 12th, 1862. + +I thank you most sincerely for your kindness in writing to me, and for +[your] very interesting letter. Your fact has surprised me greatly, and +has alarmed me not a little, for if I am in error about Acropera I may +be in error about Catasetum. Yet when I call to mind the state of +the placentae in A. luteola, I am astonished that they should produce +ovules. You will see in my book that I state that I did not look at the +ovarium of A. Loddigesii. Would you have the kindness to send me word +which end of the ovarium is meant by apex (that nearest the flower?), +for I must try and get this species from Kew and look at its ovarium. +I shall be extremely curious to hear whether the fruit, which is now +maturing, produces a large number of good and plump seed; perhaps you +may have seen the ripe capsules of other Vandeae, and may be able +to form some conjecture what it ought to produce. In the young, +unfertilised ovaria of many Vandeae there seemed an infinitude of +ovules. In desperation it occurs to me as just possible, as almost +everything in nature goes by gradation, that a properly male flower +might occasionally produce a few seeds, in the same manner as female +plants sometimes produce a little pollen. All your remarks seem to me +excellent and very interesting, and I again thank you for your kindness +in writing to me. I am pleased to observe that my description of the +structure of Acropera seems to agree pretty well with what you have +observed. Does it not strike you as very difficult to understand +how insects remove the pollinia and carry them to the stigmas? Your +suggestion that the mouth of the stigmatic cavity may become charged +with viscid matter and thus secure the pollinia, and that the +pollen-tubes may then protrude, seems very ingenious and new to me; but +it would be very anomalous in orchids, i.e. as far as I have seen. No +doubt, however, though I tried my best, I shall be proved wrong in many +points. Botany is a new subject to me. With respect to the protrusion +of pollen-tubes, you might like to hear (if you do not already know the +fact) that, as I saw this summer, in the little imperfect flowers of +Viola and Oxalis, which never open, the pollen-tubes always come out of +the pollen-grain, whilst still in the anthers, and direct themselves in +a beautiful manner to the stigma seated at some little distance. I hope +that you will continue your very interesting observations. + + +LETTER 634. TO J. SCOTT. Down, November 19th [1862]. + +I am much obliged for your letter, which is full of interesting matter. +I shall be very glad to look at the capsule of the Acropera when +ripe, and pray present my thanks to Mr. MacNab. (634/1. See Letter 608 +(Lindley, December 15th, 1861). Also "Fertilisation of Orchids," Edition +II., page 172, for an account of the observations on Acropera which were +corrected by Scott.) I should like to keep it till I could get a capsule +of some other member of the Vandeae for comparison, but ultimately all +the seeds shall be returned, in case you would like to write any +notice on the subject. It was, as I said (634/2. Letter 633.), only +"in desperation" that I suggested that the flower might be a male and +occasionally capable of producing a few seeds. I had forgotten Gartner's +remark; in fact, I know only odds and ends of Botany, and you know far +more. One point makes the above view more probable in Acropera than in +other cases, viz. the presence of rudimentary placentae or testae, for +I cannot hear that these have been observed in the male plants. They do +not occur in male Lychnis dioica, but next spring I will look to male +holly flowers. I fully admit the difficulty of similarity of stigmatic +chamber in the two Acroperas. As far as I remember, the blunt end of +pollen-mass would not easily even stick in the orifice of the chamber. +Your view may be correct about abundance of viscid matter, but seems +rather improbable. Your facts about female flowers occurring where males +alone ought to occur is new to me; if I do not hear that you object, I +will quote the Zea case on your authority in what I am now writing on +the varieties of the maize. (634/3. See "Animals and Plants," Edition +II., Volume I., page 339: "Mr. Scott has lately observed the rarer case +of female flowers on a true male panicle, and likewise hermaphrodite +flowers." Scott's paper on the subject is in "Trans. Bot. Soc. +Edinburgh," Volume VIII. See Letter 151, Volume I.) I am glad to hear +that you are now working on the most curious subject of parthenogenesis. +I formerly fancied that I observed female Lychnis dioica seeded without +pollen. I send by this post a paper on Primula, which may interest you. +(634/4. "Linn. Soc. Journal," 1862.) I am working on the subject, and if +you should ever observe any analogous case I should be glad to hear. I +have added another very clever pamphlet by Prof. Asa Gray. Have you a +copy of my Orchis book? If you have not, and would like one, I should be +pleased to send one. I plainly see that you have the true spirit of an +experimentalist and good observer. Therefore, I ask whether you have +ever made any trials on relative fertility of varieties of plants (like +those I quote from Gartner on the varieties of Verbascum). I much +want information on this head, and on those marvellous cases (as some +Lobelias and Crinum passiflora) in which a plant can be more easily +fertilised by the pollen of another species than by its own good pollen. +I am compelled to write in haste. With many thanks for your kindness. + + +LETTER 635. TO J. SCOTT. Down, 20th [1862?]. + +What a magnificent capsule, and good Heavens, what a number of seeds! +I never before opened pods of larger orchids. It did not signify a +few seed being lost, as it would be hopeless to estimate number in +comparison with other species. If you sow any, had you not better sow +a good many? so I enclose small packet. I have looked at the seeds; I +never saw in the British orchids nearly so many empty testae; but +this goes for nothing, as unnatural conditions would account for it. I +suspect, however, from the variable size and transparency, that a +good many of the seeds when dry (and I have put the capsule on my +chimney-piece) will shrivel up. So I will wait a month or two till I get +the capsule of some large Vandeae for comparison. It is more likely that +I have made some dreadful blunder about Acropera than that it should be +male yet not a perfect male. May there be some sexual relation between +A. Loddigesii and luteola; they seem very close? I should very much like +to examine the capsule of the unimpregnated flower of A. Loddigesii. +I have got both species from Kew, but whether we shall have skill to +flower them I know not. One conjectures that it is imperfect male; I +still should incline to think it would produce by seed both sexes. +But you are right about Primula (and a very acute thought it was): +the long-styled P. sinensis, homomorphically fertilised with own-form +pollen, has produced during two successive homomorphic generations only +long-styled plants. (635/1. In "Forms of Flowers," Edition II., page +216, a summary of the transmission of forms in the "homomorphic" unions +of P. sinensis is given. Darwin afterwards used "illegitimate" for +homomorphic, and "legitimate" for "heteromorphic" ("Forms of Flowers," +Edition i., page 24).) The short-styled the same, i.e. produced +short-styled for two generations with the exception of a single plant. +I cannot say about cowslips yet. I should like to hear your case of the +Primula: is it certainly propagated by seed? + + +LETTER 636. TO J. SCOTT. Down, December 3rd, [1862?]. + +What a capital observer you are! and how well you have worked the +primulas. All your facts are new to me. It is likely that I overrate the +interest of the subject; but it seems to me that you ought to publish a +paper on the subject. It would, however, greatly add to the value if you +were to cover up any of the forms having pistil and anther of the same +height, and prove that they were fully self-fertile. The occurrence of +dimorphic and non-dimorphic species in the same genus is quite the +same as I find in Linum. (636/1. Darwin finished his paper on Linum +in December 1862, and it was published in the "Linn. Soc. Journal" in +1863.) Have any of the forms of Primula, which are non-dimorphic, been +propagated for some little time by seed in garden? I suppose not. I +ask because I find in P. sinensis a third rather fluctuating form, +apparently due to culture, with stigma and anthers of same height. +I have been working successive generations homomorphically of this +Primula, and think I am getting curious results; I shall probably +publish next autumn; and if you do not (but I hope you will) publish +yourself previously, I should be glad to quote in abstract some of your +facts. But I repeat that I hope you will yourself publish. Hottonia is +dimorphic, with pollen of very different sizes in the two forms. I think +you are mistaken about Siphocampylus, but I feel rather doubtful in +saying this to so good an observer. In Lobelia the closed pistil grows +rapidly, and pushes out the pollen and then the stigma expands, and the +flower in function is monoecious; from appearance I believe this is the +case with your plant. I hope it is so, for this plant can hardly require +a cross, being in function monoecious; so that dimorphism in such a case +would be a heavy blow to understanding its nature or good in all other +cases. I see few periodicals: when have you published on Clivia? I +suppose that you did not actually count the seeds in the hybrids in +comparison with those of the parent-forms; but this is almost necessary +after Gartner's observations. I very much hope you will make a good +series of comparative trials on the same plant of Tacsonia. (636/2. See +Scott in "Linn. Soc. Journal," VIII.) I have raised 700-800 seedlings +from cowslips, artificially fertilised with care; and they presented not +a hair's-breadth approach to oxlips. I have now seed in pots of cowslip +fertilised by pollen of primrose, and I hope they will grow; I have also +got fine seedlings from seed of wild oxlips; so I hope to make out the +case. You speak of difficulties on Natural Selection: there are indeed +plenty; if ever you have spare time (which is not likely, as I am sure +you must be a hard worker) I should be very glad to hear difficulties +from one who has observed so much as you have. The majority of +criticisms on the "Origin" are, in my opinion, not worth the paper they +are printed on. Sir C. Lyell is coming out with what, I expect, will +prove really good remarks. (636/3. Lyell's "Antiquity of Man" was +published in the spring of 1863. In the "Life and Letters," Volume III., +pages 8, 11, Darwin's correspondence shows his deep disappointment at +what he thought Lyell's half-heartedness in regard to evolution. See +Letter 164, Volume I.) Pray do not think me intrusive; but if you +would like to have any book I have published, such as my "Journal of +Researches" or the "Origin," I should esteem it a compliment to be +allowed to send it. Will you permit me to suggest one experiment, which +I should much like to see tried, and which I now wish the more from +an extraordinary observation by Asa Gray on Gymnadenia tridentata (in +number just out of Silliman's N. American Journal) (636/4. In Gymnadenia +tridentata, according to Asa Gray, the anther opens in the bud, and the +pollen being somewhat coherent falls on the stigma and on the rostellum +which latter is penetrated by the pollen-tubes. "Fertilisation of +Orchids," Edition II., page 68. Asa Gray's papers are in "American +Journal of Science," Volume XXXIV., 1862, and XXXVI., 1863.); namely, +to split the labellum of a Cattleya, or of some allied orchis, remove +caudicle from pollen-mass (so that no loose grains are about) and put it +carefully into the large tongue-like rostellum, and see if pollen-tubes +will penetrate, or better, see if capsule will swell. Similar +pollen-masses ought to be put on true stigmas of two or three other +flowers of same plants for comparison. It is to discover whether +rostellum yet retains some of its primordial function of being +penetrated by pollen-tubes. You will be sorry that you ever entered +into correspondence with me. But do not answer till at leisure, and as +briefly as you like. My handwriting, I know, is dreadfully bad. Excuse +this scribbling paper, as I can write faster on it, and I have a rather +large correspondence to keep up. + + +LETTER 637. TO J. SCOTT. Down, January 21st, 1863. + +I thank you for your very interesting letter; I must answer as briefly +as I can, for I have a heap of other letters to answer. I strongly +advise you to follow up and publish your observations on the +pollen-tubes of orchids; they promise to be very interesting. If you +could prove what I only conjectured (from state of utriculi in rostellum +and in stigma of Catasetum and Acropera) that the utriculi somehow +induce, or are correlated with, penetration of pollen-tubes you will +make an important physiological discovery. I will mention, as worth +your attention (and what I have anxiously wished to observe, if time had +permitted, and still hope to do)--viz., the state of tissues or cells +of stigma in an utterly sterile hybrid, in comparison with the same +in fertile parent species; to test these cells, immerse stigmas for +48 hours in spirits of wine. I should expect in hybrids that the cells +would not show coagulated contents. It would be an interesting discovery +to show difference in female organs of hybrids and pure species. Anyhow, +it is worth trial, and I recommend you to make it, and publish if +you do. The pollen-tubes directing themselves to stigma is also very +curious, though not quite so new, but well worth investigation when +you get Cattleya, etc., in flower. I say not so new, for remember small +flowers of Viola and Oxalis; or better, see Bibliography in "Natural +History Review," No. VIII., page 419 (October, 1862) for quotation +from M. Baillon on pollen-tubes finding way from anthers to stigma in +Helianthemum. I should doubt gum getting solid from [i.e. because of] +continued secretion. Why not sprinkle fresh plaster of Paris and make +impenetrable crust? (637/1. The suggestion that the stigma should be +covered with a crust of plaster of Paris, pierced by a hole to allow the +pollen-tubes to enter, bears a resemblance to Miyoshi's experiments with +germinating pollen and fungal spores. See "Pringsheim's Jahrbucher," +1895; "Flora," 1894.) You might modify experiment by making little hole +in one lower corner, and see if tubes find it out. See in my future +paper on Linum pollen and stigma recognising each other. If you will +tell me that pollen smells the stigma I will try and believe you; but +I will not believe the Frenchman (I forget who) who says that stigma of +Vanilla actually attracts mechanically, by some unknown force, the solid +pollen-masses to it! Read Asa Gray in 2nd Review of my Orchis book on +pollen of Gymnadenia penetrating rostellum. I can, if you like, lend +you these Reviews; but they must be returned. R. Brown, I remember, says +pollen-tubes separate from grains before the lower ends of tubes reach +ovules. I saw, and was interested by, abstract of your Drosera paper +(637/2. A short note on the irritability of Drosera in the "Trans. Bot. +Soc. Edin." Volume VII.); we have been at very much the same work. + + +LETTER 638. TO J. SCOTT. Down, February 16th [1863]. + +Absence from home has prevented me from answering you sooner. I should +think that the capsule of Acropera had better be left till it shows some +signs of opening, as our object is to judge whether the seeds are good; +but I should prefer trusting to your better judgment. I am interested +about the Gongora, which I hope hereafter to try myself, as I have just +built a small hot-house. + +Asa Gray's observations on the rostellum of Gymnadenia are very +imperfect, yet worth looking at. Your case of Imatophyllum is most +interesting (638/1. A sucker of Imatophyllum minatum threw up a shoot +in which the leaves were "two-ranked instead of four-ranked," and showed +other differences from the normal.--"Animals and Plants," Edition II., +Volume I., page 411.); even if the sport does not flower it will be +worth my giving. I did not understand, or I had forgotten, that a single +frond on a fern will vary; I now see that the case does come under +bud-variation, and must be given by me. I had thought of it only +as proof [of] inheritance in cryptogams; I am much obliged for your +correction, and will consult again your paper and Mr. Bridgeman's. +(638/2. The facts are given in "Animals and Plants," Edition II., Volume +I., page 408.) I enclose varieties of maize from Asa Gray. Pray do not +thank me for trusting you; the thanks ought to go the other way. I +felt a conviction after your first letter that you were a real lover of +Natural History. + +If you can advance good evidence showing that bisexual plants are more +variable than unisexual, it will be interesting. I shall be very glad to +read the discussion which you are preparing. I admit as fully as any +one can do that cross-impregnation is the great check to endless +variability; but I am not sure that I understand your view. I do not +believe that the structure of Primula has any necessary relation to +a tendency to a dioecious structure, but seeing the difference in the +fertility of the two forms, I felt bound unwillingly to admit that they +might be a step towards dioeciousness; I allude to this subject in +my Linum paper. (638/3. "Linn. Soc. Journal," 1863.) Thanks for your +answers to my other queries. I forgot to say that I was at Kew the other +day, and I find that they can give me capsules of several Vandeae. + + +LETTER 639. TO J. SCOTT. Down, March 24th [1863]. + +Your letter, as every one you have written, has greatly interested me. +If you can show that certain individual Passifloras, under certain known +or unknown conditions of life, have stigmas capable of fertilisation +by pollen from another species, or from another individual of its own +species, yet not by its own individual pollen (its own individual pollen +being proved to be good by its action on some other species), you will +add a case of great interest to me; and which in my opinion would be +quite worth your publication. (639/1. Cases nearly similar to those +observed by Scott were recorded by Gartner and Kolreuter, but in these +instances only certain individuals were self-impotent. In "Animals and +Plants," Edition II., Volume II., page 114, where the phenomenon is +fully discussed, Scott's observations ("Trans. Bot. Soc. Edin." 1863) +are given as the earliest, except for one case recorded by Lecoq +("Fecondation," 1862). Interesting work was afterwards done by +Hildebrand and Fritz Muller, as illustrated in many of the letters +addressed to the latter.) I always imagined that such recorded cases +must be due to unnatural conditions of life; and think I said so in the +"Origin." (639/2. See "Origin of Species," Edition I., page 251, for +Herbert's observations on self-impotence in Hippeastrum. In spite of +the uniformness of the results obtained in many successive years, Darwin +inferred that the plants must have been in an "unnatural state.") I am +not sure that I understand your result, [nor] whether it means what I +have above obscurely expressed. If you can prove the above, do publish; +but if you will not publish I earnestly beg you to let me have the facts +in detail; but you ought to publish, for I may not use the facts for +years. I have been much interested by what you say on the rostellum +exciting pollen to protrude tubes; but are you sure that the rostellum +does excite them? Would not tubes protrude if placed on parts of column +or base of petals, etc., near to the stigma? Please look at the +"Cottage Gardener" (or "Journal of Horticulture") (639/3. "Journal of +Horticulture" and "Cottage Gardener," March 31st, 1863. A short note +describing Cruger's discovery of self-fertilisation in Cattleya, +Epidendrum, etc., and referring to the work of "an excellent observer, +Mr. J. Scott." Darwin adds that he is convinced that he has underrated +the power of tropical orchids occasionally to produce seeds without the +aid of insects.) to be published to-morrow week for letter of mine, in +which I venture to quote you, and in which you will see a curious fact +about unopened orchid flowers setting seed in West Indies. Dr. Cruger +attributes protrusion of tubes to ants carrying stigmatic secretion to +pollen (639/4. In Cruger's paper ("Linn. Soc. Journ." VIII., 1865; read +March 3rd 1864) he speaks of the pollen-masses in situ being acted on by +the stigmatic secretion, but no mention is made of the agency of ants. +He describes the pollen-tubes descending "from the [pollen] masses still +in situ down into the ovarian canal."); but this is mere hypothesis. +Remember, pollen-tubes protrude within anther in Neottia nidus-avis. I +did think it possible or probable that perfect fertilisation might have +been effected through rostellum. What a curious case your Gongora must +be: could you spare me one of the largest capsules? I want to estimate +the number of seed, and try my hand if I can make them grow. This, +however, is a foolish attempt, for Dr. Hooker, who was here a day or two +ago, says they cannot at Calcutta, and yet imported species have seeded +and have naturally spread on to the adjoining trees! Dr. Cruger thinks I +am wrong about Catasetum: but I cannot understand his letter. He admits +there are three forms in two species; and he speaks as if the sexes +were separate in some and that others were hermaphrodites (639/5. +Cruger ("Linn. Soc. Journal," VIII., page 127) says that the apparently +hermaphrodite form is always sterile in Trinidad. Darwin modified +his account in the second edition of the orchid book.); but I cannot +understand what he means. He has seen lots of great humble-bees buzzing +about the flowers with the pollinia sticking to their backs! Happy man!! +I have the promise, but not yet surety, of some curious results with +my homomorphic seedling cowslips: these have not followed the rule of +Chinese Primula; homomorphic seedlings from short-styled parent have +presented both forms, which disgusts me. + +You will see that I am better; but still I greatly fear that I must have +a compulsory holiday. With sincere thanks and hearty admiration at your +powers of observation... + +My poor P. scotica looks very sick which you so kindly sent me. (639/6. +Sent by Scott, January 6th, 1863.) + + +LETTER 640. TO J. SCOTT. April 12th [1863]. + +I really hardly know how to thank you enough for your very interesting +letter. I shall certainly use all the facts which you have given me (in +a condensed form) on the sterility of orchids in the work which I am now +slowly preparing for publication. But why do you not publish these facts +in a separate little paper? (640/1. See Letter 642, note, for reference +to Scott's paper.) They seem to me well worth it, and you really ought +to get your name known. I could equally well use them in my book. I +earnestly hope that you will experiment on Passiflora, and let me give +your results. Dr. A. Gray's observations were made loosely; he said in +a letter he would attend this summer further to the case, which clearly +surprised him much. I will say nothing about the rostellum, stigmatic +utriculi, fertility of Acropera and Catasetum, for I am completely +bewildered: it will rest with you to settle these points by your +excellent observations and experiments. I must own I never could help +doubting Dr. Hooker's case of the poppy. You may like to hear what I +have seen this morning: I found (640/2. See Letter 658.) a primrose +plant with flowers having three pistils, which when pulled asunder, +without any tearing, allowed pollen to be placed on ovules. This I did +with three flowers--pollen-tubes did not protrude after several days. +But this day, the sixteenth (N.B.--primulas seem naturally slowly +fertilised), I found many tubes protruded, and, what is very odd, they +certainly seemed to have penetrated the coats of the ovules, but in +no one instance the foramen of the ovule!! I mention this because +it directly bears on your explanation of Dr. Cruger's case. (640/3. +Cruger's case here referred to is doubtless the cleistogamic +fertilisation of Epidendrum, etc. Scott discusses the question of +self-fertilisation at great length in a letter to Darwin dated April, +and obviously written in 1863. In Epidendrum he observed a viscid matter +extending from the stigmatic chamber to the anther: pollen-tubes had +protruded from the anther not only where it was in contact with the +viscid matter, but also from the central part, and these spread "over +the anterior surface of the rostellum downward into the stigma." Cruger +believed the viscid matter reaching the anther was a necessary condition +for the germination of the pollen-grains. Scott points out that the +viscid matter is produced in large quantity only after the pollen-grains +have penetrated the stigma, and that it is, in fact, a consequence, not +a preliminary to fertilisation. He finally explains Cruger's case thus: +"The greater humidity and equability of temperature consequent on +such conditions [i.e. on the flowers being closed] is, I believe, the +probable cause of these abnormally conditioned flowers so frequently +fertilising themselves." Scott also calls attention to the danger +of being deceived by fungal hyphae in observations on germination of +pollen.) I believe that your explanation is right; I should never have +thought of it; yet this was stupid of me, for I remember thinking that +the almost closed imperfect flowers of Viola and Oxalis were related +to the protrusion of the pollen-tubes. My case of the Aceras with the +aborted labellum squeezed against stigma supports your view. (640/4. See +"Fertilisation of Orchids," Edition II., page 258: the pollen germinated +within the anther of a monstrous flower.) Dr. Cruger's notion about the +ants was a simple conjecture. About cryptogamic filaments, remember Dr. +C. says that the unopened flowers habitually set fruit. I think that you +will change your views on the imperfect flowers of Viola and Oxalis... + + +LETTER 641. (?) + + +LETTER 642. TO J. SCOTT. May 2nd [1863]. + +I have left home for a fortnight to see if I can, with little hope, +improve my health. The parcel of orchid pods, which you have so kindly +sent me, has followed me. I am sure you will forgive the liberty which I +take in returning you the postage stamps. I never heard of such a scheme +as that you were compelled to practise to fertilise the Gongora! (642/1. +See "Fertilisation of Orchids," Edition, II., page 169. "Mr. Scott tried +repeatedly, but in vain, to force the pollen-masses into the stigma of +Gongora atro-purpurea and truncata; but he readily fertilised them by +cutting off the clinandrum and placing pollen-masses on the now exposed +stigma.") It is a most curious problem what plan Nature follows in this +genus and Acropera. (642/2. In the "Fertilisation of Orchids," Edition +II., page 169, Darwin speculates as to the possible fertilisation of +Acropera by an insect with pollen-masses adhering to the extremity of +its abdomen. It would appear that this guess (which does not occur in +the first edition) was made before he heard of Cruger's observation on +the allied genus Gongora, which is visited by a bee with a long tongue, +which projects, when not in use, beyond and above the tip of the +abdomen. Cruger believes that this tongue is the pollinating agent. +Cruger's account is in the "Journal of the Linn. Soc." VIII., 1865, +page 130.) Some day I will try and estimate how many seeds there are in +Gongora. I suppose and hope you have kept notes on all your observations +on orchids, for, with my broken health and many other subjects, I do not +know whether I shall ever have time to publish again; though I have a +large collection of notes and facts ready. I think you show your wisdom +in not wishing to publish too soon; a young author who publishes every +trifle gets, sometimes unjustly, to be disregarded. I do not pretend +to be much of a judge; but I can conscientiously say that I have never +written one word to you on the merit of your letters that I do not fully +believe in. Please remember that I should very much wish for a copy of +your paper on sterility of individual orchids (642/3. "On the Individual +Sterility and Cross-Impregnation of Certain Species of Oncidium." [Read +June 2nd, 1864.] "Linn. Soc. Journal," VIII., 1865. This paper gives a +full account of the self-sterility of Oncidium in cases where the pollen +was efficient in fertilising other individuals of the same species and +of distinct species. Some of the facts were given in Scott's paper, +"Experiments on the Fertilisation of Orchids in the Royal Botanic Garden +of Edinburgh," published in the "Proc. Bot. Soc. Edinb." 1863. It +is probably to the latter paper that Darwin refers.) and on Drosera. +(642/4. "Trans. Bot. Soc. Edinburgh," Volume VII.) Thanks for [note] +about Campanula perfoliata. I have asked Asa Gray for seeds, to whom +I have mentioned your observations on rostellum, and asked him to +look closer to the case of Gymnadenia. (642/5. See "Fertilisation +of Orchids," Edition II., page 68.) Let me hear about the sporting +Imatophyllum if it flowers. Perhaps I have blundered about Primula; but +certainly not about mere protrusion of pollen-tubes. I have been idly +watching bees of several genera and diptera fertilising O. morio at this +place, and it is a very pretty sight. I have confirmed in several ways +the entire truth of my statement that there is no vestige of nectar in +the spur; but the insects perforate the inner coat. This seems to me a +curious little fact, which none of my reviewers have noticed. + + +LETTER 643. TO J.D. HOOKER. Down, May 23rd [1863]. + +You can confer a real service on a good man, John Scott, the writer of +the enclosed letter, by reading it and giving me your opinion. I assure +[you] John Scott is a truly remarkable man. The part struck out is +merely that he is not comfortable under Mr. McNab, and this part must be +considered as private. Now the question is, what think you of the offer? +Is expense of living high at Darjeeling? May I say it is healthy? Will +he find the opportunity for experimental observations, which are a +passion with him? It seems to me rather low pay. Will you advise me for +him? I shall say that as far as experiments in hand at the Botanical +Garden in Edinburgh are concerned, it would be a pity to hesitate to +accept the offer. + +J. Scott is head of the propagating department. I know you will not +grudge aiding by your advice a good man. I shall tell him that I have +not the slightest power to aid him in any way for the appointment. I +should think voyage out and home ought to be paid for? + + +LETTER 644. TO JOHN SCOTT. Down, May 25th, 1863. + +Now for a few words on science. I do not think I could be mistaken about +the stigma of Bolbophyllum (644/1. Bolbophyllum is remarkable for the +closure of the stigmatic cavity which comes on after the flower has been +open a little while, instead of after fertilisation, as in other genera. +Darwin connects the fact with the "exposed condition of the whole +flower."--"Fertilisation of Orchids," Edition II., page 137.); I had +the plant alive from Kew, and watched many flowers. That is a most +remarkable observation on foreign pollen emitting tubes, but not causing +orifice to close (644/2. See Scott, "Bot. Soc. Edin." 1863, page 546, +note. He applied pollinia from Cypripedium and Asclepias to flowers of +Tricopilia tortilis; and though the pollen germinated, the stigmatic +chamber remained open, yet it invariably closes eighteen hours after the +application of its own pollen.); it would have been interesting to have +observed how close an alliance of form would have acted on the orifice +of the stigma. It will probably be so many years, if ever, [before] I +work up my observations on Drosera, that I will not trouble you to send +your paper, for I could not now find time to read it. If you have spare +copy of your Orchid paper, please send it, but do not get a copy of the +journal, for I can get one, and you must often want to buy books. Let me +know when it is published. I have been glad to hear about Mercurialis, +but I will not accept your offer of seed on account of time, time, time, +and weak health. For the same reason I must give up Primula mollis. +What a wonderful, indefatigable worker you are! You seem to have made a +famous lot of interesting experiments. D. Beaton once wrote that no +man could cross any species of Primula. You have apparently proved the +contrary with a vengeance. Your numerous experiments seem very well +selected, and you will exhaust the subject. Now when you have completed +your work you should draw up a paper, well worth publishing, and give +a list of all the dimorphic and non-dimorphic forms. I can give you, +on the authority of Prof. Treviranus in "Bot. Zeitung," case of P. +longiflora non-dimorphic. I am surprised at your cowslips in this state. +Is it a common yellow cowslip? I have seen oxlips (which from some +experiments I now look at as certainly natural hybrids) in same state. +If you think the Botanical Society of Edinburgh would not do justice +and publish your paper, send it to me to be communicated to the Linnean +Society. I will delay my paper on successive dimorphic generations in +Primula (644/3. Published in the "Journ. Linn. Soc." X., 1869 [1868].) +till yours appears, so as in no way to interfere with your paper. +Possibly my results may be hardly worth publishing, but I think they +will; the seedlings from two successive homomorphic generations seem +excessively sterile. I will keep this letter till I hear from Dr. +Hooker. I shall be very glad if you try Passiflora. Your experiments on +Primula seem so well chosen that whatever the result is they will be of +value. But always remember that not one naturalist out of a dozen cares +for really philosophical experiments. + + +LETTER 645. TO J. SCOTT. Down, May 31st [1863]. + +I am unwell, and must write briefly. I am very much obliged for the +"Courant." (645/1. The Edinburgh "Evening Courant" used to publish +notices of the papers read at the Botanical Society of Edinburgh. The +paper referred to here was Scott's on Oncidium.) The facts will be of +highest use to me. I feel convinced that your paper will have permanent +value. Your case seems excellently and carefully worked out. I agree +that the alteration of title was unfortunate, but, after all, title does +not signify very much. So few have attended to such points that I do +not expect any criticism; but if so, I should think you had much better +reply, but I could if you wished it much. I quite understand about the +cases being individual sterility; so Gartner states it was with him. +Would it be worth while to send a corrected copy of the "Courant" to the +"Gardeners' Chronicle?" (645/2. An account of Scott's work appeared in +the "Gardeners' Chronicle," June 13th, 1863, which is, at least partly, +a reprint of the "Courant," since it contains the awkward sentence +criticised by Darwin and referred to below. The title is "On the +Fertilisation of Orchids," which was no doubt considered unfortunate as +not suggesting the subject of the paper, and as being the same as that +of Darwin's book.) I did not know that you had tried Lobelia fulgens: +can you give me any particulars on the number of plants and kinds used, +etc., that I may quote, as in a few days I shall be writing on this +whole subject? No one will ever convince me that it is not a very +important subject to philosophical naturalists. The Hibiscus seems a +very curious case, and I agree with your remarks. You say that you are +glad of criticisms (by the way avoid "former and latter," the reader is +always forced to go back to look). I think you would have made the +case more striking if you had first showed that the pollen of +Oncidium sphacelatum was good; secondly, that the ovule was capable of +fertilisation; and lastly, shown that the plant was impotent with its +own pollen. "Impotence of organs capable of elimination"--capable here +strictly refers to organs; you mean to impotence. To eliminate impotence +is a curious expression; it is removing a non-existent quality. But +style is a trifle compared with facts, and you are capable of writing +well. I find it a good rule to imagine that I want to explain the case +in as few and simple words as possible to one who knows nothing of the +subject. (645/3. See Letter 151, Volume I.) I am tired. In my opinion +you are an excellent observer. + + +LETTER 646. TO J. SCOTT. Down, June 6th, 1863. + +I fear that you think that I have done more than I have with respect to +Dr. Hooker. I did not feel that I had any right to ask him to remember +you for a colonial appointment: all that I have done is to speak most +highly of your scientific merits. Of course this may hereafter fructify. +I really think you cannot go on better, for educational purposes, than +you are now doing,--observing, thinking, and some reading beat, in my +opinion, all systematic education. Do not despair about your style; your +letters are excellently written, your scientific style is a little +too ambitious. I never study style; all that I do is to try to get +the subject as clear as I can in my own head, and express it in the +commonest language which occurs to me. But I generally have to think a +good deal before the simplest arrangement and words occur to me. Even +with most of our best English writers, writing is slow work; it is a +great evil, but there is no help for it. I am sure you have no cause to +despair. I hope and suppose your sending a paper to the Linnean Society +will not offend your Edinburgh friends; you might truly say that you +sent the paper to me, and that (if it turns out so) I thought it worth +communicating to the Linnean Society. I shall feel great interest in +studying all your facts on Primula, when they are worked out and the +seed counted. Size of capsules is often very deceptive. I am astonished +how you can find time to make so many experiments. If you like to send +me your paper tolerably well written, I would look it over and suggest +any criticisms; but then this would cause you extra copying. Remember, +however, that Lord Brougham habitually wrote everything important three +times over. The cases of the Primulae which lose by variation their +dimorphic characters seem to me very interesting. I find that the +mid-styled (by variation) P. sinensis is more fertile with own pollen, +even, than a heteromorphic union! If you have time it will be very good +to experiment on Linum Lewisii. I wrote formerly to Asa Gray begging for +seed. If you have time, I think experiments on any peloric flowers would +be useful. I shall be sorry (and I am certain it is a mistake on the +part of the Society) if your orchid paper is not printed in extenso. +I am now at work compiling all such cases, and shall give a very full +abstract of all your observations. I hope to add in autumn some from +you on Passiflora. I would suggest to you the advantage, at present, +of being very sparing in introducing theory in your papers (I formerly +erred much in Geology in that way): LET THEORY GUIDE YOUR OBSERVATIONS, +but till your reputation is well established be sparing in publishing +theory. It makes persons doubt your observations. How rarely R. Brown +ever indulged in theory: too seldom perhaps! Do not work too hard, +and do not be discouraged because your work is not appreciated by the +majority. + + +LETTER 647. TO J. SCOTT. July 2nd [1863?] + +Many thanks for capsules. I would give table of the Auricula (647/1. +In Scott's paper ("Linn. Soc. Journ." VIII.) many experiments on the +Auricula are recorded.), especially owing to enclosed extract, which you +can quote. Your facts about varying fertility of the primulas will be +appreciated by but very few botanists; but I feel sure that the day will +come when they will be valued. By no means modify even in the slightest +degree any result. Accuracy is the soul of Natural History. It is hard +to become accurate; he who modifies a hair's breadth will never be +accurate. It is a golden rule, which I try to follow, to put every fact +which is opposed to one's preconceived opinion in the strongest light. +Absolute accuracy is the hardest merit to attain, and the highest merit. +Any deviation is ruin. Sincere thanks for all your laborious trials on +Passiflora. I am very busy, and have got two of my sons ill--I very much +fear with scarlet fever; if so, no more work for me for some days or +weeks. I feel greatly interested about your Primula cases. I think it +much better to count seed than to weigh. I wish I had never weighed; +counting is more accurate, though so troublesome. + + +LETTER 648. TO J. SCOTT. Down, 25th [1863?] + +From what you say I looked again at "Bot. Zeitung." (648/1. "Ueber +Dichogamie," "Bot. Zeit." January 1863.) Treviranus speaks of P. +longiflora as short-styled, but this is evidently a slip of the pen, for +further on, I see, he says the stigma always projects beyond anthers. +Your experiments on coloured primroses will be most valuable if proved +true. (648/2. The reference seems to be to Scott's observation that the +variety rubra of the primrose was sterile when crossed with pollen +from the common primrose. Darwin's caution to Scott was in some +measure justified, for in his experiments on seedlings raised by +self-fertilisation of the Edinburgh plants, he failed to confirm Scott's +result. See "Forms of Flowers," Edition II., page 225. Scott's facts are +in the "Journal Linn. Soc." VIII., page 97 (read February 4th, 1864).) I +will advise to best of my power when I see MS. If evidence is not good +I would recommend you, for your reputation's sake, to try them again. It +is not likely that you will be anticipated, and it is a great thing +to fully establish what in future time will be considered an important +discovery (or rediscovery, for no one has noticed Gartner's facts). I +will procure coloured primroses for next spring, but you may rely I will +not publish before you. Do not work too hard to injure your health. I +made some crosses between primrose and cowslip, and I send the results, +which you may use if you like. But remember that I am not quite +certain that I well castrated the short-styled primrose; I believe any +castration would be superfluous, as I find all [these] plants sterile +when insects are excluded. Be sure and save seed of the crossed +differently coloured primroses or cowslips which produced least seed, +to test the fertility of the quasi-hybrid seedlings. Gartner found the +common primrose and cowslip very difficult to cross, but he knew nothing +on dimorphism. I am sorry about delay [of] your orchid paper; I should +be glad of abstract of your new observations of self-sterility in +orchids, as I should probably use the new facts. There will be an +important paper in September in "Annals and Magazine of Natural +History," on ovules of orchids being formed after application of pollen, +by Dr. F. Hildebrand of Bonn. (648/3. "Ann. Mag. Nat. Hist." XII., 1863, +page 169. The paper was afterwards published in the "Bot. Zeitung," +1863.) + + +LETTER 649. TO J. SCOTT. Down, November 7th [1863]. + +Every day that I could do anything, I have read a few pages of your +paper, and have now finished it, and return it registered. (649/1. +This refers to the MS. of Scott's paper on the Primulaceae, "Linn. Soc. +Journ." VIII. [February 4th, 1864] 1865.) It has interested me deeply, +and is, I am sure, an excellent memoir. It is well arranged, and in most +parts well written. In the proof sheets you can correct a little +with advantage. I have suggested a few alterations in pencil for your +consideration, and have put in here and there a slip of paper. There +will be no occasion to rewrite the paper--only, if you agree with me, to +alter a few pages. When finished, return it to me, and I will with the +highest satisfaction communicate it to the Linnean Society. I should be +proud to be the author of the paper. I shall not have caused much delay, +as the first meeting of the Society was on November 5th. When your +Primula paper is finished, if you are so inclined, I should like to +hear briefly about your Verbascum and Passiflora experiments. I tried +Verbascum, and have got the pods, but do not know when I shall be able +to see to the results. This subject might make another paper for you. I +may add that Acropera luteola was fertilised by me, and had produced two +fine pods. I congratulate you on your excellent paper. + +P.S.--In the summary to Primula paper can you conjecture what is the +typical or parental form, i.e. equal, long or short styled? + + +LETTER 650. TO J.D. HOOKER. Down, [January 24th, 1864]. + +(650/1. Darwin's interest in Scott's Primula work is shown by the +following extracts from a letter to Hooker of January 24th, 1864, +written, therefore, before the paper was read, and also by the +subsequent correspondence with Hooker and Asa Gray. The first part of +this letter illustrates Darwin's condition during a period of especially +bad health.) + +As I do nothing all day I often get fidgety, and I now fancy that +Charlie or some of your family [are] ill. When you have time let me have +a short note to say how you all are. I have had some fearful sickness; +but what a strange mechanism one's body is; yesterday, suddenly, I had +a slight attack of rheumatism in my back, and I instantly became almost +well, and so wonderfully strong that I walked to the hot-houses, which +must be more than a hundred yards. I have sent Scott's paper to the +Linnean Society; I feel sure it is really valuable, but I fear few +will care about it. Remember my URGENT wish to be able to send the poor +fellow a word of praise from any one. I have had work to get him to +allow me to send the paper to the Linnean Society, even after it was +written out. + + +LETTER 651. TO J. SCOTT. Down, February 9th, 1864. + +(651/1. Scott's paper on Primulaceae was read at the Linnean Society on +February 4th, 1864.) + +The President, Mr. Bentham, I presume, was so much struck by your paper +that he sent me a message to know whether you would like to be elected +an associate. As only one is elected annually, this is a decided honour. +The enclosed list shows what respectable men are associates. I +enclose the rules of admission. I feel sure that the rule that if no +communication is received within three years the associate is considered +to have voluntarily withdrawn, is by no means rigorously adhered to. +Therefore, I advise you to accept; but of course the choice is quite +free. You will see there is no payment. You had better write to me on +this subject, as Dr. Hooker or I will propose you. + + +LETTER 652. TO J.D. HOOKER. September 13th, 1864. + +I have been greatly interested by Scott's paper. I probably overrate +it from caring for the subject, but it certainly seems to me one of the +very most remarkable memoirs on such subjects which I have ever read. +From the subject being complex, and the style in parts obscure, I +suppose very few will read it. I think it ought to be noticed in the +"Natural History Review," otherwise the more remarkable facts will never +be known. Try and persuade Oliver to do it; with the summary it would +not be troublesome. I would offer, but I have sworn to myself I will do +nothing till my volume on "Variation under Domestication" is complete. +I know you will not have time to read Scott, and therefore I will just +point out the new and, as they seem to me, important points. + +Firstly, the red cowslip, losing its dimorphic structure and changing +so extraordinarily in its great production of seed with its own pollen, +especially being nearly sterile when fertilised by, or fertilising, +the common cowslip. The analogous facts with red and white primrose. +Secondly, the utter dissimilarity of action of the pollen of long- and +short-styled form of one species in crossing with a distinct species. +And many other points. Will you suggest to Oliver to review this paper? +if he does so, and if it would be of any service to him, I would (as +I have attended so much to these subjects) just indicate, with pages, +leading and new points. I could send him, if he wishes, a separate and +spare copy marked with pencil. + + +LETTER 653. TO ASA GRAY. September 13th [1864]. + +(653/1. In September, 1864, Darwin wrote to Asa Gray describing Scott's +work on the Primulaceae as:--) + +A paper which has interested me greatly by a gardener, John Scott; +it seems to me a most remarkable production, though written rather +obscurely in parts, but worth the labour of studying. I have just +bethought me that for the chance of your noticing it in the "Journal," +I will point out the new and very remarkable facts. I have paid the poor +fellow's passage out to India, where I hope he will succeed, as he is a +most laborious and able man, with the manners almost of a gentleman. + +(653/2. The following is an abstract of the paper which was enclosed in +the letter to Asa Gray.) + +Pages 106-8. Red cowslip by variation has become non-dimorphic, and with +this change of structure has become much more productive of seed than +even the heteromorphic union of the common cowslip. Pages 91-2, similar +case with Auricula; on the other hand a non-dimorphic variety of P. +farinosa (page 115) is less fertile. These changes, or variations, +in the generative system seem to me very remarkable. But far more +remarkable is the fact that the red cowslip (pages 106-8) is very +sterile when fertilising, or fertilised by the common cowslip. Here we +have a new "physiological species." Analogous facts given (page 98) on +the crossing of red and white primroses with common primroses. It is +very curious that the two forms of the same species (pages 93, 94, 95, +and 117) hybridise with extremely different degrees of facility with +distinct species. + +He shows (page 94) that sometimes a cross with a quite distinct species +yields more seed than a homomorphic union with own pollen. He shows +(page 111) that of the two homomorphic unions possible with each +dimorphic species the short-styled (as I stated) is the most sterile, +and that my explanation is probably true. There is a good summary to the +paper. + + +LETTER 654. TO J.D. HOOKER. + +(654/1. The following letters to Hooker, April 1st, April 5th and May +22nd, refer to Darwin's scheme of employing Scott as an assistant at +Down, and to Scott's appointment to the Botanic Garden at Calcutta.) + +Down, April 1st, 1864. + +I shall not at present allude to your very interesting letter (which as +yet has been read to me only twice!), for I am full of a project which I +much want you to consider. + +You will have seen Scott's note. He tells me he has no plans for +the future. Thinking over all his letters, I believe he is a truly +remarkable man. He is willing to follow suggestions, but has much +originality in varying his experiments. I believe years may pass before +another man appears fitted to investigate certain difficult and tedious +points--viz. relative fertility of varieties of plants, including +peloric and other monsters (already Scott has done excellent work +on this head); and, secondly, whether a plant's own pollen is less +effective than that of another individual. Now, if Scott is moderate +in his wishes, I would pay him for a year or two to work and publish on +these or other such subjects which might arise. But I dare not have +him here, for it would quite overwork me. There would not be plants +sufficient for his work, and it would probably be an injury to himself, +as it would put him out of the way of getting a good situation. Now, I +believe you have gardeners at Kew who work and learn there without pay. +What do you think of having Scott there for a year or two to work and +experiment? I can see enormous difficulties. In the first place you +will not perhaps think the points indicated so highly important as I do. +Secondly, he would require ground in some out-of-the-way place where the +plants could be covered by a net, which would be unsightly. On the other +hand, I presume you would like a series of memoirs published on work +done at Kew, which I am fully convinced would have permanent value. It +would, of course I conceive, be absolutely necessary that Scott should +be under the regular orders of the superintendent. The only way I can +fancy that it could be done would be to explain to the superintendent +that I temporarily supported Scott solely for the sake of science, and +appeal to his kindness to assist him. If you approved of having +him (which I can see is improbable), and you simply ordered the +superintendent to assist him, I believe everything would go to +loggerheads. As for Scott himself, it would be of course an advantage to +him to study the cultivation at Kew. You would get to know him, and if +he really is a good man you could perhaps be able to recommend him to +some situation at home or abroad. Pray turn this [over] in your mind. I +have no idea whether Scott would like the place, but I can see that +he has a burning zeal for science. He told me that his parents were in +better circumstances, and that he chose a gardener's life solely as the +best way of following science. I may just add that in his last letter he +gives me the results of many experiments on different individuals of the +same species of orchid, showing the most remarkable diversity in their +sexual condition. It seems to me a grievous loss that such a man should +have all his work cut short. Please remember that I know nothing of him +excepting from his letters: these show remarkable talent, astonishing +perseverance, much modesty, and what I admire, determined difference +from me on many points. + +What will Sir William say? + + +LETTER 655. TO J.D. HOOKER. Down, April 5th [1864]. + +I see my scheme for Scott has invincible difficulties, and I am very +much obliged to you for explaining them at such length. If ever I get +decently well, and Scott is free and willing, I will have him here for +a couple of years to work out several problems, which otherwise would +never be done. I cannot see what will become of the poor fellow. I +enclose a little pamphlet from him, which I suppose is not of much +scientific value, but is surprising as the work of a gardener. If +you have time do just glance over it. I never heard anything so +extraordinary as what you say about poisoning plants, etc. + +...The post has just come in. Your interest about Scott is +extraordinarily kind, and I thank you cordially. It seems absurd to +say so, but I suspect that X is prejudiced against Scott because he +partially supports my views. (655/1. In a letter to Scott (dated June +11th) Darwin warns him to keep his views "pretty quiet," and quotes +Hooker's opinion that "if it is known that you agree at all with my +views on species it is enough to make you unpopular in Edinburgh.") + +You must not trust my former letter about Clematis. I worked on too +old a plant, and blundered. I have now gone over the work again. It +is really curious that the stiff peduncles are acted upon by a bit of +thread weighing .062 of a grain. + +Clematis glandulosa was a valuable present to me. My gardener showed +it to me and said, "This is what they call a Clematis," evidently +disbelieving it. So I put a little twig to the peduncle, and the next +day my gardener said, "You see it is a Clematis, for it feels." That's +the way we make out plants at Down. + +My dear old friend, God bless you! + + +LETTER 656. TO J.D. HOOKER. [May 22nd, 1864]. + +What a good kind heart you have got. You cannot tell how your letter has +pleased me. I will write to Scott and ask him if he chooses to go out +and risk engagement. If he will not he must want all energy. He says +himself he wants stoicism, and is too sensitive. I hope he may not want +courage. I feel sure he is a remarkable man, with much good in him, but +no doubt many errors and blemishes. I can vouch for his high intellect +(in my judgment he is the best observer I ever came across); for his +modesty, at least in correspondence; and there is something high-minded +in his determination not to receive money from me. I shall ask him +whether he can get a good character for probity and sobriety, and +whether he can get aid from his relations for his voyage out. I will +help, and, if necessary, pay the whole voyage, and give him enough to +support him for some weeks at Calcutta. I will write when I hear from +him. God bless you; you, who are so overworked, are most generous to +take so much trouble about a man you have had nothing to do with. + +(656/1. Scott had left the Botanic Gardens at Edinburgh in March 1864, +chagrined at what, justly or unjustly, he considered discouragement and +slight. The Indian offer was most gladly and gratefully accepted.) + + +LETTER 657. TO J. SCOTT. Down, November 1st, 1871. + +Dr. Hooker has forwarded to me your letter as the best and simplest plan +of explaining affairs. I am sincerely grieved to hear of the pecuniary +problem which you have undergone, but now fortunately passed. I assure +you that I have never entertained any feelings in regard to you which +you suppose. Please to remember that I distinctly stated that I did not +consider the sum which I advanced as a loan, but as a gift; and surely +there is nothing discreditable to you, under the circumstances, in +receiving a gift from a rich man, as I am. Therefore I earnestly beg +you to banish the whole subject from your mind, and begin laying up +something for yourself in the future. I really cannot break my word and +accept payment. Pray do not rob me of my small share in the credit of +aiding to put the right man in the right place. You have done good work, +and I am sure will do more; so let us never mention the subject again. + +I am, after many interruptions, at work again on my essay on Expression, +which was written out once many months ago. I have found your remarks +the best of all which have been sent me, and so I state. + + + +CHAPTER 2.XI.--BOTANY, 1863-1881. + +2.XI.I. Miscellaneous, 1863-1866.--2.XI.II. Correspondence with Fritz +Muller, 1865-1881.--2.XI.III. Miscellaneous, 1868-1881. + + +2.XI.I. MISCELLANEOUS, 1863-1866. + + +LETTER 658. TO D. OLIVER. Down [April, 1863]. + +(658/1. The following letter illustrates the truth of Sir W. +Thiselton-Dyer's remark that Darwin was never "afraid of his facts." +(658/2. "Charles Darwin" (Nature Series), 1882, page 43.) The entrance +of pollen-tubes into the nucellus by the chalaza, instead of through the +micropyle, was first fully demonstrated by Treub in his paper "Sur les +Casuarinees et leur place dans le Systeme naturel," published in the +"Ann. Jard. Bot. Buitenzorg," X., 1891. Two years later Miss Benson gave +an account of a similar phenomenon in certain Amentiferae ("Trans. Linn. +Soc." 1888-94, page 409). This chalazogamic method of fertilisation has +since been recognised in other flowering plants, but not, so far as we +are aware, in the genus Primula.) + +It is a shame to trouble [you], but will you tell me whether the ovule +of Primula is "anatropal," nearly as figured by Gray, page 123, "Lessons +in Botany," or rather more tending to "amphitropal"? I never looked at +such a point before. Why I am curious to know is because I put pollen +into the ovarium of monstrous primroses, and now, after sixteen days, +and not before (the length of time agrees with slowness of natural +impregnation), I find abundance of pollen-tubes emitted, which cling +firmly to the ovules, and, I think I may confidently state, penetrate +the ovule. But here is an odd thing: they never once enter at (what I +suppose to be) the "orifice," but generally at the chalaza...Do you +know how pollen-tubes go naturally in Primula? Do they run down walls +of ovarium, and then turn up the placenta, and so debouch near the +"orifices" of the ovules? + +If you thought it worth while to examine ovules, I would see if there +are more monstrous flowers, and put pollen into the ovarium, and send +you the flowers in fourteen or fifteen days afterwards. But it is rather +troublesome. I would not do it unless you cared to examine the ovules. +Like a foolish and idle man, I have wasted a whole morning over them... + +In two ovules there was an odd appearance, as if the outer coat of ovule +at the chalaza end (if I understand the ovule) had naturally opened or +withered where most of the pollen-tubes seemed to penetrate, which made +me at first think this was a widely open foramen. I wonder whether the +ovules could be thus fertilised? + + +LETTER 659. TO D. OLIVER. Down [April, 1863]. + +Many thanks about the Primula. I see that I was pretty right about the +ovules. I have been thinking that the apparent opening at the chalaza +end must have been withering or perhaps gnawing by some very minute +insects, as the ovarium is open at the upper end. If I have time I will +have another look at pollen-tubes, as, from what you say, they ought +to find their way to the micropyle. But ovules to me are far more +troublesome to dissect than animal tissue; they are so soft, and muddy +the water. + + +LETTER 660. TO MAXWELL MASTERS. Down, April 6th [1863]. + +I have been very glad to read your paper on Peloria. (660/1. "On the +Existence of Two Forms of Peloria." "Natural History Review," April, +1863, page 258.) For the mere chance of the following case being new +I send it. A plant which I purchased as Corydalis tuberosa has, as you +know, one nectary--short, white, and without nectar; the pistil is bowed +towards the true nectary; and the hood formed by the inner petals slips +off towards the opposite side (all adaptations to insect agency, like +many other pretty ones in this family). Now on my plants there are +several flowers (the fertility of which I will observe) with both +nectaries equal and purple and secreting nectar; the pistil is straight, +and the hood slips off either way. In short, these flowers have the +exact structure of Dielytra and Adlumia. Seeing this, I must look at +the case as one of reversion; though it is one of the spreading of +irregularity to two sides. + +As columbine [Aquilegia] has all petals, etc., irregular, and as +monkshood [Aconitum] has two petals irregular, may not the case given by +Seringe, and referred to [by] you (660/2. "Seringe describes and figures +a flower [of Aconitum] wherein all the sepals were helmet-shaped," and +the petals similarly affected. Maxwell Masters, op. cit., page 260.), +by you be looked at as reversion to the columbine state? Would it be +too bold to suppose that some ancient Linaria, or allied form, and +some ancient Viola, had all petals spur-shaped, and that all cases of +"irregular peloria" in these genera are reversions to such imaginary +ancient form? (660/3. "'Regular or Congenital Peloria' would include +those flowers which, contrary to their usual habit, retain throughout +the whole of their growth their primordial regularity of form and +equality of proportion. 'Irregular or Acquired Peloria,' on the other +hand, would include those flowers in which the irregularity of growth +that ordinarily characterises some portions of the corolla is manifested +in all of them." Maxwell Masters, loc. cit.) + +It seems to me, in my ignorance, that it would be advantageous to +consider the two forms of Peloria WHEN OCCURRING IN THE VERY SAME +SPECIES as probably due to the same general law--viz., one as reversion +to very early state, and the other as reversion to a later state when +all the petals were irregularly formed. This seems at least to me a +priori a more probable view than to look at one form of Peloria as due +to reversion and the other as something distinct. (660/4. See Maxwell +Masters, "Vegetable Teratology," 1869, page 235; "Variation of Animals +and Plants," Edition II., Volume II., page 33.) + +What do you think of this notion? + + +LETTER 661. TO P.H. GOSSE. + +(661/1. The following was written in reply to Mr. Gosse's letter of May +30th asking for a solution of his difficulties in fertilising Stanhopea. +It is reprinted by the kind permission of Mr. Edmund Gosse from his +delightful book, the "Life of Philip Henry Gosse," London, 1890, page +299.) + +Down, June 2nd, 1863. + +It would give me real pleasure to resolve your doubts, but I cannot. +I can give only suspicions and my grounds for them. I should think the +non-viscidity of the stigmatic hollow was due to the plant not living +under its natural conditions. Please see what I have said on Acropera. +An excellent observer, Mr. J. Scott, of the Botanical Gardens, +Edinburgh, finds all that I say accurate, but, nothing daunted, he with +the knife enlarged the orifice and forced in pollen-masses; or he simply +stuck them into the contracted orifice without coming into contact +with the stigmatic surface, which is hardly at all viscid, when, lo and +behold, pollen-tubes were emitted and fine seed capsules obtained. This +was effected with Acropera Loddigesii; but I have no doubt that I have +blundered badly about A. luteola. I mention all this because, as Mr. +Scott remarks, as the plant is in our hot-houses, it is quite incredible +it ever could be fertilised in its native land. The whole case is an +utter enigma to me. Probably you are aware that there are cases (and +it is one of the oddest facts in Physiology) of plants which, under +culture, have their sexual functions in so strange a condition, that +though their pollen and ovules are in a sound state and can fertilise +and be fertilised by distinct but allied species, they cannot fertilise +themselves. Now, Mr. Scott has found this the case with certain orchids, +which again shows sexual disturbance. He had read a paper at the +Botanical Society of Edinburgh, and I daresay an abstract which I have +seen will appear in the "Gardeners' Chronicle"; but blunders have crept +in in copying, and parts are barely intelligible. How insects act with +your Stanhopea I will not pretend to conjecture. In many cases I believe +the acutest man could not conjecture without seeing the insect at +work. I could name common English plants in this predicament. But the +musk-orchis [Herminium monorchis] is a case in point. Since publishing, +my son and myself have watched the plant and seen the pollinia +removed, and where do you think they invariably adhere in dozens of +specimens?--always to the joint of the femur with the trochanter of the +first pair of legs, and nowhere else. When one sees such adaptation as +this, it would be hopeless to conjecture on the Stanhopea till we know +what insect visits it. I have fully proved that my strong suspicion was +correct that with many of our English orchids no nectar is excreted, but +that insects penetrate the tissues for it. So I expect it must be with +many foreign species. I forgot to say that if you find that you cannot +fertilise any of your exotics, take pollen from some allied form, and it +is quite probable that will succeed. Will you have the kindness to look +occasionally at your bee-Ophrys near Torquay, and see whether pollinia +are ever removed? It is my greatest puzzle. Please read what I have said +on it, and on O. arachnites. I have since proved that the account of the +latter is correct. I wish I could have given you better information. + +P.S.--If the Flowers of the Stanhopea are not too old, remove +pollen-masses from their pedicels, and stick them with a little liquid +pure gum to the stigmatic cavity. After the case of the Acropera, no one +can dare positively say that they would not act. + + +LETTER 662. TO J.D. HOOKER. Down, Saturday, 5th [December 1863]. + +I am very glad that this will reach you at Kew. You will then get rest, +and I do hope some lull in anxiety and fear. Nothing is so dreadful in +this life as fear; it still sickens me when I cannot help remembering +some of the many illnesses our children have endured. My father, who +was a sceptical man, was convinced that he had distinctly traced several +cases of scarlet fever to handling letters from convalescents. + +The vases (662/1. Probably Wedgwood ware.) did come from my sister +Susan. She is recovering, and was much pleased to hear that you liked +them; I have now sent one of your notes to her, in which you speak of +them as "enchanting," etc. I have had a bad spell--vomiting, every +day for eleven days, and some days many times after every meal. It is +astonishing the degree to which I keep up some strength. Dr. Brinton was +here two days ago, and says he sees no reason [why] I may not recover my +former degree of health. I should like to live to do a little more work, +and often I feel sure I shall, and then again I feel that my tether is +run out. + +Your Hastings note, my dear old fellow, was a Copley Medal to me and +more than a Copley Medal: not but what I know well that you overrate +what I have been able to do. (662/2. The proposal to give the medal +to Darwin failed in 1863, but his friends were successful in 1864: see +"Life and Letters," III., page 28.) Now that I am disabled, I feel more +than ever what a pleasure observing and making out little difficulties +is. By the way, here is a very little fact which may interest you. A +partridge foot is described in "Proc. Zoolog. Soc." with a huge ball of +earth attached to it as hard as rock. (662/3. "Proc. Zool. Soc." 1863, +page 127, by Prof. Newton, who sent the foot to Darwin: see "Origin," +Edition VI., page 328.) Bird killed in 1860. Leg has been sent me, and I +find it diseased, and no doubt the exudation caused earth to accumulate; +now already thirty-two plants have come up from this ball of earth. + +By Jove! I must write no more. Good-bye, my best of friends. + +There is an Italian edition of the "Origin" preparing. This makes the +fifth foreign edition--i.e. in five foreign countries. Owen will not be +right in telling Longmans that the book would be utterly forgotten in +ten years. Hurrah! + + +LETTER 663. TO D. OLIVER. Down, February 17th [1864]. + +Many thanks for the Epacrids, which I have kept, as they will interest +me when able to look through the microscope. + +Dr. Cruger has sent me the enclosed paper, with power to do what I think +fit with it. He would evidently prefer it to appear in the "Nat. Hist. +Review." Please read it, and let me have your decision pretty soon. Some +germanisms must be corrected; whether woodcuts are necessary I have not +been able to pay attention enough to decide. If you refuse, please send +it to the Linnean Society as communicated by me. (663/1. H. Cruger's +"A Few Notes on the Fecundation of Orchids, etc." [Read March, 1864.] +"Linn. Soc. Journ." VIII., 1864-5, page 127.) The paper has interested +me extremely, and I shall have no peace till I have a good boast. The +sexes are separate in Catasetum, which is a wonderful relief to me, as I +have had two or three letters saying that the male C. tridentatum seeds. +(663/2. See footnote Letter 608 on the sexual relation between the three +forms known as Catasetum tridentatum, Monacanthus viridis, and Myanthus +barbatus. For further details see Darwin, "Linn. Soc. Journ." VI., 1862, +page 151, and "Fertilisation of Orchids," Edition II., page 196.) It +is pretty clear to me that two or three forms are confounded under this +name. Observe how curiously nearly perfect the pollen of the female is, +according to Cruger,--certainly more perfect than the pollen from the +Guyana species described by me. I was right in the manner in which the +pollen adheres to the hairy back of the humble-bee, and hence the +force of the ejection of the pollina. (663/3. This view was given in +"Fertilisation of Orchids," Edition I., 1862, page 230.) I am still more +pleased that I was right about insects gnawing the fleshy labellum. +This is important, as it explains all the astounding projections on the +labellum of Oncidium, Phalaenopsis, etc. + +Excuse all my boasting. It is the best medicine for my stomach. Tell me +whether you mean to take up orchids, as Hooker said you were thinking of +doing. Do you know Coryanthes, with its wonderful basket of water? See +what Cruger says about it. It beats everything in orchids. (663/4. For +Coryanthes see "Fertilisation of Orchids," Edition II., page 173.) + + +LETTER 664. TO J.D. HOOKER. Down [September 13th, 1864]. + +Thanks for your note of the 5th. You think much and greatly too much +of me and my doings; but this is pleasant, for you have represented for +many years the whole great public to me. + +I have read with interest Bentham's address on hybridism. I am glad +that he is cautious about Naudin's view, for I cannot think that it will +hold. (664/1. C. Naudin's "Nouvelles Recherches sur l'Hydridite dans les +Vegetaux." The complete paper, with coloured plates, was presented to +the Academy in 1861, and published in full in the "Nouvelles Archives +de Museum d'Hist. Nat." Volume I., 1865, page 25. The second part only +appeared in the "Ann. Sci. Nat." XIX., 1863. Mr. Bentham's address +dealing with hybridism is in "Proc. Linn. Soc." VIII., 1864, page ix. +A review of Naudin is given in the "Natural History Review," 1864, +page 50. Naudin's paper is of much interest, as containing a mechanical +theory of reproduction of the same general character as that of +pangenesis. In the "Variation of Animals and Plants," Edition II., +Volume II., page 395, Darwin states that in his treatment of hybridism +in terms of gemmules he is practically following Naudin's treatment of +the same theme in terms of "essences." Naudin, however, does not clearly +distinguish between hybrid and pure gemmules, and makes the assumption +that the hybrid or mixed essences tend constantly to dissociate into +pure parental essences, and thus lead to reversion. It is to this view +that Darwin refers when he says that Naudin's view throws no light on +the reversion to long-lost characters. His own attempt at explaining +this fact occurs in "Variation under Domestication," II., Edition II., +page 395. Mr. Bateson ("Mendel's Principle of Heredity," Cambridge, +1902, page 38) says: "Naudin clearly enuntiated what we shall henceforth +know as the Mendelian conception of the dissociation of characters of +cross-breds in the formation of the germ-cells, though apparently he +never developed this conception." It is remarkable that, as far as we +know, Darwin never in any way came across Mendel's work. One of Darwin's +correspondents, however, the late Mr. T. Laxton, of Stamford, was close +on the trail of Mendelian principle. Mr. Bateson writes (op. cit., page +181): "Had he [Laxton] with his other gifts combined this penetration +which detects a great principle hidden in the thin mist of 'exceptions,' +we should have been able to claim for him that honour which must ever +be Mendel's in the history of discovery.") The tendency of hybrids +to revert to either parent is part of a wider law (which I am fully +convinced that I can show experimentally), namely, that crossing races +as well as species tends to bring back characters which existed in +progenitors hundreds and thousands of generations ago. Why this should +be so, God knows. But Naudin's view throws no light, that I can see, +on this reversion of long-lost characters. I wish the Ray Society would +translate Gartner's "Bastarderzeugung"; it contains more valuable matter +than all other writers put together, and would do great service +if better known. (664/2. "Versuche uber die Bastarderzeugung im +Pflanzenreich": Stuttgart, 1849.) + + +LETTER 665. TO T.H. HUXLEY. + +(665/1. Mr. Huxley had doubted the accuracy of observations on Catasetum +published in the "Fertilisation of Orchids." In what formed the +postscript to the following letter, Darwin wrote: "I have had more +Catasetums,--all right, you audacious 'caviller.'") + +Down, October 31st [1862]. + +In a little book, just published, called the "Three Barriers" (a +theological hash of old abuse of me), Owen gives to the author a new +resume of his brain doctrine; and I thought you would like to hear of +this. He ends with a delightful sentence. "No science affords more scope +or easier ground for the caviller and controversialist; and these do +good by preventing scholars from giving more force to generalisations +than the master propounding them does, or meant his readers or hearers +to give." + +You will blush with pleasure to hear that you are of some use to the +master. + + +LETTER 666. TO J.D. HOOKER. [February, 1864?] + +I shall write again. I write now merely to ask, if you have Naravelia +(666/1. Ranunculaceae.) (the Clematis-like plant told me by Oliver), +to try and propagate me a plant at once. Have you Clematis cirrhosa? It +will amuse me to tell you why Clematis interests me, and why I should +so very much like to have Naravelia. The leaves of Clematis have no +spontaneous movement, nor have the internodes; but when by growth the +peduncles of leaves are brought into contact with any object, they bend +and catch hold. The slightest stimulus suffices, even a bit of cotton +thread a few inches long; but the stimulus must be applied during six +or twelve hours, and when the peduncles once bend, though the touching +object be removed, they never get straight again. Now mark the +difference in another leaf-climber--viz., Tropaeolum: here the young +internodes revolve day and night, and the peduncles of the leaves are +thus brought into contact with an object, and the slightest momentary +touch causes them to bend in any direction and catch the object, but as +the axis revolves they must be often dragged away without catching, and +then the peduncles straighten themselves again, and are again ready to +catch. So that the nervous system of Clematis feels only a prolonged +touch--that of Tropaeolum a momentary touch: the peduncles of the latter +recover their original position, but Clematis, as it comes into contact +by growth with fixed objects, has no occasion to recover its position, +and cannot do so. You did send me Flagellaria, but most unfortunately +young plants do not have tendrils, and I fear my plant will not get them +for another year, and this I much regret, as these leaf-tendrils seem +very curious, and in Gloriosa I could not make out the action, but +I have now a young plant of Gloriosa growing up (as yet with simple +leaves) which I hope to make out. Thank Oliver for decisive answer about +tendrils of vines. It is very strange that tendrils formed of modified +leaves and branches should agree in all their four highly remarkable +properties. I can show a beautiful gradation by which LEAVES produce +tendrils, but how the axis passes into a tendril utterly puzzles me. I +would give a guinea if vine-tednrils could be found to be leaves. + +(666/2. It is an interesting fact that Darwin's work on climbing plants +was well advanced before he discovered the existence of the works of +Palm, Mohl, and Dutrochet on this subject. On March 22nd, 1864, he +wrote to Hooker:--"You quite overrate my tendril work, and there is no +occasion to plague myself about priority." In June he speaks of having +read "two German books, and all, I believe, that has been written on +climbers, and it has stirred me up to find that I have a good deal of +new matter.") + + +LETTER 667. TO J.D. HOOKER. Down, June 2nd [1864]. + +You once offered me a Combretum. (667/1. The two forms of shoot in C. +argenteum are described in "Climbing Plants," page 41.) I having C. +purpureum, out of modesty like an ass refused. Can you now send me +a plant? I have a sudden access of furor about climbers. Do you grow +Adlumia cirrhosa? Your seed did not germinate with me. Could you have +a seedling dug up and potted? I want it fearfully, for it is a +leaf-climber, and therefore sacred. + +I have some hopes of getting Adlumia, for I used to grow the plant, +and seedlings have often come up, and we are now potting all minute +reddish-coloured weeds. (667/2. We believe that the Adlumia which came +up year by year in flower boxes in the Down verandah grew from seed +supplied by Asa Gray.) I have just got a plant with sensitive axis, +quite a new case; and tell Oliver I now do not care at all how many +tendrils he makes axial, which at one time was a cruel torture to me. + + +LETTER 668. TO J.D. HOOKER. Down, November 3rd [1864]. + +Many thanks for your splendid long letter. But first for business. +Please look carefully at the enclosed specimen of Dicentra +thalictriformis, and throw away. (668/1. Dicentra thalictrifolia, a +Himalayan species of Fumariaceae, with leaf-tendrils.) When the plant +was young I concluded certainly that the tendrils were axial, or +modified branches, which Mohl says is the case with some Fumariaceae. +(668/2. "Ueber den Bau und das Winden der Ranken und Schlingpflanzen. +Eine gekronte Preisschrift," 4to, Tubingen, 1827. At page 43 Mohl +describes the tips of the branches of Fumaria [Corydalis] clavicualta +as being developed into tendrils, as well as the leaves. For this reason +Darwin placed the plant among the tendril-bearers rather than among the +true leaf-climbers: see "Climbing Plants," Edition II., 1875, page 121.) +You looked at them here and agreed. But now the plant is old, what I +thought was a branch with two leaves and ending in a tendril looks +like a gigantic leaf with two compound leaflets, and the terminal part +converted into a tendril. For I see buds in the fork between supposed +branch and main stem. Pray look carefully--you know I am profoundly +ignorant--and save me from a horrid mistake. + + +LETTER 669. TO J.D. HOOKER. + +(669/1. The following is interesting, as containing a foreshadowing of +the chemotaxis of antherozoids which was shown to exist by Pfeffer in +1881: see "Untersuchungen aus dem botanischen Institut zu Tubingen," +Volume I., page 363. There are several papers by H.J. Carter on the +reproduction of the lower organisms in the "Annals and Magazine of +Natural History" between 1855 and 1865.) + +Down, Sunday, 22nd, and Saturday, 28th [October, 1865]. + +I have been wading through the "Annals and Mag. of N. History." for last +ten years, and have been interested by several papers, chiefly, however, +translations; but none have interested me more than Carter's on lower +vegetables, infusoria, and protozoa. Is he as good a workman as he +appears? for if so he would deserve a Royal medal. I know it is not new; +but how wonderful his account of the spermatozoa of some dioecious alga +or conferva, swimming and finding the minute micropyle in a distinct +plant, and forcing its way in! Why, these zoospores must possess some +sort of organ of sense to guide their locomotive powers to the small +micropyle; and does not this necessarily imply something like a nervous +system, in the same way as complemental male cirripedes have organs of +sense and locomotion, and nothing else but a sack of spermatozoa? + + +LETTER 670. TO F. HILDEBRAND. May 16th, 1866. + +Since writing to you before, I have read your admirable memoir on +Salvia (670/1. "Pringsheim's Jahrbucher," Volume IV., 1866.), and it has +interested me almost as much as when I first investigated the structure +of orchids. Your paper illustrates several points in my "Origin of +Species," especially the transition of organs. Knowing only two or three +species in the genus, I had often marvelled how one cell of the anther +could have been transformed into the moveable plate or spoon; and how +well you show the gradations. But I am surprised that you did not more +strongly insist on this point. + +I shall be still more surprised if you do not ultimately come to the +same belief with me, as shown by so many beautiful contrivances,--that +all plants require, from some unknown cause, to be occasionally +fertilised by pollen from a distinct individual. + + +(PLATE: FRITZ MULLER.) + + +2.XI.II. CORRESPONDENCE WITH FRITZ MULLER, 1865-1881. + +(671/1. The letters from Darwin to Muller are given as a separate group, +instead of in chronological sequence with the other botanical letters, +as better illustrating the uninterrupted friendship and scientific +comradeship of the two naturalists.) + + +LETTER 671. TO F. MULLER. Down, October 17th [1865]. + +I received about a fortnight ago your second letter on climbing plants, +dated August 31st. It has greatly interested me, and it corrects and +fills up a great hiatus in my paper. As I thought you could not object, +I am having your letter copied, and will send the paper to the Linnean +Society. (671/2. "Notes on some of the Climbing Plants near Desterro" +[1865], "Linn. Soc. Journ." IX., 1867.) I have slightly modified the +arrangement of some parts and altered only a few words, as you write as +good English as an Englishman. I do not quite understand your account of +the arrangement of the leaves of Strychnos, and I think you use the word +"bracteae" differently to what English authors do; therefore I will get +Dr. Hooker to look over your paper. + +I cannot, of course, say whether the Linnean Society will publish your +paper; but I am sure it ought to do so. As the Society is rather poor, +I fear that it will give only a few woodcuts from your truly admirable +sketches. + + +LETTER 672. TO F. MULLER. + +(672/1. In Darwin's book on Climbing Plants, 1875 (672/2. First given +as a paper before the Linnean Society, and published in the "Linn. Soc. +Journ." Volume IX.,), he wrote (page 205): "The conclusion is forced on +our minds that the capacity of revolving, on which most climbing plants +depend, is inherent, though undeveloped, in almost every plant in the +vegetable Kingdom"--a conclusion which was verified in the "Power of +Movement in Plants." The present letter is interesting in referring +to Fritz Muller's observations on the "revolving nutation," or +circumnutation of Alisma macrophylla and Linum usitatissimum, the latter +fact having been discovered by F. Muller's daughter Rosa. This +was probably the earliest observation on the circumnutation of a +non-climbing plant, and Muller, in a paper dated 1868, and published in +Volume V. of the "Jenaische Zeitschrift," page 133, calls attention to +its importance in relation to the evolution of the habit of climbing. +The present letter was probably written in 1865, since it refers to +Muller's paper read before the Linnean Soc. on December 7th, 1865. If +so, the facts on circumnutation must have been communicated to Darwin +some years before their publication in the "Jenaische Zeitschrift.") + +Down, December 9th [1865]. + +I have received your interesting letter of October 10th, with its new +facts on branch-tendrils. If the Linnean Society publishes your paper +(672/3. Ibid., 1867, page 344.), as I am sure it ought to do, I will +append a note with some of these new facts. + +I forwarded immediately your MS. to Professor Max Schultze, but I did +not read it, for German handwriting utterly puzzles me, and I am so +weak, I am capable of no exertion. I took the liberty, however, of +asking him to send me a copy, if separate ones are printed, and I +reminded him about the Sponge paper. + +You will have received before this my book on orchids, and I wish I +had known that you would have preferred the English edition. Should the +German edition fail to reach you, I will send an English one. That is a +curious observation of your daughter about the movement of the apex of +the stem of Linum, and would, I think, be worth following out. (672/4. +F. Muller, "Jenaische Zeitschrift," Bd. V., page 137. Here, also, are +described the movements of Alisma.) I suspect many plants move a little, +following the sun; but all do not, for I have watched some pretty +carefully. + +I can give you no zoological news, for I live the life of the most +secluded hermit. + +I occasionally hear from Ernest Hackel, who seems as determined as you +are to work out the subject of the change of species. You will have seen +his curious paper on certain medusae reproducing themselves by seminal +generation at two periods of growth. + +(672/5. On April 3rd, 1868, Darwin wrote to F. Muller: "Your diagram of +the movements of the flower-peduncle of the Alisma is extremely curious. +I suppose the movement is of no service to the plant, but shows how +easily the species might be converted into a climber. Does it bend +through irritability when rubbed?" + + +LETTER 673. TO F. MULLER. Down, September 25th [1866]. + +I have just received your letter of August 2nd, and am, as usual, +astonished at the number of interesting points which you observe. It +is quite curious how, by coincidence, you have been observing the same +subjects that have lately interested me. + +Your case of the Notylia is quite new to me (673/1. See F. Muller, "Bot. +Zeitung," 1868, page 630; "Fertilisation of Orchids," Edition II., page +171.); but it seems analogous with that of Acropera, about the sexes +of which I blundered greatly in my book. I have got an Acropera now in +flower, and have no doubt that some insect, with a tuft of hairs on its +tail, removes by the tuft, the pollinia, and inserts the little viscid +cap and the long pedicel into the narrow stigmatic cavity, and leaves +it there with the pollen-masses in close contact with, but not inserted +into, the stigmatic cavity. I find I can thus fertilise the flowers, and +so I can with Stanhopea, and I suspect that this is the case with your +Notylia. But I have lately had an orchis in flower--viz. Acineta, +which I could not anyhow fertilise. Dr. Hildebrand lately wrote a paper +(673/2. "Bot. Zeitung," 1863, 1865.) showing that with some orchids +the ovules are not mature and are not fertilised until months after +the pollen-tubes have penetrated the column, and you have independently +observed the same fact, which I never suspected in the case of Acropera. +The column of such orchids must act almost like the spermatheca of +insects. Your orchis with two leaf-like stigmas is new to me; but I +feel guilty at your wasting your valuable time in making such beautiful +drawings for my amusement. + +Your observations on those plants being sterile which grow separately, +or flower earlier than others, are very interesting to me: they would be +worth experimenting on with other individuals. I shall give in my next +book several cases of individual plants being sterile with their +own pollen. I have actually got on my list Eschscholtzia (673/3. See +"Animals and Plants," II., Edition II., page 118.) for fertilising with +its own pollen, though I did not suspect it would prove sterile, and +I will try next summer. My object is to compare the rate of growth of +plants raised from seed fertilised by pollen from the same flower and by +pollen from a distinct plant, and I think from what I have seen I shall +arrive at interesting results. Dr. Hildebrand has lately described +a curious case of Corydalis cava which is quite sterile with its own +pollen, but fertile with pollen of any other individual plant of the +species. (673/4. "International Horticultural Congress," London, 1866, +quoted in "Variation of Animals and Plants," Edition II., Volume +II., page 113.) What I meant in my paper on Linum about plants being +dimorphic in function alone, was that they should be divided into two +equal bodies functionally but not structurally different. I have been +much interested by what you say on seeds which adhere to the valves +being rendered conspicuous. You will see in the new edition of the +"Origin" (673/5. "Origin of Species," Edition IV., 1866, page 238. A +discussion on the origin of beauty, including the bright colours of +flowers and fruits.) why I have alluded to the beauty and bright colours +of fruit; after writing this it troubled me that I remembered to have +seen brilliantly coloured seed, and your view occurred to me. There is a +species of peony in which the inside of the pod is crimson and the seeds +dark purple. I had asked a friend to send me some of these seeds, to +see if they were covered with anything which could prove attractive to +birds. I received some seeds the day after receiving your letter, and I +must own that the fleshy covering is so thin that I can hardly believe +it would lead birds to devour them; and so it was in an analogous case +with Passiflora gracilis. How is this in the cases mentioned by you? The +whole case seems to me rather a striking one. + +I wish I had heard of Mikania being a leaf-climber before your paper +was printed (673/6. See "Climbing Plants (3rd thousand, 1882), page 116. +Mikania and Mutisia both belong to the Compositae. Mikania scandens is a +twining plant: it is another species which, by its leaf-climbing habit, +supplies a transition to the tendril-climber Mutisia. F. Muller's +paper is in "Linn. Soc. Journ." IX., page 344.), for we thus get a +good gradation from M. scandens to Mutisia, with its little modified, +leaf-like tendrils. + +I am glad to hear that you can confirm (but render still more wonderful) +Hackel's most interesting case of Linope. Huxley told me that he thought +the case would somehow be explained away. + + +LETTER 674. TO F. MULLER. Down [Received January 24th, 1867]. + +I have so much to thank you for that I hardly know how to begin. I have +received the bulbils of Oxalis, and your most interesting letter of +October 1st. I planted half the bulbs, and will plant the other half +in the spring. The case seems to me very curious, and until trying some +experiments in crossing I can form no conjecture what the abortion of +the stamens in so irregular a manner can signify. But I fear from what +you say the plant will prove sterile, like so many others which increase +largely by buds of various kinds. Since I asked you about Oxalis, Dr. +Hildebrand has published a paper showing that a great number of species +are trimorphic, like Lythrum, but he has tried hardly any experiments. +(674/1. Hildebrand's work, published in the "Monatsb. d. Akad. d. Wiss. +Berlin," 1866, was chiefly on herbarium specimens. His experimental work +was published in the "Bot. Zeitung," 1871.) + +I am particularly obliged for the information and specimens of Cordia +(674/2. Cordiaceae: probably dimorphic.), and shall be most grateful for +seed. I have not heard of any dimorphic species in this family. Hardly +anything in your letter interested me so much as your account and +drawing of the valves of the pod of one of the Mimoseae with the really +beautiful seeds. I will send some of these seeds to Kew to be planted. +But these seeds seem to me to offer a very great difficulty. They do +not seem hard enough to resist the triturating power of the gizzard of a +gallinaceous bird, though they must resist that of some other birds; +for the skin is as hard as ivory. I presume that these seeds cannot +be covered with any attractive pulp? I soaked one of the seeds for ten +hours in warm water, which became only very slightly mucilaginous. +I think I will try whether they will pass through a fowl uninjured. +(674/3. The seeds proved to be those of Adenanthera pavonina. The +solution of the difficulty is given in the following extract from a +letter to Muller, March 2nd, 1867: "I wrote to India on the subject, +and I hear from Mr. J. Scott that parrots are eager for the seeds, and, +wonderful as the fact is, can split them open with their beaks; they +first collect a large number in their beaks, and then settle themselves +to split them, and in doing so drop many; thus I have no doubt they are +disseminated, on the same principle that the acorns of our oaks are most +widely disseminated." Possibly a similar explanation may hold good +for the brightly coloured seeds of Abrus precatorius.) I hope you will +observe whether any bird devours them; and could you get any young man +to shoot some and observe whether the seeds are found low down in +the intestines? It would be well worth while to plant such seeds with +undigested seeds for comparison. An opponent of ours might make a +capital case against us by saying that here beautiful pods and seeds +have been formed not for the good of the plant, but for the good of +birds alone. These seeds would make a beautiful bracelet for one of my +daughters, if I had enough. I may just mention that Euonymus europoeus +is a case in point: the seeds are coated by a thin orange layer, which I +find is sufficient to cause them to be devoured by birds. + +I have received your paper on Martha [Posoqueria (674/4. "Bot. Zeitung," +1866.)]; it is as wonderful as the most wonderful orchis; Ernst Hackel +brought me the paper and stayed a day with me. I have seldom seen a +more pleasant, cordial, and frank man. He is now in Madeira, where he is +going to work chiefly on the Medusae. His great work is now published, +and I have a copy; but the german is so difficult I can make out but +little of it, and I fear it is too large a work to be translated. Your +fact about the number of seeds in the capsule of the Maxillaria (674/5. +See "Animals and Plants," Edition II., Volume II., page 115.) came just +at the right time, as I wished to give one or two such facts. Does this +orchid produce many capsules? I cannot answer your question about the +aerial roots of Catasetum. I hope you have received the new edition +of the "Origin." Your paper on climbing plants (674/6. "Linn. Soc. +Journal," IX., 1867, page 344.) is printed, and I expect in a day or two +to receive the spare copies, and I will send off three copies as before +stated, and will retain some in case you should wish me to send them to +any one in Europe, and will transmit the remainder to yourself. + + +LETTER 675. TO F. MULLER. Down [received February 24th, 1867]. + +Your letter of November 2nd contained an extraordinary amount of +interesting matter. What a number of dimorphic plants South Brazil +produces: you observed in one day as many or more dimorphic genera than +all the botanists in Europe have ever observed. When my present book +is finished I shall write a final paper upon these plants, so that I +am extremely glad to hear of your observations and to see the dried +flowers; nevertheless, I should regret MUCH if I prevented you from +publishing on the subject. Plumbago (675/1. Plumbago has not been shown +to be dimorphic.) is quite new to me, though I had suspected it. It is +curious how dimorphism prevails by groups throughout the world, +showing, as I suppose, that it is an ancient character; thus Hedyotis is +dimorphic in India (675/2. Hedyotis was sent to Darwin by F. Muller; it +seems possible, therefore, that Hedyotis was written by mistake for some +other Rubiaceous plant, perhaps Oldenlandia, which John Scott sent him +from India.); the two other genera in the same sub-family with Villarsia +are dimorphic in Europe and Ceylon; a sub-genus of Erythroxylon (675/3. +No doubt Sethia.) is dimorphic in Ceylon, and Oxalis with you and at the +Cape of Good Hope. If you can find a dimorphic Oxalis it will be a new +point, for all known species are trimorphic or monomorphic. The case of +Convolvulus will be new, if proved. I am doubtful about Gesneria (675/4. +Neither Convolvulus nor Gesneria have been shown to be dimorphic.), +and have been often myself deceived by varying length of pistil. +A difference in the size of the pollen-grains would be conclusive +evidence; but in some cases experiments by fertilisation can alone +decide the point. As yet I know of no case of dimorphism in flowers +which are very irregular; such flowers being apparently always +sufficiently visited and crossed by insects. + + +LETTER 676. TO F. MULLER. Down, April 22nd [1867]. + +I am very sorry your papers on climbing plants never reached you. They +must be lost, but I put the stamps on myself and I am sure they were +right. I despatched on the 20th all the remaining copies, except one for +myself. Your letter of March 4th contained much interesting matter, but +I have to say this of all your letters. I am particularly glad to hear +that Oncidium flexuosum (676/1. See "Animals and Plants," Edition II., +Volume II., page 114. Observations on Oncidium were made by John Scott, +and in Brazil by F. Muller, who "fertilised above one hundred flowers of +the above-mentioned Oncidium flexuosum, which is there endemic, with +its own pollen, and with that taken from distinct plants: all the former +were sterile, whilst those fertilised by pollen from any OTHER PLANT of +the same species were fertile.') is endemic, for I always thought that +the cases of self-sterility with orchids in hot-houses might have been +caused by their unnatural conditions. I am glad, also, to hear of the +other analogous cases, all of which I will give briefly in my book +that is now printing. The lessened number of good seeds in the +self-fertilising Epidendrums is to a certain extent a new case. +You suggest the comparison of the growth of plants produced from +self-fertilised and crossed seeds. I began this work last autumn, and +the result, in some cases, has been very striking; but only, as far as +I can yet judge, with exotic plants which do not get freely crossed by +insects in this country. In some of these cases it is really a wonderful +physiological fact to see the difference of growth in the plants +produced from self-fertilised and crossed seeds, both produced by the +same parent-plant; the pollen which has been used for the cross having +been taken from a distinct plant that grew in the same flower-pot. Many +thanks for the dimorphic Rubiaceous plant. Three of your Plumbagos have +germinated, but not as yet any of the Lobelias. Have you ever thought of +publishing a work which might contain miscellaneous observations on all +branches of Natural History, with a short description of the country and +of any excursions which you might take? I feel certain that you might +make a very valuable and interesting book, for every one of your +letters is so full of good observations. Such books, for instance Bates' +"Travels on the Amazons," are very popular in England. I will give your +obliging offer about Brazilian plants to Dr. Hooker, who was to have +come here to-day, but has failed. He is an excellent good fellow, as +well as naturalist. He has lately published a pamphlet, which I think +you would like to read; and I will try and get a copy and send you. +(676/2. Sir J.D. Hooker's lecture on Insular Floras, given before +the British Association in August, 1866, is doubtless referred to. It +appeared in the "Gardeners' Chronicle," and was published as a pamphlet +in January, 1867. This fact helps to fix the date of the present +letter.) + + +LETTER 677. TO F. MULLER. + +(677/1. The following refers to the curious case of Eschscholtzia +described in "Cross and Self-Fertilisation," pages 343-4. The offspring +of English plants after growing for two generations in Brazil became +self-sterile, while the offspring of Brazilian plants became partly +self-fertile in England.) + +January 30th [1868]. + +...The flowers of Eschscholtzia when crossed with pollen from a distinct +plant produced 91 per cent. of capsules; when self-fertilised the +flowers produced only 66 per cent. of capsules. An equal number of +crossed and self-fertilised capsules contained seed by weight in the +proportion of 100 to 71. Nevertheless, the self-fertilised flowers +produced an abundance of seed. I enclose a few crossed seeds in hopes +that you will raise a plant, cover it with a net, and observe whether it +is self-fertile; at the same time allowing several uncovered plants to +produce capsules, for the sterility formerly observed by you seems to me +very curious. + + +LETTER 678. TO F. MULLER. Down, November 28th [1868]. + +You end your letter of September 9th by saying that it is a very +dull one; indeed, you make a very great mistake, for it abounds with +interesting facts and thoughts. Your account of the tameness of the +birds which apparently have wandered from the interior, is very curious. +But I must begin on another subject: there has been a great and very +vexatious, but unavoidable delay in the publication of your book. +(678/1. "Facts and Arguments for Darwin," 1869, a translation by the +late Mr. Dallas of F. Muller's "Fur Darwin," 1864: see Volume I., Letter +227.) Prof. Huxley agrees with me that Mr. Dallas is by far the best +translator, but he is much overworked and had not quite finished the +translation about a fortnight ago. He has charge of the Museum at York, +and is now trying to get the situation of Assistant Secretary at the +Geological Society; and all the canvassing, etc., and his removal, if +he gets the place, will, I fear, cause more than a month's delay in the +completion of the translation; and this I very much regret. + +I am particularly glad to hear that you intend to repeat my experiments +on illegitimate offspring, for no one's observations can be trusted +until repeated. You will find the work very troublesome, owing to the +death of plants and accidents of all kinds. Some dimorphic plant will +probably prove too sterile for you to raise offspring; and others too +fertile for much sterility to be expected in their offspring. Primula +is bad on account of the difficulty of deciding which seeds may be +considered as good. I have earnestly wished that some one would repeat +these experiments, but I feared that years would elapse before any +one would take the trouble. I received your paper on Bignonia in "Bot. +Zeit." and it interested me much. (678/2. See "Variation of Animals +and Plants," Edition II., Volume II., page 117. Fritz Muller's paper, +"Befruchtungsversuche an Cipo alho (Bignonia)," "Botanische Zeitung," +September 25th, 1868, page 625, contains an interesting foreshadowing of +the generalisation arrived at in "Cross and Self-Fertilisation." Muller +wrote: "Are the three which grow near each other seedlings from the same +mother-plant or perhaps from seeds of the same capsule? Or have they, +from growing in the same place and under the same conditions, become so +like each other that the pollen of one has hardly any more effect on +the others than their own pollen? Or, on the contrary, were the plants +originally one--i.e., are they suckers from a single stock, which +have gained a slight degree of mutual fertility in the course of an +independent life? Or, lastly, is the result 'ein neckische Zufall,'" +(The above is a free translation of Muller's words.)) I am convinced +that if you can prove that a plant growing in a distant place under +different conditions is more effective in fertilisation than one +growing close by, you will make a great step in the essence of sexual +reproduction. + +Prof. Asa Gray and Dr. Hooker have been staying here, and, oddly +enough, they knew nothing of your paper on Martha (678/3. F. Muller has +described ("Bot. Zeitung," 1866, page 129) the explosive mechanism by +which the pollen is distributed in Martha (Posoqueria) fragrans. He +also gives an account of the remarkable arrangement for ensuring +cross-fertilisation. See "Forms of Flowers," Edition II., page 131.), +though the former was aware of the curious movements of the stamens, but +so little understood the structure of the plant that he thought it was +probably a dimorphic species. Accordingly, I showed them your drawings +and gave them a little lecture, and they were perfectly charmed with +your account. Hildebrand (678/4. See Letter 206, Volume I.) has repeated +his experiments on potatoes, and so have I, but this summer with no +result. + + +LETTER 679. TO F. MULLER. Down, March 14th [1869]. + +I received some time ago a very interesting letter from you with many +facts about Oxalis, and about the non-seeding and spreading of one +species. I may mention that our common O. acetosella varies much +in length of pistils and stamens, so that I at first thought it was +certainly dimorphic, but proved it by experiment not to be so. Boiseria +(679/1. This perhaps refers to Boissiera (Ladizabala).) has after all +seeded well with me when crossed by opposite form, but very sparingly +when self-fertilised. Your case of Faramea astonishes me. (679/2. See +"Forms of Flowers," Edition II., page 129. Faramea is placed among the +dimorphic species.) Are you sure there is no mistake? The difference +in size of flower and wonderful difference in size and structure of +pollen-grains naturally make me rather sceptical. I never fail to admire +and to be surprised at the number of points to which you attend. I go +on slowly at my next book, and though I never am idle, I make but slow +progress; for I am often interrupted by being unwell, and my subject +of sexual selection has grown into a very large one. I have also had +to correct a new edition of my "Origin," (679/3. The 5th edition.), and +this has taken me six weeks, for science progresses at railroad speed. +I cannot tell you how rejoiced I am that your book is at last out; for +whether it sells largely or not, I am certain it will produce a great +effect on all capable judges, though these are few in number. + +P.S.--I have just received your letter of January 12th. I am greatly +interested by what you say on Eschscholtzia; I wish your plants had +succeeded better. It seems pretty clear that the species is much more +self-sterile under the climate of Brazil than here, and this seems to me +an important result. (679/4. See Letter 677.) I have no spare seeds at +present, but will send for some from the nurseryman, which, though not +so good for our purpose, will be worth trying. I can send some of my own +in the autumn. You could simply cover up separately two or three single +plants, and see if they will seed without aid,--mine did abundantly. +Very many thanks for seeds of Oxalis: how I wish I had more strength and +time to carry on these experiments, but when I write in the morning, I +have hardly heart to do anything in the afternoon. Your grass is most +wonderful. You ought to send account to the "Bot. Zeitung." Could you +not ascertain whether the barbs are sensitive, and how soon they +become spiral in the bud? Your bird is, I have no doubt, the Molothrus +mentioned in my "Journal of Travels," page 52, as representing a North +American species, both with cuckoo-like habits. I know that seeds from +same spike transmitted to a certain extent their proper qualities; but +as far as I know, no one has hitherto shown how far this holds good, and +the fact is very interesting. The experiment would be well worth trying +with flowers bearing different numbers of petals. Your explanation +agrees beautifully with the hypothesis of pangenesis, and delights me. +If you try other cases, do draw up a paper on the subject of inheritance +of separate flowers for the "Bot. Zeitung" or some journal. Most men, +as far as my experience goes, are too ready to publish, but you seem +to enjoy making most interesting observations and discoveries, and are +sadly too slow in publishing. + + +LETTER 680. TO F. MULLER. Barmouth, July 18th, 1869. + +I received your last letter shortly before leaving home for this place. +Owing to this cause and to having been more unwell than usual I have +been very dilatory in writing to you. When I last heard, about six or +eight weeks ago, from Mr. Murray, one hundred copies of your book had +been sold, and I daresay five hundred may now be sold. (680/1. "Facts +and Arguments for Darwin," 1869: see Volume I., Letter 227.) This will +quite repay me, if not all the money; for I am sure that your book will +have got into the hands of a good many men capable of understanding it: +indeed, I know that it has. But it is too deep for the general public. +I sent you two or three reviews--one of which, in the "Athenaeum," was +unfavourable; but this journal has abused me, and all who think with me, +for many years. (680/2. "Athenaeum," 1869, page 431.) I enclose two more +notices, not that they are worth sending: some other brief notices have +appeared. The case of the Abitulon sterile with some individuals is +remarkable (680/3. "Bestaubungsversuche an Abutilon-Arten." "Jenaische +Zeitschr." VII., 1873, page 22.): I believe that I had one plant of +Reseda odorata which was fertile with own pollen, but all that I have +tried since were sterile except with pollen from some other individual. +I planted the seeds of the Abitulon, but I fear that they were crushed +in the letter. Your Eschscholtzia plants were growing well when I left +home, to which place we shall return by the end of this month, and I +will observe whether they are self-sterile. I sent your curious account +of the monstrous Begonia to the Linnean Society, and I suppose it will +be published in the "Journal." (680/4. "On the Modification of the +Stamens in a Species of Begonia." "Journ. Linn. Soc." XI., 1871, page +472.) I sent the extract about grafted orange trees to the "Gardeners' +Chronicle," where it appeared. I have lately drawn up some notes for a +French translation of my Orchis book: I took out your letters to make an +abstract of your numerous discussions, but I found I had not strength +or time to do so, and this caused me great regret. I have [in the French +edition] alluded to your work, which will also be published in English, +as you will see in my paper, and which I will send you. (680/5. "Notes +on the Fertilisation of Orchids." "Ann. Mag. Nat. Hist." 1869, Volume +IV., page 141. The paper gives an English version of the notes prepared +for the French edition of the Orchid book.) + +P.S.--By an odd chance, since I wrote the beginning of this letter, I +have received one from Dr. Hooker, who has been reading "Fur Darwin": he +finds that he has not knowledge enough for the first part; but says +that Chapters X. and XI. "strike me as remarkably good." He is also +particularly struck with one of your highly suggestive remarks in the +note to page 119. Assuredly all who read your book will greatly profit +by it, and I rejoice that it has appeared in English. + + +LETTER 681. TO F. MULLER. Down, December 1st [1869]. + +I am much obliged for your letter of October 18th, with the curious +account of Abutilon, and for the seeds. A friend of mine, Mr. Farrer, +has lately been studying the fertilisation of Passiflora (681/1. See +Letters 701 and 704.), and concluded from the curiously crooked passage +into the nectary that it could not be fertilised by humming-birds; but +that Tacsonia was thus fertilised. Therefore I sent him the passage from +your letter, and I enclose a copy of his answer. If you are inclined to +gratify him by making a few observations on this subject I shall be +much obliged, and will send them on to him. I enclose a copy of my rough +notes on your Eschscholtzia, as you might like to see them. Somebody has +sent me from Germany two papers by you, one with a most curious account +of Alisma (681/2. See Letter 672.), and the other on crustaceans. Your +observations on the branchiae and heart have interested me extremely. + +Alex. Agassiz has just paid me a visit with his wife. He has been in +England two or three months, and is now going to tour over the Continent +to see all the zoologists. We liked him very much. He is a great admirer +of yours, and he tells me that your correspondence and book first +made him believe in evolution. This must have been a great blow to his +father, who, as he tells me, is very well, and so vigorous that he can +work twice as long as he (the son) can. + +Dr. Meyer has sent me his translation of Wallace's "Malay Archipelago," +which is a valuable work; and as I have no use for the translation, +I will this day forward it to you by post, but, to save postage, via +England. + + +LETTER 682. TO F. MULLER. Down, May 12th [1870]. + +I thank you for your two letters of December 15th and March 29th, both +abounding with curious facts. I have been particularly glad to hear in +your last about the Eschscholtzia (682/1. See Letter 677.); for I am now +rearing crossed and self-fertilised plants, in antagonism to each other, +from your semi-sterile plants so that I may compare this comparative +growth with that of the offspring of English fertile plants. I have +forwarded your postscript about Passiflora, with the seeds, to Mr. +Farrer, who I am sure will be greatly obliged to you; the turning up of +the pendant flower plainly indicates some adaptation. When I next go to +London I will take up the specimens of butterflies, and show them to +Mr. Butler, of the British Museum, who is a learned lepidopterist +and interested on the subject. This reminds me to ask you whether you +received my letter [asking] about the ticking butterfly, described at +page 33 of my "Journal of Researches"; viz., whether the sound is in +anyway sexual? Perhaps the species does not inhabit your island. (682/2. +Papilio feronia, a Brazilian species capable of making "a clicking +noise, similar to that produced by a toothed wheel passing under a +spring catch."--"Journal," 1879, page 34.) + +The case described in your last letter of the trimorphic monocotyledon +Pontederia is grand. (682/3. This case interested Darwin as the only +instance of heterostylism in Monocotyledons. See "Forms of Flowers," +Edition II., page 183. F. Muller's paper is in the "Jenaische +Zeitschrift," 1871.) I wonder whether I shall ever have time to recur +to this subject; I hope I may, for I have a good deal of unpublished +material. + +Thank you for telling me about the first-formed flower having additional +petals, stamens, carpels, etc., for it is a possible means of transition +of form; it seems also connected with the fact on which I have insisted +of peloric flowers being so often terminal. As pelorism is strongly +inherited (and [I] have just got a curious case of this in a leguminous +plant from India), would it not be worth while to fertilise some of +your early flowers having additional organs with pollen from a similar +flower, and see whether you could not make a race thus characterised? +(682/4. See Letters 588, 589. Also "Variation under Domestication," +Edition II., Volume I., pages 388-9.) Some of your Abutilons have +germinated, but I have been very unfortunate with most of your seed. + +You will remember having given me in a former letter an account of +a very curious popular belief in regard to the subsequent progeny +of asses, which have borne mules; and now I have another case almost +exactly like that of Lord Morton's mare, in which it is said the shape +of the hoofs in the subsequent progeny are affected. (Pangenesis will +turn out true some day!) (682/5. See "Animals and Plants," Edition +II., Volume I., page 435. For recent work on telegony see Ewart's +"Experimental Investigations on Telegony," "Phil. Trans. R. Soc." 1899. +A good account of the subject is given in the "Quarterly Review," 1899, +page 404. See also Letter 275, Volume I.) + +A few months ago I received an interesting letter and paper from your +brother, who has taken up a new and good line of investigation, viz., +the adaptation in insects for the fertilisation of flowers. + +The only scientific man I have seen for several months is Kolliker, who +came here with Gunther, and whom I liked extremely. + +I am working away very hard at my book on man and on sexual selection, +but I do not suppose I shall go to press till late in the autumn. + + +LETTER 683. TO F. MULLER. Down, January 1st, 1874. + +No doubt I owe to your kindness two pamphlets received a few days ago, +which have interested me in an extraordinary degree. (683/1. This refers +to F. Muller's "Bestaubungsversuche an Abutilon-Arten" in the "Jenaische +Zeitschr." Volume VII., which are thus referred to by Darwin ("Cross +and Self Fert." pages 305-6): "Fritz Muller has shown by his valuable +experiments on hybrid Abutilons, that the union of brothers and sisters, +parents and children, and of other near relations is highly injurious to +the fertility of the offspring." The Termite paper is in the same volume +(viz., VII.) of the "Jenaische Zeitschr.") It is quite new to me what +you show about the effects of relationship in hybrids--that is to say, +as far as direct proof is concerned. I felt hardly any doubt on the +subject, from the fact of hybrids becoming more fertile when grown in +number in nursery gardens, exactly the reverse of what occurred with +Gartner. (683/2. When many hybrids are grown together the pollination by +near relatives is minimised.) The paper on Termites is even still more +interesting, and the analogy with cleistogene flowers is wonderful. +(683/3. On the back of his copy of Muller's paper Darwin wrote: "There +exist imperfectly developed male and female Termites, with wings much +shorter than those of queen and king, which serve to continue the +species if a fully developed king and queen do not after swarming (which +no doubt is for an occasional cross) enter [the] nest. Curiously like +cleistogamic flowers.") The manner in which you refer to to my chapter +on crossing is one of the most elegant compliments which I have ever +received. + +I have directed to be sent to you Belt's "Nicaragua," which seems to me +the best Natural History book of travels ever published. Pray look to +what he says about the leaf-carrying ant storing the leaves up in a +minced state to generate mycelium, on which he supposes that the larvae +feed. Now, could you open the stomachs of these ants and examine the +contents, so as to prove or disprove this remarkable hypothesis? (683/4. +The hypothesis has been completely confirmed by the researches of +Moller, a nephew of F. Muller's: see his "Brasilische Pilzblumen" +("Botan. Mittheilgn. aus den Tropen," hrsg. von A.F.W. Schimper, Heft +7).) + + +LETTER 684. TO F. MULLER. Down, May 9th, 1877. + +I have been particularly glad to receive your letter of March 25th on +Pontederia, for I am now printing a small book on heterostyled plants, +and on some allied subjects. I feel sure you will not object to my +giving a short account of the flowers of the new species which you have +sent me. I am the more anxious to do so as a writer in the United States +has described a species, and seems to doubt whether it is heterostyled, +for he thinks the difference in the length of the pistil depends merely +on its growth! In my new book I shall use all the information and +specimens which you have sent me with respect to the heterostyled +plants, and your published notices. + +One chapter will be devoted to cleistogamic species, and I will just +notice your new grass case. My son Francis desires me to thank you much +for your kindness with respect to the plants which bury their seeds. + +I never fail to feel astonished, when I receive one of your letters, at +the number of new facts you are continually observing. With respect to +the great supposed subterranean animal, may not the belief have arisen +from the natives having seen large skeletons embedded in cliffs? I +remember finding on the banks of the Parana a skeleton of a Mastodon, +and the Gauchos concluded that it was a borrowing animal like the +Bizcacha. (684/1. On the supposed existence in Patagonia of a gigantic +land-sloth, see "Natural Science," XIII., 1898, page 288, where +Ameghino's discovery of the skin of Neomylodon listai was practically +first made known, since his privately published pamphlet was +not generally seen. The animal was afterwards identified with a +Glossotherium, closely allied to Owen's G. Darwini, which has been named +Glossotherium listai or Grypotherium domesticum. For a good account of +the discoveries see Smith Woodward in "Natural Science," XV., 1899, page +351, where the literature is given.) + + +LETTER 685. TO F. MULLER. Down, May 14th [1877]. + +I wrote to you a few days ago to thank you about Pontederia, and now +I am going to ask you to add one more to the many kindnesses which you +have done for me. I have made many observations on the waxy secretion on +leaves which throw off water (e.g., cabbage, Tropoeolum), and I am now +going to continue my observations. Does any sensitive species of Mimosa +grow in your neighbourhood? If so, will you observe whether the leaflets +keep shut during long-continued warm rain. I find that the leaflets open +if they are continuously syringed with water at a temperature of about +19 deg C., but if the water is at a temperature of 33-35 deg C., they +keep shut for more than two hours, and probably longer. If the plant is +continuously shaken so as to imitate wind the leaflets soon open. How is +this with the native plants during a windy day? I find that some other +plants--for instance, Desmodium and Cassia--when syringed with water, +place their leaves so that the drops fall quickly off; the position +assumed differing somewhat from that in the so-called sleep. Would you +be so kind as to observe whether any [other] plants place their leaves +during rain so as to shoot off the water; and if there are any such +I should be very glad of a leaf or two to ascertain whether they are +coated with a waxy secretion. (685/1. See Letters 737-41.) + +There is another and very different subject, about which I intend to +write, and should be very glad of a little information. Are earthworms +(Lumbricus) common in S. Brazil (685/2. F. Muller's reply is given in +"Vegetable Mould," page 122.), and do they throw up on the surface of +the ground numerous castings or vermicular masses such as we so commonly +see in Europe? Are such castings found in the forests beneath the dead +withered leaves? I am sure I can trust to your kindness to forgive me +for asking you so many questions. + + +LETTER 686. TO F. MULLER. Down, July 24th, 1878. + +Many thanks for the five kinds of seeds; all have germinated, and the +Cassia seedlings have interested me much, and I daresay that I shall +find something curious in the other plants. Nor have I alone profited, +for Sir J. Hooker, who was here on Sunday, was very glad of some of the +seeds for Kew. I am particularly obliged for the information about the +earthworms. I suppose the soil in your forests is very loose, for in +ground which has lately been dug in England the worms do not come to the +surface, but deposit their castings in the midst of the loose soil. + +I have some grand plants (and I formerly sent seeds to Kew) of the +cleistogamic grass, but they show no signs of producing flowers of any +kind as yet. Your case of the panicle with open flowers being sterile +is parallel to that of Leersia oryzoides. I have always fancied that +cross-fertilisation would perhaps make such panicles fertile. (686/1. +The meaning of this sentence is somewhat obscure. Darwin apparently +implies that the perfect flowers, borne on the panicles which +occasionally emerge from the sheath, might be fertile if pollinated from +another individual. See "Forms of Flowers," page 334.) + +I am working away as hard as I can at all the multifarious kinds of +movements of plants, and am trying to reduce them to some simple rules, +but whether I shall succeed I do not know. + +I have sent the curious lepidopteron case to Mr. Meldola. + + +LETTER 687. F. MULLER TO CHARLES DARWIN. + +(687/1. In November, 1880, on receipt of an account of a flood in Brazil +from which Fritz Muller had barely escaped with his life ("Life and +Letters," III., 242); Darwin immediately wrote to Hermann Muller begging +to be allowed to help in making good any loss in books or scientific +instruments that his brother had sustained. It is this offer of help +that is referred to in the first paragraph of the following letter: +Darwin repeats the offer in Letter 690.) + +Blumenau, Sa Catharina, Brazil, January 9th, 1881. + +I do not know how to express [to] you my deep heartfelt gratitude for +the generous offer which you made to my brother on hearing of the +late dreadful flood of the Itajahy. From you, dear sir, I should have +accepted assistance without hesitation if I had been in need of it; but +fortunately, though we had to leave our house for more than a week, and +on returning found it badly damaged, my losses have not been very great. + +I must thank you also for your wonderful book on the movements of +plants, which arrived here on New Year's Day. I think nobody else will +have been delighted more than I was with the results which you have +arrived at by so many admirably conducted experiments and observations; +since I observed the spontaneous revolving movement of Alisma I had seen +similar movements in so many and so different plants that I felt much +inclined to consider spontaneous revolving movement or circumnutation as +common to all plants and the movements of climbing plants as a +special modification of that general phenomenon. And this you have now +convincingly, nay, superabundantly, proved to be the case. + +I was much struck with the fact that with you Maranta did not sleep for +two nights after having its leaves violently shaken by wind, for here we +have very cold nights only after storms from the west or south-west, +and it would be very strange if the leaves of our numerous species of +Marantaceae should be prevented by these storms to assume their usual +nocturnal position, just when nocturnal radiation was most to be feared. +It is rather strange, also, that Phaseolus vulgaris should not sleep +during the early part of the summer, when the leaves are most likely to +be injured during cold nights. On the contrary, it would not do any harm +to many sub-tropical plants, that their leaves must be well illuminated +during the day in order that they may assume at night a vertical +position; for, in our climate at least, cold nights are always preceded +by sunny days. + +Of nearly allied plants sleeping very differently I can give you +some more instances. In the genus Olyra (at least, in the one species +observed by me) the leaves bend down vertically at night; now, +in Endlicher's "Genera plantarum" this genus immediately precedes +Strephium, the leaves of which you saw rising vertically. + +In one of two species of Phyllanthus, growing as weeds near my house, +the leaves of the erect branches bend upwards at night, while in the +second species, with horizontal branches, they sleep like those of +Phyllanthus Niruri or of Cassia. In this second species the tips of +the branches also are curled downwards at night, by which movement +the youngest leaves are yet better protected. From their vertical +nyctitropic position the leaves of this Phyllanthus might return to +horizontality, traversing 90 deg, in two ways, either to their own or to +the opposite side of the branch; on the latter way no rotation would be +required, while on the former each leaf must rotate on its own axis in +order that its upper surface may be turned upwards. Thus the way to the +wrong side appears to be even less troublesome. And indeed, in some rare +cases I have seen three, four or even almost all the leaves of one side +of a branch horizontally expanded on the opposite side, with their upper +surfaces closely appressed to the lower surfaces of the leaves of that +side. + +This Phyllanthus agrees with Cassia not only in its manner of sleeping, +but also by its leaves being paraheliotropic. (687/2. Paraheliotropism +is the movement by which some leaves temporarily direct their edges to +the source of light. See "Movements of Plants," page 445.) Like those of +some Cassiae its leaves take an almost perfectly vertical position, when +at noon, on a summer day, the sun is nearly in the zenith; but I doubt +whether this paraheliotropism will be observable in England. To-day, +though continuing to be fully exposed to the sun, at 3 p.m. the leaves +had already returned to a nearly horizontal position. As soon as there +are ripe seeds I will send you some; of our other species of Phyllanthus +I enclose a few seeds in this letter. + +In several species of Hedychium the lateral halves of the leaves when +exposed to bright sunshine, bend downwards so that the lateral margins +meet. It is curious that a hybrid Hedychium in my garden shows scarcely +any trace of this paraheliotropism, while both the parent species are +very paraheliotropic. + +Might not the inequality of the cotyledons of Citrus and of Pachira be +attributed to the pressure, which the several embryos enclosed in the +same seed exert upon each other? I do not know Pachira aquatica, but +[in] a species, of which I have a tree in my garden, all the seeds +are polyembryonic, and so were almost all the seeds of Citrus which I +examined. With Coffea arabica also seeds including two embryos are +not very rare; but I have not yet observed whether in this case the +cotyledons be inequal. + +I repeated to-day Duval-Jouve's measurements on Bryophyllum calycinum +(687/3. "Power of Movement in Plants," page 237. F. Muller's +measurements show, however, that there is a tendency in the leaves to be +more highly inclined at night than in the middle of the day, and so far +they agree with Duval-Jouve's results.); but mine did not agree with +his; they are as follows:-- + +Distances in mm. between the tips of the upper pair of leaves. + + January 9th, 1881 3 A.M. 1 P.M. 6 P.M. + 1st plant 54 43 36 + 2nd plant 28 25 23 + 3rd plant 28 27 27 + 4th plant 51 46 39 + 5th plant 61 52 45 + _______________________________________________ + + 222 193 170 + + +LETTER 688. TO F. MULLER. Down, February 23rd, 1881. + +Your letter has interested me greatly, as have so many during many past +years. I thought that you would not object to my publishing in "Nature" +(688/1. "Nature," March 3rd, 1881, page 409.) some of the more striking +facts about the movements of plants, with a few remarks added to show +the bearing of the facts. The case of the Phyllanthus (688/2. See +Letter 687.), which turns up its leaves on the wrong side, is most +extraordinary and ought to be further investigated. Do the leaflets +sleep on the following night in the usual manner? Do the same leaflets +on successive nights move in the same strange manner? I was particularly +glad to hear of the strongly marked cases of paraheliotropism. I shall +look out with much interest for the publication about the figs. (688/3. +F. Muller published on Caprification in "Kosmos," 1882.) The creatures +which you sketch are marvellous, and I should not have guessed that they +were hymenoptera. Thirty or forty years ago I read all that I could find +about caprification, and was utterly puzzled. I suggested to Dr. +Cruger in Trinidad to investigate the wild figs, in relation to their +cross-fertilisation, and just before he died he wrote that he had +arrived at some very curious results, but he never published, as I +believe, on the subject. + +I am extremely glad that the inundation did not so greatly injure your +scientific property, though it would have been a real pleasure to me to +have been allowed to have replaced your scientific apparatus. (688/4. +See Letter 687.) I do not believe that there is any one in the world who +admires your zeal in science and wonderful powers of observation more +than I do. I venture to say this, as I feel myself a very old man, who +probably will not last much longer. + +P.S.--With respect to Phyllanthus, I think that it would be a good +experiment to cut off most of the leaflets on one side of the petiole, +as soon as they are asleep and vertically dependent; when the pressure +is thus removed, the opposite leaflets will perhaps bend beyond their +vertically dependent position; if not, the main petiole might be a +little twisted so that the upper surfaces of the dependent and now +unprotected leaflets should face obliquely the sky when the morning +comes. In this case diaheliotropism would perhaps conquer the ordinary +movements of the leaves when they awake, and [assume] their diurnal +horizontal position. As the leaflets are alternate, and as the upper +surface will be somewhat exposed to the dawning light, it is perhaps +diaheliotropism which explains your extraordinary case. + + +LETTER 689. TO F. MULLER. Down, April 12th, 1881. + +I have delayed answering your last letter of February 25th, as I was +just sending to the printers the MS. of a very little book on the habits +of earthworms, of which I will of course send you a copy when published. +I have been very much interested by your new facts on paraheliotropism, +as I think that they justify my giving a name to this kind of movement, +about which I long doubted. I have this morning drawn up an account of +your observations, which I will send in a few days to "Nature." (689/1. +"Nature," 1881, page 603. Curious facts are given on the movements +of Cassia, Phyllanthus, sp., Desmodium sp. Cassia takes up a sunlight +position unlike its own characteristic night-position, but resembling +rather that of Haematoxylon (see "Power of Movement," figure 153, page +369). One species of Phyllanthus takes up in sunshine the nyctitropic +attitude of another species. And the same sort of relation occurs in the +genus Bauhinia.) I have thought that you would not object to my giving +precedence to paraheliotropism, which has been so little noticed. I will +send you a copy of "Nature" when published. I am glad that I was not +in too great a hurry in publishing about Lagerstroemia. (689/2. +Lagerstraemia was doubtfully placed among the heterostyled plants +("Forms of Flowers," page 167). F. Muller's observations showed that a +totally different interpretation of the two sizes of stamen is possible. +Namely, that one set serves merely to attract pollen-collecting bees, +who in the act of visiting the flowers transfer the pollen of the longer +stamens to other flowers. A case of this sort in Heeria, a Melastomad, +was described by Muller ("Nature," August 4th, 1881, page 308), and the +view was applied to the cases of Lagerstroemia and Heteranthera at +a later date ("Nature," 1883, page 364). See Letters 620-30.) I have +procured some plants of Melastomaceae, but I fear that they will not +flower for two years, and I may be in my grave before I can repeat my +trials. As far as I can imperfectly judge from my observations, the +difference in colour of the anthers in this family depends on one set +of anthers being partially aborted. I wrote to Kew to get plants with +differently coloured anthers, but I learnt very little, as describers of +dried plants do not attend to such points. I have, however, sowed seeds +of two kinds, suggested to me as probable. I have, therefore, been +extremely glad to receive the seeds of Heteranthera reniformis. As far +as I can make out it is an aquatic plant; and whether I shall succeed +in getting it to flower is doubtful. Will you be so kind as to send me +a postcard telling me in what kind of station it grows. In the course +of next autumn or winter, I think that I shall put together my notes (if +they seem worth publishing) on the use or meaning of "bloom" (689/3. +See Letters 736-40.), or the waxy secretion which makes some leaves +glaucous. I think that I told you that my experiments had led me to +suspect that the movement of the leaves of Mimosa, Desmodium and Cassia, +when shaken and syringed, was to shoot off the drops of water. If you +are caught in heavy rain, I should be very much obliged if you would +keep this notion in your mind, and look to the position of such leaves. +You have such wonderful powers of observation that your opinion would be +more valued by me than that of any other man. I have among my notes one +letter from you on the subject, but I forget its purport. I hope, also, +that you may be led to follow up your very ingenious and novel view +on the two-coloured anthers or pollen, and observe which kind is most +gathered by bees. + + +LETTER 690. TO F. MULLER. [Patterdale], June 21st, 1881. + +I should be much obliged if you could without much trouble send me seeds +of any heterostyled herbaceous plants (i.e. a species which would +flower soon), as it would be easy work for me to raise some illegitimate +seedlings to test their degree of infertility. The plant ought not +to have very small flowers. I hope that you received the copies of +"Nature," with extracts from your interesting letters (690/1. "Nature," +March 3rd, 1881, Volume XXIII., page 409, contains a letter from C. +Darwin on "Movements of Plants," with extracts from Fritz Muller's +letter. Another letter, "On the Movements of Leaves," was published in +"Nature," April 28th, 1881, page 603, with notes on leaf-movements sent +to Darwin by Muller.), and I was glad to see a notice in "Kosmos" on +Phyllanthus. (690/2. "Verirrte Blatter," by Fritz Muller ("Kosmos," +Volume V., page 141, 1881). In this article an account is given of a +species of Phyllanthus, a weed in Muller's garden. See Letter 687.) I +am writing this note away from my home, but before I left I had the +satisfaction of seeing Phyllanthus sleeping. Some of the seeds which +you so kindly sent me would not germinate, or had not then germinated. +I received a letter yesterday from Dr. Breitenbach, and he tells me +that you lost many of your books in the desolating flood from which you +suffered. Forgive me, but why should you not order, through your brother +Hermann, books, etc., to the amount of 100 pounds, and I would send +a cheque to him as soon as I heard the exact amount? This would be no +inconvenience to me; on the contrary, it would be an honour and lasting +pleasure to me to have aided you in your invaluable scientific work to +this small and trifling extent. (690/3. See Letter 687, also "Life and +Letters," III., page 242.) + + +LETTER 691. TO F. MULLER. + +(691/1. The following extract from a letter to F. Muller shows what was +the nature of Darwin's interest in the effect of carbonate of ammonia on +roots, etc. He was, we think, wrong in adhering to the belief that the +movements of aggregated masses are of an amoeboid nature. The masses +change shape, just as clouds do under the moulding action of the wind. +In the plant cell the moulding agent is the flowing protoplasm, but the +masses themselves are passive.) + +September 10th, 1881. + +Perhaps you may remember that I described in "Insectivorous Plants" +a really curious phenomenon, which I called the aggregation of the +protoplasm in the cells of the tentacles. None of the great German +botanists will admit that the moving masses are composed of protoplasm, +though it is astonishing to me that any one could watch the movement +and doubt its nature. But these doubts have led me to observe analogous +facts, and I hope to succeed in proving my case. + + +LETTER 692. TO F. MULLER. Down, November 13th, 1881. + +I received a few days ago a small box (registered) containing dried +flower-heads with brown seeds somewhat sculptured on the sides. There +was no name, and I should be much obliged if some time you would tell me +what these seeds are. I have planted them. + +I sent you some time ago my little book on earthworms, which, though +of no importance, has been largely read in England. I have little or +nothing to tell you about myself. I have for a couple of months been +observing the effects of carbonate of ammonia on chlorophyll and on the +roots of certain plants (692/1. Published under the title "The Action of +Carbonate of Ammonia on the Roots of Certain Plants and on Chlorophyll +Bodies," "Linn. Soc. Journ." XIX., 1882, pages 239-61, 262-84.), but the +subject is too difficult for me, and I cannot understand the meaning of +some strange facts which I have observed. The mere recording new facts +is but dull work. + +Professor Wiesner has published a book (692/2. See Letter 763.), giving +a different explanation to almost every fact which I have given in my +"Power of Movement in Plants." I am glad to say that he admits that +almost all my statements are true. I am convinced that many of his +interpretations of the facts are wrong, and I am glad to hear that +Professor Pfeffer is of the same opinion; but I believe that he is +right and I wrong on some points. I have not the courage to retry all my +experiments, but I hope to get my son Francis to try some fresh ones to +test Wiesner's explanations. But I do not know why I have troubled you +with all this. + + +LETTER 693. TO F. MULLER. [4, Bryanston Street], December 19th, 1881. + +I hope that you may find time to go on with your experiments on such +plants as Lagerstroemia, mentioned in your letter of October 29th, for +I believe you will arrive at new and curious results, more especially if +you can raise two sets of seedlings from the two kinds of pollen. + +Many thanks for the facts about the effect of rain and mud in relation +to the waxy secretion. I have observed many instances of the lower side +being protected better than the upper side, in the case, as I believe, +of bushes and trees, so that the advantage in low-growing plants is +probably only an incidental one. (693/1. The meaning is here obscure: it +appears to us that the significance of bloom on the lower surface of the +leaves of both trees and herbs depends on the frequency with which all +or a majority of the stomata are on the lower surface--where they are +better protected from wet (even without the help of bloom) than on the +exposed upper surface. On the correlation between bloom and stomata, see +Francis Darwin "Linn. Soc. Journ." XXII., page 99.) As I am writing away +from my home, I have been unwilling to try more than one leaf of the +Passiflora, and this came out of the water quite dry on the lower +surface and quite wet on the upper. I have not yet begun to put my notes +together on this subject, and do not at all know whether I shall be able +to make much of it. The oddest little fact which I have observed is that +with Trifolium resupinatum, one half of the leaf (I think the right-hand +side, when the leaf is viewed from the apex) is protected by waxy +secretion, and not the other half (693/2. In the above passage "leaf" +should be "leaflet": for a figure of Trifolium resupinatum see Letter +740.); so that when the leaf is dipped into water, exactly half the leaf +comes out dry and half wet. What the meaning of this can be I cannot +even conjecture. I read last night your very interesting article in +"Kosmos" on Crotalaria, and so was very glad to see the dried leaves +sent by you: it seems to me a very curious case. I rather doubt whether +it will apply to Lupinus, for, unless my memory deceives me, all the +leaves of the same plant sometimes behaved in the same manner; but I +will try and get some of the same seeds of the Lupinus, and sow them in +the spring. Old age, however, is telling on me, and it troubles me to +have more than one subject at a time on hand. + +(693/3. In a letter to F. Muller (September 10, 1881) occurs a sentence +which may appropriately close this series: "I often feel rather ashamed +of myself for asking for so many things from you, and for taking up so +much of your valuable time, but I can assure you that I feel grateful.") + + +2.XI.III. MISCELLANEOUS, 1868-1881. + + +LETTER 694. TO G. BENTHAM. Down, April 22nd, 1868. + +I have been extremely much pleased by your letter, and I take it as +a very great compliment that you should have written to me at such +length...I am not at all surprised that you cannot digest pangenesis: +it is enough to give any one an indigestion; but to my mind the idea +has been an immense relief, as I could not endure to keep so many large +classes of facts all floating loose in my mind without some thread of +connection to tie them together in a tangible method. + +With respect to the men who have recently written on the crossing +of plants, I can at present remember only Hildebrand, Fritz Muller, +Delpino, and G. Henslow; but I think there are others. I feel sure that +Hildebrand is a very good observer, for I have read all his papers, and +during the last twenty years I have made unpublished observations on +many of the plants which he describes. [Most of the criticisms which I +sometimes meet with in French works against the frequency of crossing I +am certain are the result of mere ignorance. I have never hitherto found +the rule to fail that when an author describes the structure of a flower +as specially adapted for self-fertilisation, it is really adapted for +crossing. The Fumariaceae offer a good instance of this, and Treviranus +threw this order in my teeth; but in Corydalis Hildebrand shows how +utterly false the idea of self-fertilisation is. This author's paper +on Salvia (694/1. Hildebrand, "Pringsheim's Jahrbucher," IV.) is really +worth reading, and I have observed some species, and know that he is +accurate]. (694/2. The passage within [] was published in the "Life +and Letters," III., page 279.) Judging from a long review in the "Bot. +Zeitung", and from what I know of some the plants, I believe Delpino's +article especially on the Apocynaea, is excellent; but I cannot read +Italian. (694/3. Hildebrand's paper in the "Bot. Zeitung," 1867, refers +to Delpino's work on the Asclepiads, Apocyneae and other Orders.) +Perhaps you would like just to glance at such pamphlets as I can lay my +hands on, and therefore I will send them, as if you do not care to see +them you can return them at once; and this will cause you less trouble +than writing to say you do not care to see them. With respect to +Primula, and one point about which I feel positive is that the Bardfield +and common oxlips are fundamentally distinct plants, and that the +common oxlip is a sterile hybrid. (694/4. For a general account of +the Bardfield oxlip (Primula elatior) see Miller Christy, "Linn. Soc. +Journ." Volume XXXIII., page 172, 1897.) I have never heard of the +common oxlip being found in great abundance anywhere, and some amount +of difference in number might depend on so small a circumstance as the +presence of some moth which habitually sucked the primrose and cowslip. +To return to the subject of crossing: I am experimenting on a very large +scale on the difference in power and growth between plants raised from +self-fertilised and crossed seeds, and it is no exaggeration to say that +the difference in growth and vigour is sometimes truly wonderful. Lyell, +Huxley, and Hooker have seen some of my plants, and been astonished; and +I should much like to show them to you. I always supposed until lately +that no evil effects would be visible until after several generations +of self-fertilisation, but now I see that one generation sometimes +suffices, and the existence of dimorphic plants and all the wonderful +contrivances of orchids are quite intelligible to me. + + +LETTER 695. TO T.H. FARRER (Lord Farrer). Down, June 5th, 1868. + +I must write a line to cry peccavi. I have seen the action in Ophrys +exactly as you describe, and am thoroughly ashamed of my inaccuracy. +(695/1. See "Fertilisation of Orchids," Edition II., page 46, where +Lord Farrer's observations on the movement of the pollinia in Ophrys +muscifera are given.) I find that the pollinia do not move if kept in a +very damp atmosphere under a glass; so that it is just possible, though +very improbable, that I may have observed them during a very damp day. + +I am not much surprised that I overlooked the movement in Habenaria, as +it takes so long. (695/2. This refers to Peristylus viridis, sometimes +known as Habenaria viridis. Lord Farrer's observations are given in +"Fertilisation of Orchids," Edition II., page 63.) + +I am glad you have seen Listera; it requires to be seen to believe in +the co-ordination in the position of the parts, the irritability, +and the chemical nature of the viscid fluid. This reminds me that +I carefully described to Huxley the shooting out of the pollinia in +Catasetum, and received for an answer, "Do you really think that I can +believe all that!" (695/3. See Letter 665.) + + +LETTER 696. TO J.D. HOOKER. Down, December 2nd, 1868. + +It is a splendid scheme, and if you make only a beginning on a "Flora," +which shall serve as an index to all papers on curious points in the +life-history of plants, you will do an inestimable good service. Quite +recently I was asked by a man how he could find out what was known on +various biological points in our plants, and I answered that I knew of +no such book, and that he might ask half a dozen botanists before one +would chance to remember what had been published on this or that point. +Not long ago another man, who had been experimenting on the quasi-bulbs +on the leaves of Cardamine, wrote to me to complain that he could not +find out what was known on the subject. It is almost certain that some +early or even advanced students, if they found in their "Flora" a +line or two on various curious points, with references for further +investigation, would be led to make further observations. For instance, +a reference to the viscid threads emitted by the seeds of Compositae, to +the apparatus (if it has been described) by which Oxalis spurts out its +seeds, to the sensitiveness of the young leaves of Oxalis acetosella +with reference to O. sensitiva. Under Lathyrus nissolia it would [be] +better to refer to my hypothetical explanation of the grass-like leaves +than to nothing. (696/1. No doubt the view given in "Climbing Plants," +page 201, that L. nissolia has been evolved from a form like L. aphaca.) +Under a twining plant you might say that the upper part of the shoot +steadily revolves with or against the sun, and so, when it strikes +against any object it turns to the right or left, as the case may be. +If, again, references were given to the parasitism of Euphrasia, +etc., how likely it would be that some young man would go on with the +investigation; and so with endless other facts. I am quite enthusiastic +about your idea; it is a grand idea to make a "Flora" a guide for +knowledge already acquired and to be acquired. I have amused myself by +speculating what an enormous number of subjects ought to be introduced +into a Eutopian (696/2. A mis-spelling of Utopian.) Flora, on the +quickness of the germination of the seeds, on their means of dispersal; +on the fertilisation of the flower, and on a score of other points, +about almost all of which we are profoundly ignorant. I am glad to read +what you say about Bentham, for my inner consciousness tells me that +he has run too many forms together. Should you care to see an elaborate +German pamphlet by Hermann Muller on the gradation and distinction of +the forms of Epipactis and of Platanthera? (696/3. "Verhand. d. Nat. +Ver. f. Pr. Rh. u. Wesfal." Jahrg. XXV.: see "Fertilisation of Orchids," +Edition II., pages 74, 102.) It may be absurd in me to suggest, but I +think you would find curious facts and references in Lecoq's enormous +book (696/4. "Geographie Botanique," 9 volumes, 1854-58.), in Vaucher's +four volumes (696/5. "Plantes d'Europe," 4 volumes, 1841.), in +Hildebrand's "Geschlechter Vertheilung" (696/6 "Geschlechter Vertheilung +bei den Pflanzen," 1 volume, Leipzig, 1867.), and perhaps in Fournier's +"De la Fecondation." (696/7. "De la Fecondation dans les Phanerogames," +par Eugene Fournier: thesis published in Paris in 1863. The facts noted +in Darwin's copy are the explosive stamens of Parietaria, the submerged +flowers of Alisma containing air, the manner of fertilisation of +Lopezia, etc.) I wish you all success in your gigantic undertaking; +but what a pity you did not think of it ten years ago, so as to have +accumulated references on all sorts of subjects. Depend upon it, you +will have started a new era in the floras of various countries. I can +well believe that Mrs. Hooker will be of the greatest possible use to +you in lightening your labours and arranging your materials. + + +LETTER 697. TO J.D. HOOKER. Down, December 5th, 1868. + +...Now I want to beg for assistance for the new edition of "Origin." +Nageli himself urges that plants offer many morphological differences, +which from being of no service cannot have been selected, and which he +accounts for by an innate principle of progressive development. (697/1. +Nageli's "Enstehung und Begriff der Naturhistorischen Art." An address +delivered at the public session of the Royal Academy of Sciences of +Munich, March 28th, 1865; published by the Academy. Darwin's copy is the +2nd edition; it bears signs, in the pencilled notes on the margins, of +having been read with interest. Much of it was translated for him by a +German lady, whose version lies with the original among his pamphlets. +At page 27 Nageli writes: "It is remarkable that the useful adaptations +which Darwin brings forward in the case of animals, and which may be +discovered in numbers among plants, are exclusively of a physiological +kind, that they always show the formation or transformation of an +organ to a special function. I do not know among plants a morphological +modification which can be explained on utilitarian principles." Opposite +this passage Darwin has written "a very good objection": but Nageli's +sentence seems to us to be of the nature of a truism, for it is clear +that any structure whose evolution can be believed to have come about +by Natural Selection must have a function, and the case falls into +the physiological category. The various meanings given to the term +morphological makes another difficulty. Nageli cannot use it in the +sense of "structural"--in which sense it is often applied, since that +would mean that no plant structures have a utilitarian origin. The +essence of morphology (in the better and more precise sense) is descent; +thus we say that a pollen-grain is morphologically a microspore. And +this very example serves to show the falseness of Nageli's view, since +a pollen-grain is an adaptation to aerial as opposed to aquatic +fertilisation. In the 5th edition of the "Origin," 1869, page 151, +Darwin discusses Nageli's essay, confining himself to the simpler +statement that there are many structural characters in plants to which +we cannot assign uses. See Volume I., Letter 207.) I find old notes +about this difficulty; but I have hitherto slurred it over. Nageli gives +as instances the alternate and spiral arrangement of leaves, and the +arrangement of the cells in the tissues. Would you not consider as a +morphological difference the trimerous, tetramerous, etc., divisions +of flowers, the ovules being erect or suspended, their attachment being +parietal or placental, and even the shape of the seed when of no service +to the plant. + +Now, I have thought, and want to show, that such differences follow in +some unexplained manner from the growth or development of plants which +have passed through a long series of adaptive changes. Anyhow, I want +to show that these differences do not support the idea of progressive +development. Cassini states that the ovaria on the circumference and +centre of Compos. flowers differ in essential characters, and so do +the seeds in sculpture. The seeds of Umbelliferae in the same relative +positions are coelospermous and orthospermous. There is a case given by +Augt. St. Hilaire of an erect and suspended ovule in the same ovarium, +but perhaps this hardly bears on the point. The summit flower, in Adoxa +and rue differ from the lower flowers. What is the difference in flowers +of the rue? how is the ovarium, especially in the rue? As Augt. St. +Hilaire insists on the locularity of the ovarium varying on the same +plant in some of the Rutaceae, such differences do not speak, as it +seems to me, in favour of progressive development. Will you turn +the subject in your mind, and tell me any more facts. Difference in +structure in flowers in different parts of the same plant seems best +to show that they are the result of growth or position or amount of +nutriment. + +I have got your photograph (697/2. A photograph by Mrs. Cameron.) over +my chimneypiece, and like it much; but you look down so sharp on me that +I shall never be bold enough to wriggle myself out of any contradiction. + +Owen pitches into me and Lyell in grand style in the last chapter of +volume 3 of "Anat. of Vertebrates." He is a cool hand. He puts words +from me in inverted commas and alters them. (697/3. The passage referred +to seems to be in Owen's "Anatomy of Vertebrata," III., pages 798, 799, +note. "I deeply regretted, therefore, to see in a 'Historical Sketch' +of the Progress of Enquiry into the origin of species, prefixed to the +fourth edition of that work (1866), that Mr. Darwin, after affirming +inaccurately and without evidence, that I admitted Natural Selection to +have done something toward that end, to wit, the 'origin of species,' +proceeds to remark: 'It is surprising that this admission should not +have been made earlier, as Prof. Owen now believes that he promulgated +the theory of Natural Selection in a passage read before the Zoological +Society in February, 1850, ("Trans." Volume IV., page 15).'" The first +of the two passages quoted by Owen from the fourth edition of the +"Origin" runs: "Yet he [Prof. Owen] at the same time admits that Natural +Selection MAY [our italics] have done something towards this end." In +the sixth edition of the "Origin," page xviii., Darwin, after referring +to a correspondence in the "London Review" between the Editor of that +Journal and Owen, goes on: "It appeared manifest to the editor, as well +as to myself, that Prof. Owen claimed to have promulgated the theory of +Natural Selection before I had done so;...but as far as it is possible +to understand certain recently published passages (Ibid. ["Anat. of +Vert."], Volume III., page 798), I have either partly or wholly again +fallen into error. It is consolatory to me that others find Prof. Owen's +controversial writings as difficult to understand and to reconcile with +each other, as I do. As far as the mere enunciation of the principle +of Natural Selection is concerned, it is quite immaterial whether or +no Prof. Owen preceded me, for both of us, as shown in this historical +sketch, were long ago preceded by Dr. Wells and Mr. Matthews.") + + +LETTER 698. TO J.D. HOOKER. Down, December 29th, 1868. + +Your letter is quite invaluable, for Nageli's essay (698/1. See +preceding Letter.) is so clever that it will, and indeed I know it has +produced a great effect; so that I shall devote three or four pages +to an answer. I have been particularly struck by your statements about +erect and suspended ovules. You have given me heart, and I will fight my +battle better than I should otherwise have done. I think I cannot resist +throwing the contrivances in orchids into his teeth. You say nothing +about the flowers of the rue. (698/2. For Ruta see "Origin," Edition +V., page 154.) Ask your colleagues whether they know anything about the +structure of the flower and ovarium in the uppermost flower. But don't +answer on purpose. + +I have gone through my long Index of "Gardeners' Chronicle," which was +made solely for my own use, and am greatly disappointed to find, as I +fear, hardly anything which will be of use to you. (698/3. For Hooker's +projected biological book, see Letter 696.) I send such as I have for +the chance of their being of use. + + +LETTER 699. TO J.D. HOOKER. Down, January 16th [1869]. + +Your two notes and remarks are of the utmost value, and I am greatly +obliged to you for your criticism on the term. "Morphological" seems +quite just, but I do not see how I can avoid using it. I found, after +writing to you, in Vaucher about the Rue (699/1. "Plantes d'Europe," +Volume I., page 559, 1841.), but from what you say I will speak more +cautiously. It is the Spanish Chesnut that varies in divergence. Seeds +named Viola nana were sent me from Calcutta by Scott. I must refer +to the plants as an "Indian species," for though they have produced +hundreds of closed flowers, they have not borne one perfect flower. +(699/2. The cleistogamic flowers of Viola are used in the discussion on +Nageli's views. See "Origin," Edition V., page 153.) You ask whether I +want illustrations "of ovules differing in position in different flowers +on the same plant." If you know of such cases, I should certainly much +like to hear them. Again you speak of the angle of leaf-divergence +varying and the variations being transmitted. Was the latter point put +in in a hurry to round the sentence, or do you really know of cases? + +Whilst looking for notes on the variability of the divisions of the +ovarium, position of the ovules, aestivation, etc., I found remarks +written fifteen or twenty years ago, showing that I then supposed that +characters which were nearly uniform throughout whole groups must be +of high vital importance to the plants themselves; consequently I was +greatly puzzled how, with organisms having very different habits +of life, this uniformity could have been acquired through Natural +Selection. Now, I am much inclined to believe, in accordance with +the view given towards the close of my MS., that the near approach +to uniformity in such structures depends on their not being of vital +importance, and therefore not being acted on by Natural Selection. +(699/3. This view is given in the "Origin," Edition VI., page 372.) If +you have reflected on this point, what do you think of it? I hope that +you approved of the argument deduced from the modifications in the small +closed flowers. + +It is only about two years since last edition of "Origin," and I am +fairly disgusted to find how much I have to modify, and how much I ought +to add; but I have determined not to add much. Fleeming Jenkin has given +me much trouble, but has been of more real use to me than any other +essay or review. (699/4. On Fleeming Jenkin's review, "N. British +Review," June, 1867, see "Life and Letters," III., page 107.) + + +LETTER 700. TO J.D. HOOKER. Down [January 22nd, 1869]. + +Your letter is quite splenditious. I am greatly tempted, but shall, +I hope, refrain from using some of your remarks in my chapter on +Classification. It is very true what you say about unimportant +characters being so important systematically; yet it is hardly +paradoxical bearing in mind that the natural system is genetic, and that +we have to discover the genealogies anyhow. Hence such parts as organs +of generation are so useful for classification though not concerned with +the manner of life. Hence use for same purpose of rudimentary organs, +etc. You cannot think what a relief it is that you do not object to this +view, for it removes PARTLY a heavy burden from my shoulders. If I lived +twenty more years and was able to work, how I should have to modify the +"Origin," and how much the views on all points will have to be modified! +Well, it is a beginning, and that is something... + + +LETTER 701. TO T.H. FARRER (Lord Farrer). Down, August 10th, 1869. + +Your view seems most ingenious and probable; but ascertain in a good +many cases that the nectar is actually within the staminal tube. +(701/1. It seems that Darwin did not know that the staminal tube in +the diadelphous Leguminosae serves as a nectar-holder, and this is +surprising, as Sprengel was aware of the fact.) One can see that if +there is to be a split in the tube, the law of symmetry would lead it +to be double, and so free one stamen. Your view, if confirmed, would be +extremely well worth publication before the Linnean Society. It is to me +delightful to see what appears a mere morphological character found +to be of use. It pleases me the more as Carl Nageli has lately been +pitching into me on this head. Hooker, with whom I discussed the +subject, maintained that uses would be found for lots more structures, +and cheered me by throwing my own orchids into my teeth. (701/2. See +Letters 697-700.) + +All that you say about changed position of the peduncle in bud, in +flower, and in seed, is quite new to me, and reminds me of analogous +cases with tendrils. (701/3. See Vochting, "Bewegung der Bluthen und +Fruchte," 1882; also Kerner, "Pflanzenleben," Volume I., page 494, +Volume II., page 121.) This is well worth working out, and I dare say +the brush of the stigma. + +With respect to the hairs or filaments (about which I once spoke) within +different parts of flowers, I have a splendid Tacsonia with perfectly +pendent flowers, and there is only a microscopical vestige of the corona +of coloured filaments; whilst in most common passion-flowers the flowers +stand upright, and there is the splendid corona which apparently would +catch pollen. (701/4. Sprengel ("Entdeckte Geheimniss," page 164) +imagined that the crown of the Passion-flower served as a nectar-guide +and as a platform for insects, while other rings of filaments served +to keep rain from the nectar. F. Muller, quoted in H. Muller +("Fertilisation," page 268), looks at the crowns of hairs, ridges in +some species, etc., as gratings serving to imprison flies which attract +the fertilising humming-birds. There is, we believe, no evidence that +the corona catches pollen. See Letter 704, note.) + +On the lower side of corolla of foxglove there are some fine hairs, but +these seem of not the least use (701/5. It has been suggested that the +hairs serve as a ladder for humble bees; also that they serve to keep +out "unbidden guests.")--a mere purposeless exaggeration of down on +outside--as I conclude after watching the bees at work, and afterwards +covering up some plants; for the protected flowers rarely set any seed, +so that the hairy lower part of corolla does not come into contact with +stigma, as some Frenchman says occurs with some other plants, as Viola +odorata and I think Iris. + +I heartily wish I could accept your kind invitation, for I am not by +nature a savage, but it is impossible. Forgive my dreadful handwriting, +none of my womenkind are about to act as amanuensis. + + +LETTER 702. TO WILLIAM C. TAIT. + +(702/1. Mr. Tait, to whom the following letter is addressed, was +resident in Portugal. His kindness in sending plants of Drosophyllum +lusitanicum is acknowledged in "Insectivorous Plants.") + +Down, March 12th, 1869. + +I have received your two letters of March 2nd and 5th, and I really do +not know how to thank you enough for your extraordinary kindness and +energy. I am glad to hear that the inhabitants notice the power of the +Drosophyllum to catch flies, for this is the subject of my studies. +(702/2. The natives are said to hang up plants of Drosophyllum in their +cottages to act as fly-papers ("Insectivorous Plants," page 332).) I +have observed during several years the manner in which this is effected, +and the results produced in several species of Drosera, and in the +wonderful American Dionoea, the leaves of which catch insects just like +a steel rat-trap. Hence I was most anxious to learn how the Drosophyllum +would act, so that the Director of the Royal Gardens at Kew wrote some +years ago to Portugal to obtain specimens for me, but quite failed. +So you see what a favour you have conferred on me. With Drosera it is +nothing less than marvellous how minute a fraction of a grain of any +nitrogenised matter the plant can detect; and how differently it behaves +when matter, not containing nitrogen, of the same consistence, whether +fluid or solid, is applied to the glands. It is also exquisitely +sensitive to a weight of even the 1/70000 of a grain. From what I can +see of the glands on Drosophyllum I suspect that I shall find only +the commencement, or nascent state of the wonderful capacities of the +Drosera, and this will be eminently interesting to me. My MS. on this +subject has been nearly ready for publication during some years, but +when I shall have strength and time to publish I know not. + +And now to turn to other points in your letter. I am quite ignorant of +ferns, and cannot name your specimen. The variability of ferns passes +all bounds. With respect to your Laugher Pigeons, if the same with +the two sub-breeds which I kept, I feel sure from the structure of +the skeleton, etc., that it is a descendant of C. livia. In regard +to beauty, I do not feel the difficulty which you and some others +experience. In the last edition of my "Origin" I have discussed the +question, but necessarily very briefly. (702/3. Fourth Edition, page +238.) A new and I hope amended edition of the "Origin" is now passing +through the press, and will be published in a month or two, and it will +give me great pleasure to send you a copy. Is there any place in London +where parcels are received for you, or shall I send it by post? With +reference to dogs' tails, no doubt you are aware that a rudimentary +stump is regularly inherited by certain breeds of sheep-dogs, and by +Manx cats. You speak of a change in the position of the axis of the +earth: this is a subject quite beyond me, but I believe the astronomers +reject the idea. Nevertheless, I have long suspected that some +periodical astronomical or cosmical cause must be the agent of the +incessant oscillations of level in the earth's crust. About a month +ago I suggested this to a man well capable of judging, but he could not +conceive any such agency; he promised, however, to keep it in mind. I +wish I had time and strength to write to you more fully. I had intended +to send this letter off at once, but on reflection will keep it till I +receive the plants. + + +LETTER 703. TO H. MULLER. Down, March 14th, 1870. + +I think you have set yourself a new, very interesting, and difficult +line of research. As far as I know, no one has carefully observed the +structure of insects in relation to flowers, although so many have +now attended to the converse relation. (703/1. See Letter 462, also H. +Muller, "Fertilisation of Flowers," English Translation, page 30, on +"The insects which visit flowers." In Muller's book references are +given to several of his papers on this subject.) As I imagine few or +no insects are adapted to suck the nectar or gather the pollen of +any single family of plants, such striking adaptations can hardly, I +presume, be expected in insects as in flowers. + + +LETTER 704. TO T.H. FARRER (Lord Farrer). + +Down, May 28th, 1870. + +I suppose I must have known that the stamens recovered their former +position in Berberis (704/1. See Farrer, "Nature," II., 1870, page 164. +Lord Farrer was before H. Muller in making out the mechanism of the +barberry.), for I formerly tried experiments with anaesthetics, but I +had forgotten the facts, and I quite agree with you that it is a +sound argument that the movement is not for self-fertilisation. The +N. American barberries (Mahonia) offer a good proof to what an extent +natural crossing goes on in this genus; for it is now almost impossible +in this country to procure a true specimen of the two or three forms +originally introduced. + +I hope the seeds of Passiflora will germinate, for the turning up of the +pendent flower must be full of meaning. (704/2. Darwin had (May 12th, +1870) sent to Farrer an extract from a letter from F. Muller, containing +a description of a Passiflora visited by humming-birds, in which the +long flower-stalk curls up so that "the flower itself is upright." +Another species visited by bees is described as having "dependent +flowers." In a letter, June 29th, 1870, Mr. Farrer had suggested that P. +princeps, which he described as having sub-erect flowers, is fitted for +humming-birds' visits. In another letter, October 13th, 1869, he +says that Tacsonia, which has pendent flowers and no corona, is not +fertilised by insects in English glass-houses, and may be adapted for +humming-birds. See "Life and Letters," III., page 279, for Farrer's +remarks on Tacsonia and Passiflora; also H. Muller's "Fertilisation of +Flowers," page 268, for what little is known on the subject; also Letter +701 in the present volume.) I am so glad that you are able to occupy +yourself a little with flowers: I am sure it is most wise in you, for +your own sake and children's sakes. + +Some little time ago Delpino wrote to me praising the Swedish book on +the fertilisation of plants; as my son George can read a little Swedish, +I should like to have it back for a time, just to hear a little what it +is about, if you would be so kind as to return it by book-post. +(704/3. Severin Axell, "Om anordningarna for de Fanerogama Vaxternas +Befruktning," Stockholm, 1869.) + +I am going steadily on with my experiments on the comparative growth +of crossed and self-fertilised plants, and am now coming to some very +curious anomalies and some interesting results. I forget whether I +showed you any of them when you were here for a few hours. You ought +to see them, as they explain at a glance why Nature has taken such +extraordinary pains to ensure frequent crosses between distinct +individuals. + +If in the course of the summer you should feel any inclination to come +here for a day or two, I hope that you will propose to do so, for we +should be delighted to see you... + + +LETTER 705. TO ASA GRAY. Down, December 7th, 1870. + +I have been very glad to receive your letter this morning. I have for +some time been wishing to write to you, but have been half worked to +death in correcting my uncouth English for my new book. (705/1. +"Descent of Man.") I have been glad to hear of your cases appearing like +incipient dimorphism. I believe that they are due to mere variability, +and have no significance. I found a good instance in Nolana prostrata, +and experimented on it, but the forms did not differ in fertility. So it +was with Amsinckia, of which you told me. I have long thought that such +variations afforded the basis for the development of dimorphism. I was +not aware of such cases in Phlox, but have often admired the arrangement +of the anthers, causing them to be all raked by an inserted proboscis. I +am glad also to hear of your curious case of variability in ovules, etc. + +I said that I had been wishing to write to you, and this was about your +Drosera, which after many fluctuations between life and death, at last +made a shoot which I could observe. The case is rather interesting; but +I must first remind you that the filament of Dionoea is not sensitive +to very light prolonged pressure, or to nitrogenous matter, but is +exquisitely sensitive to the slightest touch. (705/2. In another +connection the following reference to Dionoea is of some interest: "I am +sure I never heard of Curtis's observations on Dionoea, nor have I met +with anything more than general statements about this plant or about +Nepenthes catching insects." (From a letter to Sir J.D. Hooker, July +12th, 1860.)) In our Drosera the filaments are not sensitive to a slight +touch, but are sensitive to prolonged pressure from the smallest object +of any nature; they are also sensitive to solid or fluid nitrogenous +matter. Now in your Drosera the filaments are not sensitive to a rough +touch or to any pressure from non-nitrogenous matter, but are sensitive +to solid or fluid nitrogenous matter. (705/3. Drosera filiformis: see +"Insectivorous Plants," page 281. The above account does not entirely +agree with Darwin's published statement. The filaments moved when bits +of cork or cinder were placed on them; they did not, however, respond +to repeated touches with a needle, thus behaving differently from D. +rotundifolia. It should be remembered that the last-named species is +somewhat variable in reacting to repeated touches.) Is it not curious +that there should be such diversified sensitiveness in allied plants? + +I received a very obliging letter from Mr. Morgan, but did not see him, +as I think he said he was going to start at once for the Continent. I am +sorry to hear rather a poor account of Mrs. Gray, to whom my wife and I +both beg to be very kindly remembered. + + +LETTER 706. TO C.V. RILEY. + +(706/1. In Riley's opinion his most important work was the series +entitled "Annual Report on the Noxious, Beneficial, and other Insects +of the State of Missouri" (Jefferson City), beginning in 1869. These +reports were greatly admired by Mr. Darwin, and his copies of them, +especially of Nos. 3 and 4, show signs of careful reading.) + +Down, June 1st [1871]. + +I received some little time ago your report on noxious insects, and have +now read the whole with the greatest interest. (706/2. "Third Annual +Report on the Noxious, Beneficial, and other Insects of the State of +Missouri" (Jefferson City, Mo.). The mimetic case occurs at page 67; the +1875 pupae of Pterophorus periscelidactylus, the "Grapevine Plume," have +pupae either green or reddish brown, the former variety being found on +the leaves, the latter on the brown stems of the vine.) There are a vast +number of facts and generalisations of value to me, and I am struck with +admiration at your powers of observation. + +The discussion on mimetic insects seems to me particularly good and +original. Pray accept my cordial thanks for the instruction and interest +which I have received. + +What a loss to Natural Science our poor mutual friend Walsh has been; it +is a loss ever to be deplored... + +Your country is far ahead of ours in some respects; our Parliament would +think any man mad who should propose to appoint a State Entomologist. + + +LETTER 707A. TO C.V. RILEY. + +(706A/1. We have found it convenient to place the two letters to Riley +together, rather than separate them chronologically.) + +Down, September 28th, 1881. + +I must write half a dozen lines to say how much interested I have been +by your "Further Notes" on Pronuba which you were so kind as to send me. +(706A/2. "Proc. Amer. Assoc. Adv. Sci." 1880.) I had read the various +criticisms, and though I did not know what answer could be made, yet I +felt full confidence in your result, and now I see that I was right...If +you make any further observation on Pronuba it would, I think, be well +worth while for you to observe whether the moth can or does occasionally +bring pollen from one plant to the stigma of a distinct one (706A/3. +Riley discovered the remarkable fact that the Yucca moth (Pronuba +yuccasella) lays its eggs in the ovary of Yucca flowers, which it has +previously pollinated, thus making sure of a supply of ovules for the +larvae.), for I have shown that the cross-fertilisation of the flowers +on the same plant does very little good; and, if I am not mistaken, +you believe that Pronuba gathers pollen from the same flower which she +fertilises. + +What interesting and beautiful observations you have made on the +metamorphoses of the grasshopper-destroying insects. + + +LETTER 707. TO F. HILDEBRAND. Down, February 9th [1872]. + +Owing to other occupations I was able to read only yesterday your +paper on the dispersal of the seeds of Compositae. (707/1. "Ueber die +Verbreitungsmittel der Compositenfruchte." "Bot. Zeitung," 1872, page +1.) Some of the facts which you mention are extremely interesting. + +I write now to suggest as worthy of your examination the curious +adhesive filaments of mucus emitted by the achenia of many Compositae, +of which no doubt you are aware. My attention was first called to the +subject by the achenia of an Australian Pumilio (P. argyrolepis), which +I briefly described in the "Gardeners' Chronicle," 1861, page 5. As the +threads of mucus dry and contract they draw the seeds up into a vertical +position on the ground. It subsequently occurred to me that if these +seeds were to fall on the wet hairs of any quadruped they would adhere +firmly, and might be carried to any distance. I was informed that +Decaisne has written a paper on these adhesive threads. What is the +meaning of the mucus so copiously emitted from the moistened seeds of +Iberis, and of at least some species of Linum? Does the mucus serve as +a protection against their being devoured, or as a means of attachment. +(707/2. Various theories have been suggested, e.g., that the slime by +anchoring the seed to the soil facilitates the entrance of the radicle +into the soil: the slime has also been supposed to act as a temporary +water-store. See Klebs in Pfeffer's "Untersuchungen aus dem Bot. Inst. +zu Tubingen," I., page 581.) I have been prevented reading your paper +sooner by attempting to read Dr. Askenasy's pamphlet, but the German is +too difficult for me to make it all out. (707/3. E. Askenasy, "Beitrage +zur Kritik der Darwin'schen Lehre." Leipzig, 1872.) He seems to follow +Nageli completely. I cannot but think that both much underrate the +utility of various parts of plants; and that they greatly underrate +the unknown laws of correlated growth, which leads to all sorts of +modifications, when some one structure or the whole plant is modified +for some particular object. + + +LETTER 708. TO T.H. FARRER. (Lord Farrer). + +(708/1. The following letter refers to a series of excellent +observations on the fertilisation of Leguminosae, made by Lord Farrer in +the autumn of 1869, in ignorance of Delpino's work on the subject. The +result was published in "Nature," October 10th and 17th, 1872, and +is full of interesting suggestions. The discovery of the mechanism in +Coronilla mentioned in a note was one of the cases in which Lord Farrer +was forestalled.) + +Down [1872]. + +I declare I am almost as sorry as if I had been myself +forestalled--indeed, more so, for I am used to it. It is, however, a +paramount, though bothersome duty in every naturalist to try and make +out all that has been done by others on the subject. By all means +publish next summer your confirmation and a summary of Delpino's +observations, with any new ones of your own. Especially attend about the +nectary exterior to the staminal tube. (708/2. This refers to a species +of Coronilla in which Lord Farrer made the remarkable discovery that the +nectar is secreted on the outside of the calyx. See "Nature," July 2nd, +1874, page 169; also Letter 715.) This will in every way be far better +than writing to Delpino. It would not be at all presumptuous in you to +criticise Delpino. I am glad you think him so clever; for so it struck +me. + +Look at hind legs yourself of some humble and hive-bees; in former take +a very big individual (if any can be found) for these are the females, +the males being smaller, and they have no pollen-collecting apparatus. +I do not remember where it is figured--probably in Kirby & Spence--but +actual inspection better... + +Please do not return any of my books until all are finished, and do not +hurry. + +I feel certain you will make fine discoveries. + + +LETTER 709. TO T.H. FARRER. (Lord Farrer). Sevenoaks, October 13th, +1872. + +I must send you a line to say how extremely good your article appears to +me to be. It is even better than I thought, and I remember thinking it +very good. I am particularly glad of the excellent summary of evidence +about the common pea, as it will do for me hereafter to quote; nocturnal +insects will not do. I suspect that the aboriginal parent had bluish +flowers. I have seen several times bees visiting common and sweet +peas, and yet varieties, purposely grown close together, hardly ever +intercross. This is a point which for years has half driven me mad, +and I have discussed it in my "Var. of Animals and Plants under Dom." +(709/1. In the second edition (1875) of the "Variation of Animals and +Plants," Volume I., page 348, Darwin added, with respect to the rarity +of spontaneous crosses in Pisum: "I have reason to believe that this +is due to their stignas being prematurely fertilised in this country +by pollen from the same flower." This explanation is, we think, almost +certainly applicable to Lathyrus odoratus, though in Darwin's latest +publication on the subject he gives reasons to the contrary. See "Cross +and Self-Fertilisation," page 156, where the problem is left unsolved. +Compare Letter 714 to Delpino. In "Life and Letters," III., page 261, +the absence of cross-fertilisation is explained as due to want of +perfect adaptation between the pea and our native insects. This is +Hermann Muller's view: see his "Fertilisation of Flowers," page 214. +See Letter 583, note.) I now suspect (and I wish I had strength to +experimentise next spring) that from changed climate both species +are prematurely fertilised, and therefore hardly ever cross. When +artificially crossed by removal of own pollen in bud, the offspring are +very vigorous. + +Farewell.--I wish I could compel you to go on working at fertilisation +instead of so insignificant a subject as the commerce of the country! + +You pay me a very pretty compliment at the beginning of your paper. + + +LETTER 710. TO J.D. HOOKER. + +(710/1. The following letters to Sir J.D. Hooker and the late Mr. +Moggridge refer to Moggridge's observation that seeds stored in the nest +of the ant Atta at Mentone do not germinate, though they are certainly +not dead. Moggridge's observations are given in his book, "Harvesting +Ants and Trap-Door Spiders," 1873, which is full of interesting details. +The book is moreover remarkable in having resuscitated our knowledge of +the existence of the seed-storing habit. Mr. Moggridge points out that +the ancients were familiar with the facts, and quotes the well-known +fable of the ant and the grasshopper, which La Fontaine borrowed from +Aesop. Mr. Moggridge (page 5) goes on: "So long as Europe was taught +Natural History by southern writers the belief prevailed; but no sooner +did the tide begin to turn, and the current of information to flood from +north to south, than the story became discredited." + +In Moggridge's "supplement" on the same subject, published in 1874, the +author gives an account of his experiments made at Darwin's suggestion, +and concludes (page 174) that "the vapour of formic acid is incapable +of rendering the seeds dormant after the manner of the ants," and +that indeed "its influence is always injurious to the seeds, even when +present only in excessively minute quantities." Though unable to explain +the method employed, he was convinced "that the non-germination of the +seeds is due to some direct influence voluntarily exercised by the ants, +and not merely to the conditions found in the nest" (page 172). See +Volume I., Letter 251.) + +Down, February 21st [1873]. + +You have given me exactly the information which I wanted. + +Geniuses jump. I have just procured formic acid to try whether its +vapour or minute drops will delay germination of fresh seeds; trying +others at same time for comparison. But I shall not be able to try them +till middle of April, as my despotic wife insists on taking a house in +London for a month from the middle of March. + +I am glad to hear of the Primer (710/2. "Botany" (Macmillan's Science +Primers).); it is not at all, I think, a folly. Do you know Asa Gray's +child book on the functions of plants, or some such title? It is very +good in giving an interest to the subject. + +By the way, can you lend me the January number of the "London Journal of +Botany" for an article on insect-agency in fertilisation? + + +LETTER 711. TO J. TRAHERNE MOGGRIDGE. Down, August 27th, 1873. + +I thank you for your very interesting letter, and I honour you for your +laborious and careful experiments. No one knows till he tries how many +unexpected obstacles arise in subjecting plants to experiments. + +I can think of no suggestions to make; but I may just mention that I +had intended to try the effects of touching the dampened seeds with the +minutest drop of formic acid at the end of a sharp glass rod, so as to +imitate the possible action of the sting of the ant. I heartily hope +that you may be rewarded by coming to some definite result; but I fail +five times out of six in my own experiments. I have lately been trying +some with poor success, and suppose that I have done too much, for I +have been completely knocked up for some days. + + +LETTER 712. TO J. TRAHERNE MOGGRIDGE. Down, March 10th, 1874. + +I am very sorry to hear that the vapour experiments have failed; but +nothing could be better, as it seems to me, than your plan of enclosing +a number of the ants with the seeds. The incidental results on the power +of different vapours in killing seeds and stopping germination appear +very curious, and as far as I know are quite new. + +P.S.--I never before heard of seeds not germinating except during a +certain season; it will be a very strange fact if you can prove this. +(712/1. Certain seeds pass through a resting period before germination. +See Pfeffer's "Pflanzenphysiologie," Edition I., Volume II., page III.) + + +LETTER 713. TO H. MULLER. Down, May 30th, 1873. + +I am much obliged for your letter received this morning. I write now +chiefly to give myself the pleasure of telling you how cordially I +admire the last part of your book, which I have finished. (713/1. +"Die Befruchtung der Blumen durch Insekten": Leipzig, 1873. An English +translation was published in 1883 by Prof. D'Arcy Thompson. The +"Prefatory Notice" to this work (February 6th, 1882) is almost the last +of Mr. Darwin's writings. See "Life and Letters," page 281.) The whole +discussion seems to me quite excellent, and it has pleased me not a +little to find that in the rough MS. of my last chapter I have arrived +on many points at nearly the same conclusions that you have done, though +we have reached them by different routes. (713/2. "The Effects of Cross +and Self-Fertilisation in the Vegetable Kingdom": London, 1876.) + + +LETTER 714. TO F. DELPINO. Down, June 25th [1873]. + +I thank you sincerely for your letter. I am very glad to hear about +Lathyrus odoratus, for here in England the vars. never cross, and +yet are sometimes visited by bees. (714/1. In "Cross and +Self-Fertilisation," page 156, Darwin quotes the information received +from Delpino and referred to in the present letter--namely, that it +is the fixed opinion of the Italian gardeners that the varieties do +intercross. See Letter 709.) Pisum sativum I have also many times seen +visited by Bombus. I believe the cause of the many vars. not crossing +is that under our climate the flowers are self-fertilised at an early +period, before the corolla is fully expanded. I shall examine this point +with L. odoratus. I have read H. Muller's book, and it seems to me very +good. Your criticism had not occurred to me, but is, I think just--viz. +that it is much more important to know what insects habitually visit any +flower than the various kinds which occasionally visit it. Have you seen +A. Kerner's book "Schutzmittel des Pollens," 1873, Innsbruck. (714/2. +Afterwards translated by Dr. Ogle as "Flowers and their Unbidden +Guests," with a prefatory letter by Charles Darwin, 1878.) It is very +interesting, but he does not seem to know anything about the work of +other authors. + +I have Bentham's paper in my house, but have not yet had time to read a +word of it. He is a man with very sound judgment, and fully admits the +principle of evolution. + +I have lately had occasion to look over again your discussion on +anemophilous plants, and I have again felt much admiration at your work. +(714/3. "Atti della Soc. Italiana di Scienze Nat." Volume XIII.) + +(714/4. In the beginning of August, 1873, Darwin paid the first of +several visits to Lord Farrer's house at Abinger. When sending copies of +Darwin's letters for the "Life and Letters," Lord Farrer was good enough +to add explanatory notes and recollections, from which we quote the +following sketch.) + +"Above my house are some low hills, standing up in the valley, below the +chalk range on the one hand and the more distant range of Leith Hill +on the other, with pretty views of the valley towards Dorking in one +direction and Guildford in the other. They are composed of the less +fertile Greensand strata, and are covered with fern, broom, gorse, and +heath. Here it was a particular pleasure of his to wander, and his +tall figure, with his broad-brimmed Panama hat and long stick like an +alpenstock, sauntering solitary and slow over our favourite walks, is +one of the pleasantest of the many pleasant associations I have with the +place." + + +LETTER 715. TO T.H. FARRER (Lord Farrer). + +(715/1. The following note by Lord Farrer explains the main point of +the letter, which, however, refers to the "bloom" problem as well as to +Coronilla:-- + +"I thought I had found out what puzzled us in Coronilla varia: in most +of the Papilionaceae, when the tenth stamen is free, there is nectar in +the staminal tube, and the opening caused by the free stamen enables the +bee to reach the nectar, and in so doing the bee fertilises the plant. +In Coronilla varia, and in several other species of Coronilla, there is +no nectar in the staminal tube or in the tube of the corolla. But +there are peculiar glands with nectar on the outside of the calyx, and +peculiar openings in the tube of the corolla through which the proboscis +of the bee, whilst entering the flower in the usual way and dusting +itself with pollen, can reach these glands, thus fertilising the plant +in getting the nectar. On writing this to Mr. Darwin, I received the +following characteristic note. + +The first postscript relates to the rough ground behind my house, over +which he was fond of strolling. It had been ploughed up and then allowed +to go back, and the interest was to watch how the numerous species of +weeds of cultivation which followed the plough gradually gave way in the +struggle for existence to the well-known and much less varied flora of +an English common.") + +Bassett, Southampton, August 14th, 1873. + +You are the man to conquer a Coronilla. (715/2. In a former letter to +Lord Farrer, Darwin wrote: "Here is a maxim for you, 'It is disgraceful +to be beaten by a Coronilla.'") I have been looking at the half-dried +flowers, and am prepared to swear that you have solved the mystery. +The difference in the size of the cells on the calyx under the vexillum +right down to the common peduncle is conspicuous. The flour still +adhered to this side; I see little bracteae or stipules apparently with +glandular ends at the base of the calyces. Do these secrete? It seems +to me a beautiful case. When I saw the odd shape of the base of the +vexillum, I concluded that it must have some meaning, but little dreamt +what that was. Now there remains only the one serious point--viz.the +separation of the one stamen. I daresay that you are right in that +nectar was originally secreted within the staminal tube; but why has not +the one stamen long since cohered? The great difference in structure +for fertilisation within the same genus makes one believe that all such +points are vary variable. (715/3. Coronilla emerus is of the ordinary +papilionaceous type.) With respect to the non-coherence of the one +stamen, do examine some flower-buds at a very early age; for parts which +are largely developed are often developed to an unusual degree at a +very early age, and it seems to me quite possible that the base of the +vexillum (to which the single stamen adhered) might thus be developed, +and thus keep it separate for a time from the other stamens. The +cohering stamens to the right and left of the single one seem to me +to be pushed out a little laterally. When you have finished your +observations, you really ought to send an account with a diagram to +"Nature," recalling your generalisation about the diadelphous structure, +and now explaining the exception of Coronilla. (715/4. The observations +were published in "Nature," Volume X., 1874, page 169.) + +Do add a remark how almost every detail of structure has a meaning where +a flower is well examined. + +Your observations pleased me so much that I could not sit still for half +an hour. + +Please to thank Mr. Payne (715/5. Lord Farrer's gardener.) for his +remarks, which are of value to me, with reference to Mimosa. I am +very much in doubt whether opening the sashes can act by favouring the +evaporation of the drops; may not the movement of the leaves shake off +the drops, or change their places? If Mr. Payne remembers any plant +which is easily injured by drops, I wish he would put a drop or two on +a leaf on a bright day, and cover the plant with a clean bell-glass, +and do the same for another plant, but without a bell-glass over it, and +observe the effects. + +Thank you much for wishing to see us again at Abinger, and it is very +doubtful whether it will be Coronilla, Mr. Payne, the new garden, the +children, E. [Lady Farrer], or yourself which will give me the most +pleasure to see again. + +P.S. 1.--It will be curious to note in how many years the rough ground +becomes quite uniform in its flora. + +P.S. 2.--One may feel sure that periodically nectar was secreted within +the flower and then secreted by the calyx, as in some species of Iris +and orchids. This latter being taken advantage of in Coronilla would +allow of the secretion within the flower ceasing, and as this change was +going on in the two secretions, all the parts of the flower would become +modified and correlated. + + +LETTER 716. TO J. BURDON SANDERSON. Down, Tuesday, September 9th [1873]. + +(716/1. Sir J. Burdon Sanderson showed that in Dionoea movement +is accompanied by electric disturbances closely analogous to those +occurring in muscle (see "Nature," 1874, pages 105, 127; "Proc. R. Soc." +XXI., and "Phil. Trans." Volume CLXXIII., 1883, where the results are +finally discussed).) + +I will send up early to-morrow two plants [of Dionoea] with five goodish +leaves, which you will know by their being tied to sticks. Please +remember that the slightest touch, even by a hair, of the three +filaments on each lobe makes the leaf close, and it will not open for +twenty-four hours. You had better put 1/4 in. of water into the saucers +of the pots. The plants have been kept too cool in order to retard +them. You had better keep them rather warm (i.e. temperature of warm +greenhouse) for a day, and in a good light. + +I am extremely glad you have undertaken this subject. If you get a +positive result, I should think you ought to publish it separately, and +I could quote it; or I should be most glad to introduce any note by you +into my account. + +I have no idea whether it is troublesome to try with the thermo-electric +pile any change of temperature when the leaf closes. I could detect none +with a common thermometer. But if there is any change of temperature I +should expect it would occur some eight to twelve or twenty-four +hours after the leaf has been given a big smashed fly, and when it is +copiously secreting its acid digestive fluid. + +I forgot to say that, as far as I can make out, the inferior surface of +the leaf is always in a state of tension, and that the contraction is +confined to the upper surface; so that when this contraction ceases or +suddenly fails (as by immersion in boiling water) the leaf opens again, +or more widely than is natural to it. + +Whenever you have quite finished, I will send for the plants in their +basket. My son Frank is staying at 6, Queen Anne Street, and comes home +on Saturday afternoon, but you will not have finished by that time. + +P.S. I have repeated my experiment on digestion in Drosera with complete +success. By giving leaves a very little weak hydrochloric acid, I can +make them digest albumen--i.e. white of egg--quicker than they can do +naturally. I most heartily thank you for all your kindness. I have been +pretty bad lately, and must work very little. + + +LETTER 717. TO J. BURDON SANDERSON. September 13th [1873]. + +How very kind it was of you to telegraph to me. I am quite delighted +that you have got a decided result. Is it not a very remarkable fact? It +seems so to me, in my ignorance. I wish I could remember more distinctly +what I formerly read of Du Bois Raymond's results. My poor memory never +serves me for more than a vague guide. I really think you ought to try +Drosera. In a weak solution of phosphate of ammonia (viz. 1 gr. to 20 +oz. of water) it will contract in about five minutes, and even more +quickly in pure warm water; but then water, I suppose, would prevent +your trial. I forget, but I think it contracts pretty quickly (i.e. in +an hour or two) with a large drop of a rather stronger solution of the +phosphate, or with an atom of raw meat on the disc of the leaf. + + +LETTER 718. TO J.D. HOOKER. October 31st, 1873. + +Now I want to tell you, for my own pleasure, about the movements of +Desmodium. + +1. When the plant goes to sleep, the terminal leaflets hang vertically +down, but the petioles move up towards the axis, so that the dependent +leaves are all crowded round it. The little leaflets never go to sleep, +and this seems to me very odd; they are at their games of play as late +as 11 o'clock at night and probably later. (718/1. Stahl ("Botanische +Zeitung," 1897, page 97) has suggested that the movements of the dwarf +leaflets in Desmodium serve to shake the large terminal leaflets, and +thus increase transpiration. According to Stahl's view their movement +would be more useful at night than by day, because stagnation of the +transpiration-current is more likely to occur at night.) + +2. If the plant is shaken or syringed with tepid water, the terminal +leaflets move down through about an angle of 45 deg, and the petioles +likewise move about 11 deg downwards; so that they move in an opposite +direction to what they do when they go to sleep. Cold water or air +produces the same effect as does shaking. The little leaflets are not +in the least affected by the plant being shaken or syringed. I have no +doubt, from various facts, that the downward movement of the terminal +leaflets and petioles from shaking and syringing is to save them from +injury from warm rain. + +3. The axis, the main petiole, and the terminal leaflets are all, +when the temperature is high, in constant movement, just like that of +climbing plants. This movement seems to be of no service, any more than +the incessant movement of amoeboid bodies. The movement of the terminal +leaflets, though insensible to the eye, is exactly the same as that of +the little lateral leaflets--viz. from side to side, up and down, +and half round their own axes. The only difference is that the little +leaflets move to a much greater extent, and perhaps more rapidly; and +they are excited into movement by warm water, which is not the case with +the terminal leaflet. Why the little leaflets, which are rudimentary in +size and have lost their sleep-movements and their movements from +being shaken, should not only have retained, but have their spontaneous +movements exaggerated, I cannot conceive. It is hardly credible that +it is a case of compensation. All this makes me very anxious to examine +some plant (if possible one of the Leguminosae) with either the terminal +or lateral leaflets greatly reduced in size, in comparison with the +other leaflets on the same leaf. Can you or any of your colleagues think +of any such plant? It is indirectly on this account that I so much want +the seeds of Lathyrus nissolia. + +I hear from Frank that you think that the absence of both lateral +leaflets, or of one alone, is due to their having dropped off; I thought +so at first, and examined extremely young leaves from the tips of the +shoots, and some of them presented the same characters. Some appearances +make me think that they abort by becoming confluent with the main +petiole. + +I hear also that you doubt about the little leaflets ever standing not +opposite to each other: pray look at the enclosed old leaf which +has been for a time in spirits, and can you call the little leaflets +opposite? I have seen many such cases on both my plants, though few so +well marked. + + +LETTER 719. TO J.D. HOOKER. Down, October 23rd [1873]. + +How good you have been about the plants; but indeed I did not intend +you to write about Drosophyllum, though I shall be very glad to have +a specimen. Experiments on other plants lead to fresh experiments. +Neptunia is evidently a hopeless case. I shall be very glad of the other +plants whenever they are ready. I constantly fear that I shall become to +you a giant of bores. + +I am delighted to hear that you are at work on Nepenthes, and I hope +that you will have good luck. It is good news that the fluid is acid; +you ought to collect a good lot and have the acid analysed. I hope +that the work will give you as much pleasure as analogous work has me. +(719/1. Hooker's work on Nepenthes is referred to in "Insectivorous +Plants," page 97: see also his address at the Belfast meeting of the +British Association, 1874.) I do not think any discovery gave me more +pleasure than proving a true act of digestion in Drosera. + + +LETTER 720. TO J.D. HOOKER. Down, November 24th, 1873. + +I have been greatly interested by Mimosa albida, on which I have been +working hard. Whilst your memory is pretty fresh, I want to ask a +question. When this plant was most sensitive, and you irritated it, did +the opposite leaflets shut up quite close, as occurs during sleep, when +even a lancet could not be inserted between the leaflets? I can never +cause the leaflets to come into contact, and some reasons make me doubt +whether they ever do so except during sleep; and this makes me wish much +to hear from you. I grieve to say that the plant looks more unhealthy, +even, than it was at Kew. I have nursed it like the tenderest infant; +but I was forced to cut off one leaf to try the bloom, and one was +broken by the manner of packing. I have never syringed (with tepid +water) more than one leaf per day; but if it dies, I shall feel like a +murderer. I am pretty well convinced that I shall make out my case of +movements as a protection against rain lodging on the leaves. As far as +I have as yet made out, M. albida is a splendid case. + +I have had no time to examine more than one species of Eucalyptus. The +seedlings of Lathyrus nissolia are very interesting to me; and there is +something wonderful about them, unless seeds of two distinct leguminous +species have got somehow mingled together. + + +LETTER 721. TO W. THISELTON-DYER. Down, December 4th, 1873. + +As Hooker is so busy, I should be very much obliged if you could give +me the name of the enclosed poor specimen of Cassia. I want much to +know its name, as its power of movement, when it goes to sleep, is very +remarkable. Linnaeus, I find, was aware of this. It twists each separate +leaflet almost completely round (721/1. See "Power of Movement in +Plants," Figure 154, page 370.), so that the lower surface faces the +sky, at the same time depressing them all. The terminal leaflets are +pointed towards the base of the leaf. The whole leaf is also raised +up about 12 deg. When I saw that it possessed such complex powers of +movement, I thought it would utilise its power to protect the leaflets +from rain. Accordingly I syringed the plant for two minutes, and it was +really beautiful to see how each leaflet on the younger leaves twisted +its short sub-petiole, so that the blade was immediately directed at +an angle between 45 and 90 deg to the horizon. I could not resist the +pleasure of just telling you why I want to know the name of the Cassia. +I should add that it is a greenhouse plant. I suppose that there will +not be any better flowers till next summer or autumn. + + +LETTER 722. TO T. BELT. + +(722/1. Belt's account, discussed in this letter, is probably that +published in his "Naturalist in Nicaragua" (1874), where he describes +"the relation between the presence of honey-secreting glands on plants, +and the protection to the latter secured by the attendance of ants +attracted by the honey." (Op. cit., pages 222 et seq.)) + +Thursday [1874?]. + +Your account of the ants and their relations seems to me to possess +extraordinary interest. I do not doubt that the excretion of sweet fluid +by the glands is in your cases of great advantage to the plants by means +of the ants, but I cannot avoid believing that primordially it is a +simple excretion, as occasionally occurs from the surface of the leaves +of lime trees. It is quite possible that the primordial excretion may +have been beneficially increased to serve the plant. In the common +laurel [Prunus laurocerasus] of our gardens the hive-bees visit +incessantly the glands of the young leaves, on their under sides; and I +should altogether doubt whether their visits or the occasional visits of +ants was of any service to the laurel. The stipules of the common vetch +secrete largely during sunshine, and hive-bees collect the sweet fluid. +So I think it is with the common bean. + +I am writing this away from home, and I have come away to get some rest, +having been a good deal overworked. I shall read your book with great +interest when published, but will not trouble you to send the MS., as I +really have no spare strength or time. I believe that your book, judging +by the chapter sent, will be extremely valuable. + + +LETTER 723. TO J.D. HOOKER. + +(723/1. The following letter refers to Darwin's prediction as to the +manner in which Hedychium (Zinziberaceae) is fertilised. Sir J.D. Hooker +seems to have made inquiries in India in consequence of which +Darwin received specimens of the moth which there visits the flower, +unfortunately so much broken as to be useless (see "Life and Letters," +III., page 284).) + +Down, March 25th [1874]. + +I am glad to hear about the Hedychium, and how soon you have got an +answer! I hope that the wings of the Sphinx will hereafter prove to +be bedaubed with pollen, for the case will then prove a fine bit of +prophecy from the structure of a flower to special and new means of +fertilisation. + +By the way, I suppose you have noticed what a grand appearance the plant +makes when the green capsules open, and display the orange and crimson +seeds and interior, so as to attract birds, like the pale buff flowers +to attract dusk-flying lepidoptera. I presume you do not want seeds of +this plant, as I have plenty from artificial fertilisation. + +(723/2. In "Nature," June 22nd, 1876, page 173, Hermann Muller +communicated F. Muller's observation on the fertilisation of a +bright-red-flowered species of Hedychium, which is visited by +Callidryas, chiefly the males of C. Philea. The pollen is carried by the +tips of the butterfly's wing, to which it is temporarily fixed by the +slimy layer produced by the degeneration of the anther-wall. + + +LETTER 724. TO W. THISELTON-DYER. Down, June 4th [1874]. + +I am greatly obliged to you about the Opuntia, and shall be glad if you +can remember Catalpa. I wish some facts on the action of water, because +I have been so surprised at a stream not acting on Dionoea and Drosera. +(724/1. See Pfeffer, "Untersuchungen Bot. Inst. zu Tubingen," Bd. +I., 1885, page 518. Pfeffer shows that in some cases--Drosera, for +instance--water produces movement only when it contains fine particles +in suspension. According to Pfeffer the stamens of Berberis, and the +stigma of Mimulus, are both stimulated by gelatine, the action of which +is, generally speaking, equivalent to that of water.) Water does not +act on the stamens of Berberis, but it does on the stigma of Mimulus. +It causes the flowers of the bedding-out Mesembryanthemum and Drosera +to close, but it has not this effect on Gazania and the daisy, so I can +make out no rule. + +I hope you are going on with Nepenthes; and if so, you will perhaps like +to hear that I have just found out that Pinguicula can digest albumen, +gelatine, etc. If a bit of glass or wood is placed on a leaf, the +secretion is not increased; but if an insect or animal-matter is thus +placed, the secretion is greatly increased and becomes feebly acid, +which was not the case before. I have been astonished and much disturbed +by finding that cabbage seeds excite a copious secretion, and am now +endeavouring to discover what this means. (724/2. Clearly it had not +occurred to Darwin that seeds may supply nitrogenous food as well as +insects: see "Insectivorous Plants," page 390.) Probably in a few days' +time I shall have to beg a little information from you, so I will write +no more now. + +P.S. I heard from Asa Gray a week ago, and he tells me a beautiful fact: +not only does the lid of Sarracenia secrete a sweet fluid, but there +is a line or trail of sweet exudation down to the ground so as to tempt +insects up. (724/3. A dried specimen of Sarracenia, stuffed with cotton +wool, was sometimes brought from his study by Mr. Darwin, and made the +subject of a little lecture to visitors of natural history tastes.) + + +LETTER 725. TO W. THISELTON-DYER. Down, June 23rd, 1874. + +I wrote to you about a week ago, thanking you for information on cabbage +seeds, asking you the name of Luzula or Carex, and on some other points; +and I hope before very long to receive an answer. You must now, if you +can, forgive me for being very troublesome, for I am in that state in +which I would sacrifice friend or foe. I have ascertained that bits +of certain leaves, for instance spinach, excite much secretion in +Pinguicula, and that the glands absorb matter from the leaves. Now this +morning I have received a lot of leaves from my future daughter-in-law +in North Wales, having a surprising number of captured insects on them, +a good many leaves, and two seed-capsules. She informs me that the +little leaves had excited secretion; and my son and I have ascertained +this morning that the protoplasm in the glands beneath the little leaves +has undoubtedly undergone aggregation. Therefore, absurd as it +may sound, I am prepared to affirm that Pinguicula is not only +insectivorous, but graminivorous, and granivorous! Now I want to beg you +to look under the simple microscope at the enclosed leaves and seeds, +and, if you possibly can, tell me their genera. The little narrow leaves +are remarkable (725/1. Those of Erica tetralix.); they are fleshy, with +the edges much curled from the axis of the plant, and bear a few long +glandular hairs; these grow in little tufts. These are the commonest in +Pinguicula, and seem to afford most nutritious matter. A second leaf is +like a miniature sycamore. With respect to the seeds, I suppose that +one is a Carex; the other looks like that of Rumex, but is enclosed in a +globular capsule. The Pinguicula grew on marshy, low, mountainous land. + +I hope you will think this subject sufficiently interesting to make you +willing to aid me as far as you can. Anyhow, forgive me for being so +very troublesome. + + +LETTER 726. TO J.D. HOOKER. Down, August 30th [1874]. + +I am particularly obliged for your address. (726/1. Presidential address +(Biological Section) at the Belfast meeting of the British Association, +1874.) It strikes me as quite excellent, and has interested me in the +highest degree. Nor is this due to my having worked at the subject, for +I feel sure that I should have been just as much struck, perhaps more +so, if I had known nothing about it. You could not, in my opinion, have +put the case better. There are several lights (besides the facts) in +your essay new to me, and you have greatly honoured me. I heartily +congratulate you on so splendid a piece of work. There is a misprint at +page 7, Mitschke for Nitschke. There is a partial error at page 8, where +you say that Drosera is nearly indifferent to organic substances. This +is much too strong, though they do act less efficiently than organic +with soluble nitrogenous matter; but the chief difference is in the +widely different period of subsequent re-expansion. Thirdly, I did not +suggest to Sanderson his electrical experiments, though, no doubt, my +remarks led to his thinking of them. + +Now for your letter: you are very generous about Dionoea, but some of +my experiments will require cutting off leaves, and therefore injuring +plants. I could not write to Lady Dorothy [Nevill]. Rollisson says that +they expect soon a lot from America. If Dionoea is not despatched, have +marked on address, "to be forwarded by foot-messenger." + +Mrs. Barber's paper is very curious, and ought to be published (726/2. +Mrs. Barber's paper on the pupa of Papilio Nireus assuming different +tints corresponding to the objects to which it was attached, was +communicated by Mr. Darwin to the "Trans. Entomolog. Soc." 1874.); but +when you come here (and REMEMBER YOU OFFERED TO COME) we will consult +where to send it. Let me hear when you recommence on Cephalotus or +Sarracenia, as I think I am now on right track about Utricularia, after +wasting several weeks in fruitless trials and observations. The negative +work takes five times more time than the positive. + + +LETTER 727. TO J.D. HOOKER. Down, September 18th [1874]. + +I have had a splendid day's work, and must tell you about it. + +Lady Dorothy sent me a young plant of U[tricularia] montana (727/1. See +"Life and Letters," III., page 327, and "Insectivorous Plants," page +431.), which I fancy is the species you told me of. The roots or +rhizomes (for I know not which they are; I can see no scales or +internodes or absorbent hairs) bear scores of bladders from 1/20 to +1/100 of an inch in diameter; and I traced these roots to the depth of 1 +1/2 in. in the peat and sand. The bladders are like glass, and have the +same essential structure as those of our species, with the exception +that many exterior parts are aborted. Internally the structure is +perfect, as is the minute valvular opening into the bladder, which is +filled with water. I then felt sure that they captured subterranean +insects, and after a time I found two with decayed remnants, with clear +proof that something had been absorbed, which had generated protoplasm. +When you are here I shall be very curious to know whether they are roots +or rhizomes. + +Besides the bladders there are great tuber-like swellings on the +rhizomes; one was an inch in length and half in breadth. I suppose +these must have been described. I strongly suspect that they serve as +reservoirs for water. (727/2. The existence of water-stores is quite +in accordance with the epiphytic habit of the plant.) But I shall +experimentise on this head. A thin slice is a beautiful object, and +looks like coarsely reticulated glass. + +If you have an old plant which could be turned out of its pot (and can +spare the time), it would be a great gain to me if you would tear off a +bit of the roots near the bottom, and shake them well in water, and see +whether they bear these minute glass-like bladders. I should also much +like to know whether old plants bear the solid bladder-like bodies near +the upper surface of the pot. These bodies are evidently enlargements +of the roots or rhizomes. You must forgive this long letter, and +make allowance for my delight at finding this new sub-group of +insect-catchers. Sir E. Tennent speaks of an aquatic species of +Utricularia in Ceylon, which has bladders on its roots, and rises +annually to the surface, as he says, by this means. (727/3. Utricularia +stellaris. Emerson Tennent's "Ceylon," Volume I., page 124, 1859.) + +We shall be delighted to see you here on the 26th; if you will let us +know your train we will send to meet you. You will have to work like a +slave while you are here. + + +LETTER 728. TO J. JENNER WEIR. + +(728/1. In 1870 Mr. Jenner Weir wrote to Darwin: "My brother has but +two kinds of laburnum, viz., Cytisus purpureus, very erect, and Cytisus +alpinus, very pendulous. He has several stocks of the latter grafted +with the purple one; and this year, the grafts being two years old, +I saw in one, fairly above the stock, about four inches, a raceme of +purely yellow flowers with the usual dark markings, and above them a +bunch of purely purple flowers; the branches of the graft in no way +showed an intermediate character, but had the usual rigid growth of +purpureus." + +Early in July 1875, when Darwin was correcting a new edition of +"Variation under Domestication," he again corresponded with Mr. Weir on +the subject.) + +Down, July 8th [1875]. + +I thank you cordially. The case interests me in a higher degree than +anything which I have heard for a very long time. Is it your brother +Harrison W., whom I know? I should like to hear where the garden is. +There is one other very important point which I am most anxious to +hear--viz., the nature of the leaves at the base of the yellow racemes, +for leaves are always there produced with the yellow laburnums, and I +suppose so in the case of C. purpureus. As the tree has produced yellow +racemes several times, do you think you could ask your brother to cut +off and send me by post in a box a small branch of the purple stock with +the pods or leaves of the yellow sport? (728/2. "The purple stock" here +means the supposed C. purpureus, on which a yellow-flowered branch was +borne.) This would be an immense favour, for then I would cut the point +of junction longitudinally and examine slice under the microscope, to be +able to state no trace of bud of yellow kind having been inserted. I do +not suspect anything of the kind, but it is sure to be said that your +brother's gardener, either by accident or fraud, inserted a bud. Under +this point of view it would be very good to gather from your brother how +many times the yellow sport has appeared. The case appears to me so +very important as to be worth any trouble. Very many thanks for all +assistance so kindly given. + +I will of course send a copy of new edition of "Variation under +Domestication" when published in the autumn. + + +LETTER 729. TO J. JENNER WEIR. + +(729/1. On July 9th Mr. Weir wrote to say that a branch of the Cytisus +had been despatched to Down. The present letter was doubtless +written after Darwin had examined the specimen. In "Variation under +Domestication," Edition II., Volume I., page 417, note, he gives for a +case recorded in the "Gardeners' Chronicle" in 1857 the explanation here +offered (viz. that the graft was not C. purpureus but C. Adami), and +adds, "I have ascertained that this occurred in another instance." This +second instance is doubtless Mr. Weir's.) + +Down, July 10th, 1875. + +I do not know how to thank you enough; pray give also my thanks and kind +remembrances to your brother. I am sure you will forgive my expressing +my doubts freely, as I well know that you desire the truth more than +anything else. I cannot avoid the belief that some nurseryman has sold +C[ytisus] Adami to your brother in place of the true C. purpureus. The +latter is a little bush only 3 feet high (Loudon), and when I read your +account, it seemed to me a physical impossibility that a sporting branch +of C. alpinus could grow to any size and be supported on the extremely +delicate branches of C. purpureus. If I understand rightly your letter, +you consider the tuft of small shoots on one side of the sporting C. +alpinus from Weirleigh as C. purpureus; but these shoots are certainly +those of C. Adami. I earnestly beg you to look at the specimens +enclosed. The branch of the true C. purpureus is the largest which +I could find. If C. Adami was sold to your brother as C. purpureus, +everything is explained; for then the gardener has grafted C. Adami on +C. alpinus, and the former has sported in the usual manner; but has not +sported into C. purpureus, only into C. alpinus. C. Adami does not sport +less frequently into C. purpureus than into C. alpinus. Are the purple +flowers borne on moderately long racemes? If so, the plant is certainly +C. Adami, for the true C. purpureus bears flowers close to the branches. +I am very sorry to be so troublesome, but I am very anxious to hear +again from you. + +C. purpureus bears "flowers axillary, solitary, stalked." + +P.S.--I think you said that the purple [tree] at Weirleigh does not +seed, whereas the C. purpureus seeds freely, as you may see in enclosed. +C. Adami never produces seeds or pods. + + +LETTER 730. TO E. HACKEL. + +(730/1. The following extract refers to Darwin's book on "Cross and +Self-Fertilisation.") + +November 13th, 1875. + +I am now busy in drawing up an account of ten years' experiments in the +growth and fertility of plants raised from crossed and self-fertilised +flowers. It is really wonderful what an effect pollen from a distinct +seedling plant, which has been exposed to different conditions of life, +has on the offspring in comparison with pollen from the same flower or +from a distinct individual, but which has been long subjected to the +same conditions. The subject bears on the very principle of life, which +seems almost to require changes in the conditions. + + +LETTER 731. TO G.J. ROMANES. + +(731/1. The following extract from a letter to Romanes refers to Francis +Darwin's paper, "Experiments on the Nutrition of Drosera rotundifolia." +"Linn. Soc. Journ." [1878], published 1880, page 17.) + +August 9th [1876]. + +The second point which delights me, seeing that half a score of +botanists throughout Europe have published that the digestion of meat by +plants is of no use to them (a mere pathological phenomenon, as one man +says!), is that Frank has been feeding under exactly similar conditions +a large number of plants of Drosera, and the effect is wonderful. On +the fed side the leaves are much larger, differently coloured, and more +numerous; flower-stalks taller and more numerous, and I believe far +more seed capsules,--but these not yet counted. It is particularly +interesting that the leaves fed on meat contain very many more starch +granules (no doubt owing to more protoplasm being first formed); so that +sections stained with iodine, of fed and unfed leaves, are to the naked +eye of very different colours. + +There, I have boasted to my heart's content, and do you do the same, and +tell me what you have been doing. + + +LETTER 732. TO J.D. HOOKER. Down, October 25th [1876]. + +If you can put the following request into any one's hands pray do so; +but if not, ignore my request, as I know how busy you are. + +I want any and all plants of Hoya examined to see if any imperfect +flowers like the one enclosed can be found, and if so to send them to +me, per post, damp. But I especially want them as young as possible. + +They are very curious. I have examined some sent me from Abinger (732/1. +Lord Farrer's house.), but they were a month or two too old, and every +trace of pollen and anthers had disappeared or had never been developed. +Yet a very fine pod with apparently good seed had been formed by one +such flower. (732/2. The seeds did not germinate; see the account of +Hoya carnosa in "Forms of Flowers," page 331.) + + +LETTER 733. TO G.J. ROMANES. + +(733/1. Published in the "Life of Romanes," page 62.) + +Down, August 10th [1877]. + +When I went yesterday I had not received to-day's "Nature," and I +thought that your lecture was finished. (733/2. Abstract of a lecture +on "Evolution of Nerves and Nervo-Systems," delivered at the Royal +Institution, May 25th, 1877. "Nature," July 19th, August 2nd, August +9th, 1877.) This final part is one of the grandest essays which I ever +read. + +It was very foolish of me to demur to your lines of conveyance like the +threads in muslin (733/3. "Nature," August 2nd, page 271.), knowing how +you have considered the subject: but still I must confess I cannot feel +quite easy. Everyone, I suppose, thinks on what he has himself seen, and +with Drosera, a bit of meat put on any one gland on its disc causes +all the surrounding tentacles to bend to this point, and here there can +hardly be differentiated lines of conveyance. It seems to me that the +tentacles probably bend to that point wherever a molecular wave strikes +them, which passes through the cellular tissue with equal ease in all +directions in this particular case. (733/4. Speaking generally, the +transmission takes place more readily in the longitudinal direction than +across the leaf: see "Insectivorous Plants," page 239.) But what a fine +case that of the Aurelia is! (733/5. Aurelia aurita, one of the medusae. +"Nature," pages 269-71.) + + +LETTER 734. TO W. THISELTON-DYER. 6, Queen Anne Street [December 1876]. + +Tell Hooker I feel greatly aggrieved by him: I went to the Royal Society +to see him for once in the chair of the Royal, to admire his dignity and +enjoy it, and lo and behold, he was not there. My outing gave me much +satisfaction, and I was particularly glad to see Mr. Bentham, and to see +him looking so wonderfully well and young. I saw lots of people, and it +has not done me a penny's worth of harm, though I could not get to sleep +till nearly four o'clock. + + +LETTER 735. TO D. OLIVER. Down, October, 13th [1876?]. + +You must be a clair-voyant or something of that kind to have sent me +such useful plants. Twenty-five years ago I described in my father's +garden two forms of Linum flavum (thinking it a case of mere variation); +from that day to this I have several times looked, but never saw the +second form till it arrived from Kew. Virtue is never its own reward: +I took paper this summer to write to you to ask you to send me flowers, +[so] that I might beg plants of this Linum, if you had the other form, +and refrained, from not wishing to trouble you. But I am now sorry +I did, for I have hardly any doubt that L. flavum never seeds in any +garden that I have seen, because one form alone is cultivated by slips. +(735/1. Id est, because, the plant being grown from slips, one form +alone usually occurs in any one garden. It is also arguable that it is +grown by slips because only one form is common, and therefore seedlings +cannot be raised.) + + +(736/1. The following five letters refer to Darwin's work on "bloom"--a +subject on which he did not live to complete his researches:-- + +One of his earliest letters on this subject was addressed in August, +1873, to Sir Joseph Hooker (736/2. Published in "Life and Letters," +III., page 339.): + +"I want a little information from you, and if you do not yourself know, +please to enquire of some of the wise men of Kew. + +"Why are the leaves and fruit of so many plants protected by a thin +layer of waxy matter (like the common cabbage), or with fine hair, so +that when such leaves or fruit are immersed in water they appear as if +encased in thin glass? It is really a pretty sight to put a pod of the +common pea, or a raspberry, into water. I find several leaves are thus +protected on the under surface and not on the upper. + +"How can water injure the leaves, if indeed this is at all the case?" + +On this latter point Darwin wrote to the late Lord Farrer: + +"I am now become mad about drops of water injuring leaves. Please ask +Mr. Payne (736/3. Lord Farrer's gardener.) whether he believes, FROM +HIS OWN EXPERIENCE, that drops of water injure leaves or fruit in his +conservatories. It is said that the drops act as burning-glasses; if +this is true, they would not be at all injurious on cloudy days. As +he is so acute a man, I should very much like to hear his opinion. I +remember when I grew hothouse orchids I was cautioned not to wet their +leaves; but I never then thought on the subject." + +The next letter, though of later date than some which follow it, is +printed here because it briefly sums his results and serves as guide to +the letters dealing with the subject.) + + +LETTER 736. TO W. THISELTON-DYER. + +(736/4. Published in "Life and Letters," III., page 341.) + +Down, September 5th [1877]. + +One word to thank you. I declare, had it not been for your kindness, +we should have broken down. As it is we have made out clearly that with +some plants (chiefly succulent) the bloom checks evaporation--with +some certainly prevents attacks of insects; with SOME sea-shore plants +prevents injury from salt water, and, I believe, with a few prevents +injury from pure water resting on the leaves. This latter is as yet +the most doubtful and the most interesting point in relation to the +movements of plants. + +(736/5. Modern research, especially that of Stahl on transpiration +("Bot. Zeitung," 1897, page 71) has shown that the question is more +complex than it appeared in 1877. Stahl's point of view is that moisture +remaining on a leaf checks the transpiration-current; and by thus +diminishing the flow of mineral nutriment interferes with the process of +assimilation. Stahl's idea is doubtless applicable to the whole problem +of bloom on leaves. For other references to bloom see letters 685, 689 +and 693.) + + +LETTER 737. TO J.D. HOOKER. Down, August 19th, 1873. + +The next time you walk round the garden ask Mr. Smith (737/1. Probably +John Smith (1798-1888), for some years Curator, Royal Gardens, Kew.), or +any of your best men, what they think about injury from watering during +sunshine. One of your men--viz., Mr. Payne, at Abinger, who seems very +acute--declares that you may water safely any plant out of doors in +sunshine, and that you may do the same for plants under glass if the +sashes are opened. This seems to me very odd, but he seems positive +on the point, and acts on it in raising splendid grapes. Another good +gardener maintains that it is only COLD water dripping often on the +same point of a leaf that ever injures it. I am utterly perplexed, but +interested on the point. Give me what you learn when you come to Down. + +I should like to hear what plants are believed to be most injured by +being watered in sunshine, so that I might get such. + +I expect that I shall be utterly beaten, as on so many other points; +but I intend to make a few experiments and observations. I have already +convinced myself that drops of water do NOT act as burning lenses. + + +LETTER 738. TO J.D. HOOKER. December 20th [1873]. + +I find that it is no use going on with my experiments on the evil +effects of water on bloom-divested leaves. Either I erred in the early +autumn or summer in some incomprehensible manner, or, as I suspect to be +the case, water is only injurious to leaves when there is a good supply +of actinic rays. I cannot believe that I am all in the wrong about the +movements of the leaves to shoot off water. + +The upshot of all this is that I want to keep all the plants from Kew +until the spring or early summer, as it is mere waste of time going on +at present. + + +LETTER 739. TO W. THISELTON-DYER. Down, July 22nd [1877]. + +Many thanks for seeds of the Malva and information about Averrhoa, which +I perceived was sensitive, as A. carambola is said to be; and about +Mimosa sensitiva. The log-wood [Haematoxylon] has interested me much. +The wax is very easily removed, especially from the older leaves, and I +found after squirting on the leaves with water at 95 deg, all the older +leaves became coated, after forty-eight hours, in an astonishing manner +with a black Uredo, so that they looked as if sprinkled with soot and +water. But not one of the younger leaves was affected. This has set +me to work to see whether the "bloom" is not a protection against +parasites. As soon as I have ascertained a little more about the case +(and generally I am quite wrong at first) I will ask whether I could +have a very small plant, which should never be syringed with water above +60 deg, and then I suspect the leaves would not be spotted, as were the +older ones on the plant, when it arrived from Kew, but nothing like what +they were after my squirting. + +In an old note of yours (which I have just found) you say that you have +a sensitive Schrankia: could this be lent me? + +I have had lent me a young Coral-tree (Erythrina), which is very sickly, +yet shows odd sleep movements. I suppose I could buy one, but Hooker +told me first to ask you for anything. + +Lastly, have you any seaside plants with bloom? I find that drops of +sea-water corrode sea-kale if bloom is removed; also the var. littorum +of Triticum repens. (By the way, my plants of the latter, grown in pots +here, are now throwing up long flexible green blades, and it is very odd +to see, ON THE SAME CULM, the rigid grey bloom-covered blades and the +green flexible ones.) Cabbages, ill-luck to them, do not seem to be +hurt by salt water. Hooker formerly told me that Salsola kali, a var. of +Salicornia, one species of Suaeda, Euphorbia peplis, Lathyrus maritimus, +Eryngium maritimum, were all glaucous and seaside plants. It is very +improbable that you have any of these or of foreigners with the same +attributes. + +God forgive me: I hope that I have not bored you greatly. + +By all the rules of right the leaves of the logwood ought to move (as if +partially going to sleep) when syringed with tepid water. The leaves +of my little plant do not move at all, and it occurs to me as possible, +though very improbable, that it would be different with a larger plant +with perhaps larger leaves. Would you some day get a gardener to syringe +violently, with water kept in a hothouse, a branch on one of your +largest logwood plants and observe [whether?] leaves move together +towards the apex of leaf? + +By the way, what astonishing nonsense Mr. Andrew Murray has been +writing about leaves and carbonic acid! I like to see a man behaving +consistently... + +What a lot I have scribbled to you! + + +(FIGURE 13. Leaf of Trifolium resupinatum (from a drawing by Miss +Pertz).) + + +LETTER 740. TO W. THISELTON-DYER. [August, 1877.] + +There is no end to my requests. Can you spare me a good plant (or even +two) of Oxalis sensitiva? The one which I have (formerly from Kew) has +been so maltreated that I dare not trust my results any longer. + +Please give the enclosed to Mr. Lynch. (740/1. Mr. Lynch, now Curator +of the Cambridge Botanic Garden, was at this time in the R. Bot. Garden, +Kew. Mr. Lynch described the movements of Averrhoa bilimbi in the "Linn. +Soc. Journ," Volume XVI., page 231. See also "The Power of Movement in +Plants," page 330.) The spontaneous movements of the Averrhoa are very +curious. + +You sent me seeds of Trifolium resupinatum, and I have raised plants, +and some former observations which I did not dare to trust have proved +accurate. It is a very little fact, but curious. The half of the lateral +leaflets (marked by a cross) on the lower side have no bloom and are +wetted, whereas the other half has bloom and is not wetted, so that the +two sides look different to the naked eye. The cells of the eipdermis +appear of a different shape and size on the two sides of the leaf +[Figure 13]. + +When we have drawings and measurements of cells made, and are sure of +our facts, I shall ask you whether you know of any case of the same leaf +differing histologically on the two sides, for Hooker always says you +are a wonderful man for knowing what has been made out. + +(740/2. The biological meaning of the curious structure of the leaves of +Trifolium resupinatum remains a riddle. The stomata and (speaking from +memory) the trichomes differ on the two halves of the lateral leaflets.) + + +LETTER 741. TO L. ERRERA. + +(741/1. Professor L. Errera, of Brussels wrote, as a student, to Darwin, +asking permission to send the MS. of an essay by his friend S. Gevaert +and himself on cross and self-fertilisation, and which was afterwards +published in the "Bull. Soc. Bot. Belg." XVII., 1878. The terms +xenogamy, geitonogamy, and autogamy were first suggested by Kerner in +1876; their definition will be found at page 9 of Ogle's translation +of Kerner's "Flowers and their Unbidden Guests," 1878. In xenogamy the +pollen comes from another PLANT; in geitonogamy from another FLOWER +on the same PLANT; in autogamy from the androecium of the fertilised +FLOWER. Allogamy embraces xenogamy and geitonogamy.) + +Down, October 4th, 1877. + +I have now read your MS. The whole has interested me greatly, and +is very clearly written. I wish that I had used some such terms as +autogamy, xenogamy, etc...I entirely agree with you on the a priori +probability of geitonogamy being more advantageous than autogamy; and +I cannot remember having ever expressed a belief that autogamy, as a +general rule, was better than geitonogamy; but the cases recorded by +me seem too strong not to make me suspect that there was some unknown +advantage in autogamy. In one place I insert the caution "if this +be really the case," which you quote. (741/2. See "Cross and +Self-Fertilisation," pages 352, 386. The phrase referred to occurs in +both passages; that on page 386 is as follows: "We have also seen reason +to suspect that self-fertilisation is in some peculiar manner beneficial +to certain plants; but if this be really the case, the benefit thus +derived is far more than counterbalanced by a cross with a fresh stock +or with a slightly different variety." Errera and Gevaert conclude +(pages 79-80) that the balance of the available evidence is in favour of +the belief that geitonogamy is intermediate, in effectiveness, between +autogamy and xenogamy.) I shall be very glad to be proved to be +altogether in error on this point. + +Accept my thanks for pointing out the bad erratum at page 301. I hope +that you will experimentise on inconspicuous flowers (741/3. See Miss +Bateson, "Annals of Botany," 1888, page 255, "On the Cross-Fertilisation +of Inconspicuous Flowers:" Miss Bateson showed that Senecio vulgaris +clearly profits by cross-fertilisation; Stellaria media and Capsella +bursa-pastoris less certainly.); if I were not too old and too much +occupied I would do so myself. + +Finally let me thank you for the kind manner in which you refer to my +work, and with cordial good wishes for your success... + + +LETTER 742. TO W. THISELTON-DYER. Down, October 9th, 1877. + +One line to thank you much about Mertensia. The former plant has begun +to make new leaves, to my great surprise, so that I shall be now well +supplied. We have worked so well with the Averrhoa that unless the +second species arrives in a very good state it would be superfluous to +send it. I am heartily glad that you and Mrs. Dyer are going to have +a holiday. I will look at you as a dead man for the next month, and +nothing shall tempt me to trouble you. But before you enter your grave +aid me if you can. I want seeds of three or four plants (not Leguminosae +or Cruciferae) which produce large cotyledons. I know not in the least +what plants have large cotyledons. Why I want to know is as follows: The +cotyledons of Cassia go to sleep, and are sensitive to a touch; but what +has surprised me much is that they are in constant movement up and down. +So it is with the cotyledons of the cabbage, and therefore I am very +curious to ascertain how far this is general. + + +LETTER 743. TO W. THISELTON-DYER. Down, October 11th [1877]. + +The fine lot of seeds arrived yesterday, and are all sown, and will be +most useful. If you remember, pray thank Mr. Lynch for his aid. I had +not thought of beech or sycamore, but they are now sown. + +Perhaps you may like to see a rough copy of the tracing of movements +of one of the cotyledons of red cabbage, and you can throw it into +the fire. A line joining the two cotyledons stood facing a north-east +window, and the day was uniformly cloudy. A bristle was gummed to one +cotyledon, and beyond it a triangular bit of card was fixed, and in +front a vertical glass. A dot was made in the glass every quarter or +half hour at the point where the end of the bristle and the apex of card +coincided, and the dots were joined by straight lines. The observations +were from 10 a.m. to 8.45 p.m. During this time the enclosed figure was +described; but between 4 p.m. and 5.38 p.m. the cotyledon moved so that +the prolonged line was beyond the limits of the glass, and the course +is here shown by an imaginary dotted line. The cotyledon of Primula +sinensis moved in closely analogous manner, as do those of a Cassia. +Hence I expect to find such movements very general with cotyledons, +and I am inclined to look at them as the foundation for all the other +adaptive movements of leaves. They certainly are of the so-called sleep +of plants. + +I hope I have not bothered you. Do not answer. I am all on fire at the +work. + +I have had a short and very prosperous note from Asa Gray, who says +Hooker is very prosperous, and both are tremendously hard at work. +(743/1. "Hooker is coming over, and we are going in summer to the Rocky +Mountains together, according to an old promise of mine." Asa Gray to +G.F. Wright, May 24th, 1877 ("Letters of Asa Gray," II., page 666).) + + +LETTER 744. TO H. MULLER. Down, January 1st [1878?]. + +I must write two or three lines to thank you cordially for your very +handsome and very interesting review of my last book in "Kosmos," +which I have this minute finished. (744/1. "Forms of Flowers," 1877. H. +Muller's article is in "Kosmos," II., page 286.) It is wonderful how you +have picked out everything important in it. I am especially glad that +you have called attention to the parallelism between illegitimate +offspring of heterostyled plants and hybrids. Your previous article in +"Kosmos" seemed to me very important, but for some unknown reason the +german was very difficult, and I was sadly overworked at the time, so +that I could not understand a good deal of it. (744/2. "Kosmos," II., +pages 11, 128. See "Forms of Flowers," Edition II., page 308.) But I +have put it on one side, and when I have to prepare a new edition of my +book I must make it out. It seems that you attribute such cases as that +of the dioecious Rhamnus and your own of Valeriana to the existence of +two forms with larger and smaller flowers. I cannot follow the steps +by which such plants have been rendered dioecious, but when I read your +article with more care I hope I shall understand. (744/3. See "Forms of +Flowers," Edition II., pages 9 and 304. H. Muller's view is briefly that +conspicuous and less conspicuous varieties occurred, and that the former +were habitually visited first by insects; thus the less conspicuous form +would play the part of females and their pollen would tend to become +superfluous. See H. Muller in "Kosmos," II.) If you have succeeded +in explaining this class of cases I shall heartily rejoice, for they +utterly perplexed me, and I could not conjecture what their meaning was. +It is a grievous evil to have no faculty for new languages. + +With the most sincere respect and hearty good wishes to you and all your +family for the new year... + +P.S.--What interesting papers your wonderful brother has lately been +writing! + + +LETTER 745. TO W. THISELTON-DYER. + +(745/1. This letter refers to the purchase of instruments for the +Jodrell Laboratory in the Royal Gardens, Kew. "The Royal Commission on +Scientific Instruction and the Advancement of Science, commonly spoken +of as the Devonshire Commission, in its fourth Report (1874), page 10, +expressed the opinion that 'it is highly desirable that opportunities +for the pursuit of investigations in Physiological Botany should be +afforded at Kew to those persons who may be inclined to follow that +branch of science.' Effect was given to this recommendation by the +liberality of the late T.J. Phillips-Jodrell, M.A., who built and +equipped the small laboratory, which has since borne his name, at his +own expense. It was completed and immediately brought into use in 1876." +The above is taken from the "Bulletin of Miscellaneous Information," R. +Botanic Gardens, Kew, 1901, page 102, which also gives a list of work +carried out in the laboratory between 1876 and 1900.) + +Down, March 14th, 1878. + +I have a very strong opinion that it would be the greatest possible +pity if the Phys[iological] Lab., now that it has been built, were +not supplied with as many good instruments as your funds can possibly +afford. It is quite possible that some of them may become antiquated +before they are much or even at all used. But this does not seem to me +any argument at all against getting them, for the Laboratory cannot be +used until well provided; and the mere fact of the instruments being +ready may suggest to some one to use them. You at Kew, as guardians and +promoters of botanical science, will then have done all in your power, +and if your Lab. is not used the disgrace will lie at the feet of the +public. But until bitter experience proves the contrary I will never +believe that we are so backward. I should think the German laboratories +would be very good guides as to what to get; but Timiriazeff of Moscow, +who travelled over Europe to see all Bot. Labs., and who seemed so +good a fellow, would, I should think, give the best list of the most +indispensable instruments. Lately I thought of getting Frank or +Horace to go to Cambridge for the use of the heliostat there; but our +observations turned out of less importance than I thought, yet if there +had been one at Kew we should probably have used it, and might have +found out something curious. It is impossible for me to predict whether +or not we should ever want this or that instrument, for we are guided +in our work by what turns up. Thus I am now observing something about +geotropism, and I had no idea a few weeks ago that this would have been +necessary. In a short time we might earnestly wish for a centrifugal +apparatus or a heliostat. In all such cases it would make a great +difference if a man knew that he could use a particular instrument +without great loss of time. I have now given my opinion, which is very +decided, whether right or wrong, and Frank quite agrees with me. You +can, of course, show this letter to Hooker. + + +LETTER 746. TO F. LUDWIG. Down, May 29th, 1878. + +I thank you sincerely for the trouble which you have taken in sending +me so long and interesting a letter, together with the specimens. +Gradations are always very valuable, and you have been remarkably +successful in discovering the stages by which the Plantago has become +gyno-dioecious. (746/1. See F. Ludwig, "Zeitsch. f. d. Geo. Naturwiss." +Bd. LII., 1879. Professor Ludwig's observations are quoted in the +preface to "Forms of Flowers," Edition II., page ix.) Your view of its +origin, from being proterogynous, seems to me very probable, especially +as the females are generally the later-flowering plants. If you can +prove the reverse case with Thymus your view will manifestly be rendered +still more probable. I have never felt satisfied with H. Muller's view, +though he is so careful and admirable an observer. (746/2. See "Forms +of Flowers," Edition II., page 308. Also letter 744.) It is more than +seventeen years since I attended to Plantago, and when nothing had been +published on the subject, and in consequence I omitted to attend to +several points; and now, after so long an interval, I cannot pretend to +say to which of your forms the English one belongs; I well remember that +the anther of the females contained a good deal [of] pollen, though not +one sound grain. + +P.S.--Delpino is Professor of Botany in Genoa, Italy (746/3. Now at +Naples.); I have always found him a most obliging correspondent. + + +LETTER 747. TO W. THISELTON-DYER. Down, August 24th [1878]. + +Many thanks for seeds of Trifolium resupinatum, which are invaluable to +us. I enclose seeds of a Cassia, from Fritz Muller, and they are well +worth your cultivation; for he says they come from a unique, large and +beautiful tree in the interior, and though looking out for years, he +has never seen another specimen. One of the most splendid, largest and +rarest butterflies in S. Brazil, he has never seen except near this +one tree, and he has just discovered that its caterpillars feed on its +leaves. + +I have just been looking at fine young pods beneath the ground of +Arachis. (747/1. Arachis hypogoea, cultivated for its "ground nuts.") I +suppose that the pods are not withdrawn when ripe from the ground; +but should this be the case kindly inform me; if I do not hear I shall +understand that [the] pods ripen and are left permanently beneath the +ground. + +If you ever come across heliotropic or apheliotropic aerial roots on +a plant not valuable (but which should be returned), I should like +to observe them. Bignonia capreolata, with its strongly apheliotropic +tendrils (which I had from Kew), is now interesting me greatly. Veitch +tells me it is not on sale in any London nursery, as I applied to him +for some additional plants. So much for business. + +I have received from the Geographical Soc. your lecture, and read it +with great interest. (747/2. "On Plant-Distribution as a field for +Geographical Research." "Geog. Soc. Proc." XXII., 1878, page 412.) But +it ought not merely to be read; it requires study. The sole criticism +which I have to make is that parts are too much condensed: but, good +Lord, how rare a fault is this! You do not quote Saporta, I think; and +some of his work on the Tertiary plants would have been useful to you. +In a former note you spoke contemptuously of your lecture: all I can +say is that I never heard any one speak more unjustly and shamefully of +another than you have done of yourself! + + +LETTER 748. TO H. MULLER. Down, September 20th, 1878. + +I am working away on some points in vegetable physiology, but though +they interest me and my son, yet they have none of the fascination which +the fertilisation of flowers possesses. Nothing in my life has ever +interested me more than the fertilisation of such plants as Primula and +Lythrum, or again Anacamptis (748/1. Orchis pyramidalis.) or Listera. + + +LETTER 749. TO H. MULLER. Down, February 12th [1879]. + +I have just heard that some misfortune has befallen you, and that you +have been treated shamefully. (749/1. Hermann Muller was accused by +the Ultramontane party of introducing into his school-teaching crude +hypotheses ("unreife Hypothesen"), which were assumed to have a harmful +influence upon the religious sentiments of his pupils. Attempts were +made to bring about Muller's dismissal, but the active hostility of his +opponents, which he met in a dignified spirit, proved futile. ("Prof. +Dr. Hermann Muller von Lippstadt. Ein Gedenkblatt," von Ernst Krause. +"Kosmos," VII., page 393, 1883.)) I grieve deeply to hear this, and as +soon as you can find a few minutes to spare, I earnestly beg you to let +me hear what has happened. + + +LETTER 750. TO A. STEPHEN WILSON. + +(750/1. The following letters refer to two forms of wheat cultivated in +Russia under the names Kubanka and Saxonka, which had been sent to Mr. +Darwin by Dr. Asher from Samara, and were placed in the hands of Mr. +Wilson that he might test the belief prevalent in Russia that Kubanka +"grown repeatedly on inferior soil," assumes "the form of Saxonka." Mr. +Wilson's paper of 1880 gives the results of his inquiry. He concludes +(basing his views partly on analogous cases and partly on his study of +the Russian wheats) that the supposed transformation is explicable in +chief part by the greater fertility of the Saxonka wheat leading to +extermination of the other form. According to Mr. Wilson, therefore, +the Saxonka survivors are incorrectly assumed to be the result of the +conversion of one form into the other.) + +Down, April 24th, 1878. + +I send you herewith some specimens which may perhaps interest you, as +you have so carefully studied the varieties of wheat. Anyhow, they are +of no use to me, as I have neither knowledge nor time sufficient. They +were sent me by the Governor of the Province of Samara, in Russia, at +the request of Dr. Asher (son of the great Berlin publisher) who farmed +for some years in the province. The specimen marked Kubanka is a very +valuable kind, but which keeps true only when cultivated in fresh +steppe-land in Samara, and in Saratoff. After two years it degenerates +into the variety Saxonica, or its synonym Ghirca. The latter alone is +imported into this country. Dr. Asher says that it is universally known, +and he has himself witnessed the fact, that if grain of the Kubanka is +sown in the same steppe-land for more than two years it changes into +Saxonica. He has seen a field with parts still Kubanka and the remainder +Saxonica. On this account the Government, in letting steppe-land, +contracts that after two years wheat must not be sown until an interval +of eight years. The ears of the two kinds appear different, as you will +see, but the chief difference is in the quality of the grains. Dr. Asher +has witnessed sales of equal weights of Kubanka and Saxonica grain, +and the price of the former was to that of the latter as 7 to 4. The +peasants say that the change commences in the terminal grain of the +ear. The most remarkable point, as Dr. Asher positively asserts, is that +there are no intermediate varieties; but that a grain produces a plant +yielding either true Kubanka or true Saxonica. He thinks that it would +be interesting to sow here both kinds in good and bad wheat soil and +observe the result. Should you think it worth while to make any such +trial, and should you require further information, Dr. Asher, whose +address I enclose, will be happy to give any in his power. + + +LETTER 751. TO A. STEPHEN WILSON. Basset, Southampton, April 29th +[1878]. + +Your kind note and specimens have been forwarded to me here, where I +am staying at my son's house for a fortnight's complete rest, which +I required from rather too hard work. For this reason I will not now +examine the seeds, but will wait till returning home, when, with my son +Francis' aid, I will look to them. + +I always felt, though without any good reason, rather sceptical about +Prof. Buckman's experiment, and I afterwards heard that a most wicked +and cruel trick had been played on him by some of the agricultural +students at Cirencester, who had sown seeds unknown to him in his +experimental beds. Whether he ever knew this I did not hear. + +I am exceedingly glad that you are willing to look into the Russian +wheat case. It may turn out a mare's nest, but I have often incidentally +observed curious facts when making what I call "a fool's experiment." + + +LETTER 752. TO A. STEPHEN WILSON. Down, March 5th, 1879. + +I have just returned home after an absence of a week, and your letter +was not forwarded to me; I mention this to account for my apparent +discourtesy in not having sooner thanked you. You have worked out +the subject with admirable care and clearness, and your drawings are +beautiful. I suspected that there was some error in the Russian belief, +but I did not think of the explanation which you have almost proved +to be the true one. It is an extremely interesting instance of a more +fertile variety beating out a less fertile one, and, in this case, one +much more valuable to man. With respect to publication, I am at a +loss to advise you, for I live a secluded life and do not see many +periodicals, or hear what is done at the various societies. It seems to +me that your paper should be published in some agricultural journal; for +it is not simply scientific, and would therefore not be published by the +Linnean or Royal Societies. + +Would the Royal Agricultural Society be a fitting place? Unfortunately +I am not a member, and could not myself present it. Unless you think +of some better journal, there is the "Agricultural Gazette": I have +occasionally suggested articles for publication to the editor (though +personally unknown to me) which he has always accepted. + +Permit me again to thank you for the thorough manner in which you have +worked out this case; to kill an error is as good a service as, and +sometimes even better than, the establishing a new truth or fact. + + +LETTER 753. TO A. STEPHEN WILSON. Down, February 13th, 1880. + +It was very kind of you to send me two numbers of the "Gardeners' +Chronicle" with your two articles, which I have read with much interest. +(753/1. "Gardeners' Chronicle," 1879, page 652; 1880, pages 108, 173.) +You have quite convinced me, whatever Mr. Asher may say to the contrary. +I want to ask you a question, on the bare chance of your being able to +answer it, but if you cannot, please do not take the trouble to write. +The lateral branches of the silver fir often grow out into knobs through +the action of a fungus, Aecidium; and from these knobs shoots grow +vertically (753/2. The well-known "Witches-Brooms," or "Hexen-Besen," +produced by the fungus Aecidium elatinum.) instead of horizontally, like +all the other twigs on the same branch. Now the roots of Cruciferae and +probably other plants are said to become knobbed through the action of +a fungus: now, do these knobs give rise to rootlets? and, if so, do they +grow in a new or abnormal direction? (753/3. The parasite is probably +Plasmodiophora: in this case no abnormal rootlets have been observed, as +far as we know.) + + +LETTER 754. TO W. THISELTON-DYER. Down, June 18th, 1879. + +The plants arrived last night in first-rate order, and it was very very +good of you to take so much trouble as to hunt them up yourself. They +seem exactly what I wanted, and if I fail it will not be for want of +perfect materials. But a confounded painter (I beg his pardon) comes +here to-night, and for the next two days I shall be half dead with +sitting to him; but after then I will begin to work at the plants and +see what I can do, and very curious I am about the results. + +I have to thank you for two very interesting letters. I am delighted +to hear, and with surprise, that you care about old Erasmus D. God only +knows what I shall make of his life--it is such new kind of work to me. +(754/1. "Erasmus Darwin." By Ernst Krause. Translated from the German by +W.S. Dallas: with a preliminary notice by Charles Darwin. London, 1879. +See "Life and Letters," III., pages 218-20.) + +Thanks for case of sleeping Crotalaria--new to me. I quite agree to +every word you say about Ball's lecture (754/2. "On the Origin of the +Flora of the European Alps," "Geogr. Soc. Proc." Volume I., 1879, +page 564. See Letter 395, Volume II.)--it is, as you say, like Sir W. +Thomson's meteorite. (754/3. In 1871 Lord Kelvin (Presidential Address +Brit. Assoc.) suggested that meteorites, "the moss-grown fragments from +the ruins of another world," might have introduced life to our planet.) +It is really a pity; it is enough to make Geographical Distribution +ridiculous in the eyes of the world. Frank will be interested about the +Auriculas; I never attended to this plant, for the powder did [not] seem +to me like true "bloom." (754/4. See Francis Darwin, on the relation +between "bloom" on leaves and the distribution of the stomata. "Linn. +Soc. Journ." Volume XXII., page 114.) This subject, however, for the +present only, has gone to the dogs with me. + +I am sorry to hear of such a struggle for existence at Kew; but I have +often wondered how it is that you are all not killed outright. + +I can most fully sympathise with you in your admiration of your little +girl. There is nothing so charming in this world, and we all in this +house humbly adore our grandchild, and think his little pimple of a nose +quite beautiful. + + +LETTER 755. TO G. BENTHAM. Down, February 16th, 1880. + +I have had real pleasure in signing Dyer's certificate. (755/1. As a +candidate for the Royal Society.) It was very kind in you to write to me +about the Orchideae, for it has pleased me to an extreme degree that I +could have been of the least use to you about the nature of the parts. +They are wonderful creatures, these orchids, and I sometimes think with +a glow of pleasure, when I remember making out some little point in +their method of fertilisation. (755/2. Published in "Life and Letters," +III., page 288.) With respect to terms, no doubt you will be able to +improve them greatly, for I knew nothing about the terms as used in +other groups of plants. Could you not invent some quite new term for +gland, implying viscidity? or append some word to gland. I used for +cirripedes "cement gland." + +Your present work must be frightfully difficult. I looked at a few dried +flowers, and could make neither heads nor tails of them; and I well +remember wondering what you would do with them when you came to the +group in the "Genera Plantarum." I heartily wish you safe through your +work,... + + +LETTER 756. TO F.M. BALFOUR. Down, September 4th, 1880. + +I hope that you will not think me a great bore, but I have this minute +finished reading your address at the British Association; and it has +interested me so much that I cannot resist thanking you heartily for the +pleasure derived from it, not to mention the honour which you have done +me. (756/1. Presidential address delivered by Prof. F.M. Balfour before +the Biological Section at the British Association meeting at Swansea +(1880).) The recent progress of embryology is indeed splendid. I have +been very stupid not to have hitherto read your book, but I have had of +late no spare time; I have now ordered it, and your address will make +it the more interesting to read, though I fear that my want of knowledge +will make parts unintelligible to me. (756/2. "A Treatise on Comparative +Embryology," 2 volumes. London, 1880.) In my recent work on plants I +have been astonished to find to how many very different stimuli the +same small part--viz., the tip of the radicle--is sensitive, and has +the power of transmitting some influence to the adjoining part of +the radicle, exciting it to bend to or from the source of irritation +according to the needs of the plant (756/3. See Letter 757.); and all +this takes place without any nervous system! I think that such facts +should be kept in mind when speculating on the genesis of the nervous +system. I always feel a malicious pleasure when a priori conclusions are +knocked on the head: and therefore I felt somewhat like a devil when I +read your remarks on Herbert Spencer (756/4. Prof. Balfour discussed +Mr. Herbert Spencer's views on the genesis of the nervous system, and +expressed the opinion that his hypothesis was not borne out by recent +discoveries. "The discovery that nerves have been developed from +processes of epithelial cells gives a very different conception of their +genesis to that of Herbert Spencer, which makes them originate from +the passage of nervous impulses through a track of mingled colloids..." +(loc. cit., page 644.))...Our recent visit to Cambridge was a brilliant +success to us all, and will ever be remembered by me with much pleasure. + + +LETTER 757. TO JAMES PAGET. + +(757/1. During the closing years of his life, Darwin began to +experimentise on the possibility of producing galls artificially. A +letter to Sir J.D. Hooker (November 3rd, 1880) shows the interest which +he felt in the question:-- + +"I was delighted with Paget's essay (757/2. An address on "Elemental +Pathology," delivered before the British Medical Association, August +1880, and published in the Journal of the Association.); I hear that +he has occasionally attended to this subject from his youth...I am very +glad he has called attention to galls: this has always seemed to me a +profoundly interesting subject; and if I had been younger would take it +up." + +His interest in this subject was connected with his ever-present wish +to learn something of the causes of variation. He imagined to himself +wonderful galls caused to appear on the ovaries of plants, and by these +means he thought it possible that the seed might be influenced, and thus +new varieties arise. (757/3. There would have been great difficulties +about this line of research, for when the sexual organs of plants +are deformed by parasites (in the way he hoped to effect by poisons) +sterility almost always results. See Molliard's "Les Cecidies Florales," +"Ann. Sci. Nat." 1895, Volume I., page 228.) He made a considerable +number of experiments by injecting various reagents into the tissues of +leaves, and with some slight indications of success. (757/4. The above +passage is reprinted, with alterations, from "Life and Letters," III., +page 346.) + +The following letter to the late Sir James Paget refers to the same +subject.) + +Down, November 14th, 1880. + +I am very much obliged for your essay, which has interested me greatly. +What indomitable activity you have! It is a surprising thought that the +diseases of plants should illustrate human pathology. I have the German +"Encyclopaedia," and a few weeks ago told my son Francis that the +article on the diseases of plants would be well worth his study; but I +did not know it was written by Dr. Frank, for whom I entertain a high +respect as a first-rate observer and experimentiser, though for some +unknown reason he has been a good deal snubbed in Germany. I can give +you one good case of regrowth in plants, recently often observed by me, +though only externally, as I do not know enough of histology to follow +out details. It is the tip of the radicle of a germinating common bean. +The case is remarkable in some respects, for the tip is sensitive to +various stimuli, and transmits an order, causing the upper part of +the radicle to bend. When the tip (for a length of about 1 mm.) is cut +transversely off, the radicle is not acted on by gravitation or other +irritants, such as contact, etc., etc., but a new tip is regenerated +in from two to four days, and then the radicle is again acted on by +gravitation, and will bend to the centre of the earth. The tip of the +radicle is a kind of brain to the whole growing part of the radicle! +(757/5. We are indebted to Mr. Archer-Hind for the translation of the +following passage from Plato ("Timaeus," 90A): "The reason is every +man's guardian genius (daimon), and has its habitation in our brain; it +is this that raises man (who is a plant, not of earth but of heaven) to +an erect posture, suspending the head and root of us from the heavens, +which are the birthplace of our soul, and keeping all the body upright." +On the perceptions of plants, see "Nature," November 14th, 1901--a +lecture delivered at the Glasgow meeting of the British Association by +Francis Darwin. See also Bonitz, "Index Aristotelicus," S.V. phuton.) + +My observation will be published in about a week's time, and I would +have sent you the book, but I do not suppose that there is anything else +in the book which would interest you. I am delighted that you have +drawn attention to galls. They have always seemed to me profoundly +interesting. Many years ago I began (but failed for want of time, +strength, and health, as on infinitely many other occasions) to +experimentise on plants, by injecting into their tissues some alkaloids +and the poison of wasps, to see if I could make anything like galls. +If I remember rightly, in a few cases the tissues were thickened and +hardened. I began these experiments because if by different poisons I +could have affected slightly and differently the tissues of the same +plant, I thought there would be no insuperable difficulty in the fittest +poisons being developed by insects so as to produce galls adapted for +them. Every character, as far as I can see, is apt to vary. Judging from +one of your sentences you will smile at this. + +To any one believing in my pangenesis (if such a man exists) there does +not seem to me any extreme difficulty in understanding why plants have +such little power of regeneration; for there is reason to think that +my imaginary gemmules have small power of passing from cell to cell. +(757/6. On regeneration after injury, see Massart, "La Cicatrisation +chez les Vegetaux," in Volume 57 (1898) of the "Memoires Couronnes," +published by the Royal Academy of Belgium. An account of the literature +is given by the author.) + +Forgive me for scribbling at such unreasonable length; but you are to +blame for having interested me so much. + +P.S.--Perhaps you may remember that some two years ago you asked me to +lunch with you, and proposed that I should offer myself again. Whenever +I next come to London, I will do so, and thus have the pleasure of +seeing you. + + +LETTER 758. TO W. THISELTON-DYER. + +(758/1. "The Power of Movement in Plants" was published early in +November, 1880. Sir W. Thiselton-Dyer, in writing to thank Darwin for +a copy of the book, had (November 20th) compared a structure in +the seedling Welwitschia with the "peg" of Cucurbita (see "Power +of Movement," page 102). Dyer wrote: "One peculiar feature in the +germinating embryo is a lateral hypocotyledonary process, which +eventually serves as an absorbent organ, by which the nutriment of the +endosperm is conveyed to the seedling. Such a structure was quite new to +me, and Bower and I were disposed to see in it a representative of +the foot in Selaginella, when I saw the account of Flahault's 'peg.'" +Flahault, it should be explained, was the discoverer of the curious +peg in Cucurbita. Prof. Bower wrote a paper ("On the Germination and +Histology of the seedling of Welwitschia mirabilis" in the "Quart. +Journ. Microscop. Sci." XXI., 1881, page 15.) + +Down, November 28th [1880]. + +Very many thanks for your most kind note, but you think too highly of +our work--not but what this is very pleasant. + +I am deeply interested about Welwitschia. When at work on the pegs or +projections I could not imagine how they were first developed, before +they could have been of mere mechanical use. Now it seems possible that +a circle between radicle and hypocotyl may be permeable to fluids, and +thus have given rise to projections so as to expose larger surface. +Could you test Welwitschia with permanganate of potassium: if, like my +pegs, the lower surface would be coloured brown like radicle, and upper +surface left white like hypocotyl. If such an idea as yours, of an +absorbing organ, had ever crossed my mind, I would have tried many +hypocotyls in weak citrate of ammonia, to see if it penetrated on line +of junction more easily than elsewhere. I daresay the projection in +Abronia and Mirabilis may be an absorbent organ. It was very good fun +bothering the seeds of Cucurbita by planting them edgeways, as would +never naturally occur, and then the peg could not act properly. Many of +the Germans are very contemptuous about making out use of organs; but +they may sneer the souls out of their bodies, and I for one shall think +it the most interesting part of natural history. Indeed, you are greatly +mistaken if you doubt for one moment on the very great value of your +constant and most kind assistance to us. I have not seen the pamphlet, +and shall be very glad to keep it. Frank, when he comes home, will +be much interested and pleased with your letter. Pray give my kindest +remembrance to Mrs. Dyer. + +This is a very untidy note, but I am very tired with dissecting worms +all day. Read the last chapter of our book, and then you will know the +whole contents. + + +LETTER 759. TO H. VOCHTING. Down, December 16th, 1880. + +Absence from home has prevented me from sooner thanking you for your +kind present of your several publications. I procured some time ago your +"Organbilding" (759/1. "Organbildung im Pflanzenreich," 1878.) etc., but +it was too late for me to profit by it for my book, as I was correcting +the press. I read only parts, but my son Francis read the whole with +care and told me much about it, which greatly interested me. I also read +your article in the "Bot. Zeitung." My son began at once experimenting, +to test your views, and this very night will read a paper before the +Linnean Society on the roots of Rubus (759/2. Francis Darwin, "The +Theory of the Growth of Cuttings" ("Linn. Soc. Journ." XVIII.). [I take +this opportunity of expressing my regret that at page 417, owing to +neglect of part of Vochting's facts, I made a criticism of his argument +which cannot be upheld.--F.D.].), and I think that you will be pleased +to find how well his conclusions agree with yours. He will of course +send you a copy of his paper when it is printed. I have sent him your +letter, which will please him if he agrees with me; for your letter has +given me real pleasure, and I did not at all know what the many great +physiologists of Germany, Switzerland, and Holland would think of it +["The Power of Movement," etc.]. I was quite sorry to read Sachs' views +about root-forming matter, etc., for I have an unbounded admiration for +Sachs. In this country we are dreadfully behind in Physiological Botany. + + +LETTER 760. TO A. DE CANDOLLE. Down, January 24th, 1881. + +It was extremely kind of you to write me so long and valuable a +letter, the whole of which deserves careful consideration. I have been +particularly pleased at what you say about the new terms used, because I +have often been annoyed at the multitude of new terms lately invented in +all branches of Biology in Germany; and I doubted much whether I was not +quite as great a sinner as those whom I have blamed. When I read your +remarks on the word "purpose" in your "Phytographie," I vowed that I +would not use it again; but it is not easy to cure oneself of a vicious +habit. It is also difficult for any one who tries to make out the use of +a structure to avoid the word purpose. I see that I have probably gone +beyond my depth in discussing plurifoliate and unifoliate leaves; but +in such a case as that of Mimosa albida, where rudiments of additional +leaflets are present, we must believe that they were well developed in +the progenitor of the plant. So again, when the first true leaf differs +widely in shape from the older leaves, and resembles the older leaves in +allied species, is it not the most simple explanation that such leaves +have retained their ancient character, as in the case of the embryos of +so many animals? + +Your suggestion of examining the movements of vertical leaves with an +equal number of stomata on both sides, with reference to the light, +seems to me an excellent one, and I hope that my son Francis may follow +it up. But I will not trouble you with any more remarks about our book. +My son will write to you about the diagram. + +Let me add that I shall ever remember with pleasure your visit here last +autumn. + + +LETTER 761. TO J. LUBBOCK (Lord Avebury). Down, April 16th [1881]. + +Will you be so kind as to send and lend me the Desmodium gyrans by the +bearer who brings this note. + +Shortly after you left I found my notice of the seeds in the "Gardeners' +Chronicle," which please return hereafter, as I have no other copy. +(761/1. "Note on the Achenia of Pumilio argyrolepis." "Gardeners' +Chronicle," 1861, page 4.) I do not think that I made enough about the +great power of absorption of water by the corolla-like calyx or pappus. +It seems to me not unlikely that the pappus of other Compositae may be +serviceable to the seeds, whilst lying on the ground, by absorbing the +dew which would be especially apt to condense on the fine points and +filaments of the pappus. Anyhow, this is a point which might be easily +investigated. Seeds of Tussilago, or groundsel (761/2. It is not clear +whether Tussilago or groundsel (Senecio vulgaris) is meant; or whether +he was not sure which of the two plants becomes slimy when wetted.), +emit worm-like masses of mucus, and it would be curious to ascertain +whether wetting the pappus alone would suffice to cause such secretion. +(761/3. See Letter 707.) + + +LETTER 762. TO G.J. ROMANES. Down, April 18th, 1881. + +I am extremely glad of your success with the flashing light. (762/1. +Romanes' paper on the effect of intermittent light on heliotropism was +the "Proc. Royal Soc." Volume LIV., page 333.) If plants are acted on by +light, like some of the lower animals, there is an additional point of +interest, as it seems to me, in your results. Most botanists believe +that light causes a plant to bend to it in as direct a manner as light +affects nitrate of silver. I believe that it merely tells the plant to +which side to bend, and I see indications of this belief prevailing even +with Sachs. Now it might be expected that light would act on a plant in +something the same manner as on the lower animals. As you are at work on +this subject, I will call your attention to another point. Wiesner, of +Vienna (who has lately published a great book on heliotropism) finds +that an intermittent light, say of 20 minutes, produces the same +effect as a continuous light of, say 60 m. (762/2. Wiesner's papers on +heliotropism are in the "Denkschriften" of the Vienna Academy, Volumes +39 and 43.) So that Van Tieghem, in the first part of his book which has +just appeared, remarks, the light during 40 m. out of the 60 m. produced +no effect. I observed an analogous case described in my book. (762/3. +"Power of Movement," page 459.) + +Wiesner and Van Tieghem seem to think that this is explained by +calling the whole process "induction," borrowing a term used by some +physico-chemists (of whom I believe Roscoe is one) and implying an +agency which does not produce any effect for some time, and continues +its effect for some time after the cause has ceased. I believe that +photographic paper is an instance. I must ask Leonard (762/4. Mr. +Darwin's son.) whether an interrupted light acts on it in the same +manner as on a plant. At present I must still believe in my explanation +that it is the contrast between light and darkness which excites a +plant. + +I have forgotten my main object in writing--viz., to say that I believe +(and have so stated) that seedlings vary much in their sensitiveness +to light; but I did not prove this, for there are many difficulties, +whether the time of incipient curvature or the amount of curvature is +taken as the criterion. Moreover they vary according to age, and +perhaps from vigour of growth, and there seems inherent variability, +as Strasburger (whom I quote) found with spores. If the curious anomaly +observed by you is due to varying sensitiveness, ought not all the +seedlings to bend if the flashes were at longer intervals of time? +According to my notion of contrast between light and darkness being the +stimulus, I should expect that if flashes were made sufficiently slow +it would be a powerful stimulus, and that you would suddenly arrive at +a period when the result would SUDDENLY become great. On the other hand, +as far as my experience goes, what one expects rarely happens. + + +LETTER 763. TO JULIUS WIESNER. Down, October 4th, 1881. + +I thank you sincerely for your very kind letter, and for the present of +your new work. (763/1. "Das Bewegungsvermogen der Pflanze," 1881. One of +us has given some account of Wiesner's book in the presidential address +to Section D of the British Association, 1891. Wiesner's divergence +from Darwin's views is far-reaching, and includes the main thesis of +the "Power of Movement." See "Life and Letters," III., page 336, for an +interesting letter to Wiesner.) My son Francis, if he had been at home, +would have likewise sent his thanks. I will immediately begin to read +your book, and when I have finished it will write again. But I read +german so very slowly that your book will take me a considerable time, +for I cannot read for more than half an hour each day. I have, also, +been working too hard lately, and with very little success, so that I am +going to leave home for a time and try to forget science. + +I quite expect that you will find some gross errors in my work, for you +are a very much more skilful and profound experimentalist than I am. +Although I always am endeavouring to be cautious and to mistrust myself, +yet I know well how apt I am to make blunders. Physiology, both animal +and vegetable, is so difficult a subject, that it seems to me to +progress chiefly by the elimination or correction of ever-recurring +mistakes. I hope that you will not have upset my fundamental notion +that various classes of movement result from the modification of a +universally present movement of circumnutation. + +I am very glad that you will again discuss the view of the turgescence +of the cells being the cause of the movement of parts. I adopted De +Vries' views as seeming to me the most probable, but of late I have felt +more doubts on this head. (763/2. See "Power of Movement," page 2. De +Vries' work is published in the "Bot. Zeitung," 1879, page 830.) + + +LETTER 764. TO J.D. HOOKER. Glenrhydding House, Patterdale, Penrith, +June 15th, 1881. + +It was real pleasure to me to see once again your well-known handwriting +on the outside of your note. I do not know how long you have returned +from Italy, but I am very sorry that you are so bothered already with +work and visits. I cannot but think that you are too kind and civil +to visitors, and too conscientious about your official work. But a man +cannot cure his virtues, any more than his vices, after early youth; +so you must bear your burthen. It is, however, a great misfortune for +science that you have so very little spare time for the "Genera." I can +well believe what an awful job the palms must be. Even their size must +be very inconvenient. You and Bentham must hate the monocotyledons, for +what work the Orchideae must have been, and Gramineae and Cyperaceae +will be. I am rather despondent about myself, and my troubles are of an +exactly opposite nature to yours, for idleness is downright misery to +me, as I find here, as I cannot forget my discomfort for an hour. I have +not the heart or strength at my age to begin any investigation lasting +years, which is the only thing which I enjoy; and I have no little jobs +which I can do. So I must look forward to Down graveyard as the sweetest +place on earth. This place is magnificently beautiful, and I enjoy the +scenery, though weary of it; and the weather has been very cold and +almost always hazy. + +I am so glad that your tour has answered for Lady Hooker. We return home +on the first week of July, and should be truly glad to aid Lady Hooker +in any possible manner which she will suggest. + +I have written to my gardener to send you plants of Oxalis corniculata +(and seeds if possible). I should think so common a weed was never asked +for before,--and what a poor return for the hundreds of plants which I +have received from Kew! I hope that I have not bothered you by writing +so long a note, and I did not intend to do so. + +If Asa Gray has returned with you, please give him my kindest +remembrances. + + +LETTER 765. TO J.D. HOOKER. October 22nd, 1881. + +I am investigating the action of carbonate of ammonia on chlorophyll, +which makes me want the plants in my list. (765/1. "The Action of +Carbonate of Ammonia on Chlorophyll Bodies." "Linn. Soc. Journ." XIX., +page 262, 1882.) I have incidentally observed one point in Euphorbia, +which has astonished me--viz. that in the fine fibrous roots of +Euphorbia, the alternate rows of cells in their roots must differ +physiologically, though not in external appearance, as their contents +after the action of carbonate of ammonia differ most conspicuously... + +Wiesner of Vienna has just published a book vivisecting me in the most +courteous, but awful manner, about the "Power of Movement in Plants." +(765/2. See Letter 763, note.) Thank heaven, he admits almost all my +facts, after re-trying all my experiments; but gives widely different +interpretation of the facts. I think he proves me wrong in several +cases, but I am convinced that he is utterly erroneous and fanciful +in other explanations. No man was ever vivisected in so sweet a manner +before, as I am in this book. + + + +CHAPTER 2.XII. + +VIVISECTION AND MISCELLANEOUS SUBJECTS, 1867-1882. + +2.XII.I. VIVISECTION, 1875-1882. + + +LETTER 766. TO LORD PLAYFAIR. + +(766/1. A Bill was introduced to the House of Commons by Messrs. Lyon +Playfair, Walpole and Ashley, in the spring of 1875, but was withdrawn +on the appointment of a Royal Commission to inquire into the whole +question. Some account of the Anti-Vivisection agitation, the +introduction of bills, and the appointment of a Royal Commission +is given in the "Life and Letters," III., page 201, where the more +interesting of Darwin's letters on the question are published.) + +Down, May 26th, 1875. + +I hope that you will excuse my troubling you once again. I received some +days ago a letter from Prof. Huxley, in Edinburgh, who says with respect +to your Bill: "the professors here are all in arms about it, and as the +papers have associated my name with the Bill, I shall have to repudiate +it publicly, unless something can be done. But what in the world is to +be done?" (766/2. The letter is published in full in Mr. L. Huxley's +interesting chapter on the vivisection question in his father's "Life," +I., page 438.) Dr. Burdon Sanderson is in nearly the same frame of mind +about it. The newspapers take different views of the purport of +the Bill, but it seems generally supposed that it would prevent +demonstrations on animals rendered insensible, and this seems to me +a monstrous provision. It would, moreover, probably defeat the end +desired; for Dr. B. Sanderson, who demonstrates to his class on animals +rendered insensible, told me that some of his students had declared +to him that unless he had shown them what he had, they would have +experimented on live animals for themselves. Certainly I do not believe +that any one could thoroughly understand the action of the heart without +having seen it in action. I do not doubt that you wish to aid the +progress of Physiology, and at the same time save animals from all +useless suffering; and in this case I believe that you could not do +a greater service than to warn the Home Secretary with respect to the +appointment of Royal Commissioners, that ordinary doctors know little or +nothing about Physiology as a science, and are incompetent to judge of +its high importance and of the probability of its hereafter conferring +great benefits on mankind. + + +LETTER 767. TO LORD PLAYFAIR. Down, May 28th. + +I must write one line to thank you for your very kind letter, and to say +that, after despatching my last note, it suddenly occurred to me that I +had been rude in calling one of the provisions of your Bill "monstrous" +or "absurd"--I forget which. But when I wrote the expression it was +addressed to the bigots who, I believed, had forced you to a compromise. +I cannot understand what Dr. B. Sanderson could have been about not to +have objected with respect to the clause of not demonstrating on animals +rendered insensible. I am extremely sorry that you have had trouble and +vexation on the subject. It is a most disagreeable and difficult one. I +am not personally concerned, as I never tried an experiment on a living +animal, nor am I a physiologist; but I know enough to see how ruinous +it would be to stop all progress in so grand a science as Physiology. I +commenced the agitation amongst the physiologists for this reason, +and because I have long felt very keenly on the question of useless +vivisection, and believed, though without any good evidence, that there +was not always, even in this country, care enough taken. Pray forgive me +this note, so much about myself... + + +LETTER 768. TO G.J. ROMANES. + +(768/1. Published in "Life of Romanes," page 61, under 1876-77.) + +Down, June 4th [1876]. + +Your letter has made me as proud and conceited as ten peacocks. (768/2. +This may perhaps refer to Darwin being elected the only honorary member +of the Physiological Society, a fact that was announced in a letter from +Romanes June 1st, 1876, published in the "Life" of Romanes, page 50. +Dr. Sharpey was subsequently elected a second honorary member.) I am +inclined to think that writing against the bigots about vivisection is +as hopeless as stemming a torrent with a reed. Frank, who has just +come here, and who sputters with indignation on the subject, takes an +opposite line, and perhaps he is right; anyhow, he had the best of an +argument with me on the subject...It seems to me the physiologists are +now in the position of a persecuted religious sect, and they must grin +and bear the persecution, however cruel and unjust, as well as they can. + + +LETTER 769. TO T. LAUDER BRUNTON. + +(769/1. In November, 1881, an absolutely groundless charge was brought +by the Victoria Street Society for the Protection of Animals from +Vivisection against Dr. Ferrier for an infringement of the Vivisection +Act. The experiment complained of was the removal of the brain of a +monkey and the subsequent testing of the animal's powers of reacting to +certain treatment. The fact that the operation had been performed six +months before the case came into court would alone have been fatal to +the prosecution. Moreover, it was not performed by Dr. Ferrier, but +by another observer, who was licensed under the Act to keep the monkey +alive after the operation, which was performed under anaesthetics. +Thus the prosecution completely broke down, and the case was dismissed. +(769/2. From the "British Medical Journal," November 19th, 1881. See +also "Times," November 18th, 1881.) The sympathy with Dr. Ferrier in +the purely scientific and medical world was very strong, and the British +Medical Association undertook the defence. The prosecution did good in +one respect, inasmuch as it led to the formation of the Science Defence +Association, to which reference is made in some of Mr. Darwin's letters +to Sir Lauder Brunton. The Association still exists, and continues to do +good work. + +Part of the following letter was published in the "British Medical +Journal," December 3rd, 1881.) + +Down, November 19th, 1881. + +I saw in some paper that there would probably be a subscription to pay +Dr. Ferrier's legal expenses in the late absurd and wicked prosecution. +As I live so retired I might not hear of the subscription, and I should +regret beyond measure not to have the pleasure and honour of showing my +sympathy [with] and admiration of Dr. Ferrier's researches. I know that +you are his friend, as I once met him at your house; so I earnestly beg +you to let me hear if there is any means of subscribing, as I should +much like to be an early subscriber. I am sure that you will forgive me +for troubling you under these circumstances. + +P.S.--I finished reading a few days ago the several physiological and +medical papers which you were so kind as to send me. (769/3. Some of +Lauder Brunton's publications.) I was much interested by several of +them, especially by that on night-sweating, and almost more by others on +digestion. I have seldom been made to realise more vividly the wondrous +complexity of our whole system. How any one of us keeps alive for a day +is a marvel! + + +LETTER 770. T. LAUDER BRUNTON TO CHARLES DARWIN. 50, Welbeck Street, +London, November 21st, 1881. + +I thank you most sincerely for your kind letter and your offer of +assistance to Dr. Ferrier. There is at present no subscription list, as +the British Medical Association have taken up the case, and ought to +pay the expenses. Should these make such a call upon the funds of the +Association as to interfere with its other objects, the whole or part +of the expenses will be paid by those who have subscribed to a guarantee +fund. To this fund there are already a number of subscribers, whose +names are taken by Professor Gerald Yeo, one of the secretaries of the +Physiological Society. They have not subscribed a definite sum, but have +simply fixed a maximum which they will subscribe, if necessary, on the +understanding that only so much as is required shall be asked from each +subscriber in proportion to his subscription. It is proposed to send +by-and-by a list of the most prominent members of this guarantee fund +to the "Times" and other papers, and not only every scientific man, but +every member of the medical profession, will rejoice to see your name +in the list. Dr. Ferrier has been quite worn out by the worry of this +prosecution, or, as it might well be called, persecution, and has gone +down to Shanklin for a couple of days. He returns this afternoon, and I +have sent on your letter to await his arrival, knowing as I do that it +will be to him like cold water to a thirsty soul. + + +LETTER 771. TO T. LAUDER BRUNTON. Down, November 22nd, 1881. + +Many thanks for your very kind and interesting letter... + +I write now to beg a favour. I do not in the least know what others +have guaranteed in relation to Dr. Ferrier. (771/1. In a letter dated +November 27th, 1881, Sir Lauder Brunton wrote in reply to Mr. Darwin's +inquiry as to the amount of the subscriptions: "When I ascertain +what they intend to give under the new conditions--viz., that the +subscriptions are not to be applied to Ferrier's defence, but to the +defence of others who may be attacked and to a diffusion of knowledge +regarding the nature and purposes of vivisection, I will let you +know...") Would twenty guineas be sufficient? If not, will you kindly +take the trouble to have my name put down for thirty or forty guineas, +as you may think best. If, on the other hand, no one else has guaranteed +for as much as twenty guineas, will you put me down for ten or fifteen +guineas, though I should like to give twenty best. + +You can understand that I do not wish to be conspicuous either by too +little or too much; so I beg you to be so very kind as to act for me. I +have a multitude of letters which I must answer, so excuse haste. + + +LETTER 772. TO T. LAUDER BRUNTON. + +(772/1. The following letter was written in reply to Sir T. Lauder +Brunton's suggestion that Mr. Darwin should be proposed as President of +the Science Defence Association.) + +4, Bryanston Street, Portman Square, December 17th, 1881. + +I have been thinking a good deal about the suggestion which you made +to me the other day, on the supposition that you could not get some man +like the President of the College of Physicians to accept the office. My +wife is strongly opposed to my accepting the office, as she feels sure +that the anxiety thus caused would tell heavily on my health. But +there is a much stronger objection suggested to me by one of my +relations--namely, no man ought to allow himself to be placed at the +head (though only nominally so) of an associated movement, unless he +has the means of judging of the acts performed by the association, after +hearing each point discussed. This occurred to me when you spoke to +me, and I think that I said something to this effect. Anyhow, I have in +several analogous cases acted on this principle. + +Take, for instance, any preliminary statement which the Association may +publish. I might feel grave doubts about the wisdom or justice of some +points, and this solely from my not having heard them discussed. I am +therefore inclined to think that it would not be right in me to accept +the nominal Presidency of your Association, and thus have to act +blindly. + +As far as I can at present see, I fear that I must confine my assistance +to subscribing as large a sum to the Association as any member gives. + +I am sorry to trouble you, but I have thought it best to tell you at +once of the doubts which have arisen in my mind. + + +LETTER 773. TO LAUDER BRUNTON. + +(773/1. Sir T. Lauder Brunton had written (February 12th) to Mr. Darwin +explaining that two opinions were held as to the constitution of the +proposed Science Defence Association: one that it should consist of +a small number of representative men; the other that it should, if +possible, embrace every medical practitioner in the country. Sir Lauder +Brunton adds: "I should be very greatly obliged if you would kindly say +what you think of the two schemes.") + +Down, February 14th, 1882. + +I am very much obliged for your information in regard to the +Association, about which I feel a great interest. It seems to me highly +desirable that the Association should include as many medical and +scientific men as possible throughout the whole country, who could +illumine those capable of illumination on the necessity of physiological +research; but that the Association should be governed by a council of +powerful men, not too many in number. Such a council, as representing +a large body of medical men, would have more power in the eyes of +vote-hunting politicians than a small body representing only themselves. + +From what I see of country practitioners, I think that their annual +subscription ought to be very small. But would it not be possible to +add to the rules some such statement as the following one: "That by a +donation of... pounds, or of any larger sum, from those who feel a deep +interest in the progress of medical science, the donor shall become a +life member." I, for one, would gladly subscribe 50 or 100 pounds. If +such a plan were approved by the leading medical men of London, two or +three thousand pounds might at once be collected; and if any such +sum could be announced as already subscribed, when the program of the +Association is put forth, it would have, as I believe, a considerable +influence on the country, and would attract the attention of country +practitioners. The Anti-Corn Law League owed much of its enormous power +to several wealthy men laying down 1,000 pounds; for the subscription of +a good sum of money is the best proof of earnest conviction. You asked +for my opinion on the above points, and I have given it freely, though +well aware that from living so retired a life my judgment cannot be +worth much. + +Have you read Mr. Gurney's articles in the "Fortnightly" and "Cornhill?" +(773/2. "Fortnightly Review," XXX., page 778; "Cornhill Magazine," XLV., +page 191. The articles are by the late Edmund Gurney, author of "The +power of Sound," 1880.) They seem to me very clever, though obscurely +written; and I agree with almost everything he says, except with some +passages which appear to imply that no experiments should be tried +unless some immediate good can be predicted, and this is a gigantic +mistake contradicted by the whole history of science. + +P.S.--That is a curious fact about babies. I remember hearing on good +authority that very young babies when moved are apt to clutch hold of +anything, and I thought of your explanation; but your case during sleep +is a much more interesting one. Very many thanks for the book, which I +much wanted to see; it shall be sent back to-day, as from you, to the +Society. + + +2.XII.II. MISCELLANEOUS SUBJECTS, 1867-1882. + + +LETTER 774. TO CANON FARRAR. + +(774/1. The lecture which forms the subject of this letter was one +delivered by Canon Farrar at the Royal Institution, "On Some Defects in +Public School Education.") + +Down, March 5th, 1867. + +I am very much obliged for your kind present of your lecture. We have +read it aloud with the greatest interest, and I agree to every word. I +admire your candour and wonderful freedom from prejudice; for I feel an +inward conviction that if I had been a great classical scholar I should +never have been able to have judged fairly on the subject. As it is, I +am one of the root and branch men, and would leave classics to be learnt +by those alone who have sufficient zeal and the high taste requisite +for their appreciation. You have indeed done a great public service in +speaking out so boldly. Scientific men might rail forever, and it would +only be said that they railed at what they did not understand. I was +at school at Shrewsbury under a great scholar, Dr. Butler; I +learnt absolutely nothing, except by amusing myself by reading and +experimenting in chemistry. Dr. Butler somehow found this out, and +publicly sneered at me before the whole school for such gross waste of +time; I remember he called me a Pococurante (774/2. Told in "Life and +Letters," I., page 35.), which, not understanding, I thought was a +dreadful name. I wish you had shown in your lecture how science could +practically be taught in a great school; I have often heard it objected +that this could not be done, and I never knew what to say in answer. + +I heartily hope that you may live to see your zeal and labour produce +good fruit. + + +LETTER 775. TO HERBERT SPENCER. Down, December 9th [1867]. + +I thank you very sincerely for your kind present of your "First +Principles." (775/1. "This must have been the second edition." (Note by +Mr. Spencer.)) I earnestly hope that before long I may have strength to +study the work as it ought to be studied, for I am certain to find +or re-find much that is deeply interesting. In many parts of your +"Principles of Biology" I was fairly astonished at the prodigality of +your original views. (775/2. See "Life and Letters," III., pages 55, +56.) Most of the chapters furnished suggestions for whole volumes of +future researches. As I have heard that you have changed your residence, +I am forced to address this to Messrs. Williams & Norgate; and for the +same reason I gave some time ago the same address to Mr. Murray for a +copy of my book on variation, etc., which is now finished, but delayed +by the index-maker. + + +LETTER 776. TO T.H. HUXLEY. + +(776/1. This letter refers to a movement set on foot at a meeting held +at the Freemasons' Tavern, on November 16th, 1872, of which an account +is given in the "Times" of November 23rd, 1872, at which Mark Pattison, +Mr. Henry Sidgwick, Sir Benjamin Brodie, Professors Rolleston, Seeley, +Huxley, etc., were present. The "Times" says that the meeting was held +"by members of the Universities and others interested in the promotion +of mature study and scientific research in England." One of the +headings of the "Program of Discussion" was "The Abolition of Prize +Fellowships.") + +Sevenoaks, October 22nd [1872]. + +I have been glad to sign and forward the paper, for I have very long +thought it a sin that the immense funds of the Universities should be +wasted in Fellowships, except a few for paying for education. But when +I was at Cambridge it would have been an unjustifiable sneer to have +spoken of the place as one for education, always excepting the men who +went in for honours. You speak of another resolution "in the interest +of the anti-letter-writing association"--but alas, this never arrived! +I should like a society formed so that every one might receive pleasant +letters and never answer them. + +We return home on Saturday, after three weeks of the most astounding +dullness, doing nothing and thinking of nothing. I hope my Brain likes +it--as for myself, it is dreadful doing nothing. (776/2. Darwin returned +to Down from Sevenoaks on Saturday, October 26th, 1872, which fixes the +date of the letter.) + + +LETTER 777. TO LADY DERBY. Down, Saturday [1874?]. + +If you had called here after I had read the article you would have found +a much perplexed man. (777/1. Probably Sir W. Crookes' "Researches in +the Phenomena of Spiritualism" (reprinted from the "Quarterly Journal of +Science"), London, 1874. Other papers by Crookes are in the "Proceedings +of the Society for Psychical Research.") I cannot disbelieve Mr. +Crooke's statement, nor can I believe in his result. It has removed +some of my difficulty that the supposed power is not an anomaly, but is +common in a lesser degree to various persons. It is also a consolation +to reflect that gravity acts at any distance, in some wholly unknown +manner, and so may nerve-force. Nothing is so difficult to decide as +where to draw a just line between scepticism and credulity. It was +a very long time before scientific men would believe in the fall of +aerolites; and this was chiefly owing to so much bad evidence, as in the +present case, being mixed up with the good. All sorts of objects were +said to have been seen falling from the sky. I very much hope that a +number of men, such as Professor Stokes, will be induced to witness Mr. +Crooke's experiments. + + +(778/1. The two following extracts may be given in further illustration +of Darwin's guiding principle in weighing evidence. He wrote to Robert +Chambers, April 30th, 1861: "Thanks also for extract out of newspaper +about rooks and crows; I wish I dared trust it. I see in cutting the +pages [of Chambers' book, "Ice and Water"]...that you fulminate against +the scepticism of scientific men. You would not fulminate quite so much +if you had had so many wild-goose chases after facts stated by men +not trained to scientific accuracy. I often vow to myself that I will +utterly disregard every statement made by any one who has not shown the +world he can observe accurately." In a letter to Dr. Dohrn, of Naples, +January 4th, 1870, Darwin wrote: "Forgive me for suggesting one +caution; as Demosthenes said, 'Action, action, action,' was the soul of +eloquence, so is caution almost the soul of science.") + + +LETTER 778. TO J. BURDON SANDERSON. Down, July 16th, 1875. + +Some little time ago Mr. Simon (778/1. Now Sir John Simon) sent me the +last Report, and your statements about contagion deeply interested me. +By the way, if you see Mr. Simon, and can remember it, will you thank +him for me; I was so busy at the time that I did not write. Having been +in correspondence with Paget lately on another subject, I mentioned to +him an analogy which has struck me much, now that we know that sheep-pox +is fungoid; and this analogy pleased him. It is that of fairy rings, +which are believed to spread from a centre, and when they intersect the +intersecting portion dies out, as the mycelium cannot grow where it has +grown during previous years. So, again, I have never seen a ring within +a ring; this seems to me a parallel case to a man commonly having the +smallpox only once. I imagine that in both cases the mycelium must +consume all the matter on which it can subsist. + + +LETTER 779. TO A. GAPITCHE. + +(779/1. The following letter was written to the author (under the +pseudonym of Gapitche) of a pamphlet entitled "Quelques mots sur +l'Eternite du Corps Humaine" (Nice, 1880). Mr. Gapitche's idea was +that man might, by perfect adaptation to his surroundings, indefinitely +prolong the duration of life. We owe Mr. Darwin's letter to the kindness +of Herr Vetter, editor of the well-known journal "Kosmos.") + +Down, February 24th, 1880. + +I suppose that no one can prove that death is inevitable, but the +evidence in favour of this belief is overwhelmingly strong from the +evidence of all other living creatures. I do not believe that it is by +any means invariably true that the higher organisms always live longer +than the lower ones. Elephants, parrots, ravens, tortoises, and some +fish live longer than man. As evolution depends on a long succession of +generations, which implies death, it seems to me in the highest degree +improbable that man should cease to follow the general law of evolution, +and this would follow if he were to be immortal. + +This is all that I can say. + + +LETTER 780. TO J. POPPER. + +(780/1. Mr. Popper had written about a proposed flying machine in which +birds were to take a part.) + +Down, February 15th, 1881. + +I am sorry to say that I cannot give you the least aid, as I have never +attended to any mechanical subjects. I should doubt whether it would be +possible to train birds to fly in a certain direction in a body, though +I am aware that they have been taught some tricks. Their mental powers +are probably much below those of mammals. It is said, and I suppose +truly, that an eagle will carry a lamb. This shows that a bird may have +great power for a short distance. I cannot remember your essay with +sufficient distinctness to make any remarks on it. When a man is old and +works hard, one subject drives another out of his head. + + +LETTER 781. TO T.H. HUXLEY. Worthing, September 9th, 1881. + +(781/1. Mr. Anthony Rich left his house at Worthing as a legacy to Mr. +Huxley. See Huxley's "Life and Letters," II., pages 286, 287.) + +We have been paying Mr. Rich a little visit, and he has often spoken of +you, and I think he enjoyed much your and Mrs. Huxley's visit here. +But my object in writing now is to tell you something, which I am +very doubtful whether it is worth while for you to hear, because it is +uncertain. My brother Erasmus has left me half his fortune, which is +very considerable. Therefore, I thought myself bound to tell Mr. Rich of +this, stating the large amount, as far as the executors as yet know it +roughly. I then added that my wife and self thought that, under these +new circumstances, he was most fully justified in altering his will and +leaving his property in some other way. I begged him to take a week to +consider what I had told him, and then by letter to inform me of the +result. But he would not, however, hardly allow me to finish what I had +to say, and expressed a firm determination not to alter his will, adding +that I had five sons to provide for. After a short pause he implied (but +unfortunately he here became very confused and forgot a word, which on +subsequent reflection I think was probably "reversionary")--he implied +that there was a chance, whether good or bad I know not, of his becoming +possessed of some other property, and he finished by saying distinctly, +"I will bequeath this to Huxley." What the amount may be (I fear not +large), and what the chance may be, God only knows; and one cannot +cross-examine a man about his will. He did not bind me to secrecy, so I +think I am justified in telling you what passed, but whether it is wise +on my part to send so vague a story, I am not at all sure; but as a +general rule it is best to tell everything. As I know that you hate +writing letters, do not trouble yourself to answer this. + +P.S.--On further reflection I should like to hear that you receive this +note safely. I have used up all my black-edged paper. + + +LETTER 782. TO ANTHONY RICH. Down, February 4th, 1882. + +It is always a pleasure to me to receive a letter from you. I am very +sorry to hear that you have been more troubled than usual with your old +complaint. Any one who looked at you would think that you had passed +through life with few evils, and yet you have had an unusual amount of +suffering. As a turnkey remarked in one of Dickens' novels, "Life is +a rum thing." (782/1. This we take to be an incorrect version of Mr. +Roker's remark (in reference to Tom Martin, the Butcher), "What a rum +thing Time is, ain't it, Neddy?" ("Pickwick," Chapter XLII.). A careful +student finds that women are also apostrophised as "rum": see the +remarks of the dirty-faced man ("Pickwick," Chapter XIV.).) As for +myself, I have been better than usual until about a fortnight ago, +when I had a cough, and this pulled me down and made me miserable to a +strange degree; but my dear old wife insisted on my taking quinine, and, +though I have very little faith in medicine, this, I think, has done me +much good. Well, we are both so old that we must expect some troubles: I +shall be seventy-three on Feb. 12th. I have been glad to hear about the +pine-leaves, and you are the first man who has confirmed my account that +they are drawn in by the base, with a very few exceptions. (782/2. "The +Formation of Vegetable Mould through the Action of Worms," 1881, page +71.) With respect to your Wandsworth case, I think that if I had heard +of it before publishing, I would have said nothing about the ledges +(782/3. "Ledges of Earth on Steep Hill-sides" (ibid., page 278).); +for the Grisedale case (782/4. "The steep, grass-covered sides of a +mountainous valley in Westmorland, called Grisedale, were marked in +many places with innumerable, almost horizontal, little ledges...Their +formation was in no way connected with the action of worms (and their +absence is an inexplicable fact)...(ibid., page 282.), mentioned in my +book and observed whilst I was correcting the proof-sheets, made me feel +rather doubtful. Yet the Corniche case (782/5. Ibid., page 281.) shows +that worms at least aid in making the ledges. Nevertheless, I wish I had +said nothing about the confounded ledges. The success of this worm book +has been almost laughable. I have, however, been plagued with an +endless stream of letters on the subject; most of them very foolish +and enthusiastic, but some containing good facts, which I have used in +correcting yesterday the "sixth Thousand." + +Your friend George's work about the viscous state of the earth and tides +and the moon has lately been attracting much attention (782/6. Published +in the "Philosophical Transactions of the Royal Society," 1879, 1880, +1881.), and all the great judges think highly of the work. He intends to +try for the Plumian Professorship of Mathematics and Natural Philosophy +at Cambridge, which is a good and honourable post of about 800 pounds +a year. I think that he will get it (782/7. He was elected Plumian +Professor of Astronomy and Experimental Philosophy in 1883.) when +Challis is dead, and he is very near his end. He has all the great +men--Sir W. Thomson, Adams, Stokes, etc.--on his side. He has lately +been chief examiner for the Mathematical Tripos, which was tremendous +work; and the day before yesterday he started for Southampton for +a five-weeks' tour to Jamaica for complete rest, to see the Blue +Mountains, and escape the rigour of the early spring. I believe that +George will some day be a great scientific swell. The War Office has +just offered Leonard a post in the Government Survey at Southampton, and +very civilly told him to go down and inspect the place, and accept or +not as he liked. So he went down, but has decided that it would not +be worth his while to accept, as it would entail his giving up his +expedition (on which he had been ordered) to Queensland, in Australia, +to observe the Transit of Venus. (782/8. Major Leonard Darwin, late +R.E., served in several scientific expeditions, including the Transits +of Venus of 1874 and 1882.) Dear old William at Southampton has not been +very well, but is now better. He has had too much work--a willing horse +is always overworked--and all the arrangements for receiving the British +Association there this summer have been thrown on his shoulders. + +But, good Heavens! what a deal I have written about my sons. I have had +some hard work this autumn with the microscope; but this is over, and +I have only to write out the papers for the Linnean Society. (782/9. +i. "The Action of Carbonate of Ammonia on the Roots of Certain plants." +[Read March 16th, 1882.] "Journ. Linn. Soc." Volume XIX., 1882, page +239. ii. "The Action of Carbonate of Ammonia on Chlorophyll-bodies." +[Read March 6th, 1882.] Ibid., page 262.) We have had a good many +visitors; but none who would have interested you, except perhaps Mrs. +Ritchie, the daughter of Thackeray, who is a most amusing and pleasant +person. I have not seen Huxley for some time, but my wife heard this +morning from Mrs. Huxley, who wrote from her bed, with a bad account +of herself and several of her children; but none, I hope, are at all +dangerously ill. Farewell, my kind, good friend. + +Many thanks about the picture, which if I survive you, and this I do not +expect, shall be hung in my study as a perpetual memento of you. + +(782/10. The concluding chapter of the "Life and Letters" gives some +account of the gradual failure in health which was perceptible in the +last year of Mr. Darwin's life. He died on April 19th, 1882, in his 74th +year.) + +THE END. + + +INDEX. + + +INDEX. + + [The German a-, o-, u-diaeresis are treated as a, o, u, not as ae, oe, + ue.] + + Aberrant genera, Darwin's work on. + + Abich, on Vesuvius. + + Abinger, excavations of Roman villa at. + -plants from. + + Abinger Hall, Darwin visits. + -Lord Farrer's recollections of Darwin at. + + Abiogenesis, Huxley's address on Biogenesis and. + + Abortion, Romanes on. + + Abrolhos, plants from the. + + Abromia. + + Abrus precatorius, dispersal of seeds. + + Abstract, Darwin's dislike of writing papers in. + + Abstract, the name applied by Darwin to the "Origin." + + Abutilon, F. Muller's experiments on. + + Abyssinia, flora of. + + "Academy," Darwin's opinion of the. + + Acanthaceae. + + Acceleration of development, Cope and Hyatt on retardation and. + -reference in the "Origin" to. + + Accumulation, of deposits in relation to earth-movements. + -of specific differences. + -of sterility. + -of varieties. + + Accuracy, difficult to attain. + -the soul of Natural History. + + Aceras, fertilisation of. + -monstrous flower. + + Acineta, Darwin unable to fertilise. + + Aconitum, peloria and reversion. + + Acropera, atrophy of ovules. + -Darwin's mistake over. + -fertilisation of. + -relation to Gongora. + -J. Scott's work on. + + Acropera Loddigesii, abnormal structure of ovary. + -Darwin's account of flower. + -artificial fertilisation. + -relation to A. luteola. + -J. Scott's observations. + -two sexual conditions of. + -A. luteola, Darwin's observations on. + -fertilisation of. + -flowers of. + -structure of ovary. + + Adaptation, Darwin's difficulty in understanding. + -hybrids and. + -not the governing law in Geographical Distribution. + -more clearly seen in animals than plants. + -Natural Selection and. + -in orchids. + -resemblances due to. + -in Woodpecker. + + Adenanthera pavonina, seed-dispersal by Parrots. + + Adenocarpus, a Mediterranean genus in the Cameroons. + + Adlumia. + + Adoxa, difference in flowers of same plant. + + Aecidium elatinum, Witches'-Broom fungus. + + Aegialitis Sanctae-helenae. + + Aegilops triticoides, hybrids. + + Affaiblissement, A. St. Hilaire on. + + Africa, connection with Ceylon. + -connection with India. + -continent of Lemuria and. + -considered by Murchison oldest continent. + -plants of equatorial mountains of. + + Africa (East,) coral reefs on coast. + + Africa (South), plants of. + -relation of floras of Western Europe to. + + Africa (West), botanical relation to Java. + + Agassiz, Alex., "Three Cruises of the 'Blake.'" + -his belief in evolution the result of F. Muller's writings. + -account of Florida Coral-reefs. + -letters to. + -visits Down. + + Agassiz, Louis Jean Rodolphe (1807-73): entered a college at Bienne at the + age of ten, and from 1822 to 1824 he was a student at the Academy of + Lausanne. Agassiz afterwards spent some years as a student in the + Universities of Zurich, Heidelberg, and Munich, where he gained a + reputation as a skilled fencer. It was at Heidelberg that his studies took + a definite turn towards Natural History. He took a Ph.D. degree at + Erlangen in 1829. Agassiz published his first paper in "Isis" in 1828, and + for many years devoted himself chiefly to Ichthyology. During a visit to + Paris he became acquainted with Cuvier and Alexander von Humboldt; in 1833, + through the liberality of the latter, he began the publication of his + "Recherches sur les Poissons Fossiles," and in 1840 he completed his + "Etudes sur les Glaciers." In 1846 Agassiz went to Boston, where he + lectured in the Lowell Institute, and in the following year became + Professor of Geology and Zoology at Cambridge. During the last + twenty-seven years of his life Agassiz lived in America, and exerted a + great influence on the study of Natural History in the United States. In + 1836 he received the Wollaston Medal of the Geological Society of London, + and in 1861 he was selected for the Copley Medal of the Royal Society. In + 1873 Agassiz dictated an article to Mrs. Agassiz on "Evolution and + Permanence of Type," in which he repeated his strong conviction against the + views embodied in the "Origin of Species." See "Life, Letters, and Works + of Louis Agassiz," by Jules Marcou, 2 volumes, New York, 1896; "Louis + Agassiz: his Life and Correspondence," edited by Elizabeth Cary Agassiz, 2 + volumes, London, 1885; "Smithsonian Report," 1873, page 198. + -attack on "Origin." + -Darwin's criticism of book on Brazil. + -Darwin's opinion of. + -views on creation of species. + -on geographical distribution. + -"Methods of Study" by. + -misstatement of Darwin's views. + -Walsh on. + -"Etudes sur les Glaciers." + -Darwin on glacier work of. + -on glaciers in Ceara Mts. + -glacier-ice-lake theory of Parallel Roads of Glen Roy. + -on glacier moraines. + -on rock-cavities formed by glacier-cascades. + -on Darwin's theory. + -on Geology of the Amazons. + -doubts recent upheaval of Patagonia. + -mentioned. + + Age of the world. + + Aggressive plants, introduction of. + + Agricultural Society, experiments on potatoes. + + Airy, H. letter to. + + Albemarle Island, Darwin's collection of plants from. + -volcanoes of. + + Aldrovanda. + + Alerse ("Alerce"), occurrence in Chiloe. + + Algae, movement of male-cells to female organ. + + Alisma, F. Muller's observations on. + -submerged flowers of. + + Alisma macrophylla, circumnutation of. + + Allbutt, Prof. Clifford, on sperm-cells. + + Allen, Grant, review by Romanes of his "Physiological Aesthetics." + + Allen, J.A., on colours of birds. + -on mammals and birds of Florida. + + Allogamy, use of term. + + Almond, seedling peaches resembling. + + Alopecurus pratensis, fertilisation of. + + Alpine floras, Arctic and. + -of Azores, Canaries and Madeira. + -absence of, in southern islands. + -Ball on origin of flora. + -Darwin's work on. + -of United States. + -existence prior to Glacial period. + -Ice-action in New Zealand, and. + -Ball on origin of. + + Alpine insects. + + Alpine plants. + -change due to transplanting. + -slight change in isolated forms. + -as evidence of continental land at close of Glacial period. + + Alps, Australian. + -Murchison on structure of. + -submergence. + -Tyndall's book on. + + Alternate generations, in Hydrozoa. + + Amazonia, Insects of. + + Amazons, L. Agassiz on glacial phenomena in valley of. + -L. Agassiz on geology of. + -Bates on lepidoptera of. + -sedimentation off mouth of. + + Amber, extinct plants preserved in. + + Amblyopsis, a blind cave-fish, effect of conditions on. + + Ameghino, Prof., discovery of Neomylodon Listai. + + America (North), are European birds blown to? + -Falconer on elephants. + -fauna and flora of Japan and. + -flora of. + -mammalian fauna. + -introduction of European weeds. + -subsidence during Glacial period. + -western European plants and flora of. + -contrast during Tertiary period between South and. + -former greater distinction between fauna of South and. + -glaciation of South and. + -Rogers on coal-fields. + + America (South), Bollaert's "Antiquities" of. + -Araucarian fossil wood from. + -Carabi of. + -elevation of coast. + -fauna of. + -floras of Australia and. + -geology of. + -Darwin's "Geological Observations" on. + -deposition of sediment on coast. + -European plants in. + -frequency of earthquakes. + -D. Forbes on geology of. + -W. Jameson on geology of. + -D'Orbigny on. + -volcanic eruptions. + -Wallace opposed to continent uniting New Zealand, Australia and. + + American War. + + Ammonia, Darwin's work on effect on roots of carbonate of. + + Ammonites, degeneration of. + -reversion. + -of S. America. + + Amsinckia. + + Amsinckia spectabilis, dimorphism of. + + Anacamptis (=Orchis pyramidalis), fertilisation of. + + Anacharis (=Elodea Canadensis), spread of. + + Analogy, difference between homology and. + + Anamorphism, Huxley on. + + Anatifera, illustrating difficulty in nomenclature. + + Anatomy of Vertebrata, Owen's attack on Darwin and Lyell in. + + "Ancient Sea Margins," by R. Chambers. + + Anderson-Henry, Isaac (1799?-1884): of Edinburgh, was educated as a + lawyer, but devoted himself to horticulture, more particularly to + experimental work on grafting and hybridisation. As President of the + Botanical Society of Edinburgh he delivered two addresses on + "Hybridisation or Crossing of Plants," of which a full abstract was + published in the "Gardeners' Chronicle," April 13th, 1867, page 379, and + December 21st, 1867, page 1296. See obit. notice in "Gardeners' + Chronicle," September 27th, 1884, page 400. + -letter to. + + Andes, Darwin on geology of. + -high-road for European plants. + -comparatively recent origin. + + Anemophilous plants, Delpino's work on. + + Angiosperms, origin of. + + Angraecum sesquipedale, Duke of Argyll on. + + Animal Intelligence, Romanes on. + + Animals, difference between plants and. + -resemblance to plants. + + Annuals, adapted to short seasons. + -Hildebrand on percentages of. + + Anoplotherium, occurrence in Eocene of S. America. + + Ansted, David Thomas, F.R.S. (1814-80): Fellow of Jesus College, Cambridge, + Professor of Geology at King's College, London, author of several papers + and books on geological subjects (see "Quart. Journ. Geol. Soc." Volume + XXXVII., page 43.) + -letter to. + + Antarctic continent, Darwin on existence of Tertiary. + -hypothetical. + + "Antarctic Flora," Sir J.D. Hooker's. + + Antarctic floras. + -Darwin at work on. + + Antarctic islands, plants of. + + Antarctic Land. + + "Anti-Jacobin," quiz on Erasmus Darwin in. + + "Antiquity of Man," Sir Charles Lyell's. + -cautious views on species. + -Darwin's criticism of. + -Extract on Natural Selection from. + -Falconer on. + -Owen's criticism on. + + Antirrhinum, peloric flowers. + + Ants, account in "Origin" of Slave-. + -Forel's work on. + -Moggridge on Harvesting-. + -F. Muller's observations on neuter. + -storing leaves for plant-culture. + + Apathus, living in nests of Bombus. + + Apes, comparison as regards advance in intellect between man and. + -ears of anthropoid. + + Aphides, absence of wings in viviparous. + + Aphis, Huxley on. + + Apostasia, morphology of flowers. + + Appalachian chain, Rogers on cleavage of. + + Apteryx, Owen on. + -wings of. + + Aquilegia, Hooker and Thomson on. + -variation in. + -peloria and reversion. + + Arachis hypogaea, Darwin on. + + Arachnidae. + + Araucaria, abundant in Secondary period. + + Araucarian wood, fossil in S. America. + + Arca, Morse on. + + Archaeopteryx. + + Archer-Hind, R.D., translation of passage from Plato by. + + Archetype, Owen's book on. + -Owen's term. + + d'Archiac's "Histoire des Progres de la Geologie." + -candidate for Royal Society Foreign list. + + Arctic animals, protective colours. + + Arctic climate, cause of present. + + Arctic expeditions, Darwin on. + + Arctic floras. + -relation between Alpine and. + -relation between Antarctic and. + -Hooker's Essay on. + -Darwin's admiration of Hooker's Essay. + -migration of. + + Arctic regions, few plants common to Europe and N. America not ranging + to. + -range of plants. + -northern limit of vegetation formerly lower. + -ice piled up in. + -previous existence of plants in. + + Arenaria verna, range. + + Argus pheasant, colour. + -unadorned head. + + Argyll, Duke of, attack on Romanes in "Nature." + -rejoinder by Romanes in "Nature." + -Hooker on. + -letter to. + -"Reign of Law" by. + + Aristolochia, fertilisation of. + + Aristotle, reference to. + + Ark, Fitz-Roy on extinction of Mastodon owing to construction of. + + Armadillo. + + Army, measurement of soldiers of U.S.A. + + Artemia, Schmankewitsch's experiments on. + + Ascension Island, plants of. + -earth-movements. + -volcanic rocks. + + Ascidians, budding of. + + Asclepiadeae, fertilisation of. + + Ash, comparison of peat and coal. + + Asher, Dr., sends Russian wheat to Darwin. + + Ashley. + + Ashley Heath, Mackintosh on boulders of. + + Askenasy, E., on Darwinism. + + Aspicarpa. + + Ass, hybrids between mare and. + + Asterias. + + Astragalus hypoglottis, range of. + + Astronomical causes, crust-movements due to. + + Asturian plants in Ireland. + + Atavism, use of term by Duchesne. + -Kollmann on. + + Athenaeum Club, Huxley's election. + + "Athenaeum," correspondence on Darwin's statements on rate of increase + of elephants. + -Darwin's opinion of. + -abuse of Darwin. + + Atlantic islands, peculiar genera and their origin. + + Atlantis, America and. + -Canary I. and. + -Darwin's disbelief in. + -Heer's map. + -Wollaston's. + + Atolls, Darwin's wish for investigation by boring of coral. + -Darwin on Murray's theory. + -Darwin's work on. + + Atomogenesis, term suggested as substitute for pangenesis. + + Atriplex, buried seeds found in sandpit near Melrose. + + Attica, Gaudry on fossil animals. + + Auckland Island, flora. + + Audubon, J.J., on antics of birds during courtship. + -"Ornithological Biography." + + Aurelia, Romanes on. + + Auricula, dimorphism of. + -experiments on. + + Austen, Godwin, on changes of level on English coast. + + Australia, caves of. + -character of fauna. + -flora of. + -Hooker on flora. + -relation of flora to S. America. + -relation of flora to S. Africa. + -European plants in. + -local plants in S.W. + -naturalised plants. + -plants on mountains. + -fossil plants. + -dichogamy of trees in. + -as illustrating rate and progress of evolution. + -Mastodon from. + -products of, compared with those of Asia. + -submergence. + + Australian savages and Natural Selection. + + Australian species, occurrence in Malay Archipelago and Philippines. + + Autobiographical recollections, Charles Darwin's. + + Autobiography, extract from Darwin's. + + Autogamy, Kerner's term. + + Automatism, Huxley's Essay. + + Avebury, Lord. + -address at British Association meeting at York (1881). + -on the Finns and Kjokken moddings. + -letters to. + -on the "Origin." + -"Prehistoric Times." + -on the Progress of Science. + -on Seedlings. + -story of Darwin told by. + -Darwin regrets his entrance into politics. + -on Ramsay's lake-theory. + + Averrhoa, Darwin's work on. + + Axell, Severin, book on fertilisation of plants. + + Axon, W.E., letter from Darwin to Mrs. E. Talbot published by. + + Aye Aye, Owen on the. + + Azara. + + Azores, organic relation with America. + -birds. + -European birds as chance wanderers to. + -erratic blocks. + -flora. + -European plants in. + -Miocene beds in. + -relation to Madeira and Canaries. + -Watson on the. + -Orchids from. + -mentioned. + + Babies, habit of clutching objects. + + Babington, Prof. Charles C., at the British Association (Manchester, + 1861). + -"British Flora." + -Darwin sends seeds of Atriplex to. + + Baden-Powell, Prof. + + Baer. + + Bagehot, W., article in "Fortnightly Review" on Physics and Politics. + + Bahia Blanca, collection of plants from. + + Bailey, on Heterocentron roseum. + + Baillon, on pollen-tubes of Helianthemum. + + Baker's Flora of the Mauritius and Seychelles. + + Balancement, G. St. Hilaire's law of. + + Balanidae, Darwin's work on. + + Balanus, questions of nomenclature. + + Balfour, F.M. (1851-82): Professor of Animal Morphology at Cambridge. + He was born 1851, and was killed, with his guide, on the Aiguille + Blanche, near Courmayeur, in July 1882. (See "Life and Letters," III., + page 250.) + -letter to. + -mentioned. + + Ball, J., on origin of Alpine flora. + + Ball, P., "The effects of Use and Disuse." + + Balsaminaceae, genera of. + + Banks' Cove, volcano of. + + Barber, C., on graft-hybrids of sugar-cane. + + Barber, Mrs., on Papilio nireus. + + Barberry, abundance in N. America. + -dispersal of seeds by birds. + -Lord Farrer and H. Muller on floral mechanism. + -movement of stamens. + + Barbs, see Pigeons. + + Bardfield Oxlip (Primula elatior). + + Barnacles, Darwin's work on. + -metamorphosis in. + -F. Muller on. + -nomenclature. + -of Secondary Period. + -advance in. + -complemental males compared with plants. + + Barneoud, on irregular flowers. + + "Baronne Prevost," Rivers on the rose. + + Barrande, Joachim (died 1883): devoted himself to the investigation of + the Palaeozoic fossils of Bohemia, his adopted country. His greatest + work was the "Systeme Silurien de la Boheme," of which twenty-two + volumes were published before his death. He was awarded the Wollaston + Medal of the Geological Society in 1855. Barrande propounded the + doctrine of "colonies." He found that in the Silurian strata of + Bohemia, containing a normal succession of fossils, exceptional bands + occurred which yielded fossils characteristic of a higher zone. He + named these bands "colonies," and explained their occurrence by + supposing that the later fauna represented in these "precursory bands" + had already appeared in a neighbouring region, and that by some means + communication was opened at intervals between this region and that in + which the normal Silurian series was being deposited. This apparent + intercalation of younger among older zones has now been accounted for by + infoldings and faulting of the strata. See J.E. Marr, "On the Pre- + Devonian Rocks of Bohemia," "Quart. Journ. Geol. Soc." Volume XXXVI., + page 591 (1880); also "Defense des Colonies," by J. Barrande (Prag, + 1861), and Geikie's "Text-book of Geology" (1893), page 773. + -candidature for Royal medal. + -candidate for Royal Society foreign list. + -work on Colonies. + -Lyell on work of. + + Barriers to plant distribution in America. + + Barrow, on Emberiza longicauda. + -"Travels in S. Africa." + + Barrow, Sir J., connection with naval expeditions. + + Barrow, germination of seeds from a. + + Bartlett, Abraham Dee (1812-97): was resident superintendent of the + Zoological Society's Gardens in Regent's Park from 1859 to 1897. He + communicated several papers to the Zoological Society. His knowledge was + always at the service of Mr. Darwin, who had a sincere respect for him. + -letters to. + + Barton, on trees of N. America. + + Basalt, association with granite. + -separation of trachyte and. + + Basques, H. Christy on the. + -Hooker on Finns and. + + Bastian, "The Beginnings of Life." + + Bat, natural selection and increase in size of wings. + + Bates, Henry Walter (1825-92): was born at Leicester, and after an + apprenticeship in a hosiery business he became a clerk in Allsopp's + brewery. He did not remain long in this uncongenial position, for in 1848 + he embarked for Para with Mr. Wallace, whose acquaintance he had made at + Leicester some years previously. Mr. Wallace left Brazil after four years' + sojourn, and Bates remained for seven more years. He suffered much ill- + health and privation, but in spite of adverse circumstances he worked + unceasingly: witness the fact that his collection of insects numbered + 14,000 specimens. He became Assistant Secretary to the Royal Geographical + Society in 1864, a post which he filled up to the time of his death in + 1892. In Mr. Clodd's interesting memoir prefixed to his edition of the + "Naturalist on the Amazons," 1892, the editor pays a warm and well-weighed + tribute to Mr. Bates's honourable and lovable personal character. See also + "Life and Letters," II., page 380. + -"A Naturalist on the Amazons." + -Darwin's opinion of his work. + -on insect fauna of Amazon Valley. + -on lepidoptera of Amazons. + -letter from Hooker to. + -letters to. + -letter to Hooker from. + -Darwin reviews paper by. + -on flower of Monochaetum. + -on insects of Chili. + -supplies Darwin with facts for sexual selection. + + Bateson, Miss A., on cross fertilisation in inconspicuous flowers. + + Bateson, W., on breeding lepidoptera in confinement. + -Mendel's "Principles of Heredity." + + Batrachians, Kollmann on rudimentary digits. + + Bauer, F., drawings by. + + Bauhinia, sleep-movements of leaves. + + Beaches, S. American raised. + + "Beagle" (H.M.S.), circumstance of Darwin joining. + -Darwin's views on species when on. + -FitzRoy and voyage of. + -return of. + -voyage. + + Beans, holes bitten by bees in flowers. + -extra-floral nectaries of. + + Bear, comparison with whale. + -modification of. + + Beaton, Donald (1802-63): Biographical notices in the "Journal of + Horticulture" and the "Cottage Gardener," XIII., page 153, and "Journ. + Hort." 1863, pages 349 and 415, are referred to in Britten & Boulger's + "Biographical Index of Botanists," 1893. Dr. Masters tells us that + Beaton had a "first-rate reputation as a practical gardener, and was + esteemed for his shrewdness and humour." + -Darwin on work of. + -on Pelargonium. + + Beatson, on land birds in S. Helena. + + Beaufort. + + Beaufort, Captain, asks Darwin for information as to collecting. + + Beaumont, Elie de (1798-1874): was a pupil in the Ecole Polytechnique + and afterwards in the Ecole des Mines. In 1820 he accompanied M. + Brochant de Villiers to England in order to study the principles of + geological mapping, and to report on the English mines and metallurgical + establishments. For several years M. de Beaumont was actively engaged + in the preparation of the geological map of France, which was begun in + 1825, and in 1835 he succeeded M. B. de Villiers in the Chair of Geology + at the Ecole des Mines. In 1853 he was elected Perpetual Secretary of + the French Academy, and in 1861 he became Vice-President of the Conseil + General des Mines and a Grand Officer of the Legion of Honour. Elie de + Beaumont is best known among geologists as the author of the "Systemes + des Montagnes" and other publications, in which he put forward his + theories on the origin of mountain ranges and on kindred subjects. + ("Quart. Journ. Geol. Soc." Volume XXXI.; "Proc." page xliii, 1875.) + -on lines of elevation. + -on elevation in Cordilleras. + -elevation-crater theory. + -Darwin's disbelief in views and work of. + -on lava and dykes. + -Lyell's refutation of his theory. + -measurement of natural inclination of lava-streams. + + Beauty, criticism by J. Morley of Darwin's phraseology in regard to. + -discussion on. + -lepidoptera and display of. + -Wallace on. + -Darwin's discussion on origin. + -in female animals. + -in plumage of male and female birds. + -of seeds and fruits. + -Shaw on. + -standards of. + + Bedford, flint implements found near. + + Beech, in Chonos I. + -in T. del Fuego and Chili. + -Miquel on distribution. + + Bee-Ophrys (Ophrys apifera), see Bee-Orchis. + + Bee-Orchis, Darwin's experiments on crossing. + -fertilisation. + -self-fertilisation. + -intermediate forms between Ophrys arachnites and. + + Bees, combs. + -Haughton on cells of. + -and instinct. + -referred to in "Descent of Man." + -New Zealand clover and. + -acquisition of power of building cells. + -Darwin's observations on. + -agents in fertilisation of papilionaceous flowers. + -as pollen collectors. + -difference between sexes. + -H. Muller on. + -and parthenogenesis. + -regular lines of flight at Down. + + Beet, graft-hybrids. + + Beete-Jukes, alluded to in De la Beche's presidential address. + + Beetles, bivalves distributed by. + -Forel's work on. + -nest-inhabiting. + -stag-. + -stridulating organs. + + "Befruchtung der Blumen," H. Muller's, the outcome of Darwin's + "Fertilisation of Orchids." + + Begonia, monstrous flowers. + -B. frigida, Hooker on. + + Begoniaceae, genera of. + + Behring Straits, spreading of plants from. + + Belize, coral reefs near. + + Bell, on Owen's "Edinburgh Review" article. + + Bell, Sir C., "Anatomy of Expression." + + Belt, T., on conspicuously coloured animals distasteful to birds. + -letter to. + -"The Naturalist in Nicaragua." + + Ben Nevis, Ice-barrier under. + + Benson, Miss, on Chalazogamy in Amentiferae. + + Bentham, George (1800-83): son of Sir Samuel Bentham, and nephew of Jeremy, + the celebrated authority on jurisprudence. Sir Samuel Bentham was at first + in the Russian service, and afterwards in that of his own country, where he + attained the rank of Inspector-General of Naval Works. George Bentham was + attracted to botany during a "caravan tour" through France in 1816, when he + set himself to work out the names of flowers with De Candolle's "Flore + Francaise." During this period he entered as a student of the Faculte de + Theologie at Tours. About 1820 he was turned to the study of philosophy, + probably through an acquaintance with John Stuart Mill. He next became the + manager of his father's estates near Montpellier, and it was here that he + wrote his first serious work, an "Essai sur la Classification des Arts et + Sciences." In 1826 the Benthams returned to England, where he made many + friends, among whom was Dr. Arnott; and it was in his company that Bentham, + in 1824, paid a long visit to the Pyrenees, the fruits of which was his + first botanical work, "Catalogue des Plantes indigenes des Pyrenees, etc." + 1826. About this time Bentham entered Lincoln's Inn with a view to being + called to the Bar, but the greater part of his energies was given to + helping his Uncle Jeremy, and to independent work in logic and + jurisprudence. He published his "Outlines of a New System of Logic" + (1827), but the merit of his work was not recognised until 1850. In 1829 + Bentham finally gave up the Bar and took up his life's work as a botanist. + In 1854 he presented his collections and books (valued at 6,000 pounds) to + the Royal Gardens, Kew, and for the rest of his life resided in London, and + worked daily at the Herbarium. His work there began with the "Flora of + Hong Kong," which was followed by that of Australia published in 1867 in + seven volumes octavo. At the same time the "Genera Plantarum" was being + planned; it was begun, with Dr. Hooker as a collaborator, in 1862, and + concluded in 1883. With this monumental work his labours ended; "his + strength...suddenly gave way...his visits to Kew ended, and lingering on + under increasing debility, he died of old age on September 10th last" + (1883.) + The amount of work that he accomplished was gigantic and of the most + masterly character. In speaking of his descriptive work the writer (Sir + J.D. Hooker) of the obituary notice in "Nature" (October 2nd, 1884), from + which many of the above facts are taken, says that he had "no superior + since the days of Linnaeus and Robert Brown, and he has left no equal + except Asa Gray" ("Athenaeum," December 31st, 1850; "Contemporary Review," + May, 1873; "George Bentham, F.R.S." By Sir J.D. Hooker, "Annals Bot." + Volume XII., 1898). + -mentioned. + -address to Linnean Society. + -Darwin's criticism on address. + -letters to. + -extract from letter to. + -views on species and on "Origin." + -on fertilisation mechanism in Goodeniaceae. + -on hybridism. + -runs too many forms together. + -on Scott's Primula paper. + + Berberis, Pfeffer on stamens. + + Berkeley, Miles Joseph (1803-89): was educated at Rugby and Christ's + College, Cambridge; he took orders in 1827. Berkeley is described by + Sir William Thiselton-Dyer as "the virtual founder of British Mycology" + and as the first to treat the subject of the pathology of plants in a + systematic manner. In 1857 he published his "Introduction to + Cryptogamic Botany." ("Annals of Botany," Volume XI., 1897, page ix; + see also an obituary notice by Sir Joseph Hooker in the "Proc. Royal + Society," Volume XLVII., page ix, 1890.) + -address by. + -experiments on saltwater and seed-dispersal. + -letter to. + -mentioned. + -notice of Darwin's work by. + + Bermudas, American plants in. + -coral-reefs. + + Berzelius, on flints. + + Bhootan, Rhododendron Boothii from. + + Bible, chronology of. + + Biffen, R., potato grafts. + + Bignonia, F. Muller's paper on. + -B. capreolata, tendrils of. + + Binney, Edward William F.R.S. (1812-81): contributed numerous papers to the + Royal, Palaeontographical, Geological, and other Societies, on Upper + Carboniferous and Permian Rocks; his most important work deals with the + internal structure of Coal-Measure plants. In a paper "On the Origin of + Coal," published in the "Memoirs of the Manchester Literary and + Philosophical Society," Volume VIII., page 148, in 1848, Binney expressed + the view that the sediments of the Coal Period were marine rather than + estuarine, and were deposited on the floor of an ocean, which was + characterised by a "uniformity and shallowness unknown" in any oceanic area + of the present day. + -on marshes of Coal period. + -on coal and coal plants. + + Biogenesis, Huxley's address on abiogenesis and. + + Biology, Huxley's "Course of Practical Instruction" in. + + Biology of plants, Hooker's scheme for a Flora, with notes on. + + Birds, as agents of dispersal of plants. + -blown to Madeira. + -climate and effect on American. + -coloration of. + -comparison with mammals. + -as isolated groups. + -of Madeira. + -modification in. + -Andrew Murray on Wallace's theory of nests. + -Wallace's theory of nests. + -agents in dispersal of land-molluscs. + -antics during courtship. + -courtesy towards own image. + -expression of fear by erection of feathers. + -means of producing music. + -spurs on female. + -pairing. + -polygamy. + -proportion of sexes. + -sexual selection and colour. + -attracted by singing of bullfinch. + -tameness in Brazilian species. + -occurrence of unpaired. + -Weir's observations on. + + Bird of paradise, and polygamy. + + Birmingham, British Association meeting (1849). + + Bivalves, means of dispersal of freshwater. + + Bizcacha, burrowing animal of Patagonia. + + Blackbird, variation in tufted. + + Blair, Rev. R.H., observations on the blind. + + Blake, paper on Elephants in "Geologist." + + Blanford, H.F., on an Indo-oceanic continent. + + Blanford, W.T., obituary notice of Neumayr by. + + Blind, expression of those born. + + Blomefield, L., see Jenyns, L. + + Bloom, Darwin's work on. + -F. Darwin on connection between stomata and (see also Darwin, F.) + -effect of rain on. + -on leaf of Trifolium resupinatum. + -protection against parasites. + -on seashore plants. + + Blow-fly, Lowne on the. + + Blyth, Edward (1810-73): distinguished for his knowledge of Indian birds + and mammals. He was for twenty years Curator of the Museum of the + Asiatic Society of Bengal, a collection which was practically created by + his exertions. Gould spoke of him as "the founder of the study" of + Zoology in India. His published writings are voluminous, and include, + in addition to those bearing his name, numerous articles in the "Field, + Land and Water," etc., under the signature "Zoophilus" or "Z." He also + communicated his knowledge to others with unsparing generosity, yet-- + doubtless the chief part of his "extraordinary fund of information" died + with him. Darwin had much correspondence with him, and always spoke of + him with admiration for his powers of observation and for his judgment. + The letters to Blyth have unfortunately not come into our hands. The + indebtedness of Darwin to Blyth may be roughly gauged by the fact that + the references under his name in the index to "Animals and Plants" + occupy nearly a column. For further information about Blyth see Grote's + introduction to the "Catalogue of Mammals and Birds of Burma, by the + late E. Blyth" in the "Journal of the Asiatic Society of Bengal," Part + II., Extra number, August 1875; also an obituary notice published at the + time of his death in the "Field." Mr. Grote's Memoir contains a list of + Blyth's writings which occupies nearly seven pages of the "Journal." We + are indebted to Professor Newton for calling our attention to the + sources of this note. + -reference to letter from. + -visits Down. + -on Gallinaceae. + + Blytt, Axel Gudbrand (1843-98): the son of the well-known systematist M.N. + Blytt. He was attached to the Christiania Herbarium in 1865, and in 1880 + became Professor of Botany in the University. His best-known work is the + essay referred to above, but he was also known for purely systematic work + in Botany as well as for meteorological and geological contributions to + science. The above facts are taken from C. Holtermann's obituary notice in + the "Berichte der Deutschen Bot. Gesell." Volume XVII., 1899. + -essay on immigration of Norwegian flora during alternating rainy and + dry periods. + -letter to. + + Bog-Mammoth. + + Boiler, comparison with volcano. + + Boissier, on plants of S. Spain. + + Boissiera, crossing experiments on. + + Bolbophyllum, Darwin's account of. + + Bolivia, geology of. + + Bollaert's "Antiquities of S. America." + + Bombus, diversity in generative organs. + -Psithyrus in nests of. + -Pollen-collecting apparatus of male. + + Bombycilla, protective colours. + + Bombyx, sexes in. + + Bonaparte, L., on Basque and Finnish language. + + Bonatea speciosa, F. Muller on. + -structure of flower. + + Bonney's Edition of Darwin's "Coral Reefs." + -"Charles Lyell and Modern Geology." + + Bonnier, G., on alpine plants. + + Boragineae, dimorphism in. + + Borneo, New Zealand and Australian plants in. + -temperate plants in lowlands. + -possible region for remains of early man. + + Bory's Flora of Bourbon. + + Bosquet, cirripede monograph sent by Darwin to. + -gives Darwin note on fossil Chthamalus. + + Botanical collections (national) consolidation at Kew. + + Botanist, Darwin as. + + Botany, philosophical spirit in study of. + + Boulders, transport of erratic (see also Erratic blocks). + -Darwin on Ashley Heath. + -in Glen Roy. + -on Moel Tryfan. + + Bourbon, Bory's Flora of. + + Bournemouth, Darwin's visit to. + + Bovey Tracey, Heer on fossil plants of. + + Bower, Prof. F.O., on Welwitschia. + + Bower-bird, Bartlett's experiments on. + -colours discriminated by. + + Bowman, W., Letters to. + -supplies Darwin with facts on Expression. + + Brachiopods, Morse on. + -Silurian. + + Brackish-water plants. + + Bradshaw, H., translation of Hebrew letter by. + + Brain, Owen on. + -evolution in man. + -Wallace on Natural Selection and Evolution of. + + Branchipus, Schmankewitsch's experiments on. + + Branta, mentioned in reference to nomenclature of Barnacles. + + Brassica sinapistrum, germination at Down of old seeds. + + Braun, A., convert to Darwin's views. + + Bravais, on lines of old sea-level in Finmark. + + Brazil, L. Agassiz's book on. + -Agassiz on glacial phenomena in. + -F. Muller's residence in. + -plants on mountains of. + -basalt in association with granite. + -Darwin on origin of lakes in. + -dimorphism of plants in S. + + Bree, Dr., on Celts. + -misrepresents Darwin. + + Breeders, views on Selection held by. + + Breeding, chapter in "Origin" on. + + Brehm, on birds. + + Breitenbach, Dr. + + Brewster, Sir D., on Glen Roy. + + Bridgeman. + + Brinton, Dr., attends Darwin. + + British Association, + Meetings: Belfast (1874), Birmingham (1849), Cambridge (1862), Ipswich + (1851), Leeds (1858), Liverpool (1870), Manchester (1861), Norwich + (1868), Nottingham (1866), Oxford (1847), Oxford (1860), Southampton + (1846), Swansea (1880), York (1881). + Addresses: Berkeley, Fawcett, Hooker, Hooker on Insular Floras, (see + also Hooker, Sir J.D.), Huxley on Abiogenesis, Lord Kelvin, Wallace on + Birds' Nests. + + British Association, Committee for investigation of Coral Atoll by + boring. + + British Medical Association, undertakes defence of Dr. Ferrier. + + British Museum, disposal of Botanical Collections. + + Brodie, Sir Benjamin. + + Brongniart, Ad., on Sigillaria. + + Bronn, H.G., Letter to. + -on German translation of "Origin." + -reference in his translation of "Origin" to tails of mice as difficulty + opposed to Natural Selection. + -on Natural Selection. + -"Entwickelung." + -"Morphologische Studien." + -"Naturgeschische der drei Reiche." + + Brougham, Lord, on Structure of Bees' cells. + -habit of writing everything important three times. + + Brown, H.T., and F. Escombe, on vitality of seeds. + -on influence of varying amounts of CO2 on plants. + + Brown, R., accompanies Flinders on Australian voyage. + -meets Darwin. + -dilatoriness over King's collection. + -illness. + -on course of vessels in orchid flowers. + -mentioned. + -on pollen-tubes. + -seldom indulged in theory. + + Brulle, Gaspard-Auguste (1809-73): held a post in the Natural History + Museum, Paris, from 1833 to 1839; on leaving Paris he occupied the chair + of Zoology and Comparative Anatomy at Dijon. ("Note sur la Vie et les + Travaux Entomologiques d'Auguste Brulle" by E. Desmarest. "Ann. Soc. + Entom." Volume II., page 513.) + -reference to work by. + -his pupils' eagerness to hear Darwin's views. + + Brunonia, Hamilton on fertilisation mechanism. + + Brunton, Sir T. Lauder, letters to. + -letter to Darwin from. + + Brydges and Anderson, collection of S. American plants. + + Bryophyllum calycinum, Duval-Jouve and F. Muller on movements of leaves. + + Bryozoa, specimens found during voyage of "Beagle." + + Buch, von, on craters of Albermarle I. + -Darwin's disbelief in his views. + -mentioned. + -"Travels in Norway." + + Buckland, William (1784-1856): became a scholar of Corpus Christi + College, Oxford, in 1801; in 1808 he was elected Fellow and ordained + priest. Buckland travelled on horseback over a large part of the + south-west of England, guided by the geological maps of William Smith. + In 1813 he was appointed to the Chair of Mineralogy at Oxford, and soon + afterwards to a newly created Readership in Geology. In 1823 the + "Reliquiae Diluvianae" was published, a work which aimed at supporting + the records of revelation by scientific investigations. In 1824 + Buckland was President of the Geological Society, and in the following + year he left Oxford for the living of Stoke Charity, near Whitchurch, + Hampshire. "The Bridgewater Treatise" appeared in 1836. In 1845 + Buckland was appointed Dean of Westminster; he was again elected + president of the Geological Society in 1840, and in 1848 he received the + Wollaston medal. An entertaining account of Buckland is given in Mr. + Tuckwell's "Reminiscences of Oxford," London, 1900, page 35, with a + reproduction of the portrait from Gordon's "Life of Buckland." + -on Glen Roy. + -mentioned. + + Buckle, Darwin reads book by. + + Buckley, Miss. + + Buckman, on N. American plants. + + Buckman, Prof., experiments at Cirencester. + + Bud, propagation by. + -Hooker's use of term. + -fertilisation in. + + Bud-variation. + + Buenos-Ayres, fossils sent by Darwin from. + + Bull-dog, as example of Design. + + Bullfinch, experiment on colouring. + -attracted by German singing-bird. + -Weir on pairing. + + Bunbury, Sir Charles James Fox, Bart. (1809-85): was born at Messina in + 1809, and in 1829 entered Trinity College, Cambridge. At the end of 1837 + he went with Sir George Napier to the Cape of Good Hope, and during a + residence there of twelve months Bunbury devoted himself to botanical + field-work, and afterwards (1848) published his "Journal of a Residence at + the Cape of Good Hope." In 1844 Bunbury married the second daughter of Mr. + Leonard Horner, Lady Lyell's sister. + In addition to several papers dealing with systematic and geographical + Botany Bunbury published numerous contributions on palaeobotanical + subjects, a science with which his name will always be associated as one + of those who materially assisted in raising the study of Fossil Plants + to a higher scientific level. His papers on fossil plants were + published in the "Journal of the Geological Society" between 1846 and + 1861, and shortly before his death a collection of botanical + observations made in South Africa and South America was issued in book + form in a volume entitled "Botanical Fragments" (London, 1883). Bunbury + was elected into the Royal Society in 1851, and from 1847 to 1853 he + acted as Foreign Secretary to the Geological Society. "Life, Letters, + and Journals of Sir Charles J.F. Bunbury, Bart." edited by his wife + Frances Joanna Bunbury, and privately printed. (Undated.) + -Darwin's opinion of. + -views on Evolution. + -on Agassiz's statements on glaciation of Brazil. + -on plants of Madeira. + -illness. + -mentioned. + + Bunsen, Copley medal awarded to. + -mentioned. + + Burbidge, F.W., on Malaxis. + + Burleigh, Lord. + + Burnett. + + Busk, G., visit to the Continent with Falconer. + -on caves of Gibraltar. + + Butler, A.G., identification of butterflies. + + Butler, Dr., Darwin at Shrewsbury School under. + -mentioned. + + Butterflies, attracted by colours. + -and mimicry. + -tameness of. + -colour and sexual selection. + -description by Darwin of ticking. + + Butterfly-orchis, (see also Habenaria.) + + Cabbage, Darwin's work on. + -effect of salt water on. + -Pinguicula and seeds of. + -sleep-movements of cotyledons. + -waxy secretion on leaves. + + Caddis-flies, F. Muller on abortion of hairs on legs of. + + Caenonympha, breeding in confinement. + + Caird, on Torbitt's potato experiments. + + Calcutta, J. Scott's position in Botanic Garden. + + Callidryas philea, and Hedychium. + + Callithrix Sciureus, wrinkling of eyes during screaming. + + Calluna vulgaris, in Azores. + + Cambrian, piles of unconformable strata below. + + Cambridge, Darwin and Henslow. + -Honorary LL.D. given to Darwin. + -mentioned. + -Darwin's recollections of. + -Owen's address. + -Philosophical Society meeting. + -Darwin visits. + -specimens of Darwin's plants in Botanical Museum. + + Camel, Cuvier's statement on teeth. + -in N. America. + + Cameroons, commingling of temperate and tropical plants. + -Hooker on plants of. + -plants of. + + Campanula, fertilisation mechanism. + -C. perfoliata, note by Scott on. + + Campanulaceae, crossing in. + + Campbell Island, flora. + + Campodea, Lord Avebury on. + + Canada, Sir William Dawson's work. + + Canaries, fertility of hybrids. + -plumage. + -wildness of hybrids. + + Canary Islands, flora. + -Humboldt on. + -insects of. + -Madeira formerly connected with. + -relation to Azores and Madeira. + -d'Urville on. + -African affinity of eastern. + -elevation of. + -Von Buch on. + -Trunks of American trees washed on shores of. + + Candolle, Alphonse Louis Pierre Pyramus De (1806-93): was the son of + Augustin Pyramus, and succeeded his father as Professor of Botany at + Geneva in 1835. He resigned his Chair in 1850, and devoted himself to + research for the rest of his life. At the time of his father's death, + in 1841, seven volumes of the "Prodromus" had appeared: Alphonse + completed the seventeenth volume in 1873. In 1855 appeared his + "Geographie botanique raisonnee," "which was the most important work of + his life," and if not a precursor, "yet one of the inevitable + foundation-stones" of modern evolutionary principles. He also wrote + "Histoire des Savants," 1873, and "Phytographie," 1880. He was lavish + of assistance to workers in Botany, and was distinguished by a dignified + and charming personality. (See Sir W. Thiselton-Dyer's obituary in + "Nature," July 20th, 1893, page 269.) + -on influence of climate. + -on Cupuliferae. + -on extinction of plants in cultivated land. + -"Geographie botanique." + -letters to. + -on introduced plants. + -on naturalised plants and variation. + -review by Asa Gray of. + -on relation of size of families to range of species. + -on social plants. + -mentioned. + + Candolle, C. de, on latent life in seeds. + + Canestrini, on proportion of sexes in Bombyx. + + Canna, fertilisation of. + + Cape of Good Hope (see also Africa). + -Australian flora compared with that of. + -flora. + -variable heaths of. + -Darwin's geological observations on metamorphism at. + -European element in flora. + -Meyer and Doege on plants of. + + Cape Tres Montes, the "Beagle's" southern limit. + + Caprification, F. Muller in "Kosmos" on. + + Capsella bursa-pastoris, cross-fertilisation of. + + Carabus, origin of. + -in Chili. + -A. Murray on. + + Carbon dioxide, percentage in atmosphere. + + Carboniferous period, glacial action. + -subsidence during. + + Cardamine, quasi-bulbs on leaves. + + Carduelis elegans, length of beak. + + Carex. + + Carices, of Greenland. + + Carlisle, Sir A., on Megatherium. + + Carlyle, Mrs., remark on Owen. + + Carmichael, on Tristan d'Acunha. + + Carmichaelia. + + Carnarvonshire, Darwin on glaciers of. + + Caroline Islands, want of knowledge on flora. + + Carpenter, Dr., on influence of blood in crossing. + + Carrier-pigeon (see Pigeon), preference for certain colours in pairing. + + Carrot, flowers of. + + Carruthers, W., on potato experiments. + + Carter, H.J., on reproduction of lower animals and foreshadowing of + Chemotaxis. + + Carus, Professor Victor: translated several of Mr. Darwin's books into + German (see "Life and Letters, III., page 48). + -letters to. + + Casarea, a snake peculiar to Round Island. + + Case, G., Darwin at school of. + + Cassia, Darwin's experiments on. + -sleep-movements of leaves. + -two kinds of stamens. + -Todd on flowers of. + + Cassini, observations on pollen. + -on ovaries of Compositae. + + Cassiope hypnoides. + + Castes, Galton on. + + Catalpa. + + Catasetum, fertilisation of. + -Huxley's scepticism as to mechanism of. + -morphology of flower. + -aerial roots. + -sexual forms of. + -C. saccatum, flower of. + -C. tridentatum, three sexual forms. + + Caterpillars, colour and protection. + -experiments by Weir. + + Cats, Belgian society to encourage homing of. + -habits of. + + Cattell, on crossing sweet peas. + + Cattleya, Darwin suggests experiments on. + -self-fertilisation. + + Caucasus, wingless insects of. + + Cauquenes, baths of. + + Cave-fish, reference in the "Origin" to blind. + + Cave-rat. + + Caves, animals in Australian. + + Cavia, specimens collected by Darwin. + + Ceara Mountains, L. Agassiz on glaciers of. + + Cebus, expression when astonished. + + Cecidomyia, ancestor of. + + Cedars, Hooker on. + + Celebes, geographical distribution in. + + Cellaria. + + Celosia, experiment on. + + Celts, Bree on. + + Centipedes, luminosity of. + + Centradenia, two sets of stamens in. + -position of pistil. + + Cephalanthera, flower. + -single pollen-grains. + -C. grandiflora, fertilisation mechanism. + + Cephalopods, Hyatt on embryology of. + -Hyatt on fossil. + + Cephalotus. + + Cervus campestris, of La Plata. + + Cetacea, Lyell on. + + Ceylon, Malayan types in. + -plants. + -former connection with Africa. + -dimorphic plants of. + + Chaffinch, courtship of. + + Chalazal fertilisation, Miss Benson on. + -foreshadowed by Darwin. + -Treub on. + + Chalk, occurrence of Angiosperms in. + -as oceanic deposit. + + "Challenger" (H.M.S.), reports reviewed by Huxley. + -account of sedimentation in. + + Challis, Prof. + + Chambers, Robert (1802-71): began as a bookseller in Edinburgh in 1816, and + from very modest beginnings he gradually increased his business till it + became the flourishing publishing firm of W. & R. Chambers. After writing + several books on biographical, historical and other subjects, Chambers + published anonymously the "Vestiges of the Natural History of Creation" in + 1844; in 1848 his work on "Ancient Sea Margins" appeared; and this was + followed by the "Book of Days" and other volumes. ("Dict. Nat. Biog." + 1887; see also Darwin's "Life and Letters," I., pages 355, 356, 362, 363.) + -announced as author of "Vestiges of Creation." + -on derivation of marine from land and fresh-water organisms. + -Darwin visits. + -on Glen Roy. + -on land-glaciation of Scotland. + -letters to. + -letter to Milne-Home from. + -on scepticism of scientific men. + -mentioned. + + Chance, use of term. + + Chandler, S.E. (see Farmer, J.B.) + + Changed conditions, Schmankewitsch's experiments on effect of. + + Charles Island, Darwin's plants from. + + Charlock, germination of old seeds. + + Chatham Island, Darwin's collection of plants from. + -Travers on. + + Checks, use of artificial. + + Chemotaxis, foreshadowed by Carter. + + Chiasognathus Grantii. + + Childhood, Charles Darwin's. + + Children, Darwin on. + -experiment on emotions of. + -colour-sense. + -coloured compared with white. + -comparison between those of educated and uneducated parents. + -expression. + -development of mind. + -intelligence of monkeys and. + + Chili, elevation of coast. + -geology of. + -plants common to New Zealand and. + -Carabus of. + -Darwin on earthquakes and terraces in. + + Chillingham cattle, Darwin and Hindmarsh on. + + Chiloe, description of. + -forests. + -geology. + -plants on mountains. + -boulders. + + China, expedition to. + + Chinese, explanation of affinities with Mexicans. + + "Chips from a German Workshop," Max Muller's. + + Chloeon dimidiatum, Lord Avebury on. + + Chlorite, segregation of. + + Chlorophyll, Darwin's work on action of carbonate of ammonia on. + + Chonos Islands, Darwin's collections of plants from. + -Darwin's account of. + -geology of. + -potato. + + Christy, H. + + Christy, Miller, on oxlip. + + Chrysosplenium oppositifolium. + + Chthamalus, in the chalk. + + Cicada, experiments on eggs. + -Muller on rivalry of. + -Walsh on. + -C. septendecim, Sharp's account of. + + Cinchona, Hooker on different rates of growth in seedlings. + + Circumnutation, F. Muller's observations on. + + Cirripedes, see Barnacles. + + Cistus, hybridism of. + + Citrus, unequal cotyledons. + -polyembryonic seeds. + + Civilisation, effect on savages. + + Claparede, convert to Darwin's views. + -and Mdlle. Royer. + + Clapperton's "Scientific Meliorism," letter of Gaskell in. + + Clark, on classification of sponges. + + Clark, Sir James (1788-1870): was for some years a medical officer in + the Navy; he afterwards practised in Rome till he moved to London in + 1826. On the accession of Queen Victoria he was made Physician in + Ordinary and received a baronetcy; he was elected into the Royal Society + in 1832. ("Dict. Nat. Biog." 1857; article by Dr. Norman Moore.) + -on Glen Roy. + + Clarke, W.B., "Wreck of the 'Favourite.'" + + Clarkia, two kinds of stamens. + -C. elegans. + + Classification, Bentham on. + -Cuvier on. + -Dana on mammalian. + -Darwin on. + -Darwin and Huxley on. + -genealogy and. + -value of reproductive organs in. + + Clay-slate, metamorphism of. + + Cleavage and foliation. + -Darwin on his work on. + -history of work on. + -parallelism of foliation and. + -relation to stratification. + -relation to rock-curves. + -Rogers on. + -Sedgwick on. + -uniformity of foliation and. + -result of chemical action. + -metamorphic schists. + -lines of incipient tearing form planes of. + -Tyndall on Sorby's observations. + + Cleistogamic flowers, fertilisation. + -of grass. + -of Oxalis and Viola. + -pollen of. + -comparison with Termites. + + Clematis, Darwin's error in work on. + -Darwin's experiments on. + -irritability. + + Clematis glandulosa, identified at Down by power of feeling. + + Cleodora, specific differences in. + + Clethra, absence in Azores. + -remnant of Tertiary Flora. + + Clianthus. + + Clift, William (1775-1849): Conservator of the Museum of the Royal College + of Surgeons. + -on fossil bones from Australia. + -Owen assistant to. + + Climate, changes in. + -effect on species. + -effect on species of birds. + -migration of organisms and change in. + -relation to distribution and structure of plants. + -extinct mammals as evidence of change in. + -and sexual differentiation. + -variation and. + -Lyell on former. + -mild Miocene. + + Climbing Plants, Darwin's work on. + -circumnutation of. + -F. Muller's work on. + + Clivia, Scott's work on. + + Clodd's memoir of Bates. + + Close species, absence of intermediate forms between. + -definition of. + -Asa Gray on. + -in warm temperate lands of N. and S. hemispheres. + -relation to flora of N. America. + + Clover, relation between bees and. + + Club, dinner at Linnean. + -Philosophical. + + Coal, Darwin on origin of. + -Lesquereux on the flora of. + -marine marshes and plants of. + -ash of. + + Coal period, higher percentage of CO2 during. + + Coast-lines, parallelism with lines of volcanoes. + + Cobbe, Miss, article in "Theological Review" on "Descent of Man." + + Cockburn Island, boulders from. + + Cochin hen, experiments on. + + Coelogyne, fertilisation mechanism. + + Coffea arabica, seeds with two embryos. + + Cohn, F., notice in "Cornhill" of his botanical work. + + Coldstream, Dr. + + Colenso, on Maori races of New Zealand. + + Coleoptera, apterous form of Madeira. + -colonisation of ants' nests by. + + Colias edusa, wings of. + + Collecting, Darwin's early taste for. + + Collier, Hon. John: Royal Academician, son-in-law to Professor Huxley. + -Art primer by. + -letter to. + -portrait of Darwin by. + + Collingwood, Dr., on mimetic forms. + + Colonies, Barrande's. + + Colonisation, conditions of. + + Coloration, Walsh on unity of. + + Colour, butterflies attracted by. + -mimicry in butterflies by means of. + -of dioecious flowers. + -and fertilisation of flowers. + -in grouse, and Natural Selection. + -in birds. + -in male birds, not simply due to Natural Selection. + -Darwin's work on. + -Darwin differs from Wallace in views on. + -evolution of. + -experiments on birds. + -Hackel on lower animals and. + -Krause on. + -Magnus on. + -protection and. + -relation to sex. + -in seeds and fruits. + -and Sexual Selection. + -sense of, in children. + -Wallace on. + + Columba aenas, habits of. + -C. livia, descent of pigeons from. + + Combretum. + + Combs, bees', (see also Bees). + + Comparative anatomy, Huxley's book on. + + Compensation, belief of botanists in. + + Compiler, Darwin's opinion of a. + + Compositae, Harvey on. + -Masters' reference to. + -monstrosities in. + -morphological characters. + -Schleiden on. + -Darwin on crossing. + -fertilisation mechanism. + -Hildebrand on dispersal of seeds. + -viscid threads of seeds. + + Comte, Huxley on. + + Concepcion Island, geology of. + -Darwin's account of earthquake. + + Conchoderma, in reference to nomenclature. + + Concretions, origin of. + + Conditions of life, effect on animals and plants. + -effect on elephants. + -effect on reproductive system. + -hybrids and. + -importance in maintaining number of species. + -species and changes in. + -and sterility. + -variability depends more on nature of organisms than on. + + Confervae and sexuality. + + Coniferae, abundant in humid temperate regions. + + Connecting links. + -Gaudry on. + + Conscience, Morley on Darwin's treatment of. + + Conspectus crustaceorum, Dana's. + + Constancy, in abnormally developed organs. + + Contemporaneity, Darwin on. + + Continental elevation, volcanic eruptions and. + + Continental extension, Darwin on. + -evidence in favour of. + -Hooker on. + -Lyell on. + -and means of distribution. + -New Zealand and. + + Continental forms, versus insular. + + Continents, inhabitants of islands and. + -movements of. + -Wallace on sinking imaginary. + + Controversy, Darwin's hatred and avoidance of. + + Convallaria majalis, in Virginia. + + Convolvulus, supposed dimorphism of. + + Cooling of crust, disagreement among physicists as to rate. + + Cope, Edward Drinker (1840-97): was for a short time Professor at Haverford + College; he was a member of certain United States Geological Survey + expeditions, and at the time of his death he held a Professorship in the + University of Pennsylvania. He wrote several important memoirs on + "Vertebrate Paleontology," and in 1887 published "The Origin of the + Fittest." + -style of. + -and Hyatt, theories of. + + Copley medal, Darwin and the. + -Falconer, and Darwin's. + -Lindley considered for the. + -awarded to Lyell. + -awarded to Bunsen. + -Darwin describes letter from Hooker as a. + + Coquimbo, Darwin visits. + -upraised shells. + + Coral islands, and subsidence. + -plants of. + + Coral reefs, Darwin's work on. + -Bonney's edition of Darwin's book on. + -A. Agassiz on. + -Dana on. + -fossil. + -Murray on. + -conditions of life of polyps. + -solution by CO2 of. + -subsidence of. + + Coral tree, (see Erythrina). + + Corallines, nature of. + + Cordiaceae, dimorphism in. + + Cordilleras, glaciers of. + -high-road for plants. + -plants of. + -birds of. + -comparison between Glen Roy and terraces of. + -Darwin on earth-movements of. + -Forbes on. + -submarine lava-streams. + -volcanic activity and elevation. + + Coronilla, Lord Farrer on. + -C. emerus. + -C. varia. + + Coryanthes, "beats everything in orchids." + + Corydalis, Hildebrand shows falsity of idea of self-fertilisation of. + -C. cava, Hildebrand on self-sterility of. + -C. claviculata, tendrils of. + -C. tuberosa, possible case of reversion in floral structure. + + "Cottage Gardener," Darwin offers reward for Hyacinth grafts. + + Cotyledons, Darwin's experiments on. + + Counterbalance, Watson on divergent variation and. + + Cowslips, Primroses and. + -Darwin's experiments on artificial fertilisation. + -homomorphic seedlings. + -loss of dimorphism. + + Craig Dhu, shelves of. + + Craters, in Galapagos Island. + -of denudation, Lyell on. + -of elevation. + -Darwin on. + + Crawford, John (1783-1868): Orientalist, Ethnologist, etc. Mr. Crawford + wrote a review on the "Origin," which, though hostile, was free from + bigotry (see "Life and Letters," II., page 237).) + + Creation, acts of. + -doctrine of. + -of species as eggs. + -Owen on. + -Romanes on individual. + + Creation-by-variation, doctrine of. + + "Creed of Science," Graham's. + + Cresy, E., letters to. + + Cretaceous flora, Heer on Arctic. + + Crick, W.D., letter to. + + Crinum, crossing experiments on. + -C. passiflora, fertility of. + + Crocker, W., work on hollyhocks. + + Croll, James (1821-90): was born at Little Whitefield, in Perthshire. + After a short time passed in the village school, he was apprenticed as a + wheelwright, but lack of strength compelled him to seek less arduous + employment, and he became agent to an insurance company. In 1859 he was + appointed keeper in the Andersonian University and Museum, Glasgow. His + first contribution to science was published in the "Philosophical Magazine" + for 1861, and this was followed in 1864 by the essay "On the Physical Cause + of the Change of Climate during the Glacial Period." From 1867 to 1881 he + held an appointment in the department of the Geological Survey in + Edinburgh. In 1876 Croll was elected a Fellow of the Royal Society. His + last work, "The Philosophical Basis of Evolution," was published in the + year of his death. ("Nature," Volume XLIII., page 180, 1891.) + -Darwin on his theory. + -on icebergs as grinding agents. + -letters to. + -Lyell on his theory. + -on sub-aerial denudation. + -on time. + + Crookes, Sir W., on spiritualism. + + "Cross and Self-fertilisation," Darwin's book on. + + Cross-fertilisation, Darwin's experiments on self- and. + -check to endless variability. + -Darwin states that as a rule flowers described as adapted to self- + fertilisation are really adapted to. + -of inconspicuous flowers. + -all plants require occasional. + -small advantages when confined to same plant. + + Crosses, fertility and sterility of. + + Crossing, agreement between Darwin's and breeders' views. + -counterbalance of. + -Darwin's views on. + -effects of. + -experiments on. + -Hooker's views. + -in animals and plants. + -influence of blood in. + -intermediate character of results. + -Natural Selection and disinclination towards. + -offspring of. + -of primroses and cowslips. + -and sterility. + -Westphalian pig and English boar. + -botanists' work on. + -importance of. + -pains taken by Nature to ensure. + -in Pisum. + -in Primula. + -in individuals of same species. + -F. Muller compliments Darwin on his chapter on. + -and separate sexes in trees. + + Crotalaria. + + Crotalus. + + Cruciferae, action of fungus on roots. + + Cruciferous flower, morphology. + + Cruger, Dr., on cleistogamic fertilisation of Epidendrum. + -death of. + -on fertilisation of figs. + -on pollinia of Acropera. + -on Melastomaceae. + -on fertilisation of orchids. + + Crustacea, comparison of classification of mammals and. + -Darwin on. + -F. Muller on. + -sex in. + + Crying, action of children in. + -physiology of. + -wrinkling of eyes in. + + Crystal Palace, Darwin's visit to. + + Crystals, separation in lava-magmas. + + Cucurbita, seeds and seedlings of. + + Cucurbitaceae, Dr. Wight on. + + Cudham Wood. + + Cultivated plants, Darwin's work on. + + Cultivation and self-sterility. + + Cuming, on Galapagos Islands. + + Cupuliferae, A. de Candolle on. + + Curculionidae, Schoenherr's catalogue. + + Currents, as means of dispersal. + + Cuvier, on camels' teeth. + -on classification. + -mentioned. + + Cybele, H.C. Watson's. + + Cycadaceae, supposed power to withstand excess of CO2. + + Cyclas cornea. + + Cyclops (H.M.S.) dredging by. + + Cynips, dimorphism in. + -Walsh on. + + Cypripedium, fertilisation mechanism. + -C. hirsutissimum. + + Cyrena, range and variability. + + Cytisus Adami, Darwin on. + -note on. + -C. alpinus. + -C. laburnum, graft-hybrids between C. purpureus and. + -J.J. Weir on. + + Cyttarogenesis, suggested substitute for pangenesis. + + Dallas, W.S., translator of F. Muller's "Fur Darwin." + + Dampiera, Hamilton on fertilisation mechanism. + + Dana, James Dwight (1813-95): published numerous works on Geology, + Mineralogy, and Zoology. He was awarded the Copley Medal by the Royal + Society in 1877, and elected a foreign member in 1884. + -Darwin's opinion of. + -health. + -letters to. + -mentioned. + -on classification of mammalia. + -Darwin's criticism of. + -on Kilauea. + -Lyell on his claims for Royal Society foreign list. + -volume on geology in Wilkes' Reports. + + Dareste, C., letter to. + + Darwin, Annie: Charles Darwin's daughter. + + Darwin, Bernard: Charles Darwin's grandson, observations on, as a child. + + Darwin, Caroline (1800-99): Charles Darwin's sister. + -Charles Darwin's early recollections of. + -letter to. + + Darwin, Catherine (1810-66): Charles Darwin's sister. + -death. + -letter to. + + Darwin, Charles, boyhood. + -went to Mr. Case's school. + -went to Shrewsbury School. + -abused as an atheist. + -Collier's picture of. + -complains of little time for reading. + -contribution to Henslow's biography. + -Copley medal awarded to. + -engagement to Miss Emma Wedgwood. + -Falconer's list of scientific labours of. + -first meeting with Hooker. + -friendship with Huxley. + -on Gray's work on distribution. + -growth of his evolutionary views. + -health. + -honorary degree at Cambridge. + -intimacy with Hooker. + -Judd's recollections of. + -Lamarck and. + -letters to "Nature." + -marriage. + -friendship with F. Muller. + -prefatory note to Meldola's translation of Weismann. + -recollections of Cambridge. + -relation between J. Scott and. + -review on Bates. + -attends meeting of Royal Society. + -slowness in giving up old beliefs. + -tendency to restrict interest to Natural History. + -and the "Vestiges." + -visits London. + -Wallace and. + -and Weismann. + -working hours. + -book on S. American Geology. + -pleasure in angling. + -on making blunders. + -slight knowledge of Botany. + -visits Cambridge. + -love of children. + -on cleavage and foliation. + -on origin of coal. + -his theory of Coral reefs supported by Funafuti boring. + -large correspondence. + -on danger of trusting in science to principle of exclusion. + -death of his child from scarlet fever. + -on difficulty of writing good English. + -feels need of stimulus in work. + -subscribes to Dr. Ferrier's defence. + -on flaws in his reasoning. + -follows golden rule of putting adverse facts in strongest light. + -"Geological Instructions." + -geological work on Lochaber. + -visit to Glen Roy. + -bad handwriting. + -idleness a misery. + -on immortality and death. + -on lavas. + -letter to "Scotsman" on Glen Roy. + -indebtedness to Lyell. + -on Lyell as a geologist. + -on Lyell's "Second Visit to the U.S.A." + -work on Man and Sexual Selection. + -on mountain-chains. + -offer of help to F. Muller. + -never afraid of his facts. + -an honorary member of the Physiological Society. + -pleasure in discussing Geology with Lyell. + -reads paper before Linnean Society. + -A. Rich leaves his fortune to. + -on satisfaction of aiding fellow-workers in Science. + -reminiscences of school-days. + -visits Sedgwick. + -sits to an artist. + -on speculation. + -style in writing. + -gives testimonial in support of Hooker's candidature for Botanical + Chair in Edinburgh. + -theological abuse in the "Three Barriers." + -visits to Abinger. + -visit to Patterdale. + -on vitality of seeds. + -on volcanic phenomena. + -on Welsh glaciers. + -work on action of carbonate of ammonia on plants. + + Darwin, Mrs. Charles, impressions of Down. + -letter to. + -passage from Darwin's autobiography on. + -mentioned. + -illness. + + Darwin, Emma, see Mrs. Charles Darwin. + + Darwin, Erasmus Alvey (1804-81): elder brother of Charles Darwin. + -death of. + -letters to. + -mentioned. + -visit to. + + Darwin, Dr. Erasmus: Charles Darwin's grandfather. + -Charles Darwin's preliminary notice to Krause's memoir of. + -Charles Darwin and evolutionary views of. + + Darwin, Francis: Charles Darwin's son. + -on bloom and stomata. + -on Dipsacus. + -on Huxley's speech at Cambridge. + -on the Knight-Darwin law. + -on lobing of leaves. + -experiments on nutrition. + -experiments on plant-movements. + -lecture at Glasgow (British Association, 1901) on perceptions of + plants. + -suggestion for Romanes' experiments on intelligence. + -on vivisection. + -on Vochting's work. + -on Wiesner's work. + + Darwin, George: Charles Darwin's son. + -success at Cambridge. + -criticism of Wallace. + -elected Plumian Professor at Cambridge. + -suggested experiments with magnetic needles and insects. + -on Galton's work on heredity. + -article in "Contemporary Review" on origin of language. + + Darwin, Henrietta (Mrs. Litchfield): Charles Darwin's daughter. + -criticism of Huxley. + + Darwin, Horace: Charles Darwin's son. + -remark as a boy on Natural Selection. + -mentioned. + + Darwin, Leonard: Charles Darwin's son. + + Darwin, Robert W.: Charles Darwin's father. + -letter to. + + Darwin, Susan: Charles Darwin's sister. + -alluded to in early recollections of Charles Darwin. + -illness. + -sends Wedgwood ware to Hooker. + + Darwin, William Erasmus: Charles Darwin's eldest son. + -on fertilisation of Epipactis palustris. + -letter to. + + "Darwin and after Darwin," Romanes'. + + "Darwiniana," Asa Gray's. + -extract from Huxley's. + + "Darwinsche Theorie," Wagner's book. + + "Darwinism," Wallace's. + + Darwinismus, at the British Association meeting at Norwich (1868). + + Daubeny, Prof. Charles Giles Bridle, F.R.S. (1795-1867): Fellow of + Magdalen College, Oxford; elected Professor of Chemistry in the + University 1822; in 1834 he became Professor of Botany, and in 1840 + Professor of Rural Economy. + -invites Darwin to attend British Association at Oxford. + -mentioned. + + David, Prof. Edgeworth, and the Funafuti boring. + + Dawn of life, oldest fossils do not mark the. + + Dawson, Sir J. William, C.M.G., F.R.S. (1820-99), was born at Pictou, + Nova Scotia, and studied at Edinburgh University in 1841-42. He was + appointed Principal of the McGill University, Montreal, in 1855,--a post + which he held thirty-eight years. See "Fifty Years of Work in Canada, + Scientific and Educational," by Sir William Dawson, 1901. + -antagonism to Darwinism. + -criticism of "Origin" by. + -criticism of Hooker's arctic paper. + -Hooker on. + + Dayman, Captain, on soundings. + + De la Beche, Sir Henry Thomas (1796-1855): was appointed Director of the + Ordnance Geological Survey in 1832; his private undertaking to make a + geological survey of the mining districts of Devon and Cornwall led the + Government to found the National Survey. He was also instrumental in + forming the Museum of Practical Geology in Jermyn Street. + + Death, Darwin on immortality and. + + Decaisne. + + Decapods, Zoea stage of. + + Dedication of Hackel's "Generelle Morphologie" to Darwin. + + Dedoublement, theory of. + + Deep-sea soundings, Huxley's work on. + + Degeneration, in ammonites. + -of culinary plants. + -and parasitism. + + Degradation. + + Deification of Natural Selection. + + Deinosaurus, and free-will. + + Delboeuf's "La Psychologie," etc. + + Delpino, F., on Asclepiadeae and Apocyneae. + -on crossing. + -on dichogamy. + -on fertilisation mechanism. + -letter to. + -praises Axell's book. + -mentioned. + + Demosthenes, quoted by Darwin. + + Denudation, Dana on. + -Darwin on marine. + -comparison of subaerial and marine. + -Ramsay and Jukes overestimate subaerial. + + Deodar, Hooker on the. + + Deposition and denudation as measure of time. + + Derby, Lady, letter to. + + Descent, Falconer on intermediate forms. + -from single pair. + -Owen's belief in doctrine of. + -resemblance due to. + + Descent of Man. + + "Descent of Man," reference in, to effect of climate on species. + -reviewed by John Morley. + -transmission of characters dealt with in. + -Darwin's work on. + -Sir W. Turner supplies facts for. + -Wallace on. + + Descent with modification, Wallace on. + + Desert animals, and protective colouring. + + Design, Darwin on. + -examples of. + -Lord Kelvin on. + + Deslongchamps, L., on fertilisation of closed flowers. + + Desmodium gyrans, Darwin's experiments on. + -leaf movements. + + Development, acceleration and retardation in. + -floral. + -importance of, in classification. + -rate of. + -sudden changes during. + + Devonshire Commission, report on physiological investigation at Kew. + + Devonshire, flora of. + + Dewar, Prof., and Sir Wm. Thiselton-Dyer, on vitality of seeds in liquid + hydrogen. + + Diaheliotropism, F. Muller's observations. + + Dialogue, title of paper by Asa Gray. + + Diatomaceae, beauty of. + -conjugation in. + + Dicentra thalictriformis, morphology of tendrils. + + Dichaea, fertilisation mechanism. + + Dichogamy, Delpino on. + -ignorance of botanists of, prior to publication of "Fertilisation of + Orchids." + + Dick, Sir T. Lauder, Survey of Glen Roy by. + + Dickens, quotation from. + + Dickson, Dr. + + Dickson, W.K. + + Dicotyledons, Heer on oldest known. + -sudden appearance. + + Didelphys. + + Digestion, beneficial effect on plants. + + Dillwyn, paper in "Gardeners' Chronicle." + + Diluvium, tails of. + + Dimorphism, in Cynips. + -Darwin on. + -difficult to explain. + -and mimicry. + -in parasitic plants. + -Wallace on. + -Walsh on. + -Weismann on Sexual. + -in Cicadas. + -flowers illustrating. + -Darwin knows no case in very irregular flowers. + -in Melastomaceae. + -in Linum. + -in eight Natural Orders. + -in Primula. + -apparent cases due to mere variability. + -explanation of. + + Dingo. + + Diodia. + + Dioeciousness, origin of. + + Dionoea, experiments on. + response to stimuli. + Curtis' observations on. + + Dipsacus, F. Darwin on. + + Dipterocarpus, survival during glacial period. + + Direct action, arguments against. + -Darwin led to believe more in. + -Darwin's desire not to underestimate. + -Darwin's underestimates. + -facts proving. + -Falconer on. + -and hybridity. + -importance of. + -of pollen. + -variation and. + + Direction, sense of, in animals. + + Disease, Dobell on "Germs and Vestiges" of. + + Dispersal, (see also Distribution), of seeds. + -of shells. + + Distribution, Forbes on. + -Hooker on Arctic plants. + -of land and sea in former times. + -of plants. + -factors governing. + -of shells. + -Thiselton-Dyer on plant-. + -Wallace on. + -Blytt's work on. + + Disuse, Darwin on. + -effect of. + -Owen on. + + Divergence, Hooker on. + -principle of. + + Diversification, Darwin's doctrine of the good of. + + Dobell, H., letter to. + + Dogs, descent of. + -experiment in painting. + -expression. + -habits. + -rudimentary tail inherited in certain sheep-. + + Dohrn, Dr., visits Darwin. + -serves in Franco-Prussian war. + -extract from letter to. + + "Dolomit Riffe," Darwin on Mojsisovics'. + + Domestic animals, crossing in. + -Darwin's work on. + -Settegast on. + -variability of. + -treatment in "Variation of Animals and Plants." + + Domestication, effects of. + -and loss of sterility. + + Domeyko, on Chili. + + Dominant forms. + + Don, D., on variation. + -mentioned. + + Donders, F.C., on action of eyelids. + -letters to. + + Dorkings, power of flight. + + Down, description of house and country. + -Darwin's satisfaction with his house. + -instances of vitality of seeds recorded from. + -method of determining plants at. + -Darwin on geology of. + -observations on regular lines of flight of bees at. + + Down (lanugo), on human body. + + Dropmore. + + Drosera, F. Darwin's experiments. + -"a disguised animal." + -Darwin's observations on. + -Darwin's pleasure on proving digestion in. + -effect of inorganic substance on. + -experiments on absorption of poison. + -Pfeffer on. + -J. Scott's paper on. + -response to stimuli. + -D. filiformis, experiments on. + -D. rotundifolia, experiments on. + + Drosophyllum, vernation of. + -Darwin's work on. + -Drosophyllum lusitanicum, sent by Tait to Darwin. + -used in Portugal to hang up as fly-paper. + + Druidical mounds, seeds from. + + Drummond, J., on fertilisation in Leschenaultia formosa. + + Duchesne, on atavism. + + Ducks, period of hatching. + -skeletons. + -hybrids between fowls and. + + Dufrenoy, Pierre Armand: published "Memoires pour servir a une + Description Geologique de la France," as well as numerous papers in the + "Annales des Mines, Comptes Rendus, Bulletin Soc. Geol. France," and + elsewhere on mineralogical and geological subjects. + -geological work of. + + Duncan, Rev. J., encourages J. Scott's love for plants. + + Dung, plants germinated from locust-. + + Dutrochet, on climbing plants. + + Duval-Jouve, on leaf-movement in Bryophyllum. + + Dyer, see Thiselton-Dyer. + + Dytiscus, as means of dispersal of bivalves. + + Ears, loss of voluntary movement. + -in man and monkeys. + -rudimentary muscles. + -Wallis's work on. + + Earth, age of the. + + Earth-movements, cause of. + -in England. + -relation to sedimentation. + -subordinate part played by heat in. + + Earthquakes, coincidence of shocks in S. America and elsewhere. + -connection with elevation. + -connection with state of weather. + -Darwin on. + -in England. + -frequency of. + -Hopkins on. + -in Scotland. + + Earthworms, Darwin's book on. + -geological action of. + -influence of sea-water on. + -F. Muller gives Darwin facts on. + -Typhlops and true. + + Echidna, anomalous character of. + + Edentata, migration into N. America. + + Edgeworth, mentioned. + + Edinburgh, Darwin's student-days in. + -Hooker's candidature for Chair of Botany. + + "Edinburgh Review," article on Lyell's "Antiquity of Man." + -reference to Huxley's Royal Institution Lectures. + -Owen's article. + + Education, effect of. + -influence on children of parents'. + + Edwardsia, seeds possibly floated from Chili to New Zealand. + -in Sandwich Is. and India. + + Egerton, Sir Philip de Malpas Grey- (1806-81): devoted himself to the + study of fossil fishes, and published several memoirs on his collection, + which was acquired by the British Museum. + + Eggs, creation of species as. + -means of dispersal of molluscan. + + Ehrenberg, Ascension I. plants sent to. + -on rock-building by infusoria. + -Darwin's wish that he should examine underclays. + + Eichler, A.W., on morphology of cruciferous flower. + -on course of vessels as guide to floral morphology. + -reference to his Bluthendiagramme. + + Eildon Hills, need of examination of. + + Elateridae, luminous thorax of. + + Elective affinity. + + Electric organs of fishes, the result of external conditions. + + Electricity, and plant-movements. + + "Elements of Geology," Wallace's review of Lyell's. + + Elephants, Falconer's work on. + -rate of increase of. + -and variation. + -found in gravel at Down. + -manner of carrying tail. + -shedding tears. + + Elephas Columbi, Falconer on. + -Owen's conduct in regard to Falconer's work on. + -E. primigenius, as index of climate. + -woolly covering of. + -E. texianus, Owen and nomenclature of. + + Elevation, in Chili. + -lines of. + -New Zealand and. + -continental extension, subsidence and. + -connection with earthquakes. + -equable nature of movements of subsidence and. + -evidence in Scandinavia and Pampas of equable. + -Hopkins on. + -large areas simultaneously affected by. + -d'Orbigny on sudden. + -rate of. + -Rogers on parallelism of cleavage and axes of. + -sedimentary deposits exceptionally preserved during. + -subsidence and. + -vulcanicity and. + + Elodea canadensis, successful American immigrant. + + Emberiza longicauda, long tail-feathers and Sexual Selection. + + Embryology, argument for. + -succession of changes in animal-. + -Darwin's explanation of. + -of flowers. + -of Peneus. + -Balfour's work on comparative. + + Embryonic stages, obliteration of. + + Endlicher's "Genera Plantarum." + + Engelmann, on variability of introduced plants in N. America. + + England, former union with Continent. + -men of science of Continent and. + + Entada scandens, dispersal of seeds. + + Entomologists, evolutionary views of. + + "Entstehung und Begriff der naturhistorischen Art," Nageli's Essay. + -Darwin on. + + Environment, and colour protection. + + Eocene, Anoplotherium in S. America. + -monkeys. + -mammals. + -co-existence with recent shells. + + Eozoon, illustrating difficulty of distinguishing organic and inorganic + bodies. + + Ephemera dimidiatum, Lord Avebury on. + + Epidendreae, closely related to Malaxeae. + + Epidendrum, Cruger on fertilisation of. + -self-fertilisation of. + + Epiontology, De Candolle's term. + + Epipactis, fertilisation mechanism. + -F. Muller on. + -pollinia of. + -E. palustris, fertilisation mechanism. + + Epithecia, fertilisation mechanism. + + Equatorial refrigeration. + + Equus, Marsh's work on. + -geographical distribution. + -in N. and S. America. + + Erica tetralix, Darwin on. + + Erigeron canadense, successful immigrant from America. + + Erodium cicutarium, introduced from Spain to America. + -range in U.S.A. + + Erratic blocks, in Azores. + -in S. America. + -Darwin on transport. + -of Jura. + -Mackintosh on. + -on Moel Tryfan. + + Errera, Prof. L., letter to. + -and S. Gevaert, on cross and self-fertilisation. + + Eruptions, parallelism of lines of, with coast-lines. + + Eryngium maritimum, bloom on. + + Erythrina, MacArthur on. + -of New S. Wales. + -sleep movements of. + + Erythroxylon, dimorphism of sub-genus of. + + Eschscholtzia, crossing and self-fertility. + -Darwin's experiments on self-sterility. + -F. Muller's experiments in crossing. + + Eschricht, on lanugo on human embryo. + + Escombe, F., on vitality of seeds. + -see Brown, H.T. + + Esquimaux, Natural Selection and. + + "Essays and Reviews," attitude of laymen towards. + + Eternity, Gapitche on. + + Etheridge, Robert, F.R.S.: President of Geological Society in 1880-81. + + Etna, Sir Charles Lyell's work on. + -map of. + + Eucalyptus, species setting seed. + -mentioned. + + Euonymus europaeus, dispersal of seeds. + + Euphorbia, Darwin on roots of. + -E. peplis, bloom on. + + Euphrasia, parasitism of. + + Europe, movement of. + + Eurybia argophylla, musk-tree of Tasmania, an arborescent Composite. + + Evergreen vegetation, connection with humid and equable climate. + + Evolution, Darwin's early views. + -Fossil Cephalopods used by Hyatt as test of. + -Huxley's lectures on. + -of mental traits. + -F. Muller's contributions to. + -Nageli's Essay, "Entstehung und Begriff der Naturhistorischen Art." + -Palaeontology as illustrating. + -Romanes' lecture on. + -Saporta's belief in. + -unknown law of. + -of Angiosperms. + -of colour. + -and death. + -Heer opposed to. + -of language. + -Lyell's views (see also Lyell). + -Turner on man and. + -Wallace on. + + Ewart, Prof. C., on Telegony. + + Exacum, dimorphism of. + + Experiments, botanical. + -Tegetmeier's on pigeons. + -time expended on. + + Expression, queries on. + -Bell on anatomy of. + -Darwin at work on. + + "Expression of the Emotions," Wallace's review. + + External conditions, Natural Selection and. + -See also Direct Action. + + Extinction, behaviour of species verging towards. + -contingencies concerned in. + -Hooker on. + -races of man and. + -Proboscidea verging towards. + -St. Helena and examples of. + + Eyebrows, use of. + + Eyes, behaviour during meditation. + -contraction in blind people of muscles of. + -children's habit of rubbing with knuckles. + -gorged with blood during screaming. + -contraction of iris. + -wrinkling of children's. + + Fabre, J.H.: is best known for his "Souvenirs Entomologiques," in No. + VI. of which he gives a wonderfully vivid account of his hardy and + primitive life as a boy, and of his early struggles after a life of + culture. + -letters to. + + "Facts and Arguments for Darwin," translation of F. Muller's "Fur + Darwin." + -delay in publication. + -sale. + -unfavourable review in "Athenaeum." + + Fairy rings, Darwin compares with fungoid diseases in man and animals. + + Falconer, Hugh (1809-65): was a student at the Universities of Aberdeen and + Edinburgh, and went out to India in 1830 as Assistant-Surgeon on the Bengal + Establishment. In 1832 he succeeded Dr. Royle as the Superintendent of the + Botanic Gardens at Saharunpur; and in 1848, after spending some years in + England, he was appointed Superintendent of the Calcutta Botanical Garden + and Professor of Botany in the Medical College. Although Falconer held an + important botanical post for many years, he is chiefly known as a + Palaeozoologist. He seems, however, to have had a share in introducing + Cinchona into India. His discovery, in company with Colonel Sir Proby T. + Cautley, of Miocene Mammalia in the Siwalik Hills, was at the time perhaps + the greatest "find" which had been made. The fossils of the Siwalik Hills + formed the subject of Falconer's most important book, "Fauna Antiqua + Sivalensis," which, however, remained unfinished at the time of his death. + Falconer also devoted himself to the investigation of the cave-fauna of + England, and contributed important papers on fossils found in Sicily, + Malta, and elsewhere. Dr. Falconer was a Vice-President of the Royal + Society and Foreign Secretary of the Geological Society. "Falconer did + enough during his lifetime to render his name as a palaeontologist immortal + in science; but the work which he published was only a fraction of what he + accomplished...He was cautious to a fault; he always feared to commit + himself to an opinion until he was sure he was right, and he died in the + prime of his life and in the fulness of his power." (Biographical sketch + contributed by Charles Murchison to his edition of Hugh Falconer's + "Palaeontological Memoirs and Notes," London, 1868; "Proc. R. Soc." Volume + XV., page xiv., 1867: "Quart. Journ. Geol. Soc." Volume XXI., page xlv, + 1865.) Hugh Falconer was among those who did not fully accept the views + expressed in the "Origin of Species," but he could differ from Darwin + without any bitterness. Two years before the book was published, Darwin + wrote to Asa Gray: "The last time I saw my dear old friend Falconer he + attacked me most vigorously, but quite kindly, and told me, 'You will do + more harm than any ten naturalists will do good. I can see that you have + already corrupted and half spoiled Hooker.'" ("Life and Letters," II., + page 121.) The affectionate regard which Darwin felt for Falconer was + shared by their common friend Hooker. The following extract of a letter + from Hooker to Darwin (February 3rd, 1865) shows clearly the strong + friendships which Falconer inspired: "Poor old Falconer! how my mind runs + back to those happiest of all our days that I used to spend at Down twenty + years ago--when I left your home with my heart in my mouth like a + schoolboy. We last heard he was ill on Wednesday or Thursday, and sent + daily to enquire, but the report was so good on Saturday that we sent no + more, and on Monday night he died...What a mountainous mass of admirable + and accurate information dies with our dear old friend! I shall miss him + greatly, not only personally, but as a scientific man of unflinching and + uncompromising integrity--and of great weight in Murchisonian and other + counsels where ballast is sadly needed." + -article in "Natural History Review." + -Darwin's Copley medal and. + -Darwin's criticism of his elephant work. + -Darwin's regard for. + -Forbes attacked by. + -his opinion of Forbes. + -goes to India. + -Hooker's regard for. + -letter to Darwin. + -letter to Sharpey. + -letters to. + -letter to "Athenaeum." + -Lyell and. + -on Mastodon andium. + -on Mastodon of Australia. + -on elephants. + -Owen and. + -on phyllotaxis. + -on Plagiaulax. + -speech at Cambridge. + -"Memoirs." + + Falkland Islands, Darwin visits. + -Polyborus sp. in. + -brightly coloured female hawk. + -effect of subsidence. + -streams of stones. + + Fanciers, use made of Selection by. + + Fantails, see Pigeons. + + Faraday, memorial to. + + Faramea, dimorphism. + + Farmer, Prof. J.B., and S.E. Chandler, on influence of excess of CO2 on + anatomy of plants. + + Faroe Islands, Polygala vulgaris of. + + Farrer, Canon, lecture on defects in Public School Education. + -letter to. + + Farrer, Lady. + + Farrer, Thomas Henry, Lord (1819-99): was educated at Eton and Balliol + College, Oxford. He was called to the Bar, but gave up practice for the + public service, where he became Permanent Secretary of the Board of Trade. + According to the "Times," October 13th, 1899, "for nearly forty years he + was synonymous with the Board in the opinion of all who were brought into + close relation with it." He was made a baronet in 1883; he retired from + his post a few years later, and was raised to the peerage in 1893. His + friendship with Mr. Darwin was of many years' standing, and opportunities + of meeting were more frequent in the last ten years of Mr. Darwin's life, + owing to Lord Farrer's marriage with Miss Wedgwood, a niece of Mrs. + Darwin's, and the subsequent marriage of his son Horace with Miss Farrer. + His keen love of science is attested by the letters given in the present + volume. He published several excellent papers on the fertilisation of + flowers in the "Ann. and Mag. of Natural History," and in "Nature," between + 1868 and 1874. + In Politics he was a Radical--a strong supporter of free trade: on this + last subject, as well as on bimetallism, he was frequently engaged in + public controversy. He loyally carried out many changes in the legislature + which, as an individualist, he would in his private capacity have + strenuously opposed. + In the "Speaker," October 21st, 1899, Lord Welby heads his article on Lord + Farrer with a few words of personal appreciation:-- + "In Lord Farrer has passed away a most interesting personality. A great + civil servant; in his later years a public man of courage and lofty ideal; + in private life a staunch friend, abounding as a companion in humour and + ripe knowledge. Age had not dimmed the geniality of his disposition, or an + intellect lively and eager as that of a boy--lovable above all in the + transparent simplicity of his character." + -interest in Torbitt's potato experiment. + -letters to. + -on earthworms. + -observations on fertilisation of Passiflora. + -recollections of Darwin. + -seeds sent to. + + Fawcett, Henry (1833-84): Professor of Political Economy at Cambridge, + 1863, Postmaster-General 1880-84. See Leslie Stephen's well-known "Life." + -defends Darwin's arguments. + -letter to. + -letter to Darwin. + + Fear, expression of. + + Felis, range. + + Fellowships, discussion on abolition of Prize-. + + Felspar, segregation of. + + Females, modification for protection. + + "Fenland, Past and Present," by Miller and Skertchley. + + Fergusson on Darwinism. + + Fernando Po, plants of. + + Ferns, Scott on spores. + -Darwin's ignorance of. + -variability "passes all bounds." + + Ferrier, Dr., groundless charge brought against, for infringement of + Vivisection Act. + + Fertilisation, articles in "Gardeners' Chronicle." + -of flowers. + -H. Muller's work on. + -and sterility. + -Darwin fascinated by study of. + -different mechanisms in same genus. + -travelling of reproductive cells in. + + Fertilisation of orchids, Darwin's work on. + -paper by Darwin in "Gardeners' Chronicle" on. + + "Fertilisation of Orchids," Asa Gray's review. + -Hooker's review. + -description of Acropera and Catasetum in. + -H. Muller's "Befruchtung der Blumen," the outcome of Darwin's. + + Fertility, Natural Selection and. + -and sterility. + -Primula. + -Scott on varieties and relative. + + Festuca. + + Figs, F. Muller on fertilisation of. + + Finmark, Bravais on sea-beaches of. + + Fir (Silver), Witches' brooms of. + + "First Principles," Spencer's. + + Fish, Pictet and Humbert on fossil. + + Fiske, J., letter to. + + Fissure-eruptions. + + Fitton, reference to his work. + + FitzRoy (Fitz-Roy), Captain, and the "Beagle" voyage. + -writes preface to account of the voyage. + -Darwin nearly rejected by. + -letter to "Times." + + Flagellaria, as a climber. + + Flahault, on the peg in Cucurbita. + + Fleeming Jenkin, review of "Origin" by, see Jenkin. + + Flinders, M., voyage to Terra Australis by. + + Flint implements found near Bedford. + + Flints, abundance and derivation of, at Down. + -Darwin on their upright position in gravel. + + Floating ice, Darwin on agency of. + -J. Geikie underestimates its importance. + -transporting power of. + + Flora, Darwin's idea of an Utopian. + -Hooker's scheme for a. + -Hooker's work on Tasmanian. + + "Flora antarctica," Hooker's. + + "Flora fossilis arctica," Heer's. + + Floras: + N. American. + Arctic. + British. + Colonial. + European. + French. + Greenland. + Holland. + India. + Japan. + New Zealand. + -distribution of. + -of islands. + -local. + -tabulation of. + + Florida, A. Agassiz on Coral reefs. + -Coral reefs. + + Flourens, experiments on pigeons. + + Flower, Sir William H., Letter to. + -on muscles of the os coccyx. + + Flowering plants, possible origin on a Southern Continent. + -sudden appearance of. + + Flowers, at Down. + -Darwin's work on forms of. + -monstrous. + -morphological characters. + -regular and irregular. + -cross-fertilisation in inconspicuous. + -ignorance of botanists on mechanism of. + + "Flowers and their unbidden Guests," Dr. Ogle's translation of Kerner's + "Schutzmittel des Pollens." + + Flying machine, Darwin on Popper's proposed. + + Folding of strata. + + Foliation and cleavage, reference by A. Harker to work on. + + Foliation, aqueous deposition and. + -Darwin considers his observations on cleavage less deserving of + confidence than those on. + -Darwin on. + -parallelism with cleavage. + -relation to rock-curvature. + + Food, as determining number of species. + + Foraminifera. + + Forbes, D., on the Cordilleras. + -on elevation in Chili. + -on nitrate of soda beds in S. America. + + Forbes, Edward, F.R.S. (1815-1854): filled the office of Palaeontologist to + the Ordnance Geological Survey, and afterwards became President of the + Geological Society; in 1854--the last year of his life--he was appointed to + the chair of Natural History in the University of Edinburgh. Forbes + published many papers on geological, zoological, and botanical subjects, + one of his most remarkable contributions being the well-known essay "On the + Connexion between the Distribution of the Existing Fauna and Flora of the + British Isles and the Geological Changes which have affected their area" + ("Mem. Geol. Surv." Volume I., page 336, 1846). (See "Proc. Roy. Soc." + Volume VII., page 263, 1856; "Quart. Journl. Geol. Soc." Volume XI., page + xxvii, 1855, and "Ann. Mag. Nat. Hist." Volume XV., 1855. + -on flora of Azores. + -on Chambers as author of the "Vestiges." + -on continental extension. + -Darwin opposed to his views on continental extension. + -Darwin's opinion of. + -Article on distribution. + -on continuity of land. + -on plant-distribution. + -introductory lecture as professor in Edinburgh. + -on former lower extension of glaciers in Cordillera. + -lecture by. + -letter to Darwin from. + -on Madagascar insects. + -on post-Miocene land. + -Polarity theory. + -on British shells. + -too speculative. + -on subsidence. + -visits Down. + -mentioned. + -royal medal awarded to. + -essay on connection between distribution of existing fauna and flora of + the British Isles and geological changes. + + Forbes, H.O., on Melastoma. + + Force and Matter, Huxley on. + + Forel, Auguste: the distinguished author of "Les Fourmis de la Suisse," + Zurich, 1874, and of a long series of well-known papers. + -on ants and beetles. + -author of "Les Fourmis de la Suisse." + -letter to. + + Forfarshire, Lyell on glaciers of. + + "Forms of Flowers," De Candolle's criticism of Darwin's. + homomorphic and heteromorphic unions described in. + + Forsyth-Major, zoological expedition to Madagascar. + + "Fortnightly Review," Huxley's article on Positivism. + Romanes on Evolution. + + Fossil Cephalopods, Hyatt on. + + Fossil corals. + + Fossil plants, small proportion of. + of Australia. + sudden appearance of Angiosperms indicated by. + + Fossil seeds, supposed vivification of. + + Fossils as evidence of variability. + + Fournier, E., De la Fecundation dans les Phanerogames. + + Fowls, difference in sexes. + -purred female. + + Fox, tails of, used by Esquimaux as respirators. + + Fox, Rev. W. Darwin. + + Foxglove, use of hairs in flower. + + France, edition of "Origin" in. + -opinion favourable to Darwin's views in. + -birth-rate. + + Franco-Prussian war, opinion in England. + -Science retarded by. + + Frank, Albert Bernhard (1839-1900): began his botanical career as + Curator of the University Herbarium, Leipzig, where he afterwards became + Privatdocent and finally "Ausserordentlicher Professor." In 1881 Frank + was appointed Professor of Plant-Physiology in the Landwirthschaftliche + Hochschule, Berlin. In 1899 he was appointed to the Imperial + Gesundheits-Amt in Berlin, and raised to the rank of Regierungsrath. + Frank is chiefly known for his work on "The Assimilation of Free + Nitrogen, etc.," and for his work on "The Diseases of Plants" ("Die + Krankheiten der Pflanzen," 1880). It was his brilliant researches on + growth-curvature ("Beitrage zur Pflanzen-physiologie," 1868, and "Die + Naturlichen wagerechte Richtung von Pflanzen-theilen," 1870) which + excited Darwin's admiration. + -Darwin's admiration for his work. + + Franklin, Sir J., search expedition. + + Fraser, G., letter to. + + "Fraser's Magazine," article by Hopkins. + -article by Galton on twins. + -Huxley on review in. + + Freemasons' Tavern, meeting held at. + + Freewill, a preordained necessity. + + Freke, Dr., paper by. + + Freshwater, Bee-orchis at. + + Freshwater fauna, ocean faunas compared with. + -poverty of. + -preservation of. + + Friendly Islands, rats regarded as game. + + Fringillidae, colour and sexual selection. + + Frogs, article on spawn of. + -F. Muller on. + -salt water and spawn of. + -frozen in glaciers. + + Fruits, bright colours of. + + Fucus, variation in. + + Fuegia, plants of, (see also Tierra del Fuego). + + Fumaria (Corydalis) claviculata, Mohl on tendrils. + + Fumariaceae, cross- and self-fertilisation. + -morphology of tendrils. + + Funafuti, Darwin's theory supported by results of boring in coral island + of. + + Fungoid diseases, Darwin on. + + Fungus, effect on roots and shoots. + + "Fur Darwin," F. Muller's (see "Facts and Arguments for Darwin). + -Darwin quotes. + -Hooker's opinion of. + -publication of. + + Furze, seeds and seedlings. + + Galapagos Islands, visited during the "Beagle" voyage. + -birds of. + -character of species of, the beginning of Darwin's evolutionary views. + -distribution of animals. + -distribution of plants. + -flora of. + -Hooker on plants of. + -insects. + -craters. + -fissure eruptions in. + -restricted fauna. + -Sandwich Islands and. + -subsidence in the. + + Galashiels, terraces near. + + Galaxias, distribution of. + + Gallinaceae, Blyth on. + -colour of. + + Galls, artificial production of. + -Cynips and. + -hybrids and. + -Walsh on willow-. + + Gallus bankiva, colour of wings. + -colour and environment. + -wings of. + + Galton, F., experiments on transfusion of blood. + -letters to. + -letter to Darwin from. + -on twins. + -on variation. + -on heredity. + -on human faculty and its development. + -on prayer. + -proposal to issue health certificates for marriage. + + Game-cock and Sexual Selection. + + Gamlingay, lilies-of-the-valley at. + + Ganoid fishes, preservation in fresh water. + + Gapitche, A., letter to. + + "Gardeners' Chronicle," Darwin's article on fertilisation. + -Darwin's opinion of. + -Darwin's experiment on immersion of seeds in salt water. + -article on Orchids. + -Harvey on Darwin. + -Rivers' articles. + -Wallace on nests. + -Darwin's index. + + Gardner, G., "Travels in the Interior of Brazil." + + Gartner, on Aquilegia. + -experiments on crossing and variation. + -on Primula. + -on Verbascum. + -Darwin's high opinion of his "Bastarderzeugung." + -Beaton's criticism of. + -on self-fertilisation in flowers. + -mentioned. + + Gaskell, G.A., Letter to. + + Gatke, on "Heligoland as an Ornithological Observatory." + + Gaudry, Albert: Professor of Palaeontology in the Natural History + Museum, Paris, Foreign Member of the Royal Society of London, author of + "Animaux Foss. et Geol. de l'Attique." + -letter to. + -on Pikermi fossils. + + Gay, on lizards. + + Gazania. + + Gegenbauer, Karl: Professor of Anatomy at Heidelberg. + -as convert to Darwinism. + -views on regeneration. + + Geikie, Sir A., on age of the Earth. + -edition of "Hutton's Theory of the Earth." + -memoir of Sir A.C. Ramsay. + + Geikie, Prof. J., "Ice Age." + -on intercrossing of erratics. + -Letters to. + -"Prehistoric Europe." + -Presidential address, Edinburgh British Association meeting. + + Geitonogamy, Kerner suggests term. + + Gemmation and dimorphism. + + Gemmules, in reproductive organs. + -and bud-variation. + + Genealogy and classification. + + Genera, aberrant. + -range of large and small. + -variation of. + -Wallace on origin of. + + "Genera Plantarum," work on the. + + Generalisations, evil of. + -easier than careful observation. + -importance. + + "Generelle Morphologie," Darwin on Hackel's. + + "Genesis of Species," Mivart's + + Geographical distribution, L. Agassiz on. + -Darwin on. + -Darwin's high opinion of value of. + -Darwin's interest in. + -E. Forbes on. + -Huxley on birds and. + -proposed work by Hooker on. + -relation of genera an important element in. + -Humboldt the founder of. + + "Geographical Distribution of Animals," Darwin's criticism of Wallace's. + + "Geographical Distribution of Mammals," A. Murray's. + + Geographical regions, Darwin on. + + Geological Committee on the Parallel Roads of Glen Roy. + + "Geological Gossip," Ansted's. + + "Geological Instructions," Darwin's manual of. + + "Geological Observations in S. America," Darwin's. + -Darwin on his. + + Geological record, imperfection of the. + -Morse on the. + + Geological Society, award of medal to Darwin. + -Darwin signs Hooker's certificate. + -museum of. + -Darwin attends Council meeting. + + Geological Survey, foundation of. + -investigation of the Parallel Roads of Glen Roy. + + Geological Time, article in "N. British Review." + + Geologist, Darwin as. + + Geologists, evolutionary views of. + + Geology, arguments in favour of evolution from. + -chapter in "Origin" on. + -practical teaching of. + -English work in. + -Hooker talks of giving up. + -Lyellian school. + -progress of. + + Geotropism, Darwin on. + + German, Darwin's slight knowledge of. + + Germany, converts to evolution in. + -opinion on the "Origin" in. + -Englishmen rejoice over victory of. + + Germination of seeds, Darwin's experiments on effect of salt water. + + "Germs and Vestiges of Disease," Dobell's. + + Gesneria, Darwin on dimorphism of. + + Gestation of hounds. + + Gibraltar, elevation and subsidence of. + + Gilbert, Sir J.H.: of Rothamsted. + -letter to. + -on nitrogen in worms' casting. + -and Sir J. Lawes, Rothamsted experiments. + + Glacial period, absence of phanerogams near polar regions in N. America + during. + -Bates on. + -climatic changes since. + -conditions during. + -continental changes since. + -Darwin's views on geographical changes as cause of. + -destruction of organisms during. + -destruction of Spanish plants in Ireland. + -distribution of organisms affected by. + -duration of. + -effect on animals and plants. + -and elephants. + -S.E. England dry land during. + -Greenland depopulated during. + -introduction of Old World forms into New World subsequent to. + -migration during. + -mundane character of. + -subsidence of Alps during. + -Croll on. + -existence of Alpine plants before. + -Hooker on. + -Glen Roy and. + -Lyell on. + -extinction of mammals during. + -Wallace on. + -movement of Europe since and during. + + Glaciers, Agassiz on. + -Lyell on. + -Tyndall's book on. + -as agents in the formation of lakes. + -Darwin on structure of. + -Hooker on Yorkshire. + -Moseley on motion of. + -physics of. + -Parallel Roads of Glen Roy formed by. + -rock-cavities formed by cascades in. + -in S. America. + -in Wales. + + Gladstone, Herbert Spencer on criticisms by. + + Glass, Dr., on grafting sugar-canes. + + Glen Collarig, absence of terminal moraines. + -terraces in. + + Glen Glaster, absence of terminal moraines. + -barriers of detritus. + -Milne on. + -shelves of. + + Glen Gluoy, shelves of. + + Glen Roy, Parallel Roads of. + -L. Agassiz on. + -Darwin on. + -Darwin's mistake over. + -Darwin on ice-lake theory of Agassiz and Buckland. + -glacier theory of. + -history of work on. + -Hooker on. + -marine theory of. + -Milne-Home's paper on. + -investigated by Geological Survey. + -coincidence of shelves with watersheds. + -measurement of terraces. + + Glen Spean. + + Glen Turret, MacCulloch on. + + Gloriosa, Darwin's experiments on leaf-tendrils. + + Glossotherium Listai. + + Gloxinia, peloric forms of. + + Gnaphalium. + + Gneiss, Darwin on. + + God, Darwin on existence of personal. + + Godron, on Aegilops. + + Godron's "Flora of France." + + Goethe, Darwin's reference to. + -Owen on. + + Goldfinch, difference in beaks of male and female. + + Gongora, and Acropera. + -Darwin on. + -G. fusca (see Acropera luteola). + -G. galeata (see A. Loddigesii). + + Gondwana Land. + + Goodenia, Hamilton on fertilisation of. + + Goodeniaceae. + + Gordon, General, Huxley on Darwin and. + + Gosse, E., "Life of P.H. Gosse" by. + + Gosse, Philip Henry (1810-88): was an example of that almost extinct type-- + a naturalist with a wide knowledge gained at first hand from nature as a + whole. This width of culture was combined with a severe and narrow + religious creed, and though, as Edmund Gosse points out, there was in his + father's case no reconcilement of science and religion, since his + "impressions of nature" had to give way absolutely to his "convictions of + religion," yet he was not debarred by his views from a friendly intercourse + with Darwin. He did much to spread a love of Natural History, more + especially by his seaside books, and by his introduction of the aquarium-- + the popularity of which (as Mr. Edmund Gosse shows) is reflected in the + pages of "Punch," especially in John Leech's illustrations. Kingsley said + of him (quoted by Edmund Gosse, page 344) "Since White's "History of + Selborne" few or no writers on Natural History, save Mr. Gosse and poor Mr. + Edward Forbes, have had the power of bringing out the human side of + science, and giving to seemingly dry disquisitions...that living and + personal interest, to bestow which is generally the special function of the + poet." Among his books are the "Naturalist's Sojourn in Jamaica," 1851; "A + Naturalist's Rambles on the Devonshire Coast," 1853; "Omphalos," 1857; "A + Year at the Shore," 1865. He was also author of a long series of papers in + scientific journals. + -letter to. + + Gould, on sex in nightingales. + + Gower Street, Darwin's house in. + + Gradation in plants. + + Graft-hybrids, experiments on. + -of Cytisus. + -Hildebrand on. + -of potatoes. + -of sugar-canes. + + Grafting, Darwin on. + -difficulty of. + -in hyacinth bulbs. + + Graham's "Creed of Science." + + Gramineae, Darwin on crossing. + + Granite, explanation of association with basalt. + + Grasses, range of genera. + -cleistogamous. + -fertilisation of. + -F. Muller on Brazilian. + + Gratiolet, on behaviour of eyes in rage. + + Gravity, comparison between variation and laws of. + + Gray, Asa (1810-88): was born in the township of Paris, Oneida Co., New + York. He became interested in science when a student at the Fairfield + Academy; he took his doctor's degree in 1831, but instead of pursuing + medical work he accepted the post of Instructor in Chemistry, Mineralogy, + and Botany in the High School of Utica. Gray afterwards became assistant + to Professor Torrey in the New York Medical School, and in 1835 he was + appointed Curator and Librarian of the New York Lyceum of Natural History. + From 1842 to 1872 he occupied the Chair of Natural History in Harvard + College, and the post of Director of the Cambridge Botanical Gardens; from + 1872 till the time of his death he was relieved of the duties of teaching + and of the active direction of the Gardens, but retained the Herbarium. + Professor Gray was a Foreign Member of the Linnean and of the Royal + Societies. The "Flora of North America" (of which the first parts appeared + in 1838), "Manual of the Botany of the Northern United States, the Botany + of Commodore Wilkes' South Pacific Exploring Expedition" are among the most + important of Gray's systematic memoirs; in addition to these he wrote + several botanical text-books and a great number of papers of first-class + importance. In an obituary notice written by Sir Joseph Hooker, Asa Gray + is described as "one of the first to accept and defend the doctrine of + Natural Selection..., so that Darwin, whilst fully recognising the + different standpoints from which he and Gray took their departures, and + their divergence of opinion on important points, nevertheless regarded him + as the naturalist who had most thoroughly gauged the "Origin of Species," + and as a tower of strength to himself and his cause" ("Proc. R. Soc." + Volume XLVI., page xv, 1890: "Letters of Asa Gray," edited by Jane Loring + Gray, 2 volumes, Boston, U.S., 1893). + -articles by. + -as advocate of Darwin's views. + -Darwin's opinion of. + -on Hooker's Antarctic paper. + -on large genera varying. + -letters to Darwin from. + -letters to. + -on Darwin's views. + -plants of the Northern States. + -on variation. + -book for children by. + -on crossing. + -visits Down. + -on dimorphism. + -on Agassiz. + -extract from letter to G.F. Wright from. + -on fertilisation of Cypripedium. + -on Gymnadenia tridentata. + -on Habenaria. + -on Passiflora. + -on relative ranges of U. States and European species. + -on Sarracenia. + -mentioned. + + Gray, Mrs. + + Gray, Dr. John Edward, F.R.S. (1800-75): became an assistant to the + Natural History Department of the British Museum in 1824, and was + appointed Keeper in 1840. Dr. Gray published a great mass of zoological + work, and devoted himself "with unflagging energy to the development of + the collections under his charge." ("Ann. Mag. Nat. Hist." Volume XV., + page 281, 1875.) + -and British Museum. + + Greatest Happiness principle. + + Grebes, as seed-eaters. + + Greenland, absence of Arctic Leguminosae. + -connection with Norway. + -flora of. + -introduction of plants by currents. + -as line of communication of alpine plants. + -migration of European birds to. + + Greg, W.R.: Author of "The Enigmas of Life," 1872. + -Darwin on his "Enigmas of Life." + -letter to. + + Grey, Sir G., on Australian Savages. + + Grinnell expedition, reference to the second. + + Grisebach, A. + + Grisebach, A.W. + + Grossulariaceae. + + Grouse, Natural Selection and colours of. + -Owen describes as distinct creation. + + Grypotherium Darwini. + -G. domesticum. + + Guiana, Bates on. + + Gulf-weed, Darwin on. + + Gully Dr. + + Gunther, Dr., visit to Down. + + Gurney, E., articles in "Fortnightly" and "Cornhill." + -"Power of Sound." + + Gymnadenia, course of vessels in flower of. + -Asa Gray on. + -penetration by pollen of rostellum. + + Gynodioecism in Plantago. + + Haast, Sir Julius von, (1824-87): published several papers on the + Geology of New Zealand, with special reference to glacial phenomena. + ("Quart. Journ. Geol. Soc." Volume XXI., pages 130, 133, 1865; Volume + XXIII., page 342, 1867.) + -on glacial deposits. + + Habenaria, Azorean species (see also Peristylus viridis). + -course of vessels in flower. + -Lord Farrer on. + -morphology of flower. + -H. bifolia, flowers. + -a subspecies of H. chlorantha. + -H. chlorantha, considered by Bentham a var. of H. bifolia. + -structure of ovary. + + Hackel, E., convert to Darwin's views. + -"Generelle Morphologie." + -Die Kalkschwamme. + -"Freedom in Science and Teaching." + -letters to. + -on pangenesis. + -proposed translation of his book. + -on reviews of "Origin" in Germany. + -on sponges. + -substitutes a molecular hypothesis for pangenesis. + -visits Down. + -on absence of colour-protection in lower animals. + -on change of species. + -on Linope. + -on medusae. + + Haematoxylon, bloom-experiments on. + -sleep-movements. + + Halictus, Fabre's paper on. + + Halimeda, Darwin's description of. + + Halleria, woody nature of. + + Hallett, on varieties of wheat. + + Hamilton, on fertilisation of Dampiera. + + Hamilton, Sir W., on Law of Parsimony. + + Hancock, Albany (1806-73): author of many zoological and palaeontological + papers. His best-known work, written in conjunction with Joshua Alder, and + published by the Ray Society is on the British Nudibranchiate Mollusca. + The Royal Medal was awarded to him in 1858. + -on British shells. + -and Royal medal. + + Hanley, Dr., Darwin's visit to. + + Harker, A., note on Darwin's work on cleavage and foliation. + + Hartman, Dr., on Cicada septendecim. + + "Harvesting Ants and Trap-door Spiders," Moggridge's. + + Harvey, William Henry (1811-66): was the author of several botanical + works, principally on Algae; he held the botanical Professorship at + Trinity College, Dublin, and in 1857 succeeded Professor Allman in the + Chair of Botany in Dublin University. (See "Life and Letters," II., + pages 274-75.) + -criticism of "Origin." + -Darwin's opinion of his book. + -letter to. + -mentioned. + -on variation in Fucus. + + Haughton, Samuel (1821-97): author of "Animal Mechanics, a Manual of + Geology," and numerous papers on Physics, Mathematics, Geology, etc. In + November 1862 Darwin wrote to Sir J.D. Hooker: "Do you know whether + there are two Rev. Prof. Haughtons at Dublin? One of this name has made + a splendid medical discovery of nicotine counteracting strychnine and + tetanus? Can it be my dear friend? If so, he is at full liberty for + the future to sneer [at] and abuse me to his heart's content." + Unfortunately, Prof. Haughtons' discovery has not proved of more + permanent value than his criticism on the "Origin of Species." + -on Bees' cells. + -on depth of ocean. + -review by. + -mentioned. + + Hawaiian Islands, Hillebrand's Flora. + -plants. + + Hawks and owls as agents in seed-dispersal. + -bright colours in female. + + Head, expression in movement of. + + Hearne, on black bear. + + Heat, action on rocks. + + Heathcote, Miss. + + Heaths, as examples of boreal plants in Azores. + -and climate. + + Heberden, Dr., mentioned. + + Hector. + + Hedgehog, movements of spines. + + Hedychium, Darwin's prediction as to fertilisation of. + -paraheliotropism. + + Hedyotis, dimorphism of. + + Hedysarum, Darwin's experiments on (see Desmodium gyrans). + + Heer, Oswald (1809-83): was born at Niederutzwyl, in the Canton of St. + Gall, Switzerland, and for many years (1855-82) occupied the chair of + Botany in the University of Zurich. While eminent as an entomologist Heer + is chiefly known as a writer on Fossil Plants. He began to write on + palaeobotanical subjects in 1841; among his most important publications, + apart from the numerous papers contributed to scientific societies, the + following may be mentioned: "Flora Tertiaria Helvetiae," 1855-59; the + "Flora Fossilis Arctica," 7 volumes, 1869-83; "Die Urwelt der Schweiz," + 1865; "Flora Fossilis Helvetiae," 1876-7. He was awarded the Wollaston + medal of the Geological Society in 1874, and in 1878 he received a Royal + medal. (Oswald Heer, "Bibliographie et Tables Iconographiques," par G. + Malloizel, precede d'une Notice Biographique" par R. Zeiller; Stockholm.) + -on continental extension. + -on plants of Madeira. + -on origin of species from monstrosities. + -Darwin sends photograph to. + -"Flora fossilis arctica." + -letter to. + + Heeria (see also Heterocentron). + -F. Muller on. + + Heifers, and sterility. + + Helianthemum, Baillon's observations on pollen. + + Heligoland, birds alight on sea near. + + Heliotropism, experiments on. + -of roots. + + Hemsley, W.B., mentioned. + + Hennessey. + + Henry, I.A. (see Anderson-Henry) + -letter to. + + Henslow, Prof. J.S., life of. + -Darwin's affection for. + -Darwin's Cambridge recollections of. + -death of. + -letters to. + -mentioned. + -on Mus messorius. + -visits Down. + -Darwin on his parish work. + -work on crossing. + + Henslow, Miss, mentioned. + + Herbaceous orders, in relation to trees. + + Herbert, Dean, on heaths of S. Africa. + -on Polygala. + -on Cytisus Adami. + -on self-fertility of Hippeastrum. + -mentioned. + + "Hereditary Genius," Francis Galton's. + + Hereditary Improvement, Francis Galton on. + + Heredity, Darwin's criticism of Galton's theory. + + Hermaphroditism, in trees. + -Weir on Lepidoptera and. + -and nature of generative organs. + + Herminium monorchis. + + Heron, Sir R., on peacocks and colour. + + Herons, as fruit-feeders. + + Herschel, Sir J.F.W., edits "Manual of Scientific Enquiry." + -on Natural Selection. + -on the "Origin." + -"Physical Geography." + -on providential laws. + -on heating of rocks. + -on importance of generalising. + -on study of languages. + -versus Lyell on volcanic islands. + -mentioned. + + Heteranthera, two kinds of stamens. + -H. reniformis. + + Heterocentron, experiments on. + -seeds of. + -two kinds of stamens. + -H. roseum, fertilisation mechanism of. + + Heterogeny, Owen on. + + Heteromorphic, use of term. + + Heterosmilax, de Candolle on. + + Heterostylism, Darwin's experiments on. + -example in monocotyledons of. + + Hewitt, on pheasant-hybrids. + -mentioned. + + Hibiscus. + + Hicks, H., on pre-Cambrian rocks. + + Hieracium, American species. + -Nageli on. + -variability of. + + Highness, lowness and. + + Hilaire, A. St., see St. Hilaire. + + Hildebrand, F., article in "Botanische Zeitung." + -experiments on direct action of pollen. + -"Die Lebensdauer der Pflanzen." + -letter to. + -crossing work by. + -on Delpino's work. + -on dispersal of seeds. + -self-sterility in Corydalis cava. + -"Geschlechter-Vertheilung bei den Pflanzen." + -on orchids. + -on ovules formed after pollination. + -experiment on potatoes. + -on Salvia. + -mentioned. + + Hilgendorf, controversy with Sandberger. + + Hillebrand's Flora of the Hawaiian Islands. + + "Himalayan Journals," dedicated by Hooker to Darwin. + + "Himalayan Plants, Illustrations of." + + Himalayas, British plants in. + -commingling of temperate and tropical plants. + -tortoise of. + -ice-action in. + -mixed character of the vegetation. + + Hinde, Dr., examination of Funafuti coral-reef cores by. + + Hindmarsh, L., letter to. + + Hippeastrum, Herbert on self-sterility of. + + Hippopotamus, fossil in Madagascar. + + Historic spirit, J. Morley's criticism of Darwin's lack of. + + Hitcham, collection of Azorean plants made near. + + Hobhouse, Sir A., Darwin meets. + + Hochberg, K., letter to. + + Hofmann, A.W., receives royal medal. + + Holland, evolutionary opinions in. + -flora of. + + Holland, Sir H., on pangenesis. + -mentioned. + -on influence of mind on circulation. + + Holly, effective work of insects in fertilisation of. + + Hollyhock, Darwin's crossing experiments. + + Holmsdale. + + Home, see Milne-Home. + + Homing experiments. + + Homo, Pithecus compared with. + + Homology, analogy and. + -course of vessels in flowers as guide to. + + Homomorphic, use of term. + + Honeysuckle, oak-leaved variety. + + Hooker, Mrs., assists Sir J.D. Hooker. + + Hooker, Sir J.D., addresses at British Association meetings. + -on Arctic plants. + -Australian Flora by. + -botanical appointment. + -C.B. conferred upon. + -on coal plants and conditions of growth. + -criticism on Lyell's work. + -on Darwin's MS. on geographical distribution. + -Darwin's admiration for letters of. + -Darwin assisted in his work by. + -Darwin on good gained by "squabbles" with. + -Darwin on success of. + -enjoyment of correspondence with Darwin. + -expedition to Syria. + -extract from letter to. + -Falconer and. + -first meeting with Darwin. + -on Insular Floras. + -introductory essay to Flora of Tasmania. + -lecture at Royal Institution. + -letters to. + -letters to Darwin from. + -on new colonial flora. + -on New Zealand flora. + -on Natural Selection. + -on naturalised plants. + -on the "Origin." + -and Owen. + -on pangenesis. + -on plants of Fernando Po and Abyssinia. + -on preservation of tropical plants during cool period. + -and reviews. + -royal medal awarded to. + -and J. Scott. + -on species. + -on Torbitt's potato experiments. + -on use of terms centripetal and centrifugal. + -on variation in large and small genera. + -on Welwitschia. + -on Cameroon plants. + -Darwin on his address at Belfast. + -Darwin writes testimonial for. + -Darwin values scientific opinion of. + -Darwin receives encouragement from. + -Darwin's pleasure at visits from. + -on Glacial period. + -on Glacial deposits in India. + -on glaciers in Yorkshire. + -notice in "Gardeners' Chronicle" on. + -photograph by Mrs. Cameron. + -Primer of Botany by. + -review of Darwin's "Fertilisation of Orchids." + -scheme for Flora. + -represents "whole great public" to Darwin. + -use of structure in plants. + -visits Down. + -opinion of "Fur Darwin." + -mentioned. + + Hooker, Sir William Jackson (1785-1865): was called to the Chair of Botany + at Glasgow in 1820, where by his success as a teacher he raised the annual + fees from 60 pounds to 700 pounds. In 1841 he became Director of the Royal + Botanic Gardens at Kew, which under his administration increased enormously + in activity and importance. His private Herbarium, said to be "by far the + richest ever accumulated in one man's lifetime," formed the nucleus of the + present collection. He produced, as author or editor, about a hundred + volumes devoted to Botany ("Dict. of Nat. Biog."). + -Herbarium at Kew belonging to. + -letters to. + -mentioned. + + Hopkins, William, F.R.S. (1793-1866) entered Peterhouse, Cambridge, at + the age of thirty, and in 1827 took his degree as seventh wrangler. For + some years Hopkins was very successful as a mathematical tutor; about + 1833 he began to take a keen interest in geological subjects, and + especially concerned himself with the effects of elevating forces acting + from below on the earth's crust. He was President of the Geological + Society in 1851 and 1852 ("Quart. Journ. Geol. Soc." Volume XXIII., page + xxix, 1867). + -Article in "Fraser's Magazine." + -on elevation and earthquakes. + -on mountain-building. + -researches in physical geology. + -mentioned. + + Horner, Leonard, F.R.S. (1785-1862): was born in Edinburgh, at the age + of twenty-one he settled in London, and devoted himself more + particularly to Geology and Mineralogy, returning a few years later to + Edinburgh, where he took a prominent part in founding the School of Art + and other educational institutions. In 1827 Mr. Horner was invited to + occupy the post of Warden in the London University,a position which he + resigned in 1831; he also held for some years an Inspectorship of + Factories. As a Fellow of the Royal Society, Mr. Horner "took an active + part in bringing about certain changes in the management of the Society, + which resulted in limiting to fifteen the number of new members to be + annually elected..." In 1846 Horner was elected President of the + Geological Society; and in 1860 he again presided over the Society, to + the interests of which he had long devoted himself. His contributions + to the Society include papers on Stratigraphical Geology, Mineralogy, + and other subjects.--"Memoirs of Leonard Horner," edited by his + daughter, Katherine M. Lyell (privately printed, 1890). + -letters to. + -memoirs of. + -address to Geological Society. + -on coal. + -on Darwin's "Geological Observations." + -visits Down. + -mentioned. + + Horner, Mrs. L. + + Horse, ancestry. + -Arab-Turk and English race-. + -hybrids between Quagga and. + -in N. and S. America. + -equality of sexes in race-. + + Horsfall, W., letter to. + + Hottonia, dimorphism of. + + Hounds, gestation of. + + Howard, L.O. + + Hoya carnosa, Darwin's work on. + + Humble-bees, as agents of fertilisation of orchids. + + Humboldt, Bates' description of tropical forests compared with that by. + -conversation with. + -on heath regions. + -on migration and double creation. + -"Personal Narrative." + -on violet of Teneriffe. + -Darwin's opinion of. + -on elevation and volcanic activity. + -mentioned. + + Humboldt and Webb, on Zones on Teneriffe. + + Hume, Darwin on Huxley's "Life" of. + + Humming-birds, agents of fertilisation. + + Hunger, expression by sheldrakes of. + + Husbands, resemblance between wives and. + + Hutton, Frederick Wollaston, F.R.S., formerly Curator of the Canterbury + Museum, Christchurch, New Zealand, author of "Darwinism and Lamarckism, Old + and New," London, 1899. + -letter to. + -review of "Origin." + + Hutton, James, (1726-97): author of "Theory of the Earth." + + Huxley, L., reference to his "Life of T.H. Huxley." + -information given by. + + Huxley, Prof. T.H., biographical note, Volume I. + -Article in "Annals and Magazine" in reply to Falconer. + -on Aphis. + -on automatism. + -catalogue of collections in Museum of Practical Geology. + -comparative anatomy by. + -on Comte. + -on Cuvier's classification. + -Darwin's value of his opinion. + -election to the Athenaeum. + -friendship with Darwin. + -on growth of Darwin's views. + -lectures at the Royal Institution. + -lectures on evolution by. + -lectures to working men. + -legacy and gift to. + -letters to. + -"Life of Hume." + -"Man's Place in Nature." + -marriage. + -misrepresented by Owen. + -founds "Natural History Review." + -obituary notice of Darwin. + -on the "Origin of Species." + -on Owen's archetype book. + -president of the British Association meeting at Liverpool (1870). + -on Priestley. + -quoted by Lord Kelvin as an unbeliever in spontaneous generation. + -reviews by. + -review of "Vestiges of Creation" by. + -on Sabine's address. + -on saltus. + -prefatory note to Hackel's "Freedom in Science and Teaching." + -address to Geological Society (1869). + -on classification of man. + -on contemporaneity. + -on Catasetum. + -on deep-sea soundings. + -legacy from A. Rich. + -on Lyell's "Principles." + -on use of term physiological species. + -on vivisection. + -and H.N. Martin, "Elementary Biology" by. + -mentioned. + + Huxley, Mrs. T.H., queries on expression sent by Darwin to. + -observations on child crying. + -mentioned. + + Hyacinth, experiment on bulbs. + + Hyatt, Alpheus (1838-1902): was a student under Louis Agassiz, to whose + Laboratory he returned after serving in the Civil War, and under whom he + began the researches on Fossil Cephalopods for which he is so widely known. + In 1867 he became one of the Curators of the Essex Institute of Salem, + Mass. In 1870 he was made Custodian, and in 1881 Curator of the Boston + Society of Natural History. He held professorial chairs in Boston + University and in the Massachusetts Institute of Technology, and "was at + one time or another officially connected with the Museum of Comparative + Zoology and the United States Geological Survey." See Mr. S. Henshaw + ("Science," XV., page 300, February 1902), where a sketch of Mr. Hyatt's + estimable personal character is given. See also Prof. Dall in the "Popular + Science Monthly," February 1902. + -and Hilgendorf. + -letters to. + -letters to Darwin from. + -on tetrabranchiata. + + Hyatt and Cope, theories of. + + Hybridism, chapter in "Origin" on. + -Bentham's address on. + -treatment by Darwin in "Variation of Animals and Plants." + + Hybrids, and adaptation. + -Darwin's views on. + -evidence in favour of pangenesis from. + -experiments on. + -fertility of. + -intermediate character of. + -primrose and cowslip. + -article in "Quarterly Review" on. + -sterility of. + -Max Wichura on. + -Bronn on. + -F. Muller's work on. + -and heterostyled plants. + -rarity of natural. + -J. Scott's work on. + -tendency to reversion. + + Hydra, sexuality of. + + Hydropathy, Darwin and. + + Hydrozoa, alternation of generations in. + + Hymenoptera, affinities of. + -H. Muller on. + + Hypericum perforatum, a social plant in U.S.A. + + Hyracotherium cuniculus, Owen on. + + Iberis, mucus in seeds of. + + Ice, as agent in dispersal of boulders. + -agent in dispersal of plants. + -Forbes on transport by. + -agent in lake-formation. + -cleavage in. + -work of, a new factor in geology. + + Ice-action, on land and sea. + + Icebergs, as factor in explaining European plants in Azores. + -Croll on action of. + -Darwin on. + -evidence in S. America of. + -Hopkins on action of. + + Ice-cap, of Arctic regions. + + Iceland, importance of records of volcanic phenomena in. + + Ignorance, Darwin on immensity of man's. + + Ilkley, Darwin's visit to. + + Illegitimate offspring, need for repetition of Darwin's experiments on + plants'. + + Imatophyllum. + + Immortality, Darwin on. + + Immutability of species. + -Falconer disbelieves in. + -Darwin on. + + Imperfection of the Geological Record, see Geological Record. + + Impotence in plants. + -see also Self-sterility. + + India, British rule in. + -flora of. + -Hooker in. + -varieties of domestic animals in. + -H.F. Blanford on. + -Darwin on origin of lakes in. + -evidence of colder climate in. + -J. Scott accepts post in. + + Infants, Mrs. E Talbot on development of mind in. + -observations on ears of. + + Infusoria, possible occurrence in underclays of coal. + + Inglis, Sir R., Darwin at breakfast party. + + Inheritance, atavism and. + -conservative tendency of long. + -Hackel on. + -hypothesis on. + -Jager on. + -and Natural Selection. + -power of. + -J.C. Prichard on. + -and variability. + -Darwin on. + -Galton on. + + Insanity, concealment of. + + "Insect Life," Howard's. + + Insectivorous plants, Darwin's work on. + + Insects, alpine. + -Lord Avebury on. + -Bates on. + -fossil. + -luminous. + -of Madeira. + -F. Muller on metamorphosis of. + -Sharp's book on. + -study of habits more valuable than description of new species. + -wingless. + -Wollaston on. + -antiquity of stridulating organs in. + -colour and Sexual Selection. + -H. Muller's work on adaptation to fertilisation of flowers. + -metamorphosis of. + -music as attraction to. + -observation on fertilisation of flowers by. + -Ramsay on. + -Riley's work on. + -tropical climate and colours of. + + Instinct, Darwin and. + -in nest-making. + -selection of varying. + + Insular floras. + -Hooker's lecture on. + + Insular forms, in Galapagos, Canaries and Madeira. + -beaten by continental forms. + + Intelligence, meaning of. + -Romanes on Animal. + -in worms. + + Intercrossing, in pigeons. + -Darwin on effects of. + -and sterility. + + Interglacial periods, Darwin on evidence for. + + Intermediate forms. + -Bates' paper on. + -S. American types as. + -crossing and frequent absence of. + -extinction of. + -Falconer on existence of. + -as fossils. + -Asa Gray on. + -Plagiaulax as evidence of. + -Wollaston on rarity in insects. + + Introduced plants, Sonchus in New Zealand as example of. + -in N. America and Australia. + -variability of. + -Darwin on. + + Introductory Essay to Tasmanian "Flora," Hooker's. + + Ipswich, British Association meeting (1851). + + Iquique, nitrate of soda beds at. + + Ireland, Spanish plants in. + + Iris, flowers of. + -nectar secretion of. + + Islands, comparison between species of rising and sinking. + -fauna of. + -introduction of plants. + -products of. + -plants with irregular flowers on. + -subsidence of coral. + -survival of ancient forms in. + -volcanic. + -comparison of age of continents and. + -former greater extension of. + + "Island Life," Darwin's criticism of Wallace's. + + Isle of Wight, occurrence of Bee-orchis in. + + Isnardia palustris, range of. + + Isolation, Bentham underestimates importance of. + -Darwin's opinion of. + -importance of. + -Wagner exaggerates importance of. + -Weismann on effects of. + + Itajahy, F. Muller's narrow escape from flood of. + + Italy, flora of. + + Ivy, difference in growth of flowering and creeping branches. + + Jaeger, G., letter to. + -on pangenesis and inheritance. + + James', Sir H., discussion in "Athenaeum" on change of climate. + -map of the world. + + James Island, Darwin's plants from. + + Jameson. + + Jamieson, W., on S. America. + -Darwin converted to glacial theory of Glen Roy after publication of + paper by. + + Janet, on Natural Selection. + + Japan, American types in. + -flora of. + -Gray's work on plants of. + -progress of. + + Java, botanical relation to Africa. + -Alpine plants of. + -Wallace on. + + Jays, Crows and. + -repeated pairing of. + + Jeffreys, Gwyn, shells sent by Darwin to. + + Jenkin, Fleeming, review by. + + Jenners, taste for natural history in the. + + Jenyns (Blomefield), Rev. Leonard: The following sketch of the life of + Rev. Leonard Blomefield is taken from his "Chapters in my Life; Reprint + with Additions" (privately printed), Bath, 1889. He was born, as he states + with characteristic accuracy, at 10 p.m., May 25th, 1800; and died at Bath, + September 1st, 1893. His father--a second cousin of Soame Jenyns, from + whom he inherited Bottisham Hall, in Cambridgeshire--was a parson-squire of + the old type, a keen sportsman, and a good man of business. Leonard + Jenyns' mother was a daughter of the celebrated Dr. Heberden, in whose + house in Pall Mall he was born. Leonard was educated at Eton and + Cambridge, and became curate of Swaffham Bulbeck, a village close to his + father's property; he was afterwards presented to the Vicarage of the + parish, and held the living for nearly thirty years. The remainder of his + life he spent at Bath. He was an excellent field-naturalist and a minute + and careful observer. Among his writings may be mentioned the Fishes in + "Zoology of the Voyage of the 'Beagle,'" 1842, a "Manual of British + Vertebrate Animals," 1836, a "Memoir" of Professor Henslow,1862, to which + Darwin contributed recollections of his old master, "Observations in + Natural History," 1846 and "Observations in Meteorology," 1858, besides + numerous papers in scientific journals. In his "Chapters" he describes + himself as showing as a boy the silent and retiring nature, and also the + love of "order, method, and precision," which characterised him through + life; and he adds, "even to old age I have been often called a VERY + PARTICULAR GENTLEMAN." In a hitherto unpublished passage in his + autobiographical sketch, Darwin wrote, "At first I disliked him from his + somewhat grim and sarcastic expression; and it is not often that a first + impression is lost; but I was completely mistaken, and found him very kind- + hearted, pleasant, and with a good stock of humour." Mr. Jenyns records + that as a boy he was by a stranger taken for a son of his uncle, Dr. + Heberden (the younger), whom he closely resembled. + -letters to. + -mentioned. + + Jodrell Laboratory, Darwin's interest in. + -note on. + + Jordanhill, Smith of, on Gibraltar. + + "Journal of Researches," Darwin's. + + Judd, Prof. J.W., letter to. + -recollections of Darwin. + -on Darwin's "Volcanic Islands." + -Darwin in praise of work of. + + Jukes, on imperfection of the Geological Record. + -on changes of climate. + -on formation of river-valleys. + -over estimates sub-aerieal denudation. + + Jumps, variation by. + + Juncus, range of. + -J. bufonius. + -variation of. + -germination of seed from mud carried by woodcock. + + Jura, Darwin on erratic blocks of. + + Jussieu, A. de. + + Kane's, E.K., "Arctic Explorations," use of foxtails by Esquimaux + referred to in. + + Kelvin, Lord, Address at the British Association Meeting at Edinburgh + (1871). + -on geological time. + -on age of the earth. + -on origin of plant-life from meteorites. + + Kemp, W., sends seeds to Darwin. + -on vitality of seeds. + + Kensington, proposed removal of British Museum (Bloomsbury) collections + to. + + Kerguelen cabbage, Chambers versus Hooker on the. + + Kerguelen island, coal-beds of. + -relation of flora to that of Fuegia. + -similarity between plants of S. America and of. + -importance of collecting fossil plants on. + -moth from. + -sea-shells of. + -volcanic mountain on. + + Kerner, A. von Marilaun, on Tubocytisus. + -"Pflanzenleben." + -"Schutzmittel des Pollens." + -on xenogamy and autogamy. + -mentioned. + + Kerr, on frozen snow. + + Kerr, Prof. Graham. + + Kew, proposed consolidation of botanical collections at. + -rarity of insects and shells in Royal Garden. + -Darwin visits Garden. + -Darwin obtains plants from. + -Darwin sends seeds to. + -Jodrell, Laboratory at. + -struggle for existence at. + -suggestion that J. Scott should work in Garden. + + Kilauea, lava in crater of. + + Kilfinnin, shelves in valley of. + + Kilima Njaro, plants of. + + King, Captain, collection of plants by. + -"Voyages of the 'Adventure' and 'Beagle.'" + + King, Sir George, reminiscences of J. Scott. + -Darwin receives seeds from. + + King, Dr. Richard (1811?-1876): He was surgeon and naturalist to Sir + George Back's expedition (1833-5) to the mouth of the Great Fish River + in search of Captain Ross, of which he published an account. In 1850 he + accompanied Captain Horatio Austin's search expedition in the + "Resolute." + -Arctic expedition. + + Kingfisher, sexual difference in. + + Kingsley, C., quoted in the "Origin." + -story of a heathen Khan. + -reference to E. Forbes and P.H. Gosse. + + Kini Balu, vegetation of. + + Kirby and Spence. + + Klebs, on use of mucus in seeds. + + Knight, A., on crossing. + -hybrid experiments. + -on sports. + + Knight's Law. + + Knight-Darwin Law, F. Darwin on. + + Knuth, on morphology of cruciferous flower. + + Koch's "Flora Germanica." + + Kolliker, visits Down. + + Kollmann, Dr., on atavism. + + Kolreuter, on Aquilegia. + -on hybrids. + -observations on pollen. + -on self-fertilisation. + -on varieties of tobacco. + + "Kosmos," F. Muller's article on Crotolaria. + -F. Muller's paper on Phyllanthus in. + + Krause, E., letter to. + -memoir of Erasmus Darwin. + -memoir of H. Muller. + + Kroyer. + + Kubanka, form of Russian wheat. + + Kurr, on flowers of Canna. + + La Plata, H.M.S. "Beagle's" visit to. + -Cervus of. + -Mylodon of. + -plants of. + -extinct animals from. + -slates and schists of. + + Labellum, nature of. + + Labiatae, large genera of. + + Laboratory, Darwin on the instruments for botanical. + -founding of Jodrell. + + Laburnum, peloric flowers of. + -Darwin on hybrid (see also Cytisus). + + Ladizabala, crossing experiments on. + + Lagerstraemia (Lagerstroemia), F. Muller on. + + Lakes, Darwin on Ramsay's theory of. + -as agents in forming Parallel Roads of Glen Roy. + -of Friesland. + -Geological action of. + -Ramsay on. + + Lamarck, Darwin on views of. + -difference between views of Darwin and. + -"Hist. Zoolog." of. + -Hopkins on Darwin and. + -Packard's book on. + -quotation from. + + Lamellicorns, F. Muller on sexes in. + -stridulating organs of. + + Lamont, James, F.G.S., F.R.G.S.: author of "Seasons with the Sea-horses; + etc.; Yachting in the Arctic Seas, or Notes of Five Voyages of Sport and + Discovery in the Neighbourhood of Spitzbergen and Novaya Zemlya," + London, 1876; and geological papers on Spitzbergen. + -letters to. + + Lampyridae, luminous organs of. + + Land, fauna of sea compared with that of. + -changes in level of sea the cause of those on. + + Land-birds, resting on the sea. + + Land-shells, dispersal of. + -of glacial period. + -modification of. + + Land-surfaces, preservation for long periods. + + Landois, reference to paper by. + + Language, observations bearing on origin of. + -Sir J. Herschel on study of. + + Lankester, E. Ray, letter to. + -drawing of earthworm used in Darwin's book. + + Lankester, E. (Senior), speech at Manchester British Association meeting + (1861), on Darwin's theory. + + Lantana, in Ceylon. + + Lanugo, on human foetus. + + Lapland, richness of flora. + + Latania Lodigesii, peculiar to Round Island. + + Latent characters, tendency to appear temporarily in youth. + + Lathyrus aphaca. + -L. grandiflorus, fertilisation of. + -L. nissolia, evolution of. + -explanation of grass-like leaves. + -Darwin on. + -L. maritimus, bloom on. + -L. odoratus, fertilisation of. + -intercrossing of varieties. + + Lauder-Dick, Sir Thomas, on Parallel Roads of Glen Roy. + + Laurel, extra-floral nectaries of. + + Lava, Darwin and Scrope on separation of constituent minerals of. + -Elie de Beaumont's measurements of inclination of. + -fluidity of. + -junction between dykes and. + -and metamorphic schists. + -Scrope on basaltic and trachytic. + -subsidence due to outpouring of. + + Law, of balancement. + -of growth. + -of higgledy-piggledy. + -of perfectibility by Nageli. + -of sterility. + -of succession. + -of variation. + + Lawes, Sir J.B., and Sir J.H. Gilbert, Rothamsted experiments. + + Laxton, T., close on the trail of Mendelian principle. + + "Lay Sermons," Huxley's. + + Leaves, movements of. + -used by worms in plugging burrows. + + Lebanon, glacial action on. + -plants of. + -Hooker on Cedars of. + + Lecky, Rt. Hon. W.E.H., Darwin's interest in book by. + -quoted in "Descent of Man." + + Lecoq, "Geographie Botanique." + -on self-sterility. + -mentioned. + + Lectures, Darwin on Edinburgh University, (see also Hooker and Huxley). + -Max Muller's, on Science of Language. + + Ledebour, allusion to book by. + + Leeds, address by Owen at. + + Leersia oryzoides, cleistogamic flowers of. + + Leggett, W.H., on Rhexia virginica. + + Legitimate unions, heteromorphic or. + + Leguminosae, absence in Greenland. + -absent in New Zealand. + -anomalous genera in. + -crossing in. + -scarcity in humid temporate regions. + -seeds of. + -example of inherited pelorism in. + -Lord Farrer's observations on fertilisation of. + -nectar-holders in flowers. + -reason for absence of. + + Leibnitz, rejection of theory of gravity by. + + Lemuria, continent of. + + Lepadidae, Darwin's work on, (see also Barnacles). + -fossil. + + Lepas, nomenclature of. + + Lepidodendron. + + Lepidoptera, Sexual Selection in. + -breeding in confinement. + -F. Muller on mimicry in. + -protection afforded by wings. + -want of colour-perception. + -Weir on apterous. + + Lepidosiren, reason for preservation of. + + Leptotes. + + Leschenaultia, fertilisation mechanism. + -self-fertilisation of. + -L. biloba, fertilisation mechanism of. + -L. formosa, fertilisation mechanism of. + + Lesquereux, Leo (1806-89): was born in Switzerland, but his most + important works were published after he settled in the United States in + 1848. Beginning with researches on Mosses and Peat, he afterwards + devoted himself to the study of fossil plants. His best known + contributions to Palaeobotany are a series of monographs on Cretaceous + and Tertiary Floras (1878-83), and on the Coal-Flora of Pennsylvania and + the United States generally, published by the Second Geological Survey + of Pennsylvania between 1880 and 1884 (see L.F. Ward, Sketch of + Palaeobotany, "U.S. Geol. Surv., 5th Ann. Rep." 1883-4; also "Quart. + Journ. Geol. Soc." Volume XLVI., "Proc." page 53, 1890. + -convert to evolution. + -on Coal floras. + + Leuckart, Rudolf (1822-98): Professor of Zoology at Leipzig. + -convert to Darwin's views. + + Lewes, G.H., (1817-78): author of a "History of Philosophy," etc. + -letter to. + + Lewy, Naphtali, letter to Darwin from. + + Lias, cephalopods from the. + + Life, Bastian's book on the beginnings of. + -mystery of, + -origin of. + -principle of. + -bearing of vitality of seeds on problem of. + + Light, action on plants of flashing. + + Lima, Darwin visits. + + Limulus. + + Linaria, peloria as reversions. + + Lindley, John (1799-1865): was born at Catton, near Norwich. His first + appointment was that of Assistant Librarian to Sir Joseph Banks. He was + afterwards Assistant Secretary to the Horticultural Society, and during his + tenure of that office he organised the first fruit and flower shows held in + this country. In 1829 he was chosen to be the first Professor of Botany at + University College, London, and a few years later he became Lecturer to the + Apothecaries' Company. He is the author of a large number of botanical + books, of which the best known is the "Vegetable Kingdom," 1846. He was + one of the founders of the "Gardeners' Chronicle," and was its principal + editor up to the time of his death. He was endowed with great powers of + work and remarkable energy. He is said as a young man to have translated + Richard's "Analyse du Fruit" in a single sitting of three nights and two + days. (From the article on Lindley in the "Dictionary of National + Biography," which is founded on the "Gardeners' Chronicle," 1865, pages + 1058, 1082.) + -Hooker's eloge of. + -and Royal Medal. + -"Vegetable Kingdom" by. + -on Acropera and Gongora. + -Darwin on his classification of orchids. + -letters to. + -on Melastomaceae. + -on orchids. + -Hooker reviews Darwin's Orchid book in style of. + -mentioned. + + Lingula, persistence of. + -Silurian species. + + Link, on Alpine and Arctic plants. + + Linnaeus. + + Linnean Society, Bentham's address. + -Collier's picture of Darwin in rooms of. + -Darwin's paper on Linum. + -Darwin advises Bates to give his views on species before. + -Wallace's paper on the Malayan papilionidae. + + Linnet, a migratory bird. + + Linope, E. Hackel on. + + Linum, Darwin's work on. + -dimorphism of. + -interaction of pollen and stigma. + -mucus in seeds of. + + Linum flavum. + -L. grandiflorum, two forms of. + -L. Lewisii, experiments on. + -L. trigynum. + -L. usitatissimum, circumnutation of. + + Lister, Lord, on spines of Hedgehog. + + Listera, fertilisation of. + -L. cordata, fertilisation of. + -L. ovata, fertilisation of. + + Litchfield, Mrs. (see Darwin, Henrietta). + -criticism of Huxley. + + Littoral shells, glacial period and. + + Liverpool, British Association meeting at (1870). + + Livingstone, D., on the distribution of thorny plants. + + Lobelia, Darwin's experiments on. + -fertilisation mechanism of. + -fertility of. + -L. fulgens, Scott's experiments on. + + Lochaber, Parallel Roads of (see also Glen Roy). + -evidence of ice-action. + + Lochs, Laggan (Loggan), ice-action in. + -Roy, Darwin disbelieves in existence of. + -Spey, shelves of. + -Treig, ice-action in. + -Milne's account of. + + Locust grass, germination of. + + Locusts, blown out to sea. + -plants from dung of. + + Logwood, leaf-movement of. + -See Haematoxylon. + + Loiseleuria procumbens. + + London clay, supposed germination of seeds from. + + "London Review," Darwin's opinion of. + -correspondence between Owen and editor in reference to "Origin." + + Longchamps, L. de, on crossing in Gramineae. + + Longevity, Darwin on animals' and man's. + + Lonsdale, William (1794-1871): obtained a commission in the 4th Regiment + at the age of sixteen, and served at Salamanca and Waterloo. From 1829 + to 1842 he held the office of Assistant-Secretary and Curator of the + Geological Society. Mr. Lonsdale contributed important papers on the + Devonian System, the Oolitic Rocks, and on palaeontological subjects. + ("Quart. Journ. Geol. Soc." Volume XXVIII., page xxxv., 1872.) + -mentioned. + + Lopezia, fertilisation of. + + Lophura viellottii, colour of. + + Loss, nature of. + + Love, evidence of existence low in scale. + + Loven, S.L.: published numerous papers on Cirripedes and other + zoological subjects in the Stockholm "Ofversigt" and elsewhere between + 1838 and 1882. + -translation of paper on Cirripedes. + -mentioned. + + Lowe, R.T., on Madeira. + + Lowell, Prof., on custom in Italy of shaking head in affirmation. + + Lowland plants, ascending mountains. + + Lowne, B.T., on anatomy of blowfly. + + Lowness and highness. + + Lubbock, Lady. + + Lubbock, Sir J., see Lord Avebury. + + Lucas, Dr. P., on tendency to vary independent of conditions. + + Ludwig, F., letter to. + + Lumbricus (see also Earthworms). + + Luminosity in animals. + -result of external conditions. + + Lupinus, Darwin's experiments on. + + Luzula. + + Lychnis dioica, structure of flower. + -sets seed without pollen. + + Lycopodium, variation in. + + Lyell, Sir Charles, Bart., F.R.S. (1797-1875): was born at Kinnordy, the + family home in central Forfarshire. At the age of seventeen he entered + at Exeter College, Oxford, and afterwards obtained a second class in the + final Honours School in Classics. As an undergraduate Lyell attended + Prof. Buckland's lectures on Geology. On leaving Oxford Lyell was + entered at Lincoln's Inn; a weakness of the eyes soon compelled him to + give up reading, and he travelled abroad, finding many opportunities for + field work. He was called to the Bar in 1825, and in the same year + published some papers on geological subjects. From 1823-26 Lyell filled + the post of Secretary to the Geological Society, and in 1826 was elected + into the Royal Society. In 1830 the first volume of the "Principles of + Geology" was published; the second volume appeared two years later. + Speaking of this greatest of Lyell's services to Geology, Huxley writes: + "I have recently read afresh the first edition of the "Principles of + Geology," and when I consider that this remarkable book had been nearly + thirty years in everybody's hands [in 1859], and that it brings home to + any reader of ordinary intelligence a great principle and a great fact-- + the principle that the past must be explained by the present, unless + good cause be shown to the contrary; and the fact that, so far as our + knowledge of the past history of life on our globe goes, no such cause + can be shown--I cannot but believe that Lyell, for others, as for + myself, was the chief agent in smoothing the road for Darwin" (Huxley's + "Life and Letters," Volume II., page 190). As Professor of Geology in + King's College, London, Lyell delivered two courses of lectures in 1832- + 33; in the latter year he received a Royal medal, and in 1858 he was the + recipient of the Copley medal of the Royal Society. The "Elements of + Geology" was published in 1833; this work is still used as a text-book, + a new edition having been lately (1896) brought out by Prof. Judd; in + 1845 and in 1849 appeared the "Travels in North America" and "A Second + Visit to the United States of North America." The "Antiquity of Man" + was published in 1863. Lyell was knighted in 1848, and in 1864 was + raised to the rank of a Baronet. He was buried in Westminster Abbey. + Darwin wrote in his Autobiography: "The Science of Geology is enormously + indebted to Lyell, more so, as I believe, than to any other man who ever + lived" ("Life and Letters," Volume I., page 72). In a letter to Lyell-- + November 23rd, 1859--Darwin wrote: "I rejoice profoundly that you intend + admitting the doctrine of modification in your new edition [a new edition + of the "Manual" published in 1865]; nothing, I am convinced, could be more + important for its success. I honour you most sincerely. To have + maintained, in the position of a master, one side of a question for thirty + years, and then deliberately give it up, is a fact to which I much doubt + whether the records of science offer a parallel" ("Life and Letters," + Volume II., pages 229-30). See "Life, Letters, and Journals of Sir Charles + Lyell, Bart." edited by his sister-in-law, Mrs. Lyell, 2 Volumes, London, + 1881. "Charles Lyell and Modern Geology," Prof. T.G. Bonney, London, + 1895.) + -"Antiquity of Man." + -on Barrande. + -cautious attitude towards "Origin of Species." + -cautious judgment of. + -on Cetacea. + -Copley medal awarded to. + -on continental extension. + -controversy with Owen. + -Darwin's pleasure in reading his "Geology." + -on distribution. + -Falconer and. + -German opinion of. + -on immutability. + -interest in celts. + -letters to. + -letters to Darwin from. + -map of Tertiary geography by. + -on mutability. + -on pangenesis. + -"Principles of Geology." + -on Ramsay's theory of lakes. + -urges Darwin to publish his views with those of Wallace. + -visits Down. + -work in France. + -address to Geological Society. + -attacked by Owen in his "Anatomy of Vertebrata." + -criticism of Murchison. + -on craters of denudation. + -Darwin's indebtedness to. + -death of. + -death of his father. + -gives up opposition to Evolution. + -on glaciers of Forfarshire. + -on glacial period in S. hemisphere. + -versus Herschel on volcanic islands. + -on iceberg action. + -memorial in Westminster Abbey. + -on Parallel Roads of Glen Roy. + -as founder of school of Geology. + -second visit to the United States. + -trip to Wales. + -mentioned. + + Lyell, Lady, letter to. + -translation of paper for Darwin. + -visits Down. + -mentioned. + + Lynch, R.I. + + Lythraceae, dimorphism in. + + Lythrum, cross-fertilisation of. + -Darwin's work on. + -trimorphism of. + -L. hyssopifolium, range of. + -L. salicaria, dimorphism of. + -Darwin's work on. + + Macacas, Owen on. + -M. Silenus, mane as a protection. + + Macalister, Prof. A. + + Macarthur, Sir W., on Erythrina. + + Macaw, beauty of plumage. + + McClennan, on primitive man. + + MacCulloch, on Glen Turret. + -on metamorphic rocks. + -on Parallel Roads of Glen Roy. + + M'Donnell, Darwin on work of. + + Macgillivray, reference to his "History of British Birds." + + Machetes pugnax, polygamy of. + + Mackintosh, Daniel (1815-91): was well-known in the South of England as a + lecturer on scientific subjects. He contributed several papers to the + Geological Society on Surface Sculpture, Denudation, Drift Deposits, etc. + In 1869 he published a work "On the Scenery of England and Wales" (see + "Geol. Mag." 1891, page 432. + -on boulders of Ashley Heath. + -letters to. + -on Moel Tryfan. + -on sources of erratic blocks in England. + + McNab, Prof., J. Scott and. + -mentioned. + + Macrauchenia, skull of. + + Madagascar, existence of insects capable of fertilising Angraecum in. + -fossil Hippopotamus of. + -Owen on fauna of. + -plants of. + -former extension of. + -as a geographical region. + -Viola of. + + Madeira, birds of. + -British plants compared with those of. + -Canary Islands formerly connected with. + -flora of. + -insects of. + -land-extension, of. + -land-shells of. + -Lowe on. + -Tertiary plants of. + -elevation of. + + Maer, the home of the Wedgwoods. + + Magellan Straits, H.M.S. "Beagle" in. + + Magnus, review by Krause of his work on colour. + + Magpies, pairing of. + + Mahon, Lord, compliment to Darwin. + + Mahonia, natural crossing of. + + Maillet, evolutionary views of. + + Maize, hybrids of, see also Zea. + + Malaxeae, and Epidendreae. + + Malaxis, course of vessels in flower. + -fertilisation of. + + Malaxis paludosa, epiphytic on Sphagnum. + + Malay archipelago, Darwin on Wallace's book on. + -translation by Meyer of Wallace's book. + + Malay region, glacial epoch and the. + -Wallace on butterflies and pigeons of. + + Malpighiaceae, degraded flowers of. + -Erythroxylon included in. + + Malta, Forbes on geology of. + + Malthus, Darwin derives help from reading. + -Haughton sneers at. + -misunderstood. + + Malva. + + Mammae, as rudimentary organs in man. + + Mammals, alteration in skulls of. + -Australian cave-. + -birds compared with. + -Dana's classification. + -distribution. + -as indices of climatic changes. + -as proof of union between England and Continent since Glacial period. + -Waterhouse's "Natural History" of. + -Glacial period and extinction of. + -Origin and migration. + + Mammoth (Bog). + + Mammoth, Darwin's eagerness to collect bones of. + -Falconer on the. + + Man, antiquity of (see "Antiquity of Man," and Lyell, Sir C.). + -and apes. + -brain of. + -criticism of Lyell's chapter on. + -Huxley's book on. + -McClennan on primitive. + -and Natural Selection. + -origin of. + -races of. + -selection by Nature contrasted with selection by. + -slow progress of. + -Darwin on Wallace's paper on. + -descent of. + -ears of. + -geological age of. + -and geological classification. + -hairyness of. + -introduction of. + -rank in classification. + -Turner on evolution of. + -Wallace on evolution of. + + Mankind, descent from single pair. + -early history of. + -progress of. + + Mantell, Owen's attack on. + + "Manual of Scientific Inquiry," Darwin's. + + Manx cats. + + Maranta, sleep-movements of. + + Marble, MacCulloch on metamorphism of. + + Marianne Islands, subsidence of. + -want of knowledge of flora. + + Marion, "L'evolution du Regne vegetal," by Saporta and. + + Marlatt, C.L., on Cicada. + + Marquesas Islands, subsidence of. + + Marr, J.E., on the rocks of Bohemia. + -mentioned. + + Marriage, Darwin on. + -Galton's proposal to issue health-certificates for. + + Marshall, W., on Elodea. + + Marsupialia, compared with placentata. + -Darwin on nature of. + -evidence of antiquity. + -abundance in Secondary period. + + Martens, see Martins. + + Martha (=Posoqueria), F. Muller's paper on. + + Martin, H.N., Darwin's opinion of "Elementary Biology" by Huxley and. + + Martins, experiments on immersion of seeds in sea by. + + Maruta cotula of N. America. + + Masdevallia, Darwin's work on. + + Massart, on regeneration after injury. + + Masters, M., letters to. + -lecture at Royal Institution. + -"Vegetable Teratology." + + Mastodon, Australian. + -extinction of. + -Falconer on. + -in Timor. + -migration into S. America. + -skeleton found by Darwin. + -M. andium, Falconer on intermediate character of. + + "Materialism of the Present day," Janet's. + + Matteucci on electric fishes. + + Matthew, P., on forest trees in Scotland. + -quoted by Darwin as having enunciated principle of Natural Selection + before "Origin." + + Maurienne, note on earthquake in province of. + + Mauritius, craters of. + -elevation of. + -extinction of snakes of. + -oceanic character of. + + Maury's map, as illustrating continental extension. + + Maxillaria. + + Maypu River, Darwin visits. + + Mays, J.A., publishes lectures by Huxley. + + Medals: + -(Copley), Darwin, Lyell. + -(Royal). + -(Wollaston), Darwin. + + Medical Department of Army, statistics from Director-General of. + + Meditation, expression of eyes in. + + Mediterranean Islands, flora of. + + Medusae, Romanes' work on. + + Meehan, T., letter to. + + Megalonyx. + + Megatherium, Darwin collects bones of. + -Sir A. Carlisle on. + + Melastoma, Darwin on. + + Melastomaceae, Darwin on. + -crossing in. + -two kinds of stamens in. + + Meldola, Prof. Raphael F.R.S.: Professor of Chemistry in Finsbury + Technical College (City and Guilds of London Institute), and a well- + known entomologist; translated and edited Weismann's "Studies in the + Theory of Descent," 1882-83. + -address to Entomological Society. + -letters to. + -translation of Weismann's "Studies in Descent" by. + -on Weismann and Darwin. + -mentioned. + + Melipona. + + Meloe, Lord Avebury on. + + Melrose, seeds from sandpit near. + + Memorial to the Chancellor of the Exchequer. + + Mendel, G., W. Bateson on his "Principles of Heredity." + -Darwin ignorant of work of. + -Laxton and. + + Mendoza, Darwin visits. + + "Mental Evolution in Animals," Romanes'. + + Mentha, of N. America. + -M. borealis, variety in N. America. + + Menura superba, colour and nests of. + + Menzies and Cumming, visit Galapagos Islands. + + Mercurialis. + + Mertensia, Darwin's experiments on. + + Mesembryanthemum. + + Mesotherium, Falconer on. + + Metamorphic schists. + + Metamorphism, Darwin on. + -heat and. + -Sorby on. + + Metamorphosis, Lord Avebury on insects and. + -F. Muller on. + -Quatrefages on. + + Meteorites, Lord Kelvin suggests their agency in introduction of plants. + + "Methods of Study," Agassiz' book on. + + Mexicans, explanation of natural affinities of Chinese and. + + Meyen, on insectivorous plants. + + Meyer, Dr., translator of Wallace's "Malay Archipelago." + + Meyer and Doege, on plants of Cape of Good Hope. + + Mica, in foliated rocks. + + Mica-slate, clay-slate and. + + Mice, ears of. + -experiments by Tait on. + + Microscope, Darwin on convenient form of. + -indispensable in work on flowers. + -use of compound without simple, injurious to progress of Natural + History. + + Migration of animals and plants. + -Darwin on plant-. + -of elephants. + -Glacial period and. + -of plants. + -in tropics. + -of birds. + + Mikania, a leaf-climber. + -M. scandens, gradation between Mutisia and. + + Mill, J.S., on Darwin's reasoning. + -on greatest happiness principle. + + Miller, Hugh, "First Impressions of England and its People." + + Miller, S.H., "Fenland Past and Present" by Skertchley and. + + Miller, Prof. William Hallowes, F.R.S. (1801-80), held the Chair of + Mineralogy at Cambridge from 1832 to 1880 (see "Obituary Notices of + Fellows," "Proc. R. Soc." Volume XXXI., 1881). He is referred to in the + "Origin of Species" (Edition VI., page 221) as having verified Darwin's + statement as to the structure of the comb made by Melipona domestica, a + Mexican species of bee. The cells of Melipona occupy an intermediate + position between the perfect cells of the hive-bee and the much simpler + ones of the humble-bee; the comb consists "of cylindrical cells in which + the young are hatched, and, in addition, some large cells of wax for + holding honey. These latter cells are nearly spherical and of nearly equal + sizes, and are aggregated into an irregular mass. But the important point + to notice is that these cells are always made at that degree of nearness to + each other that they would have intersected or broken into each other if + the spheres had been completed; but this is never permitted, the bees + building perfectly flat walls of wax between the spheres which thus tend to + intersect." It occurred to Darwin that certain changes in the architecture + of the Melipona comb would produce a structure "as perfect as the comb of + the hive-bee." He made a calculation, therefore, to show how this + structural improvement might be effected, and submitted the statement to + Professor Miller. By a slight modification of the instincts possessed by + Melipona domestica, this bee would be able to build with as much + mathematical accuracy as the hive-bee; and by such modifications of + instincts Darwin believed that "the hive-bee has acquired, through natural + selection, her inimitable architectural powers" (loc. cit., page 222). + -letters to. + + Million years, Darwin on meaning of a. + + Milne-Edwards, Darwin's cirripede work and. + -Darwin's opinion of. + -on retrograde development. + + Milne-Home, David (1805-90): was a country gentleman in Berwickshire who + became interested in geology at an early age. He wrote on the Midlothian + Coal-field, the Geology of Roxburghshire, the Parallel Roads of Glen Roy, + and compiled the Reports presented by a Committee appointed by the Royal + Society of Edinburgh to investigate the observation and registration of + boulders in Scotland ("Quart. Journ. Geol. Soc." Volume XLVII., 1891; + "Proc." page 59). + -believes in connection between state of weather and earthquakes. + -on Glen Roy. + -letters to. + -letter from R. Chambers to. + -on oscillation of sea. + + Milton, quotation from. + + Mimicry, Bates on. + -and dimorphism. + -Volucella as an example of. + -Wallace on. + -and colour. + -F. Muller on Lepidoptera and. + + Mimosa, Darwin's experiments on. + -M. albida, Darwin on. + -M. sensitiva. + + Mimoseae, F. Muller's account of seeds of. + + Mimulus, Pfeffer on movement of stigma. + + Mind, development of. + -evolution of. + -influence on nutrition. + + Miocene land. + + Miquel, F.A.W., on Flora of Holland. + -on distribution of the beech. + -on flora of Japan. + -mentioned. + + Mirabilis. + + Mirbel, G.F.B. de. + + Miscellaneous letters, botanical. + -geological. + + Miscellaneous subjects, letters on. + + Mississippi, Lyell on pampas and deposits of the. + + Mitchella. + + Mivart, St. George F.R.S. (1827-1900): was educated at Harrow, King's + College, London, and St. Mary's College, Oscott. He was called to the Bar + in 1851; in 1862 he was appointed Lecturer in the Medical School of St. + Mary's Hospital. In the "Genesis of Species," published in 1871, Mivart + expressed his belief in the guiding action of Divine power as a factor in + Evolution. + -false reasoning of. + -"Genesis of Species." + + Modification, Darwin's disbelief in sudden. + -explanation of. + -of insects. + -of jays and crows. + -of land and freshwater faunas. + -selection and. + -of species. + -Walsh on specific. + + Moel Tryfan, Darwin on shells on. + -Mackintosh on shells on. + + Moggridge, J. Traherne (1842-74): is described by a writer in "Nature" + Volume XI., 1874, page 114, as "one of our most promising young + naturalists." He published a work on "Harvesting Ants and Trap-door + Spiders," London, 1873, and wrote on the Flora of Mentone and on other + subjects. (See "The Descent of Man" Volume I., Edition II., page 104, + 1888.) + -letters to. + -note on. + -experiments on ants and seeds. + + Mohl, von, on climbing plants. + + Mojsisovics, E. von: Vice-Director of the Imperial Geological Institute, + Vienna. + -letters to. + -work on Palaeontology and Evolution. + + Molecular movement in foliated rocks. + + Moller, "Brasilische Pilzblumen." + + Molliard, on Les Cecidies florales. + + Mollusca, distribution by birds. + -Huxley on. + -means of dispersal of. + -Morse on protective colours of. + -Wallace on distribution of. + + Molothrus, occurrence in Brazil. + + Monacanthus viridis, female form of Catasetum tridentatum. + + Monkeys, distribution of birds affected by. + -range of. + -ears of. + -mane as protection. + -wrinkling of eyes during screaming. + + Monochaetum (Monochoetum), absence of nectar in. + -experiments on. + -flowers of. + -neglected by bees. + -seeds of. + -M. ensiferum, two kinds of stamens. + + Monocotyledons, range of. + -heterostylism in. + + Monotremes, birds compared with. + -as remnant of ancient fauna. + + Monotropa uniflora, in New Granada. + -in Himalayas. + -in separate areas in U.S.A. + + Monotypic genera, variation of. + + Monstrosities, Harvey on. + -Masters' work on. + -no sharp distinction between slight variations and. + -origin of species from. + -variations and. + + Monte Video, Darwin visits. + -Darwin on cleavage at. + + Moon, effect on earthquakes. + + Moraines, glacial. + + Moral sense, J. Morley on Darwin's treatment of. + + Morality, foundation of. + + More, Alexander Goodman (1830-95): botanist and zoologist, distinguished + chiefly by his researches on the distribution of Irish plants and animals. + He was born in London, and was educated at Rugby and Trinity College, + Cambridge. He became Assistant in the Natural History Museum at Dublin in + 1867, and Curator in 1881. He was forced by ill-health to resign his post + in 1887, and died in 1895. He is best known for the Cybele Hibernica and + for various papers published in the "Ibis." He was also the author of + "Outlines of the Natural History of the Isle of Wight," of a "Supplement to + the Flora Vectensis," and innumerable shorter papers. His "Life and + Letters" has been edited by Mr. C.B. Moffat, with a preface by Miss Frances + More (1898). There is a good obituary notice by Mr. R. Barrington in the + "Irish Naturalist," May, 1895. + -letters to. + + Morgan. + + Morley, J., letters to. + + Mormodes, labellum of. + -M. ignea, flower of. + + Morphological, Hooker's criticism of term. + -sense in which used by Nageli. + + Morphology, Darwin's explanation of. + -Kollmann on batrachian. + -of plants. + + Morse, Prof. E.S.: of Salem, Mass. + -letters to. + -on shell-mounds of Omori. + + Morton, Lord, his mare. + + Moscow, opinion on Darwin's work from. + + Moseley, Canon H., on glacier-motion. + + Moseley, Prof. Henry Nottidge F.R.S. (1844-91): was an undergraduate of + Exeter College, Oxford, and afterwards studied medicine at University + College, London. In 1872 he was appointed one of the naturalists on the + scientific staff of the "Challenger," and in 1881 succeeded his friend and + teacher, Professor Rolleston, as Linacre Professor of Human and Comparative + Anatomy at Oxford. Moseley's "Notes by a Naturalist on the Challenger," + London, 1879, was held in high estimation by Darwin, to whom it was + dedicated. (See "Life and Letters," III., pages 237-38.) + -letter to. + -proposal to examine Kerguelen Coal beds. + + Moss-rose, sudden variation in. + + Mostyn, Lord, horse and quagga belonging to. + + Moths, hermaphroditism in hybrid. + -survival of distinct races. + -colours of. + -and Sexual Selection. + + Mould, Darwin's opinion of his paper on. + + Mountain-building, Rogers on. + + Mountain-chains, Darwin on. + -and earthquakes. + -and elevation. + -false views of geologists on. + -Hopkins on. + -volcanic rocks in. + + Movement, of land-areas. + -of plants, Darwin on. + -F. Muller on. + -Wiesner on Darwin's book on. + + Mucus of seeds, significance of. + + Mukkul, Pass of. + + Mules, meaning of stripes of. + -J.J. Weir's observations on. + + Muller, Ferd., on advance of European plants in Australia. + + Muller, (Fritz) Dr. Johann Friedrich Theodor (1822-97): was born in + Thuringia, and left his native country at the age of thirty to take up his + residence at Blumenau, Sta Catharina, South Brazil, where he was appointed + teacher of mathematics at the Gymnasium of Desterro. He afterwards held a + natural history post, from which he was dismissed by the Brazilian + Government in 1891 on the ground of his refusal to take up his residence at + Rio de Janeiro ("Nature," December 17th, 1891, page 156). Muller published + a large number of papers on zoological and botanical subjects, and rendered + admirable service to the cause of evolution by his unrivalled powers of + observation and by the publication of a work entitled "Fur Darwin" (1865), + which was translated by Dallas under the title "Facts and Arguments for + Darwin" (London, 1869). The long series of letters between Darwin and + Muller bear testimony to the friendship and esteem which Darwin felt for + his co-worker in Brazil. In a letter to Dr. Hermann Muller (March 29th, + 1867), Mr. Darwin wrote: "I sent you a few days ago a paper on climbing + plants by your brother, and I then knew for the first time that Fritz + Muller was your brother. I feel the greatest respect for him as one of the + most able naturalists living, and he has aided me in many ways with + extraordinary kindness." See "Life and Letters," III., page 37; "Nature," + October 7th, 1897, Volume LVI., page 546. + -book by. + -convert to Darwin's views. + -Darwin's opinion of his book. + -friendship with Darwin. + -Hooker on. + -letters to. + -on Lord Morton's mare. + -on mutual specialisation of insects and plants. + -on prawns. + -reference to letter from. + -on sponges. + -on Cassia and caterpillars in S. Brazil. + -on climbing plants. + -on crossing plants. + -Darwin offers to make good loss by flood. + -Darwin's admiration of. + -on Darwin's work on lepidoptera. + -Darwin urges him to write Natural History book. + -explanation of two kinds of stamens in flowers. + -on fertilisation mechanisms. + -letter to Darwin from. + -narrow escape from flood. + -article in "Kosmos" on Phyllanthus. + -on Melastomaceae. + -on orchids. + -on stripes and spots in animals. + -on Termites. + -disinclined to publish. + -mentioned. + + Muller, Hermann (1829-83): began his education in the village school of + Muhlberg, and afterwards studied in Halle and Berlin. From an early age he + was a keen naturalist, and began his scientific work as a collector in the + field. In 1855 he became Science teacher at Lippstadt, where he continued + to work during the last twenty-eight years of his life. Muller's greatest + contribution to Botany "Die Befruchtung der Blumen durch Insekten," was the + outcome to Charles Darwin's book on the "Fertilisation of Orchids." He was + a frequent contributor to "Kosmos" on subjects bearing on the origin of + species, the laws of variation, and kindred problems; like his brother, + Fritz, Hermann Muller was a zealous supporter of evolutionary views, and + contributed in no small degree to the spread of the new teaching. ("Prof. + Dr. Hermann Muller von Lippstadt: Ein Gedenkblatt," by Ernst Krause, + "Kosmos," Volume VII., page 393, 1883.) + -extract from letter to. + -Darwin's admiration for his book. + -on fertilisation of flowers. + -on clover and bees. + -on Epipactis and Platanthera. + -extract from Darwin's preface to his "Befruchtung der Blumen." + -letters to. + -on Melastoma. + -persecuted by Ultramontane party. + -review in "Kosmos" of "Forms of Flowers." + -mentioned. + + Muller, Prof. Max, "Lectures on the Science of Language." + -letter to. + + Muller, Rosa, observations on circumnutation. + + Mummy wheat. + + Mundane cold period, Darwin on supposed. + + Mundane genera, distribution of. + + Munro, Col., on Bermuda. + + Munro, on eyes of parrots. + + Murchison, Sir R.I., apotheosis of. + -Darwin's conversations with. + -letter to. + -address to Geological Society. + -on structure of Alps. + -Lyell's criticism of. + + Murder, expression of man arrested for. + + Murdoch, G.B., letter to. + + Murray, A., address to Botanical Society of Edinburgh. + -criticism of Wallace's theory of nests. + -Darwin criticised by. + -Darwin's criticism of work of. + -on geological distribution of mammals. + -on leaves and CO2. + -review of "Origin" by. + -mentioned. + + Murray, Sir J., Darwin on his theory of coral reefs. + + Murray, J., Darwin's agreement with. + -"Journal of Researches" published by. + -MS. of "Origin" sent to. + -sale of "Origin." + -publication of "Fur Darwin." + + Mus, range of. + + Musca vomitoria, Lowne on. + + Muscles, contraction in evacuation and in labour pains. + -in man and apes. + + Museum (British), enquiry as to disposal of Natural History Collections + by Trustees of. + + Music, birds and production of. + -insects, and. + -origin of taste for. + + Musk-duck, hatching of eggs. + + Musk-orchids, pollinia of. + + Musk ox, as index of climate. + -found in gravel at Down. + + Mussels, seize hold of fishing hooks. + + Mutability of species, Lyell on. + + Mutation, use of term. + + Mutisia, a tendril-climber, compared with Mikania. + + Myanthus barbatus, hermaphrodite form of Catasetum tridentatum. + + Mylodon. + + Myosotis, in N. America. + + Myosurus, range of. + + Mytilus, as fossil in the Andes. + + Nageli, Carl Wilhelm von (1817-91): was born at Kilchberg, near Zurich. He + graduated at Zurich with a dissertation on the Swiss species of Cirsium. + At Jena he came under the influence of Schleiden, who taught him + microscopic work. He married in 1845, and on his wedding journey in + England, collected seaweeds for "Die neueren Algen-systeme." He was called + as Professor to Freiburg im Breisgau in 1852; and to Munich in 1857, where + he remained until his death on May 10th, 1891. In the "Zeitschrift fur + wiss. Botanik," 1844-46, edited by Nageli and Schleiden, and of which only + a single volume appeared, Nageli insists on the only sound basis for + classification being "development as a whole." The "Entstehung und + Begriff" (1865) was his first real evolutionary paper. He believed in a + tendency of organisms to vary towards perfection. His idea was that the + causes of variability are internal to the organism: see his work, "Ueber + den Einfluss ausserer Verhaltnisse auf die Varietatenbildung. Among his + other writings are the "Theorie der Bastardbildung," 1866, and "Die + Mechanisch-physiologische Theorie der Abstammungslehre," 1884. The chief + idea of the latter book is the existence of Idioplasm, a part of protoplasm + serving for hereditary transmission. (From Dr. D.H. Scott's article in + "Nature," October 15th, 1891, page 580.) + -Darwin on his work. + -Essay on Natural Selection. + -on Hieracium. + -"Ueber Entstehung und Begriff der naturhistoriscehn Art." + -Weismann on work of. + -on arrangement of leaves. + -criticism of Darwin. + -on innate principle of development. + -on physiological nature of useful adaptations in plants. + + Napier, Rt. Hon. J.R., speech at British Association (1861) on Darwin's + work. + + Naravelia. + + Narborough, Sir J., description of W. coast of S. America by. + + Nascent organs, rudimentary and. + -wing of Apteryx as. + + Natural classification. + + "Natural Conditions of Existence," Semper's. + + Natural History, Darwin's taste for. + -Darwin's contributions to. + -accuracy the soul of. + -Darwin urges F. Muller to write book on. + + Natural History Collections, enquiry as to disposal by British Museum + Trustees of. + + "Natural History Review," Lord Avebury on Walsh's paper on dimorphism. + -Bentham in the. + -Darwin's opinion of. + -Darwin reviews Bates in. + -Falconer in the. + -founding of. + -Huxley and. + + "Natural Inheritance," Galton's. + + Natural preservation, as substitute for Natural Selection. + + "Natural Science," A.S. Woodward on Neomylodon in. + + Natural Selection, accumulation of varieties by. + -and adaptation in orchids. + -Allen on slowness of action. + -Angraecum in relation to. + -Ansted on. + -applied to politics. + -and artificial. + -Bates' belief in. + -Bronn on. + -comparison with architecture. + -with force and matter. + -with laws of gravity. + -conservative influence of. + -Cope's and Hyatt's views on. + -Darwin accused of making too much of a Deus of. + -Darwin's anxiety not to overestimate effect of. + -Darwin lays stress on importance of. + -Darwin on use of term. + -deification of. + -and direct action. + -Eocene or Secondary organisms would be beaten in competition with + recent on theory of. + -and external conditions. + -Falconer on. + -and fertility. + -Asa Gray on. + -Harvey misunderstands Darwin's meaning. + -Haughton partially admits. + -Hooker thinks Darwin probably rides too hard his hobby of. + -Hooker on supposed falling off in belief in. + -Hooker and Bates believe in. + -Huxley's belief in. + -Huxley gives in a lecture inadequate idea of. + -Hyatt and Cope on. + -importance of. + -Lamont on. + -Lyell on. + -and monstrosities. + -Nageli's Essay on. + -no limit to perfection of co-adaptations produced by. + -non-acceptance of. + -objections to. + -"plants are splendid for making one believe in." + -possibility of race of bears being rendered aquatic through. + -with the principle of divergence the keystone of "Origin." + -production of thorns through. + -tends to progression of organisation. + -providential arrangement and superfluity of. + -struggle between reversion, variability and. + -Scott on. + -slowness of action. + -and sterility. + -success of. + -tails of mice a difficulty as regards. + -Sir W. Thomson's misconception of. + -uses of. + -value of. + -and variation. + -variation of species sufficient for selection and accumulation of new + specific characters by. + -and useful characters. + -Wallace on. + -Watson on. + -applied to man and brutes. + -Australian savages and. + -beauty and. + -Darwin on action of. + -Darwin's historical sketch in "Origin" of. + -difficulties of. + -Donders nearly preceded Darwin in views on. + -evolution of man from point of view of. + -Owen's attitude towards. + -primogeniture destructive of. + -Sexual Selection less powerful than. + -Wallace attributes theory entirely to Darwin. + -Wallace on brain and. + + Naturalisation, of European plants. + -of plants in India. + -of plants in islands. + + Naturalised plants, Bentham on. + -comparison of variability of indigenous and. + -De Candolle on. + -variability of. + -fewness of American species of, in Britain. + + "Naturalist in Nicaragua," Belt's. + -Belt's account of honey-glands of plants in. + + "Naturalist on the Amazons," Bates'. + -Darwin's opinion of. + + Naturalists, views on species held by. + -few care for philosophical experiments + + Nature, Wallace on personification of. + -use of term. + + "Nature not lying," principle of. + + "Nature," Darwin's opinion of. + -letters or notes from Darwin in. + -Galton in. + -F. Muller in. + -Thiselton-Dyer in. + + Naudin, C., on hybridism. + -on Melastomaceae. + + Nauplius stages. + + Nautilus, of Silurian age. + + Necrophorus, Darwin's observations on. + + Nectar, in leguminous flowers. + -Lord Farrer on secretion of, in Coronilla. + + Nectaries, Belt on extra-floral. + + Nectarines and peaches. + -Rivers on production from seed. + -variation in. + + Negative geological evidence, Darwin and Lyell on. + + Negro, resemblance between expression of Cebus and. + + Nelumbium, as example of transport. + + Neottia nidus-avis, fertilisation mechanism. + -pollen-tubes of. + + Nepenthes, Hooker's work on. + -Thiselton-Dyer on. + + Neptunia. + + Nervous system, genesis of. + -influence on nutrition. + + Nests, Wallace's theory, of. + -colour in relation to. + -instinct in making. + + Neumann, on Catasetum. + + Neumayr, Melchior (1845-90): passed his early life at Stuttgart, and + entered the University of Munich in 1863 with the object of studying law, + but he soon gave up legal studies for Geology and Palaeontology. In 1873 + he was recalled from Heidelberg, where he held a post as Privatdocent, to + occupy the newly created Chair of Palaeontology in Vienna. Dr. Neumayr was + a successful and popular writer, as well as "one of the best and most + scientific palaeontologists"; he was an enthusiastic supporter of Darwin's + views, and he devoted himself "to tracing through the life of former times + the same law of evolution as Darwin inferred from that of the existing + world." (See Obit. Notice, by Dr. W.T. Blanford, "Quart. Journ. Geol. + Soc." Volume XLVI., page 54, 1890.) + -essay on descent theory. + -services to geology. + -"Die Stamme des Thierreichs." + + Nevill, Lady Dorothy. + + New Zealand, absence of leguminosae opposed to continental extension of. + -British plants in. + -clover never seeded before introduction of bees. + -comparison between flora of Tasmania and. + -elevation of mountains in. + -flora of. + -flora of Australia and. + -Flora of Raoul Island and. + -Hooker on flora of. + -Darwin's opinion of Hooker's "Flora." + -former connection of islands. + -former extension of. + -naturalised plants. + -peopling of mountains by plants. + -proportion of annuals. + -species of plants common to America, Chili and. + -stocked from Antarctic land. + -colonising of. + -glacial action in. + -mountain-rat of. + -trees of. + + Newton, Prof. A., note on Strickland by. + -description of partridge as agent in dispersal of seeds. + + Newton's law of gravity. + + Niagara, Darwin on Lyell's work on. + + Nightingale, Gould on the. + + Noises, observations on children's. + + Nolana prostrata, Darwin's experiments on. + + Nomenclature, discussion on. + + "North British Review," Fleeming Jenkin's review in. + -Tait in. + + Norton, Professor Charles Elliot: of Harvard, the son of the late Dr. + Andrews Norton, Professor of Theology in the Harvard Divinity School. + -visits Down. + + Norway, Von Buch's travels in. + -Blytt on flora of. + + Norwich, Berkeley's address at British Association (1868) meeting at. + -Hooker's address. + + Nottingham, British Association meeting (1866) at. + -Hooker's lecture on insular floras at. + + Notylia, F. Muller on. + + Nucula, a persistent type. + + Nuneham, Darwin's recollection of trip to. + + Nutrition, influence of mind on. + + Nyctitropic movements, see Sleep-movements. + + Observation, spirit of astronomers in. + -harder work than generalisation. + -pleasure of. + + Observations, not to be trusted without repetition. + + Observer, a good theoriser makes a good. + + Oceanic islands, difference in floras and means of stocking. + -connection between continents and. + -former extension of. + -Reade on. + -volcanic nature of. + + Oceans, age and depth of. + -permanence of. + -as sinking areas. + + Ogle, W., on the sense of smell. + -letter to. + -translation of book by Kerner. + + Ogleby, reference to his nomenclature scheme. + + Oken, on Lepas. + -Owen on. + + Old characters, reappearance of. + + Oldenburgia. + + Oldenlandia. + + Olfers. + + Oliver, D., Darwin indebted to for information. + -letters to. + -mentioned. + + Olyra, sleep-movements of. + + Omori, Morse on shell-mounds of. + + Oncidium, J. Scott's work on. + -structure of labellum. + -O. flexuosum, observations by Muller and Scott on. + -self-sterility of. + -O. sphacelatum, Scott on fertilisation of. + + Ophrys. + -O. apifera, fertilisation-mechanism. + -self-fertilisation of. + -O. arachnites, fertilisation of. + -habitat. + -O. aranifera. + -O. morio, fertilisation of. + -O. muscifera, Lord Farrer's observations on. + -O. scolopax. + + Opossums. + + Oppel, service to geology. + -mentioned. + + Opuntia, Henslow describes new species from Galapagos. + + Orang-utang, Rolleston on brain of. + -Wallace on. + + Orange trees, grafting of. + + d'Orbigny, on geology of S. America. + -theory of formation of Pampas mud. + -"Voyage dans l'Amerique meridionale. + -mentioned. + + Orchids, adaptation in. + -Darwin's work on. + -Darwin's view that seedlings are parasitic on Cryptogams. + -Falconer's estimate of Darwin's work on. + -few species in humid temperate regions. + -flourish in cool temperate regions. + -illustrate diversity of means to same end. + -monstrous. + -quoted as argument against species arising from monstrosities. + -utility and. + -fertilisation mechanisms of. + -Brazilian. + -Darwin decides to publish his work in book-form. + -Darwin sends copy of his book to F. Muller. + -Darwin underrates power of producing seeds without insects. + -French translation of Darwin's book. + -germinative power of pollen. + -Hildebrand's paper on. + -Nectar not excreted in some English. + -and nectar secretion. + -formation of ovule after pollination. + -Scott points out error in Darwin's work. + -Scott on pollen-tubes of. + -Scott on self-sterility. + -self-fertilisation in. + -setting of seed in unopened flower. + -sterility of. + -course of vessels in flowers. + -wonderful contrivances intelligible. + + Orchis, flowers of. + -nectaries of. + -pollinia of. + + Orchis (Bee) (see also Ophrys apifera), Darwin's experiments on. + -O. pyramidalis, fertilisation mechanism. + -O. ustulata. + + Order of Nature. + + Ordination. + + Organ mountains, Darwin on plants of. + -glacial action on. + + Organisms, simultaneous change in. + -amount of change in fresh water and marine. + + Organs, transition of + -use of. + + "Origin of the Fittest," Cope's. + + "Origin of Genera," Cope's work on. + + Origin of life. + + "Origin of Species," acceptance of doctrine of Evolution due to the. + -Darwin's belief in the permanence of the framework of the. + -Darwin's opinion of his book. + -Dawson's review of. + -direct action underestimated in the. + -editions of the. + -errors in. + -Falconer's estimate of. + -Huxley's Cambridge speech, and reference to the. + -Huxley's lecture on coming of age of. + -Huxley's review of. + -Lesquereux's articles in "Silliman" against the. + -publication of the Abstract of. + -publication by Murray of. + -sale of the. + -Seemann on the. + -translation of. + -Wallace's criticism of. + -Walsh on the. + -Darwin on necessity for modifications in the. + -review by Fleeming Jenkin. + -review by A. Murray. + -Owen's criticism of Darwin's Historical Sketch in 4th edition of. + -Owen's review of. + -study of natural history revolutionised by the. + -valueless criticism on. + + Origin of species, Darwin's early views on. + -Darwin's views on. + -Falconer antagonistic to Darwin's views on. + -Oxford discussion (British Association, 1860) on the. + -spread of Darwin's views in America. + + Origin of species and genera, Wallace in the "Nineteenth Century" on. + + Original work, time taken up by, at expense of reading. + + Ormerod's Index to the Geological Society's Journal. + + Ornithorhynchus, aberrant nature of. + -preservation of. + + Orthoptera, auditory organs of. + + Oscillariae, abundance in the ocean. + + Oscillataria. + + Oscillation of land, Darwin's views on. + + Os coccyx, as rudimentary organ. + + Ostrea. + + Ostrich, modification of wings. + + Outliers, plants as. + + "Outlines of Cosmic Philosophy," Fiske's. + + Ovary, abnormal structure in orchid. + + Owen, Sir Richard (1804-92): was born at Lancaster, and educated at the + local Grammar School, where one of his schoolfellows was William Whewell, + afterwards Master of Trinity. He was subsequently apprenticed to a surgeon + and apothecary, and became deeply interested in the study of anatomy. He + continued his medical training in Edinburgh and at St. Bartholomew's + Hospital in London. In 1827 Owen became assistant to William Clift (whose + daughter Owen married in 1835), Conservator to the Hunterian Museum of the + Royal College of Surgeons. It was here that he became acquainted with + Cuvier, at whose invitation he visited Paris, and attended his lectures and + those of Geoffroy St. Hilaire. The publication, in 1832, of the "Memoir on + the Pearly Nautilus" placed the author "in the front rank of anatomical + monographers." On Clift's retirement, Owen became sole Conservator to the + Hunterian Museum, and was made first Hunterian Professor of Comparative + Anatomy and Physiology at the Royal College of Surgeons. In 1856 he + accepted the post of Superintendent of the Natural History department of + the British Museum, and shortly after his appointment he strongly urged the + establishment of a National Museum of Natural History, a project which was + eventually carried into effect in 1875. In 1884 he was gazetted K.C.B. + Owen was a strong opponent of Darwin's views, and contributed a bitter and + anonymous article on the "Origin of Species" to the "Edinburgh Review" of + 1860. The position of Owen in the history of anatomical science has been + dealt with by Huxley in an essay incorporated in the "Life of Richard + Owen," by his grandson, the Rev. Richard Owen (2 volumes, London, 1894). + Huxley pays a high tribute to Owen's industry and ability: "During more + than half a century Owen's industry remained unabated; and whether we + consider the quality or the quantity of the work done, or the wide range of + his labours, I doubt if, in the long annals of anatomy, more is to be + placed to the credit of any single worker." The record of his work is + "enough, and more than enough, to justify the high place in the scientific + world which Owen so long occupied. If I mistake not, the historian of + comparative anatomy and palaeontology will always assign to Owen a place + next to, and hardly lower than, that of Cuvier, who was practically the + creator of those sciences in their modern shape, and whose works must + always remain models of excellence in their kind." On the other hand, + Owen's contributions to philosophical anatomy are on a much lower plane; + hardly any of his speculations in this field have stood the test of + investigation: "...I am not sure that any one but the historian of + anatomical science is ever likely to recur to them, and considering Owen's + great capacity, extensive learning, and tireless industry, that seems a + singular result of years of strenuous labour." + -address at Leeds (British Association, 1858) by. + -admission of descent of species. + -articles by. + -on a badger of Pliocene age. + -on the brain. + -Mrs. Carlyle's impression of. + -and Hooker. + -conduct towards Huxley. + -Darwin abused by. + -on Darwin and Maillet. + -and Darwinism. + -on ephemeral influence of the "Origin." + -Falconer and. + -Huxley on. + -on Huxley's election to the Athenaeum. + -ignores Darwin's work. + -influence of. + -isolation among scientific men. + -lecture on birds by. + -letters to. + -letter to the "Athenaeum." + -"Life of." + -on lowness of animals. + -on Macacus. + -on mammals of Old World. + -on morphology of vertebrata. + -review in the "Quarterly" of the "Origin." + -"Palaeontology" by. + -on parthenogenesis. + -review in the "Edinburgh Review" by. + -on simple and multiple organs. + -on use and disuse. + -and Bishop Wilberforce's review. + -visits Down. + -attack on Darwin in his "Anatomy of Vertebrata." + -attitude towards Natural Selection. + -mentioned. + + Owls and hawks, as agents in seed-dispersal. + + Oxalis, bulbils of. + -cleistogamic flowers of. + -dimorphism of. + -pollen-tubes of. + -seeds of. + -trimorphism of. + -O. acetosella, sensitive leaves of. + -variation in length of pistil and stamens. + -O. sensitiva, Darwin's work on. + -O. corniculata, variation of. + + Oxford, meeting of the British Association at (1847). + -Tuckwell's reminiscences of. + + Oxlips, Darwin's experiment on cowslips, primroses, and. + -Darwin on hybrid character of. + -scarcity of. + + Oxyspora paniculata, Wallich on. + + Pachira, inequality of cotyledons. + -P. aquatica. + + Pacific Ocean, Darwin wishes Hooker to investigate floras of. + -islands of the. + -coral reefs of. + + Packard's "Lamarck the Founder of Evolution." + + Paget, Sir J., on regeneration. + -address on elemental pathology. + -illness of. + -on influence of mind on nutrition. + -"Lectures on Surgical Pathology." + -letters to. + -mentioned. + + Pairing, in birds. + -vigour of birds and effect on time of. + + Palaeolithic flints, in gravels near Southampton. + + Palaeontology, rapid progress of. + + Palaeozoic period. + + Paley, idea of interference of Creator in construction of each species + due to. + + "Pall Mall," article on "Dr. Hooker on Religion and Science" in. + -letter to editor of. + + Pallas, Darwin's conviction of truth of doctrine of. + -doctrine of. + -on hybrids and fertility. + + Palm, Malayan climbing. + + Palm, L.H., work on climbing plants by. + + Palma, crater of. + + Pampas, geology of the. + -formation of. + -Lyell on Mississippi beds and. + -D'Orbigny's theory of formation of. + -thistle of the. + + Pangenesis, adverse opinion on. + -Bentham on. + -Berkeley on. + -bud-propagation and. + -Darwin on. + -Darwin's suggestion as to term. + -difference between Galton's theory of heredity and. + -evidence from hybridisation in favour of. + -Hooker on. + -Huxley's views on. + -Jager on. + -Lyell on. + -and molecular hypothesis of Hackel. + -Ranyard on. + -Romanes on. + -self-fertilisation and. + -Wallace on. + -the idea a relief to Darwin as connecting facts. + -F. Muller and. + -bearing on regeneration. + -"will turn out true some day." + -mentioned. + + Panmixia. + + Panniculus carnosus in man. + + Papilio Memnon, Wallace on. + -P. nireus, Mrs. Barber on. + -P. pammon, Wallace on. + + Papilionaceaous flowers, absence in New Zealand. + -and hermaphroditism. + + Papilionidae, Wallace on Malayan. + + Paraheliotropism, Muller's observations on. + -in Phyllanthus. + + Parallel Roads of Glen Roy (see Glen Roy). + + Parana, Darwin finds Mastodon at. + + Pararge, breeding in confinement. + + Parasites, and degeneration. + -extermination of game by. + -bloom as protection against. + -and galls. + + Parietaria, explosive stamens of. + + Parrots, as agents in seed-dispersal. + + Parsimony, Hamilton's law of. + + Parthenogenesis, Darwin on. + -Owen's Hunterian lecture on. + -in Primula. + -J. Scott's work on. + + Partridges, as agents of seed-dispersal. + -rudimentary spurs on legs of. + + Parus caeruleus, protective colouring of. + + Passiflora, bloom experiments on. + -Lord Farrer's work on. + -position of flowers of. + -Muller assists Lord Farrer in work on. + -Scott's work on. + -self-sterility of. + -Sprengel on. + -visited by humming-birds. + -P. gracilis, dispersal of seeds. + -P. princeps, adapted to humming birds. + + Patagonia, L. Agassiz on elevation of. + -Darwin on geology of. + -gigantic land-sloth of. + -Admiral Sulivan on. + + Pathology, Paget's lectures on. + + Pattison, Mark. + + Pavo nigripennis. + + Payne, on effect of rain on plants. + -observations by. + + Peaches, bud-variation in. + -raised from seed. + + Peacock, evolution and Sexual Selection of. + -experiments on cutting tail of male. + -muscles of tail of. + + Pearson, H.H.W., on the botany of Ceylon patanas. + + Peas, course of vessels in ovary of sweet-. + -crossing in. + -fertilisation of. + -waxy secretion in. + + Pecten, P. latissimus. + + Pelargonium, peloric. + -Beaton on. + -Darwin's experiments on. + -flowers of. + -P. multiflora alba, Darwin's experiments on crossing. + + Pelobius, Darwin on. + + Peloria, effect of pollen on regular flowers. + -Darwin suggests experiments on. + -Masters on. + -in Pelargonium. + -inheritance of. + + Peneus, F. Muller on. + + Pentateuch, N. Lewy on. + + Periodicals, Darwin's opinion of scientific. + -foreign compared with English. + + Peripatus, Moseley's work on. + + Peristylus viridis, Lord Farrer's observations on. + + Permanence of ocean basins. + + Permian period, glacial action during. + -freshwater beds in India. + + "Personal Narrative," Humboldt's. + + Peru, anarchy in. + -Darwin on terraces in. + -D. Forbes on geology of. + + Peuquenes Pass, Darwin visits. + + Pfeffer, Prof., on chemotaxis. + -considers Wiesner wrong in some of his interpretations. + -on Drosera. + -"Periodische Bewegungen." + + Pfitzer, on classification of orchids. + + Pfluger. + + Phalaenopsis. + + Phanerogams, comparison with one class of animals rather than with one + kingdom. + + Phaseoli, crossing in. + + Phaseolus vulgaris, sleep-movements of. + + Pheasants, display of colour by golden. + -Hewitt on hybrids of. + -hybrids between fowls and. + -protective colouring. + + Phillips, J., defines species. + -evolutionary views. + -"Life on the Earth." + -mentioned. + + Phillips-Jodrell, T.T., founder of Jodrell Laboratory at Kew. + + Philosophical Club. + + Philosophical experiments, few naturalists care for. + + Philosophising, means and laws of. + + Phlox, Darwin's observations on flowers of. + -heterostylism of. + -P. Drummondii. + -P. subulata. + + Phyllanthus, F. Muller's paper in "Kosmos" on. + -sleep-movements of. + -P. Niruri, sleep-movements of. + + Phryma, de Candolle on. + -occurrence in N. America. + + Phyllotaxis, Darwin and Falconer on. + + Physical conditions, effect of. + + "Physical Geography," Herschel's. + + Physicists, disagree as to rate of cooling of earth's crust. + + "Physiological Aesthetics," Grant Allen's. + + Physiological germs. + + Physiological selection, Romanes'. + + Physiological species, Huxley's term. + + Physiological units, Herbert Spencer's. + + Physiological variations. + + "Physiology," Huxley's "Elementary Lessons in." + -Darwin on difficulty of. + -Darwin's want of knowledge of. + -Darwin's work on plant-. + -England behind in vegetable. + -small knowledge of ordinary doctors of. + -and vivisection. + + Phytophagic varieties, Walsh on. + + Phytophthora, potatoes and. + + "Pickwick," quotation from. + + Pictet, on the succession of forms. + -mentioned. + + Pictet and Humbert, on fossil fishes of Lebanon. + + Pieris, breeding in confinement. + -colour the result of mimicry. + -protective colouring. + -P. napi. + -Weismann on. + + Pigeons, breeding of. + -drawings of. + -experiments on crossing. + -experiments bearing on direct action. + -production of varieties. + -reduction of wings. + -and sterility. + -Tegetmeier's work on. + -Wallace on Malayan. + -Darwin's work on. + -experiments in painting. + -Flourens' experiments on. + -gay deceiver. + -pairing for whole life. + (Barbs.) + (Carriers.) + (Fantails.) + (Laugher.) + (Pouters.) + (Rock.) + (Runts.) + (Tumblers.) + + Pigs, crossing of. + + "Pikermi," Gaudry's "Animaux fossiles de." + + Pinguicula, Darwin's observations on. + + Pistyll Rhiadr. + + Pisum, cross-fertilisation of. + -P. sativum, visited by Bombus. + + Pithecoid man, Huxley's term. + + Pithecus, Owen on Homo and. + + Placentata. + + Plagiaulax, Falconer on. + + Planaria. + + Planorbis, Hyatt on genesis of species of. + -P. multiformis, graduated forms of. + + Plantago, Ludwig's observations on. + -Darwin on. + + Plants, change in animals compared with change in. + -comparison between high and low as regards resistance to injurious + conditions. + -contractility of. + -difference between animals and. + -distribution of. + -fossil. + -of Madeira. + -morphological characters. + -resemblance to animals. + -Saporta's work on fossil. + -small proportion preserved as fossils. + -splendid for helping belief in Natural Selection. + -thorns in. + -wide range as compared with animals. + -Darwin's interest in movements of. + -Darwin on physiology of. + -disease in. + -effect of stimuli on. + + Plas Edwards. + + Plasmodiophora, action on cruciferous roots. + + Platanthera, H. Muller on. + + Plato, comparison between plants and man in his "Timaeus." + + Platysma myoides, contraction during terror. + -Darwin's error concerning. + + Playfair, Lord. + + Pleistocene Antarctic land, plants derived from. + + Pliocene, Falconer on mammal from the. + + Plovers, protective colouring of. + + Plumage, immature and adult. + + Plumbago, Darwin's experiments on. + -said to be dimorphic. + + Podostemaceae, fertilisation of. + + Poisons, natives of Australia injured by vegetable. + -absorption by roots of. + -effect of injection into plants. + + Polar bear, modification of. + + Polar ice-cap, Darwin on the. + + Polarity, E. Forbes' theory of. + + Pollen, direct action of. + -experiments on. + -time of maturity in Eucalyptus and Mimosa. + -mechanism for distribution in Martha. + -Miyoshi's experiments on tubes of. + + Polyanthus, crossing in. + + Polyborus Novae Zelandiae, in Falkland Islands. + + Polydactylism, and inheritance. + + Polyembryony, in Coffea and Pachira. + + Polygala. + -P. vulgaris, variation of. + + Polygamy, in birds. + -in Machetes. + + Polygonum, germination of seeds found in sandpit. + + Polymorphism, Darwin and Hooker on. + -Wallace on. + + Polytypic genera, variation of. + + Pontederia, heterostylism of. + + Pontodrilus, Lankester on. + + Poplar, Heer on fossil species. + + Popper, J., letter to. + + Poppig, on civilisation and savagery. + + Poppy (corn-), indigenous in Sicily. + + Porpoises, Flower on. + -freshwater. + -Murray on. + + Portillo Pass. + + Porto-Santo, land-snails of. + -plants of. + + Positivism, Huxley's article in "Fortnightly Review" on. + + Posoqueria, F. Muller's paper on. + + Potatoes, crossing experiments. + -cultivated and wild. + -disease of. + -experiments suggested. + -graft-hybrids. + -sterility and variability in. + -Torbitt's experiments on. + -Traill's experiments. + -varieties of. + -Darwin's work on varieties of. + -Hildebrand's experiments on. + + Poulton, Prof., on Prichard as an evolutionist. + -"Charles Darwin and the Theory of Natural Selection." + + Poultry, skulls of. + -Tegetmeier's book on. + -experiments on colour and sexual selection. + + Powell, Prof. Baden. + + "Power of Movement in Plants," Darwin's account of capacity of revolving + in plants, in his book. + -Continental opinion of. + -Wiesner's criticism of. + + Prawns, F. Muller on metamorphosis of. + + Prayer, Galton's article on. + + Pre-Cambrian rocks, Hicks on. + + Predominant forms. + + "Prehistoric Europe," J. Geikie's. + + "Prehistoric Times," Lord Avebury's. + + Preordination, speculation as to. + + Prepotency of pollen. + + Prescott, reference to work by. + + Preservation, suggested as an alternative term for Natural Selection. + + Pressure, effect on liquefaction by heat. + + Preston, S. Tolver, letter to. + + Prestwich, Prof. J., letter to. + -on Parallel Roads of Glen Roy. + -on superficial deposits of S. England. + -work on Tertiaries. + -mentioned. + + Prevost, C., as candidate for Royal Society Foreign List. + -mentioned. + + Price, J., extract from letter from Darwin to. + + Prichard, James Cowles (1786-1848): He came on both sides from Quaker + families, but, according to the "Encyclopaedia Britannica," he + ultimately joined the Church of England. He was a M.D. of Edinburgh, + and by diploma of Oxford. He was for a year at Trinity College, + Cambridge, and afterwards at St. John's and New College, Oxford, but did + not graduate at either University. He practised medicine, and was + Physician to the Infirmary at Bristol. Three years before his death he + was made a Commissioner in Lunacy. He not only wrote much on Ethnology, + but also made sound contributions to the science of language and on + medical subjects. His treatise on insanity was remarkable for his + advanced views on "moral insanity." + -on immutability. + -quotations from his "Physical History of Mankind." + + Priestley, "Green matter" of. + -Huxley's essay on. + + Primogeniture, antagonistic to Natural Selection. + + Primrose (see also Primula), Darwin's experiments on cowslip and. + -dimorphism of. + -J. Scott on. + + Primula, Darwin's work on. + -difficulty of experimenting with. + -dimorphism of. + -dimorphism lost by variation. + -entrance of pollen-tubes at chalaza. + -varying fertility of. + -fertilisation of. + -homomorphic unions and. + -ovules of. + -J. Scott's work on. + -stamens of. + -P. elatior. + -P. longiflora, non-dimorphism of. + -Treviranus on. + -P. mollis. + -P. scotica. + -P. sinensis. + -fertility of. + -legitimate and illegitimate unions. + -movement of cotyledons. + + Principle of divergence. + + "Principles of Biology," Spencer's. + + "Principles of Geology," Lyell's. + -Darwin on. + -Wallace's review of. + + Pringlea antiscorbutica (Kerguelen cabbage). + + Priority, Falconer and Owen on. + + Proboscidean group, extinction of. + + Progress, in forms of life and organisation. + + Progression, tendency in organisms towards. + + Progressive development. + + Pronuba, the Yucca moth, Riley on. + + Proteaceae, former extension of. + + Protean genera, list of N. American. + + Protection, colour in butterflies and. + -thorns as. + -Wallace on. + -colour and. + -colour of birds and. + -colour of caterpillars and. + -colour of shells and. + -Darwin's views on Sexual Selection and. + -evolution of colour and. + -mimicry and. + -monkeys' manes as. + -Wallace on colour and. + -Wallace on wings of lepidoptera and. + + Protective resemblance, Wallace on. + + Proterogyny, in Plantago. + + Prothero, G.W. + + Protococcus. + + Protozoa. + + Providential arrangement. + + Prunus laurocerasus, extra-floral nectaries visited by ants. + + Psithyrus. + + Psychology, Delboeuf on. + -Romanes' work on comparative. + + Ptarmigan, protective colouring of. + + Pterophorus periscelidactylus. + + Publishing, over-readiness of most men in. + + Pumilio argyrolepis, Darwin on seeds of. + + Purbeck, Plagiaulax from the. + + Purpose, Darwin on use of term. + + Pyrola, fertilisation mechanism in. + + Quagga, hybrid between horse and. + + Quails, seed-dispersal by migratory. + + "Quarterly Journal of Science," article on Darwin and his teaching in. + -review by Wallace of the Duke of Argyll's "Reign of Law." + + "Quarterly Review," Mivart's article. + -Bishop Wilberforce's review of "Origin" in. + -article on zebras, horses, and hybrids. + + Quartz, segregation in foliated rocks. + + Quatrefages, Jean Louis Armand de, de Breau (1810-92): was a scion of an + ancient family originally settled at Breau, in the Cevennes. His work was + largely anthropological, and in his writings and lectures he always + combated evolutionary ideas. Nevertheless he had a strong personal respect + for Darwin, and was active in obtaining his election at the Institut. For + details of his life and work see "A la Memoire de J.L.A. de Quatrefages de + Breau," 4o, Paris (privately printed); also "L'Anthropologie," III., 1892, + page 2. + -letters to. + -translation of paper by. + -on proportion of sexes in Bombyx. + + Quenstedt, work on the Lias by. + + Queries on expression. + + Rabbits, Angora, skeletons of. + -Darwin's work on. + + Race, nature's regard for. + + Racehorse, selection by man. + -Wallace on fleetness of. + -equality of sexes in. + + Races of man. + -causes of difference in. + -Wallace on. + + Rafflesia, parasites allied to. + + Rain, effect on leaves. + -movements of leaves as means of shooting off. + + Ramsay, Sir A.C., on origin of lakes. + -Geological Society hesitates to publish his paper on Lakes. + -on ice-action. + -on insects in tropics. + -memoir by Geikie of. + -on denudation and earth-movements. + -overestimates subaerial denudation. + -on Parallel Roads of Glen Roy. + -on Permian glaciers. + -proposal that he should investigate glacial deposits in S. America. + -mentioned. + + Range, De Candolle on large families and their. + -coleoptera and restricted. + -of genera. + -of shells. + -size of genera in relation to species and their. + -of species. + + Ranunculaceae, evidence of highness in. + + Ranunculus auricomus. + + Ranyard, A.C., letter to "Nature" on pangenesis. + + Raoul Island, Hooker on. + + Raphael's Madonna, referred to by Darwin. + + Raspberry, germination of seeds from a barrow. + -waxy secretion of. + + Rattlesnake, Wright on uses of rattle of. + + Raven, said to pair for whole life. + + Ray Society, work of. + + Raymond, Du Bois, work on plants. + + Reade, T.M., letters to. + -on age of the world. + + "Reader," sold to the Anthropological Society. + + Reading, Darwin complains of lack of time for. + -little time given by scientific workers to. + + Reciprocal crosses, half-sterility of. + + Rede Lecture, by Phillips (1860). + + Reduction, cessation of selection as cause of. + -organs of flight and. + -wings of ostrich and. + + References, Darwin on importance of giving. + -Wallace on. + + Regeneration, power of. + -reference in "Variation of Animals and Plants" to. + + "Reign of Law," the Duke of Argyll's. + -reviewed by Wallace. + + Reindeer, of Spitzbergen. + -horns of. + + Religion and science. + + Representative species. + -in floras of Japan and N. America. + -in Galapagos Islands. + + Reproduction, difference in amount of energy expended by male and female + in. + + Reproductive organs, St.-Hilaire's view of affaiblissement and + development of. + -in relation to theoretical questions. + + Research, Huxley and. + -justification of. + + Reseda lutea, sterile with own pollen. + -R. odorata, experiment on cross-and self-fertilisation. + + Resemblance, mimetic. + + Resignation, expression in. + + Restiaceae, former extension of. + + Restricted distribution. + + Retardation, Cope on. + + Retrogression. + + Reversion, in ammonites. + -Darwin on. + -and degeneration of characters. + -factors causing. + -hybridism and. + -Lord Morton's mare and. + -stripes of mules due to. + -struggle between Natural Selection and. + -and crossing. + -peloria and. + + Review of the "Descent of Man," by J. Morley. + + Reviews, Darwin on an author writing his own. + -on the "Origin of Species," by Asa Gray. + -Haughton. + -Hopkins. + -Hutton. + -Huxley. + -F. Jenkin. + -Owen. + -Wilberforce. + + Rhamnus. + + Rhexia, flowers of. + -R. virginica, W.H. Leggett on anthers. + + Rhinoceros. + + Rhinochetus. + + Rhizocephala, retrograde development in. + + Rhododendron Boothii. + + Rhopalocera, breeding in confinement. + + Rhynchoea, colour of. + + Rich, Anthony (1804?-1891): Educated at Caius College, Cambridge, of + which he was afterwards an Honorary Fellow. Author of "Illustrated + Companion to the Latin Dictionary and Greek Lexicon," 1849, said to be a + useful book on classical antiquities. Mr. Darwin made his acquaintance + in a curious way--namely, by Mr. Rich writing to inform him that he + intended to leave him his fortune, in token of his admiration for his + work. Mr. Rich was the survivor, but left his property to Mr. Darwin's + children, with the exception of his house at Worthing, bequeathed to Mr. + Huxley. + -legacy to Huxley. + -letter to. + -leaves his fortune to Darwin. + + Rich, Mrs., mentioned. + + Richardson, R., on tablet to commemorate Darwin's lodgings at 11, + Lothian Street, Edinburgh. + + Richardson, Darwin on merits of. + + Rigaud, on formation of coal. + + Riley, Charles Valentine (1843-95): was born in England: at the age of + seventeen he ran away from home and settled in Illinois, where at first + he supported himself as a labourer; but he soon took to science, and his + first contributions to Entomology appeared in 1863. He became + entomological editor of the "Prairie Farmer" (Chicago), and came under + the influence of B.D. Walsh. In 1868 Riley became State Entomologist of + Missouri, and in 1878 Entomologist to the U.S. Department of + Agriculture, a post he resigned in 1894 owing to ill-health; his death + was the result of a bicycle accident. (Taken principally from the + "Proceedings of the Entomological Society of Washington," Volume III., + 1893-6, page 293.) + -letters to. + -mentioned. + + Rio Janeiro, absence of erratic boulders near. + -Agassiz on drift-formation near. + + Rio Negro. + + Rio Plata. + + Ritchie, Mrs., visit to Down. + + Rivers, The late Mr. Thomas: of Sawbridgeworth, was an eminent + horticulturist and writer on horticulture. + -letters to. + + Robin, attracted by colour of Triphaena (Triphoea). + + Robinia, insect visitors of. + + Rocks, bending when heated. + -condition in interior of earth. + -fluidity of. + -metamorphism of (see also Metamorphism). + + Rocky Mountains, wingless insects of the. + + Rogers, W.B. and H.D., on cleavage. + -on coalfields of N. America. + -on parallelism of axis-planes of elevation and cleavage. + + Rolleston, George (1829-81): obtained a first-class in Classics at + Oxford in 1850; he was elected Fellow of Pembroke College in 1851, and + in the same year he entered St. Bartholomew's Hospital. Towards the + close of the Crimean War, Rolleston was appointed one of the Physicians + to the British civil hospital at Smyrna. In 1860 he was elected the + first Linacre Professor of Anatomy and Physiology, a post which he held + until his death. "He was perhaps the last of a school of English + natural historians or biologists in the widest sense of the term." In + 1862 he gave the results of his work on the classification of brains in + a lecture delivered at the Royal Institution, and in 1870 published his + best known book, "Forms of Animal Life (Dict. Nat. Biography). + -address in "Nature" by. + -on the orang-utang. + -adhesion to Darwin's views. + -letter to. + -letter to Darwin from. + -mentioned. + + Rollisson. + + Roman villa at Abinger. + + Romanes, G.J. (1848-94): was one of Mr. Darwin's most devoted disciples. + The letters published in Mrs. Romanes' interesting "Life and Letters" of + her husband (1896) make clear the warm feelings of regard and respect + which Darwin entertained for his correspondent. + -Darwin on controversy between Duke of Argyll and. + -on graft-hybrids. + -letters to. + -letter to Darwin from. + -letter to "Nature" in reply to the Duke of Argyll. + -on physiological selection. + -review of Roux's book. + -on heliotropism. + -lecture on animal intelligence by. + -lecture on evolution of nerves. + -letter to "Times" from. + -"Life and Letters" of. + -on minds of animals. + + Roots, heliotropism of. + -sensitive tip of. + + Roses, N. American species. + -bud-variation. + -raising from seed. + -resemblance of seedling moss-rose to Scotch. + -varieties of. + + Ross, Sir J. + + Rosse, Lord. + + Round Island, fauna and flora of. + + Roux's "Struggle of Parts in the Organism." + + Royal Commission on Vivisection. + + Royal Institution, lectures at. + + Royal medals. + + Royal Society, council meeting of. + + Royer, Mdlle., translatress of the "Origin." + + Royle, John Forbes (1800-58): was originally a surgeon in the H.E.I.C. + Medical Service, and was for some years Curator at Saharunpur. From 1837- + 56 he was Professor of Materia Medica at King's College, London. He wrote + principally on economic and Indian botany. One of his chief works was + "Illustrations of the Botany and other branches of the Natural History of + the Himalayan Mountains and of the Flora of Cashmere." (London, 1839.) + -letters to. + -mentioned. + + Rubiaceae, dimorphism in. + -fertilisation in. + + Rubus, N. American species. + -variation in. + -F. Darwin on roots of. + + Rubus and Hieracium, comparison of variability of N. American and + European species. + + Rucker. + + Rudimentary organs. + -in frogs. + -nascent and. + -variation of. + -in man. + -use in classification. + + Rudinger, Dr., on regeneration. + + Rue, flowers of. + + Ruffs, polygamy of. + + Rumex, germination of old seeds. + + Russia, forms of wheat cultivated in. + + Rutaceae, A. St.-Hilaire on difference in ovary of same plants of. + + Sabine, General Sir E. Sabine (1788-1883): President of the Royal + Society 1861-71. (See "Life and Letters," III., page 28.) + -address to Royal Society. + -award of Copley medal to Darwin during presidency of. + -recognition by Government. + -mentioned. + + Sabrina, elevation of. + + Sagitta. + + St. Dabeoc's heath, in Azores. + + St. Helena, Darwin suggests possibility of finding lost plants in earth + from. + -extinction in. + -Hooker on flora of. + -land-birds of. + -plants of. + -trees of. + -Darwin on craters of. + -geology of. + -subsidence in. + -White on hemiptera of. + + St.-Hilaire, A.F.C.P. de, on affaiblissement. + -erect and suspended ovules in same ovary. + -"Lecons de Botanique." + -Life of. + + St.-Hilaire, J.G., on monstrosities. + -author of "Life of A.F.C.P. de St.-Hilaire." + + St. Jago, Darwin on craters of. + -elevation of. + + St. Paul's rocks, plants of. + -geological structure. + + Saintpaulia, dimorphic flowers. + + St. Ventanao, conglomerates of. + + Salicaceae. + + Salicornia, bloom on. + + Salix, varieties of. + + Salsola Kali, bloom on. + + Salt water, effect on plants. + + Salter, on vitality of seeds after immersion in the sea. + + Saltus, Darwin's views on. + + Salvages, flora of the. + + Salvia, Hildebrand's paper on. + + Samara, Russian wheat sent to Darwin from. + + Samoyedes, power of finding their way in fog. + + Sandberger, controversy with Hilgendorf. + + Sanderson, Sir J.B., electrical experiments on plants. + -letters to. + -on vivisection. + + Sandwich Islands, absence of Alpine floras. + -flora of. + -Geranium of. + -Dana on valleys and craters. + -Galapagos and. + + Sanicula, occurrence of species in Azores. + -range of. + + Santa Cruz. + + Santorin, crater of. + -linear vent in. + -Lyell's account of. + + Saporta, Marquis de, (1823-95): devoted himself to the study of fossil + plants, and by his untiring energy and broad scientific treatment of the + subject he will always rank as one of the pioneers of Vegetable + Palaeontology. In addition to many important monographs on Tertiary and + Jurassic floras, he published several books and papers in which Darwin's + views are applied to the investigation of the records of plant-life + furnished by rocks of all ages. ("Le Marquis G. de Saporta, sa Vie et + ses Travaux," by R. Zeiller. "Bull. Soc. Geol. France," Volume XXIV., + page 197, 1896.) + -letters to. + -on rapid development of higher plants. + + Sargassum, Forbes on. + + Sarracenia. + + Savages, civilisation of. + -comparison between animals and. + -decrease of. + -Selection among. + + Saxifrages, destruction in Ireland of Spanish. + -formation of hairs in. + + Saxonika, form of Russian wheat. + + Scaevola, fertilisation mechanism of. + -S. microcarpa, fertilisation mechanism of. + + Scalesia. + + Scandinavia, Hooker on potency of flora. + -Blytt on distribution of plants of. + -elevation of. + + Scarlet fever, Darwin's dread of. + + "Scenery of Scotland," Sir A. Geikie's. + + Scepticism, Darwin on. + + Schimper, review by Hooker of "Paleontologie Vegetale" by. + + Schlagintweit. + + Schleiden, convert to Darwin's views. + + Schmankewitsch, experiments on Artemia by. + + Schobl, J., on ears of mice. + + Schoenherr, C.J. + + Schomburgk, Sir R., on Catasetum, Monacanthus, and Myanthus. + + School, Darwin at Mr. Case's. + -of Mines. + + Schrankia, a sensitive species of. + + Schultze, Max. + + Science, and superstition. + -progresses at railroad speed. + + Science Defence Association, Darwin asked to be president of. + + Scientific men, attributes of. + -domestic ties and work of. + -article in "Reader" on. + + Scientific periodicals, Darwin's opinion of. + + Scotland, forest trees of. + -comparison between flora of T. del Fuego and that of. + -elevation of. + -frequency of earthquakes in. + -land-glaciation of. + -tails of diluvium in. + + "Scotsman," Forbes' lecture published in. + -Darwin's letter on the Parallel Roads of Glen Roy in the. + + Scott, D.H., obituary notice of Nageli by. + + Scott, John (1838-80): Short obituary notices of Scott appeared in the + "Journal of Botany," 1880, page 224, and in the "Transactions of the Bot. + Soc. of Edinburgh" Volume XIV., November 11th, 1880, page 160; but the + materials for a biographical sketch are unfortunately scanty. He was the + son of a farmer, and was born at Denholm (the birthplace the poet Leiden, + to whom a monument has been erected in the public square of the village), + in Roxburghshire. At four years of age he was left an orphan, and was + brought up in his aunt's household. + He early showed a love of plants, and this was encouraged by his cousin, + the Rev. James Duncan. Scott told Darwin that he chose a gardening life as + the best way of following science; and this is the more remarkable inasmuch + as he was apprenticed at fourteen years of age. He afterwards (apparently + in 1859) entered the Royal Botanic Garden at Edinburgh, and became head of + the propagating department under Mr. McNab. His earliest publication, as + far as we are aware, is a paper on Fern-spores, read before the Bot. Soc., + Edinburgh, on June 12th, 1862. In the same year he was at work on orchids, + and this led to his connection with Darwin, to whom he wrote in November + 1862. In 1864 he got an appointment at the Calcutta Botanic Garden, a + position he owed to Sir J.D. Hooker, who was doubtless influenced by + Darwin's high opinion of Scott. It was on his way to India that Scott had, + we believe, his only personal interview with Darwin. + We are indebted to Sir George King for the interesting notes given below, + which enable us to form an estimate of Scott's personality. He was + evidently of a proud and sensitive nature, and that his manner was pleasing + and dignified appears from Darwin's brief mention of the interview. He + must have been almost morbidly modest, for Darwin wrote to Hooker (January + 24th, 1864): "Remember my URGENT wish to be able to send the poor fellow a + word of praise from any one. I have had hard work to get him to allow me + to send the [Primula] paper to the Linn. Soc., even after it was written + out!" And this was after the obviously genuine appreciation of the paper + given in Darwin's letters. Sir George King writes:-- + "He had taught himself a little Latin and a good deal of French, and he had + read a good deal of English literature. He was certainly one of the most + remarkable self-taught men I ever met, and I often regret that I did not + see more of him...Scott's manner was shy and modest almost to being + apologetic; and the condition of nervous tension in which he seemed to live + was indicated by frequent nervous gestures with his hands and by the + restless twisting of his long beard in which he continuously indulged. He + was grave and reserved; but when he became interested in any matter he + talked freely, although always deliberately, and he was always ready to + deafen his opinions with much spirit. He had, moreover, a considerable + sense of humour. What struck me most about Scott was the great acuteness + of his powers of observing natural phenomena, and especially of such as had + any bearing on variation, natural selection or hybridity. While most + attentive to the ordinary duties of the chief of a large garden, Scott + always continued to find leisure for private study, and especially for the + conduct of experiments in hybridization. For the latter his position in + the Calcutta garden afforded him many facilities. + After obtaining a post in the Calcutta Botanic Gardens, Scott continued to + work and to correspond with Darwin, but his work was hardly on a level with + the promise of his earlier years. According to the "Journal of Botany," he + was attacked by an affection of the spleen at Darjeeling, where he had been + sent to report on the coffee disease. He returned to Edinburgh in the + spring of 1880, and died in the June of that year. + At the time of his death many experiments were in hand, but his records of + these were too imperfect to admit of their being taken up and continued + after his death. In temper Scott was most gentle and loveable, and to his + friends he was loyal almost to a fault. He was quite without ambition to + 'get on' in the world; he had no low or mean motives; and than John Scott, + Natural Science probably had no more earnest and single-minded devotee." + -correspondence with. + -criticism on the "Origin" by. + -letters to. + -on Natural Selection. + -on a red cowslip. + -confirms Darwin's work, also points out error. + -Darwin assists financially. + -Darwin's opinion of. + -Darwin offers to present books to. + -Darwin writes to Hooker about Indian appointment for. + -Darwin's proposal that he should work at Down as his assistant. + -Darwin suggests that he should work at Kew. + -on dispersal of seed of Adenanthera by parrots. + -on fertilisation of Acropera. + -a good observer and experimentalist. + -a lover of Natural History. + -observations on acclimatisation of seeds. + -on Oncidium flexuosum. + -letter to Darwin from. + -offered associateship of Linnean Society. + -on Imatophyllum. + -on self-sterility in Passiflora. + -on Primula. + -on sexes in Zea. + -mentioned. + + Scrope, P., on volcanic rocks. + + Scrophularineae. + + Scudder, on fossil insects. + + Sea, Dana underestimates power of. + -changes in level of land due to those of. + -marks left on land by action of. + + Seakale, bloom on. + + Seashore plants, use of bloom on. + + Sea-sickness, Darwin suffers from. + + "Seasons with the Sea Horses," Lamont's. + + Secondary period, abundance of Araucarias and Marsupials during. + -equality of elevation in British rocks of. + -insects prior to. + + Sections of earth's crust, need for accurate. + + Sedgwick, Prof. A., extract from letter to Owen from. + -letter to Darwin from. + -on the "Vestiges of Creation." + -and the Philosophical Society's meeting at Cambridge. + -and the "Spectator." + -Darwin's visit to. + -Feelings towards Darwin. + -on the structure of large mineral masses. + -proposes Forbes for Royal medal. + -quotation from letter to Darwin from. + -suggested as candidate for Royal medal. + -mentioned. + + Sedgwick, A., address at the British Association (1899). + + Sedimentary strata, conversion into schists. + + Sedimentation, connection with elevation and subsidence. + -near coast-lines. + + Seedlings, sensitiveness to light. + + Seeds, collected by girls in Prof. Henslow's parish. + -dispersal of. + -effect of immersion on. + -of furze. + -Asa Gray on Darwin's salt-water experiments. + -germination after 21 1/2 hours in owl's stomach. + -moss-roses raised from. + -peaches from. + -variation in. + -bright colours of fruits and. + -difficulty of finding in samples of earth. + -dormant state of. + -germination from pond mud. + -Hildebrand on dispersal of. + -mucus emitted by. + -stored by ants. + -supposed vivification of fossil. + -vitality of. + + Seeley, Prof. + + Seemann, on commingling of temperate and tropical plants in mountains of + Panama. + -on the "Origin" in Germany. + -mentioned. + + Segregation of minerals in foliated rocks. + + Selaginella, foot of, compared with organ in Welwitschia seedling. + + Selection, a misleading term. + -artificial. + -as means of improving breeds. + -importance of. + -influence of speedy. + -utilised by pigeon-fanciers. + -Sexual (see Sexual Selection). + -sterility and. + -unconscious. + -and variation. + -voluntary. + -and inheritance. + + Self-fertilisation, abundance of seeds from. + -Darwin's experiments on cross- and. + -evil results of. + -comparison between seeds from cross- and. + -in Goodeniaceae. + -in Orchids. + + Self-interest, Preston on. + + Self-sterility, in Eschscholtzia. + -in plants. + -connection with unnatural conditions. + + Selliera, Hamilton on fertilisation-mechanism. + + Semper, Karl (1832-93): Professor of Zoology at Wurzburg. He is known + for his book of travels in the Philippine and Pelew Islands, for his + work in comparative embryology, and for the work mentioned in the above + letter. See an obituary notice in "Nature," July 20th, 1893, page 271. + -letter to. + + Senecio. + -S. vulgaris, profits by cross-fertilisation. + + Sensitive plants, Darwin's work on. + + Sensitiveness, diversified kinds in allied plants. + + Separate creations, Darwin on. + + Sequoia. + + Seringe, on Aconitum flowers. + + Sertularia. + + Sethia, dimorphism of. + + Settegast, H., letter to. + + Severn, Darwin on floods of. + + Seward, A.C., "Fossil Plants as Tests of Climate." + + Sexes, colour, and difference in. + -proportion at birth. + -proportion in animals. + + Sexual likeness, secondary. + + Sexual organs, as collectors of generative elements. + -appendages in insects complemental to. + + Sexual reproduction, Galton on. + -bearing of F. Muller's work on essence of. + + Sexual Selection, Bates on. + -Darwin on. + -article in "Kosmos" on. + -colour and. + -man and. + -in moths and butterflies. + -subordinate to Natural Selection. + -Wallace on colour and. + -Wallace on difficulties of. + + Sexuality, Bentham on. + -in lower forms. + -origin of. + + Shanghai, tooth of Mastodon from. + + Sharp, David, on Bombus. + -on Volucella. + -"Insects." + + Sharpe, Daniel (1806-56): left school at the age of sixteen, and became + a clerk in the service of a Portuguese merchant. At the age of + twenty-four he went for a year to Portugal, and afterwards spent a + considerable amount of time in that country. The results of his + geological work, carried out in the intervals of business, were + published in the Journal of the Geological Society of London ("Quart. + Journ. Geol. Soc." Volume V., page 142; Volume VI., page 135). Although + actively engaged in business all his life, Sharpe communicated several + papers to the Geological Society, his researches into the origin of + slaty cleavage being among the ablest and most important of his + contributions to geology ("Quart. Journ. Geol. Soc." Volume III., page + 74; Volume V., page 111). A full account of Sharpe's work is given in + an abituary notice published in the "Quart. Journ. Geol. Soc." Volume + XIII., page xlv. + -on elevation. + -Darwin meets. + -letters to. + -on cleavage and foliation. + + Sharpey, W., letter from Falconer to. + -Honorary member of Physiological Society. + + Shaw, J., letter to. + + Sheep, varieties of. + + Sheldrake, dancing on sand to make sea-worms come out. + + Shells, Forbes and Hancock on British. + -distorted by cleavage. + -means of dispersal. + -protective colour of. + + Sherborn, C.D., "Catalogue of Mammalia" by A.S. Woodward and. + + Shetland, comparison between flora of T. del Fuego and that of. + + Shrewsbury, school. + + Siberia, Rhinoceros and steppes of central. + + Sicily, elephants of. + -flora of. + + Sidgwick, Prof. H. + + Siebold, von. + + Sigillaria, an aquatic plant. + + Silene, Gartner's crossing-experiments on. + + Silurian, comparison between recent organisms and. + -life of. + -Lingula from the. + -corals. + -volcanic strata. + + Simon, Sir John: he was for many years medical officer of the Privy + Council, and in that capacity issued a well-known series of Reports. + -reports by. + + Simple forms, existence of. + -survival of. + + Simpson, Sir J., on regeneration in womb. + + Siphocampylus. + + Sitaris, Lord Avebury on Meloe and. + + Siwalik hills. + + Skertchley, S.B.J., on palaeolithic flints in boulder-clay of E. Anglia. + -letter to. + + Skin, influence of mind on eruptions of. + + Slate, cleavage of schists and. + + Slave-ants, account in the "Origin" of. + + Sleep, plants' so-called. + + Sleep-movements, in plants. + -of cotyledons. + + Slime of seeds. + + Sloths. + + Smell, Ogle's work on sense of. + + Smerinthus populi-ocellatus, Weir on hybrid. + + Smilaceae, reference to genera of. + + Smilax, De Candolle on flower of. + + Smith, Goldwin. + + Smith, J., note on. + + Snails of Porto Santo. + + Snipe, protective colour of. + + Snow, red. + -geological action of frozen. + + Snowdon, elevation in recent times. + + Social instincts, actions as result of. + + Social plants, De Candolle on. + -in the U.S.A. + + "Sociology," H. Spencer's. + + Soda, nitrate beds. + + Soil, in relation to plant distribution. + + Solanaceae. + + Solanum rostratum, Todd on stamens of. + + Solenhofen, bird-creature from. + + Sollas, Prof., director of the Funafuti boring expedition. + -account of the boring operations by. + + Sonchus, introduced into New Zealand. + + Song, importance in animal kingdom. + + Sophocles, Prof., on expression of affirmation by Turks. + + Sorby, on metamorphism. + + Sound, and music. + + Southampton, British Association meeting (1846). + -Darwin on gravel deposits at. + -Darwin's visits to. + + Spanish chesnut, variation in leaf divergence. + + Spanish plants in Ireland. + -in La Plata. + + Spawn, dispersal of frogs'. + + Spean, terraces in valley of. + + Special ordination. + + Specialisation. + + Species, antiquity of plant-. + -belief in evolution of. + -changing into one another. + -creation of. + -Darwin recognises difficulties in and objections to his views on. + -definition of. + -descriptive work influenced by Darwin's views on. + -facts from Hooker bearing on. + -food as important factor in keeping up number of. + -frequency of. + -Asa Gray on. + -Hooker on. + -intermediate forms absent in close. + -little tendency during migration to form new. + -modification of. + -and monstrosities. + -mutability of. + -Nageli's views on. + -origin of (see Origin of Species). + -permanence of. + -Prichard on meaning of term. + -range of. + -representative. + -separate creation of. + -spreading of. + -sterility between allied. + -and sterility. + -time necessary to change. + -time of creation of new. + -variation of. + -Wallace on origin of. + -Walsh on modification of. + -Weismann on. + -Gaudry on affiliation of. + -Hackel on change of. + -isolation of. + -value of careful discrimination of. + + "Species not transmutable," Bree's book on. + + Specific character, Falconer on persistence of. + + Speculation, Darwin on. + + Spencer, H., Darwin on the advantage of his expression "survival of the + fittest." + -letter to. + -on electric organs. + -on genesis of nervous system. + -on survival of the fittest. + -Romanes on his theory of nerve-genesis. + -Wallace's admiration for. + -Darwin on his work. + -extract from letter to. + -mentioned. + + Spermacoce. + + Spey, terraces of. + + Sphagnum, parasitism of orchids on. + + Spiders, mental powers of. + -Moggridge on. + + Spiranthes, fertilisation of. + + Spiritualism, Darwin on. + + Sptizbergen, Lamont's book on. + -reindeer of. + + Sponges, Clark on classification of. + -Hackel's work on. + -F. Muller on. + + Spontaneous generation. + -Darwin's disbelief in. + -Huxley's disbelief in. + + Sports. + + Sprengel, (C.C.) Christian Konrad (1750-1816): was for a time Rector of + Spandau, near Berlin; but his enthusiasm for Botany led to neglect of + parochial duties, and to dismissal from his living. His well-known + work, "Das Entdeckte Geheimniss der Natur," was published in 1793. An + account of Sprengel was published in "Flora," 1819, by one of his old + pupils. See also "Life and Letters," I., page 90, and an article in + "Natural Science," Volume II., 1893, by J.C. Willis. + -on Passion-flowers. + + Stag-beetle, forms of. + + Stahl, Prof., on Desmodium. + -on transpiration. + + Stainton. + + Stanhope, Lord. + + Stanhopea, fertilisation of. + + Stapelia, fertilisation of. + + Starling, paired three times in one day. + + State-entomologist, appointment of in America, not likely to occur in + England. + + Statistics, of births and deaths. + -Asa Gray's N. American plant-. + + Steinheim, Lias rocks of. + + Stellaria media, cross-fertilisation of. + + Stephens, Miss Catherine: was born in 1794, and died, as the Countess of + Essex, in 1882. + + Sterile, use of term. + + Sterility, accumulation through Natural Selection. + -arguments relating to. + -artificial production of. + -between allied species aided by Natural Selection. + -connection with sexual differentiation. + -and crossing. + -domestication and loss of. + -experiments on. + -of hybrids. + -in human beings. + -Huxley on. + -increase of races and. + -laws governing. + -Natural Selection and. + -in pigeons. + -in plants (see also self-sterility). + -reciprocal crosses and unequal. + -selection and. + -variations in amount of. + -varieties and. + + Stirling, and Huxley. + + Stokes, Sir G. + + Strasburger, on fertilisation of grasses. + + Stratification, and cleavage. + + Strephium, vertical position of leaves. + + Strezlecki. + + Strickland, H., letters to. + -on zoological nomenclature. + + Stripes, loss and significance of. + + Structural dissimilarity, and sterility. + + Structure, external conditions in relation to. + + Struggle for existence. + -and crossing. + -factors concerned in. + -and hybrids. + -J. Scott on. + + Strychnos, F. Muller on. + + Student, Darwin as an Edinburgh. + + Studer, Bernhard: Several of Studer's papers were translated and published + in the "Edinburgh New Phil. Journ." See Volume XLII., 1847; Volume XLIV., + 1848, etc. + -on cleavage and foliation. + + "Studien zur Descendenz-Theorie," Weismann's. + + "Studies in the Theory of Descent," Meldola's translation of Weismann's + book. + + "Study of Sociology," H. Spencer's. + + Stur, Dionys (1827-93): Director of the Austrian Geological Survey from + 1885 to 1892; author of many important memoirs on palaeobotanical subjects. + + Style, Darwin on. + -Darwin on Huxley's. + -effect of controversy on. + + Suaeda, bloom on. + + Submergence. + + Subsidence, evidence of. + -coral reefs and. + -and elevation. + -equable nature of. + -large areas simultaneously affected by. + -in oceans. + -and sedimentation. + -volcanic action. + + Subterranean animal, existence in Patagonia of supposed. + + Subularia, fertilisation of. + + Succession of types. + + Sudden appearance of organisms, due to absence of fossils in pre- + Cambrian rocks. + + Sudden jumps, modification by. + -Darwin's disbelief in. + + Suess, "Antlitz der Erde." + + Suffolk Crag, comparison with recent strata. + + Sugar-cane, Barber on hybrids of. + -new varieties of. + + Sulivan, Admiral, on Patagonia. + + Superficial deposits, geological nature of. + + Supernumerary members. + -amputation followed by regeneration of. + + "Survival of the fittest," Darwin on use of the expression. + -Wallace on the expression. + -sharpness of thorns the result of. + -colour of birds and. + + Swainson, on wide range of genera. + + Switzerland, Tyndall on valleys of. + + Sydney. + + Symonds, William Samuel (1818-87): a member of an old West-country + family, was an undergraduate of Christ's College, Cambridge, and in 1845 + became Rector of Pendock, Worcestershire. He published in 1858 a book + entitled "Stones of the Valley;" in 1859 "Old Bones, or Notes for Young + Naturalists;" and in 1872 his best-known work, "Records of the Rocks." + Mr. Symonds passed the later years of his life at Sunningdale, the house + of his son-in-law, Sir Joseph Hooker. (See "Quart. Journ. Geol. Soc." + Volume XLIV., page xliii.) + -on imperfection of geological record. + + Tacsonia, Darwin on flowers of. + -fertilisation by humming-birds. + -Scott's work on. + + Tahiti, coral reefs of. + -Darwin on. + + Tails of diluvium, in Scotland. + + Tait, Prof. P.G., article in "North British Review." + -on age of world. + + Tait, L., letters to. + + Tait, W.C., letter to. + -on rudimentary tails in dogs and Manx cats. + -sends Drosophyllum to Darwin. + + Talbot, Mrs. E., letter to. + + Tandon, Moquin, "Elements de Teratologie Vegetale." + + Tankerville, Lord. + + Tasmania, comparison between floras of New Zealand and. + -Hooker's Flora of. + -trees of. + + Taylor, W., "Life and Correspondence" of. + + Tears, and muscular contraction. + + Tees, Hooker on glacial moraines in valley of. + + Tegetmeier, W.B., assistance rendered to Darwin by. + -letters to. + + Telegraph-plant (see also Desmodium). + + "Telliamed" (de Maillet), evolutionary views of. + + Tendrils, morphology of. + + Teneriffe, flora of. + -violet of Peak of. + -Webb and Humboldt on zones of. + + Tennent, Sir J.E., on elephants' tears. + -on Utricularia. + + Tentacles, aggregation of protoplasm in cells of plant-. + + Teodoresco, on effect of excess of CO2 on vegetation. + + Teratology, Masters on vegetable. + -Moquin Tandon on. + + Terebratula. + + Termites compared with cleistogamic flowers. + -F. Muller's paper on. + + Terraces, Darwin on Patagonian. + + Tertiary, Antarctic continent, Darwin on existence of. + -Mastodon from Shanghai. + -flora in Madeira. + + Tertiary period, action of sea and earth-movement. + -island floras of the. + -Saporta's work on plants. + -succession of types during the. + -Prestwich's work on. + + Testimonials, Darwin on. + + Tetrabranchiata, Hyatt on the. + + Thayer's "Letters of Chauncey Wright." + + Theologians, Huxley on. + + Theological articles, by Asa Gray. + + Theology, Darwin's opinion on. + + Theorising, observing and. + + Theory, Darwin's advice to Scott to be sparing in use of. + + Thibet, Hooker prohibited crossing into. + + Thierzucht, Settegast's. + + Thiselton-Dyer, Lady. + + Thiselton-Dyer, Sir W., assists Darwin in bloom-experiments. + -Darwin signs his certificate for Royal Society. + -lecture on plant distribution as field for geographical research. + -letter to "Nature" from. + -notes on letter from Darwin to Bentham. + -on partial submergence of Australia. + -letters to. + -extract from letter to. + -on Darwin. + + Thiselton-Dyer, Sir W., and Prof. Dewar, on immersion of seeds in liquid + hydrogen. + + Thlaspi alpestre, range of. + + Thompson, Prof. D'Arcy, prefatory note by Darwin to his translation of + H. Muller's book. + + Thompson, W., natural-historian of Ireland. + + Thomson, Sir W., see Kelvin, Lord. + + Thomson, Sir Wyville, on Natural Selection. + -mentioned. + + Thomson, review of Jordan's "Diagnoses d'especes" by. + + Thorns, forms of. + + "Three Barriers," theological hash of old abuse of Darwin. + + Thury on sex. + + Thwaites, Dr. G.H.K. (1811-82): held for some years the post of Director of + the Botanic Gardens at Peradenyia, Ceylon; and in 1864 published an + important work on the flora of the island, entitled "Enumeratio Plantarum + Zeylaniae." + -on Ceylon plants. + -letters to. + -on the "Origin." + + Thymus. + + Tieghem, Prof. van, on course of vessels in orchid flowers. + -on effect of flashing light on plants. + + Tierra del Fuego, flora of. + -comparison with Glen Roy. + -evidence of glaciers in. + -micaschists of. + + Time, and evolutionary changes. + -geological. + -meaning of millions of years. + -Niagara as measure of geological. + -rate of deposition as measure of. + -Wallace on geological. + + "Times," article by Huxley in. + -letter by Fitz-Roy in. + + Timiriazeff, Prof. + + Timor, Mastodon from. + + Toad, power of Indian species to resist sea-water. + + Tobacco, Kolreuter on varieties of. + + Todd, on Solanum rostratum. + + "Toledoth Adam," title of book on evolution by N. Lewy. + + Torbitt, J., experiments on potatoes, and letter to. + + Torquay, Darwin's visit to. + + Tortoises, conversion of turtles into land-. + + Tortugas, A. Agassiz on reefs of. + + Toryism, defence of. + + Toucans, colour of beaks in breeding season. + + Trachyte, separation of basalt and. + + Tragopan. + + Traill, experiments on grafting. + + Transfusion experiments, by Galton. + + Translations of Darwin's books. + + Transplanting, effect on Alpine plants. + + Transport, occasional means of. + + Travels, Bates' book of. + -Humboldt's. + -Wallace's. + + Travers, H.H., on Chatham Islands. + + Trecul, on Drosera. + + Trees, herbaceous orders and. + -occurrence in islands. + -older forms more likely to develop into. + -Asa Gray on. + -conditions in New Zealand favourable to development of. + -crossing in. + -separate sexes in. + + Treub, M., on Chalazogamy. + + Treviranus, Prof., on Primula longiflora. + + Trifolium resupinatum, Darwin's observations on bloom on leaflets. + + Trigonecephalus. + + Trilobites, change of genera and species of. + + Trimen, on painting butterflies. + + Trimorphism, in plants. + + Trinidad, Catasetum of. + -Cruger on caprification in. + + Triphaena (Triphoea) pronuba, robin attracted by colour of. + + Tristan d'Acunha, Carmichael on. + -vegetation of. + + Triticum repens var. littorum, bloom-experiments on. + + Trollope, A., quotation by Darwin from. + + Tropaeolum, Darwin's experiments on. + -peloric variety of. + -waxy secretion on leaves. + + Tropical climate, in relation to colouring of insects. + + Tropical plants, possible existence during cooler period. + -retreat of. + + Tropics, climatic changes in. + -description of forests in. + -similarity of orders in. + + Tubocytisus, Kerner on. + + Tuckwell, on the Oxford British Association meeting (1860). + + Tucotuco. + + Tuke, D.H., on influence of mind on body. + -letter to. + + Tulips. + + Turkey, colour of wings, and courtship. + -muscles of tail of. + + Turner, Sir W., Darwin receives assistance from. + -on Darwin's methods of correspondence. + -letters to. + + Turratella. + + Turtles, conversion into land-tortoises. + + Tussilago, Darwin on seeds of groundsel and. + + Twins, Galton's article on. + + Tylor, article in "Journal of the Royal Institution" by. + -on "Early History of Mankind." + + Tyndall, lack of caution. + -lecture by. + -on the Alps. + -review in the "Athenaeum" of. + -on valleys due to glaciers. + -work of. + -dogmatism of. + -on glaciers. + -on Sorby's work on cleavage. + -mentioned. + + Typhlops. + + Typical forms, difficult to select. + -vagueness of phrase. + + Typotherium, Falconer on. + + Tyrol, Mojsisovics on the Dolomites of the. + + Umbelliferae, morphological characters of. + -difference in seeds from the same flower. + + Undulation of light, comparison between Darwin's views and the theory + of. + + Ungulates, development in N. America during Tertiary period. + + United States, flora of. + -spread of Darwin's views in. + + Unity of coloration, Walsh on. + + Uredo, on Haematoxylon. + + Ursus arctos, Lamont on. + -U. maritimus, Lamont on. + + Urticaceae. + + Uruguay. + + D'Urville, on Canary Islands. + + Use and disuse. + -in plants. + + Uses, Natural Selection and. + + Uspallata. + + Utilitarianism, Darwin on. + + Utility and inheritance. + + Utopian "Flora," Darwin's idea of. + + Utricularia, Darwin's work on. + -U. stellaris, Sir E. Tennent on. + + Vaginulus, Darwin finds new species of. + + Valeriana, two forms of. + + Valleys, action of ice in formation of. + -Dana on Australian. + -Darwin on origin of. + + Valparaiso. + + Van Diemen's Land, flora of, in relation to New Zealand. + + Vanda. + + Vandeae, structure of ovary. + + Vanessa, two sexual forms of. + -breeding in confinement. + -colour of. + + Vanilla. + + Variability, backward tendency of. + -Bentham on. + -causes of. + -De Candolle on. + -dependent more on nature of organism than on environment. + -Huxley and Scott on. + -importance of subject of cause of. + -Natural Selection and. + -in oaks. + -greater in bisexual than in unisexual plants. + -of ferns "passes all bounds." + -greater in male than female. + -in ovaries of flowers. + -tendency of genera at different periods towards. + + Variation. + -an innate principle. + -Bates on. + -in blackbirds. + -causes of. + -centrifugal nature of. + -checked by Natural Selection. + -climate and. + -Darwin attaches importance to useless. + -Darwin on favourable. + -divergence of. + -and external conditions. + -in elephants. + -in Fucus. + -of large genera. + -laws of. + -of monotypic and polytypic genera. + -and monstrosities. + -and Natural Selection. + -ordination and. + -in peaches. + -in plants. + -produced by crossing. + -rate of action of. + -of small genera. + -sterility advantageous to. + -Weismann on. + -galls as cause of. + -and loss of dimorphism in Primula and Auricula. + -Sexual Selection and minute. + -transmission to sexes. + -Verlot on. + -Wallace on. + + "Variation of Animals and Plants under Domestication," completion of. + -delay in publication. + -Lyell on. + -translation of. + -Wallace's opinion of. + -Darwin at work on. + + Varieties, accumulation of. + -distinction between species and. + -fertility of. + -in insects. + -in large genera. + -of molluscs. + -production of. + -species the product of long series of. + -use of. + -Wallace on. + -elimination by crossing. + -zoologists neglect study of. + + Vaucher, "Plantes d'Europe." + + "Vegetable Teratology," Masters'. + + Vegetative reproduction, Darwin on. + + Veitch, J. + + Velleia, fertilisation mechanism of. + + Verbascum, crossing and varieties in. + -Scott's work on. + + Verbenaceae. + + Verlot, on variation in flowers. + + Veronica, Antarctic species of. + + Vessels, course of, as guide to morphology of flowers. + + "Vestiges of Creation," Huxley's review of. + -the "Origin of Species" and. + -Vetch, extra-floral nectaries of. + + Vetter, editor of "Kosmos." + + Viburnum lantanoides, in Japan and east U.S.A. + + Victoria Street Society for Protection of Animals against Vivisection, + charge brought against Dr. Ferrier by. + + Villa Franca, Baron de, on varieties of sugar-cane. + + Villarsia. + + Vine, graft-hybrids of. + -varieties of. + -morphology of tendrils. + + Viola, ancestral form of. + -cleistogamic flowers of. + -pollen-tubes of. + -Madagascan. + -Pyrenean. + -on Peak of Teneriffe. + -V. canina, fertilisation of. + -V. nana. + -V. odorata, floral biology of. + + Virchow, Huxley's criticism of. + -publication by Hackel of Darwin's criticism of. + + Viscum. + + Vitality of seeds, in salt-water experiments. + + Viti group of islands, effect of subsidence. + + Vivisection. + + Vochting, H., "Bewegung der Bluthen und Fruchte." + -letter to. + -"Organbildung im Pflanzenreich." + + "Volcanic Geology," Dana's. + + Volcanic islands, polymorphic species in. + -Darwin's geological observations on. + -Darwin's opinion of his book on. + -Lyell and Herschel on. + -relation to continents. + + Volcanic phenomena, cause of. + -Darwin on. + -and elevation. + -as mere accidents in swelling up of dome of plutonic rocks. + -and subsidence. + + Volcanic rocks. + + Volcano, in interior of Asia. + + Volcanoes, in S. America. + -compared with boilers. + -maritime position of. + -of St. Jago, Mauritius, and St. Helena. + -simultaneous activity of. + -and subsidence. + + Volucella, as example of mimicry. + + Vries, H. de, on plant-movements. + + Vulcanicity. + + Wagner, M., attacks Darwin. + -essay by. + -mentioned. + + "Wahl der Lebens-Weise." + + Wahlenberg, on variation of species in U.S.A. + + Wales, Darwin's visit to. + -comparison of valleys of Lochaber and. + -Darwin on glaciers of. + -elevation of land in Scotland and. + -Murchison sees no trace of glaciers in. + -Ramsay on denudation of S. + + Wallace, A.R., on beauty. + -criticises the expression, "Natural Selection." + -Darwin on cleverness of. + -letters to. + -letters to Darwin from. + -on Mastodon from Timor. + -notes by. + -on pangenesis. + -review of Bastian's "Beginnings of Life." + -on sterility. + -on success of Natural Selection. + -attributes Natural Selection to Darwin. + -on colour and birds' nests. + -Darwin's criticism of his "Geographical Distribution of Animals." + -differs from Darwin. + -on evolution of man. + -"Island Life." + -on wings of lepidoptera. + -review of Darwin's book on Expression. + -review of Lyell's "Principles of Geology." + -on Round Island. + -same ideas hit on by Darwin and. + -supplies information to Darwin on Sexual Selection. + -on variation. + -at work on narrative of travels. + + Wallace, Dr., on sexes in Bombyx. + -on caterpillars. + + Wallich, on Oxyspora paniculata. + + Wallis, H.M., on ears. + -letters to. + + Walpole. + + Walsh, Benjamin Dann: was born at Frome, in England, in 1808, and died in + America in 1869, from the result of a railway accident. He entered at + Trinity College, Cambridge, and obtained a fellowship there after being + fifth classic in 1831. He was therefore a contemporary of Darwin's at the + University, though not a "schoolmate," as the "American Entomologist" puts + it. He was the author of "A Historical Account of the University of + Cambridge and its Colleges," London, 2nd edition, 1837; also of a + translation of part of "Aristophanes," 1837: from the dedication of this + book it seems that he was at St. Paul's School, London. He settled in + America in 1838, but only began serious Entomology about 1858. He never + returned to England. + In a letter to Mr. Darwin, November 7th, 1864, he gives a curious account + of the solitary laborious life he led for many years. "When I left England + in 1838," he writes, "I was possessed with an absurd notion that I would + live a perfectly natural life, independent of the whole world--in me ipso + totus teres atque rotundus. So I bought several hundred acres of wild land + in the wilderness, twenty miles from any settlement that you would call + even a village, and with only a single neighbor. There I gradually opened + a farm, working myself like a horse, raising great quantities of hogs and + bullocks...I did all kinds of jobs for myself, from mending a pair of boots + to hooping a barrel." After nearly dying of malaria, he sold his land at a + great loss, and found that after twelve years' work he was just 1000 + dollars poorer than when he began. He then went into the lumber business + at Rock Island, Illinois. After seven years he invested most of his + savings in building "ten two-storey brick houses for rent." He states that + the repairs of the houses occupied about one-fourth of his time, and the + remainder he was able to devote to entomology. He afterwards edited the + "Practical Entomologist." In regard to this work he wrote (February 25th, + 1867):--"Editing the 'Practical Entomologist' does undoubtedly take up a + good deal of my time, but I also pick up a good deal of information of real + scientific value from its correspondents. Besides, this great American + nation has hitherto had a supreme contempt for Natural History, because + they have hitherto believed that it has nothing to do with the dollars and + cents. After hammering away at them for a year or two, I have at last + succeeded in touching the 'pocket nerve' in Uncle Sam's body, and he is + gradually being galvanised into the conviction that science has the power + to make him richer." It is difficult to realise that even forty years ago + the position of science in Illinois was what Mr. Walsh describes it to be: + "You cannot have the remotest conception of the ideas of even our best- + educated Americans as to the pursuit of science. I never yet met with a + single one who could be brought to understand how or why a man should + pursue science for its own pure and holy sake." + Mr. L.O. Howard ("Insect Life," Volume VII., 1895, page 59) says that + Harris received from the State of Massachusetts only 175 dollars for his + classical report on injurious insects which appeared in 1841 and was + reprinted in 1842 and 1852. It would seem that in these times + Massachusetts was in much the same state of darkness as Illinois. In the + winter of 1868-9 Walsh was, however, appointed State Entomologist of + Illinois. He made but one report before his death. He was a man of + liberal ideas, hating oppression and wrong in all its forms. On one + occasion his life was threatened for an attempt to purify the town council. + As an instance of "hereditary genius" it may be mentioned that his brother + was a well-known writer on natural history and sporting subjects, under the + pseudonym "Stonehenge." The facts here given are chiefly taken from the + "American Entomologist" (St. Louis, Mo.), Volume II., page 65. + -as entomologist. + -letters to. + -letter to Darwin from. + -death of. + -and C.V. Riley. + + Warming, E., "Lehrbuch der okologischen Pflanzengeographie." + + Washingtonia. + + Wasps, power of building cells. + + Water, effect on leaves (see also Rain). + + Water-weed, Marshall on. + + Waterhouse, George Robert (1810-88): held the post of Keeper of the + Department of Geology in the British Museum from 1851 to 1880. + -review by Darwin of his book on Mammalia. + -on skeletons of rabbits. + -on wide range of genera. + -mentioned. + + Waterloo, Darwin's recollections of. + + Waterton. + + Watson, H.C., alluded to. + -on the Azores. + -on British agrarian plants. + -on northward range of plants common to Britain and America. + -objection to Darwin's views. + -on Natural Selection. + -mentioned. + + Waves, depth of action of. + + Wax, secretion on leaves (see also Bloom). + + Wealden period. + + Weale, J.P.M., sends locust dung from Natal to Darwin. + + Webb, on flora of Teneriffe. + + Wedgwood, Elizabeth. + + Wedgwood, Emma (Mrs. Darwin), letter to. + + Wedgwood, Hensleigh: brother-in-law to Charles Darwin. + -Darwin visits. + -influenced by Lyell's book on America. + -on Tyndall. + + Wedgwood, Josiah, letter to. + + Weeds, adaptation to cultivated ground. + -English versus American. + -Asa Gray on pertinacity of. + + Weeping, physiology of. + + Weir, H.W., on Cytisus. + + Weir, Mr. John Jenner (1822-94): came of a family of Scotch descent; in + 1839 he entered the service of the Custom House, and during the final + eleven years of his service, i.e. from 1874 to 1885, held the position + of Accountant and Controller-General. He was a born naturalist, and his + "aptitude for exact observation was of the highest order" (Mr. M'Lachlan + in the "Entomologist's Monthly Magazine," May 1894). He is chiefly + known as an entomologist, but he had also extensive knowledge of + Ornithology, Horticulture, and of the breeds of various domestic animals + and cage-birds. His personal qualities made him many friends, and he + was especially kind to beginners in the numerous subjects on which he + was an authority ("Science Gossip," May 1894). + -experiments on caterpillars. + -letters to. + -extract from letter to Darwin from. + -on birds. + -invited to Down. + -value of his letters to Darwin. + -mentioned. + + Weismann, A., Darwin asked to point out how far his work follows same + lines as that of. + -on dimorphism. + -"Einfluss der Isolirung." + -letters to. + -Meldola's translation of "Studies in Descent." + -"Studies in Theory of Descent." + -faith in Sexual Selection. + + Wellingtonia. + + Wells, Dr., essay on dew. + -quoted by Darwin as having enunciated principle of Natural Selection + before publication of "Origin." + + Welwitschia, Hooker's work on. + -Darwin on. + -a "vegetable Ornithorhynchus." + + Welwitschia mirabilis, seedlings of. + + Wenlock, coral limestone of. + + West Indies, plants of. + -coral reefs. + -elevation and subsidence of. + -orchids of. + + Westminster Abbey, memorial to Lyell. + + "Westminster Review," Huxley's review of the "Origin" in. + -Wallace's article. + + Westwood, J.O. (1805-93): Professor of Entomology at Oxford. The Royal + medal was awarded to him in 1855. He was educated at a Friends' School + at Sheffield, and subsequently articled to a solicitor in London; he was + for a short time a partner in the firm, but he never really practised, + and devoted himself to science. He is the author of between 350 and 400 + papers, chiefly on entomological and archaeological subjects, besides + some twenty books. To naturalists he is known by his writings on + insects, but he was also "one of the greatest living authorities on + Anglo-Saxon and mediaeval manuscripts" ("Dictionary of National + Biography"). + -on range of genera. + -and Royal medal. + -mentioned. + + Whales, Flower on. + + Wheat, mummy. + -fertilisation of. + -forms of Russian. + + Whewell, W. + + Whiston. + + Whitaker, W., on escarpments. + + White, F.B., letter to. + -on hemiptera of St. Helena. + + White, Gilbert, Darwin writes an account of Down in the manner of. + + White, on regeneration. + + Whiteman, R.G., letter to. + + Whitney, on origin of language. + + Wichura, Max, on hybrid willows. + -on hybridisation. + + Widow-bird, experiments on. + + Wiegmann. + + Wiesner, Prof. J., disagrees with Darwin's views on plant movement. + "Das Bewegungsvermogen der Pflanzen." + -on heliotropism. + -letter to. + + Wigand, A., "Der Darwinismus..." + -Jager's work contra. + + Wight, Dr., on Cucurbitaceae. + + Wilberforce, Bishop, review in the "Quarterly." + + Wildness of game. + + Wilkes' exploring expedition, Dana's volume in reports of. + + Williamson, Prof. W.C. + + Willis, J.C., reference to his "Flowering Plants and Ferns." + + Willows, Walsh on galls of. + -Wichura on hybrid. + + Wilson, A.S., letters to. + -on Russian wheat. + + Wind-fertilised trees and plants, abundant in humid and temperate + regions. + + Wingless birds, transport of. + + Wings of ostrich. + + Wire-bird, of St. Helena. + + Witches' brooms. + + Wives, resemblance to husbands. + + Wollaston, Thomas Vernon (1821-78): Wollaston was an under-graduate at + Jesus College, Cambridge, and in late life published several books on + the coleopterous insects of Madeira, the Canaries, the Cape Verde + Islands, and other regions. He is referred to in the "Origin of + Species" (Edition VI page 109) as having discovered "the remarkable fact + that 200 beetles, out of the 550 species (but more are now known) + inhabiting Madeira, are so far deficient in wings that they cannot fly; + and that, of the twenty-nine endemic genera, no less than twenty-three + have all their species in this condition!" See Obituary Notice in + "Nature," Volume XVII., page 210, 1878, and "Trans. Entom. Soc." 1877, + page xxxviii.) "Catalogue" (Probably the "Catalogue of the Coleopterous + Insects of the Canaries in the British Museum," 1864.) + -catalogue of insects of Canary Islands. + -Darwin and Royal medal. + -in agreement with Falconer in opposition to Darwin's views on species. + -"Insecta Maderensia." + -on rarity of intermediate varieties in insects. + -review on the "Origin" by. + -on varieties. + -mentioned. + + Wolverhampton, abrupt termination of boulders near. + + Wood, fossil. + + Wood, T.W., drawings by. + + Woodcock, germination of seeds carried by. + -protective colouring of. + + Woodd, C.H.L., letter to. + + Woodpecker, adaptation in. + -and direct action. + -form of tail of. + + Woodward, A.S., on Neomylodon. + -and C.D. Sherborn, "Catalogue of British Fossil Vertebrata." + + Woodward, Samuel Pickworth (1821-65): held an appointment in the British + Museum Library for a short time, and then became Sub-Curator to the + Geological Society (1839). In 1845 he was appointed Professor of Geology + and Natural History in the recently founded Royal Agricultural College, + Cirencester; he afterwards obtained a post as first-class assistant in the + Department of Geology and Mineralogy in the British Museum. Woodward's + chief work, "The Manual of Mollusca," was published in 1851-56. ("A Memoir + of Dr. S.P. Woodward," "Trans. Norfolk and Norwich Naturalists' Society," + Volume III., page 279, 1882. By H.B. Woodward.) + -letters to. + + World, age of the. + + Worms, Darwin's work on. + -destruction by rain of. + -intelligence of. + + Wrangel's "Travels in Siberia." + + "Wreck of the 'Favourite'," Clarke's. + + Wright, C., on bees' cells. + -letters to. + -review by. + + Wright, G.F., extract from letter from Asa Gray, to. + + Wydler, on morphology of cruciferous flower. + + Wyman, Jeffries (1814-74): graduated at Harvard in 1833, and afterwards + entered the Medical College at Boston, receiving the M.D. degree in + 1837. In 1847 Wyman was appointed Hervey Professor of Anatomy at + Harvard, which position he held up to the time of his death. His + contributions to zoological science numbered over a hundred papers. + (See "Proc. Amer. Acad. Arts and Sciences," Volume II., 1874-75, pages + 496-505.) + -letter from. + -on spontaneous generation. + -mentioned. + + Xenogamy, term suggested by Kerner. + + Xenoneura antiquorum, Devonian insect. + + Xerophytic characters, not confined to dry-climate plants. + + Yangma Valley, Hooker's account of dam in. + + Yeo, Prof. Gerald. + + Yew, origin of Irish. + + York, British Association meeting (1881), (1844). + -Dallas in charge of museum. + + Yorkshire, Hooker on glaciers in. + + Yucca, fertilisation by moths. + + Zacharias, Otto, letter to. + + Zante, colour of Polygala flowers in. + + Zea, Gartner's work on. + -hermaphrodite and female flowers on a male panicle. + -varieties received from Asa Gray. + + Zeiller, R., "Le Marquis G. de Saporta, sa Vie..." + + Zinziberaceae. + + Zittel, Karl A. von, "Handbuch der Palaeontologie." + + Zoea stage, in life-history of decapods. + + Zoological Gardens, dangerous to suggest subsidising. + + Zoological nomenclature. + + Zoologist, Darwin as. + + "Zoonomia," Erasmus Darwin's. + + Zygaena (Burnet-moth), mentioned by Darwin in his early recollections. + + + + + +End of the Project Gutenberg EBook of More Letters of Charles Darwin Volume +II, by Charles Darwin + +*** END OF THIS PROJECT GUTENBERG EBOOK MORE LETTERS OF CHARLES DARWIN *** + +***** This file should be named 2740.txt or 2740.zip ***** +This and all associated files of various formats will be found in: + http://www.gutenberg.org/2/7/4/2740/ + +Produced by Sue Asscher + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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