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diff --git a/old/2mlcd10.txt b/old/2mlcd10.txt new file mode 100644 index 0000000..b22c8ea --- /dev/null +++ b/old/2mlcd10.txt @@ -0,0 +1,26843 @@ +Project Gutenberg Etext of More Letters of Charles Darwin Vol. 2 + +Copyright laws are changing all over the world, be sure to check +the copyright laws for your country before posting these files!! + +Please take a look at the important information in this header. +We encourage you to keep this file on your own disk, keeping an +electronic path open for the next readers. Do not remove this. + + +**Welcome To The World of Free Plain Vanilla Electronic Texts** + +**Etexts Readable By Both Humans and By Computers, Since 1971** + +*These Etexts Prepared By Hundreds of Volunteers and Donations* + +Information on contacting Project Gutenberg to get Etexts, and +further information is included below. We need your donations. + + +Title: More Letters of Charles Darwin Volume II + +Author: Charles Darwin + +Editors: Francis Darwin and A.C. 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FOR PUBLIC DOMAIN ETEXTS*Ver.04.29.93*END* + + + + + +This etext was prepared by Sue Asscher <asschers@dingoblue.net.au> + + + + + +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. + + + + + +MORE LETTERS OF CHARLES DARWIN + + + + +A RECORD OF HIS WORK IN A SERIES OF HITHERTO UNPUBLISHED LETTERS + +EDITED BY FRANCIS DARWIN, FELLOW OF CHRIST'S COLLEGE, +AND +A.C. SEWARD, FELLOW OF EMMANUEL COLLEGE, CAMBRIDGE + +IN TWO VOLUMES + + + + +VOLUME II.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. + +[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 Project Gutenberg Etext of More Letters of Charles Darwin Vol. 2 + |