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diff --git a/16136.txt b/16136.txt new file mode 100644 index 0000000..bb1b9dd --- /dev/null +++ b/16136.txt @@ -0,0 +1,3744 @@ +The Project Gutenberg eBook, American Addresses, with a Lecture on the +Study of Biology, by Tomas Henry Huxley + + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + + + + +Title: American Addresses, with a Lecture on the Study of Biology + + +Author: Tomas Henry Huxley + + + +Release Date: June 26, 2005 [eBook #16136] + +Language: English + +Character set encoding: ISO-646-US (US-ASCII) + + +***START OF THE PROJECT GUTENBERG EBOOK AMERICAN ADDRESSES, WITH A LECTURE +ON THE STUDY OF BIOLOGY*** + + +E-text prepared by Clare Boothby, Jeremy Weatherford, and the Project +Gutenberg Online Distributed Proofreading Team (https://www.pgdp.net) + + + +Note: Project Gutenberg also has an HTML version of this + file which includes the original illustrations. + See 16136-h.htm or 16136-h.zip: + (https://www.gutenberg.org/dirs/1/6/1/3/16136/16136-h/16136-h.htm) + or + (https://www.gutenberg.org/dirs/1/6/1/3/16136/16136-h.zip) + + + + + +AMERICAN ADDRESSES, WITH A LECTURE ON THE STUDY OF BIOLOGY + +by + +THOMAS H. HUXLEY. + +London: MacMillan and Co. +London: R. Clay, Sons, and Taylor, Printers, Bread Street Hill, + Queen Victoria Street. + +1877 + + + + + + + + "Naturae leges et regulae, secundum quas omnia fiunt et ex unis + formis in alias mutantur, sunt ubique et semper eadem." + + B. DE SPINOZA, _Ethices_, Pars tertia, Praefatio. + + + + + +CONTENTS. + + I. THREE LECTURES ON EVOLUTION (New York, September 18, 20, 22, 1876). + + LECTURE I. THE THREE HYPOTHESES RESPECTING THE HISTORY OF NATURE + + LECTURE II. THE HYPOTHESIS OF EVOLUTION. THE NEUTRAL AND THE + FAVOURABLE EVIDENCE + + LECTURE III. THE DEMONSTRATIVE EVIDENCE OF EVOLUTION + + + II. AN ADDRESS ON THE OCCASION OF THE OPENING OF THE JOHNS HOPKINS + UNIVERSITY (Baltimore, September 12, 1876) + + +III. A LECTURE ON THE STUDY OF BIOLOGY, IN CONNECTION WITH THE LOAN + COLLECTION OF SCIENTIFIC APPARATUS (South Kensington Museum, + December 16, 1876) + + + + +NEW YORK. + +LECTURES ON EVOLUTION. + + + + +LECTURE I. + +THE THREE HYPOTHESES RESPECTING THE HISTORY OF NATURE. + + +We live in and form part of a system of things of immense diversity and +perplexity, which we call Nature; and it is a matter of the deepest +interest to all of us that we should form just conceptions of the +constitution of that system and of its past history. With relation to +this universe, man is, in extent, little more than a mathematical point; +in duration but a fleeting shadow; he is a mere reed shaken in the winds +of force. But, as Pascal long ago remarked, although a mere reed, he is +a thinking reed; and in virtue of that wonderful capacity of thought, he +has the power of framing for himself a symbolic conception of the +universe, which, although doubtless highly imperfect and inadequate as a +picture of the great whole, is yet sufficient to serve him as a chart +for the guidance of his practical affairs. It has taken long ages of +toilsome and often fruitless labour to enable man to look steadily at +the shifting scenes of the phantasmagoria of Nature, to notice what is +fixed among her fluctuations, and what is regular among her apparent +irregularities; and it is only comparatively lately, within the last few +centuries, that the conception of a universal order and of a definite +course of things, which we term the course of Nature, has emerged. + +But, once originated, the conception of the constancy of the order of +Nature has become the dominant idea of modern thought. To any person who +is familiar with the facts upon which that conception is based, and is +competent to estimate their significance, it has ceased to be +conceivable that chance should have any place in the universe, or that +events should depend upon any but the natural sequence of cause and +effect. We have come to look upon the present as the child of the past +and as the parent of the future; and, as we have excluded chance from a +place in the universe, so we ignore, even as a possibility, the notion +of any interference with the order of Nature. Whatever may be men's +speculative doctrines, it is quite certain, that every intelligent +person guides his life and risks his fortune upon the belief that the +order of Nature is constant, and that the chain of natural causation is +never broken. + +In fact, no belief which we entertain has so complete a logical basis as +that to which I have just referred. It tacitly underlies every process +of reasoning; it is the foundation of every act of the will. It is based +upon the broadest induction, and it is verified by the most constant, +regular, and universal of deductive processes. But we must recollect +that any human belief, however broad its basis, however defensible it +may seem, is, after all, only a probable belief, and that our widest and +safest generalizations are simply statements of the highest degree of +probability. Though we are quite clear about the constancy of the order +of Nature, at the present time, and in the present state of things, it +by no means necessarily follows that we are justified in expanding this +generalisation into the infinite past, and in denying, absolutely, that +there may have been a time when Nature did not follow a fixed order, +when the relations of cause and effect were not definite, and when +extra-natural agencies interfered with the general course of Nature. +Cautious men will allow that a universe so different from that which we +know may have existed; just as a very candid thinker may admit that a +world in which two and two do not make four, and in which two straight +lines do inclose a space, may exist. But the same caution which forces +the admission of such possibilities demands a great deal of evidence +before it recognises them to be anything more substantial. And when it +is asserted that, so many thousand years ago, events occurred in a +manner utterly foreign to and inconsistent with the existing laws of +Nature, men, who without being particularly cautious, are simply honest +thinkers, unwilling to deceive themselves or delude others, ask for +trustworthy evidence of the fact. + +Did things so happen or did they not? This is a historical question, and +one the answer to which must be sought in the same way as the solution +of any other historical problem. + + * * * * * + +So far as I know, there are only three hypotheses which ever have been +entertained, or which well can be entertained, respecting the past +history of Nature. I will, in the first place, state the hypotheses, and +then I will consider what evidence bearing upon them is in our +possession, and by what light of criticism that evidence is to be +interpreted. + +Upon the first hypothesis, the assumption is, that phenomena of Nature +similar to those exhibited by the present world have always existed; in +other words, that the universe has existed from all eternity in what may +be broadly termed its present condition. + +The second hypothesis is, that the present state of things has had only +a limited duration; and that, at some period in the past, a condition of +the world, essentially similar to that which we now know, came into +existence, without any precedent condition from which it could have +naturally proceeded. The assumption that successive states of Nature +have arisen, each without any relation of natural causation to an +antecedent state, is a mere modification of this second hypothesis. + +The third hypothesis also assumes that the present state of things has +had but a limited duration; but it supposes that this state has been +evolved by a natural process from an antecedent state, and that from +another, and so on; and, on this hypothesis, the attempt to assign any +limit to the series of past changes is, usually, given up. + +It is so needful to form clear and distinct notions of what is really +meant by each of these hypotheses that I will ask you to imagine what, +according to each, would have been visible to a spectator of the events +which constitute the history of the earth. On the first hypothesis, +however far back in time that spectator might be placed, he would see a +world essentially, though perhaps not in all its details, similar to +that which now exists. The animals which existed would be the ancestors +of those which now live, and similar to them; the plants, in like +manner, would be such as we know; and the mountains, plains, and waters +would foreshadow the salient features of our present land and water. +This view was held more or less distinctly, sometimes combined with the +notion of recurrent cycles of change, in ancient times; and its +influence has been felt down to the present day. It is worthy of remark +that it is a hypothesis which is not inconsistent with the doctrine of +Uniformitarianism, with which geologists are familiar. That doctrine was +held by Hutton, and in his earlier days by Lyell. Hutton was struck by +the demonstration of astronomers that the perturbations of the planetary +bodies, however great they may be, yet sooner or later right themselves; +and that the solar system possesses a self-adjusting power by which +these aberrations are all brought back to a mean condition. Hutton +imagined that the like might be true of terrestrial changes; although no +one recognised more clearly than he the fact that the dry land is being +constantly washed down by rain and rivers and deposited in the sea; and +that thus, in a longer or shorter time, the inequalities of the earth's +surface must be levelled, and its high lands brought down to the ocean. +But, taking into account the internal forces of the earth, which, +upheaving the sea-bottom give rise to new land, he thought that these +operations of degradation and elevation might compensate each other; and +that thus, for any assignable time, the general features of our planet +might remain what they are. And inasmuch as, under these circumstances, +there need be no limit to the propagation of animals and plants, it is +clear that the consistent working-out of the uniformitarian idea might +lead to the conception of the eternity of the world. Not that I mean to +say that either Hutton or Lyell held this conception--assuredly not; +they would have been the first to repudiate it. Nevertheless, the +logical development of their arguments tends directly towards this +hypothesis. + +The second hypothesis supposes that the present order of things, at some +no very remote time, had a sudden origin, and that the world, such as it +now is, had chaos for its phenomenal antecedent. That is the doctrine +which you will find stated most fully and clearly in the immortal poem +of John Milton--the English _Divina Commedia--Paradise Lost_. I believe +it is largely to the influence of that remarkable work, combined with +the daily teachings to which we have all listened in our childhood, that +this hypothesis owes its general wide diffusion as one of the current +beliefs of English-speaking people. If you turn to the seventh book of +_Paradise Lost_, you will find there stated the hypothesis to which I +refer, which is briefly this: That this visible universe of ours came +into existence at no great distance of time from the present; and that +the parts of which it is composed made their appearance, in a certain +definite order, in the space of six natural days, in such a manner that, +on the first of these days, light appeared; that, on the second, the +firmament, or sky, separated the waters above, from the waters beneath +the firmament; that, on the third day, the waters drew away from the dry +land, and upon it a varied vegetable life, similar to that which now +exists, made its appearance; that the fourth day was signalised by the +apparition of the sun, the stars, the moon, and the planets; that, on +the fifth day, aquatic animals originated within the waters; that, on +the sixth day, the earth gave rise to our four-footed terrestrial +creatures, and to all varieties of terrestrial animals except birds, +which had appeared on the preceding day; and, finally, that man appeared +upon the earth, and the emergence of the universe from chaos was +finished. Milton tells us, without the least ambiguity, what a spectator +of these marvellous occurrences would have witnessed. I doubt not that +his poem is familiar to all of you, but I should like to recall one +passage to your minds, in order that I may be justified in what I have +said regarding the perfectly concrete, definite picture of the origin of +the animal world which Milton draws. He says:-- + + "The sixth, and of creation last, arose + With evening harps and matin, when God said, + 'Let the earth bring forth soul living in her kind, + Cattle and creeping things, and beast of the earth, + Each in their kind!' The earth obeyed, and, straight + Opening her fertile womb, teemed at a birth + Innumerous living creatures, perfect forms, + Limbed and full-grown. Out of the ground uprose, + As from his lair, the wild beast, where he wons + In forest wild, in thicket, brake, or den; + Among the trees in pairs they rose, they walked; + The cattle in the fields and meadows green; + Those rare and solitary; these in flocks + Pasturing at once, and in broad herds upsprung. + The grassy clods now calved; now half appears + The tawny lion, pawing to get free + His hinder parts--then springs, as broke from bonds, + And rampant shakes his brinded mane; the ounce, + The libbard, and the tiger, as the mole + Rising, the crumbled earth above them threw + In hillocks; the swift stag from underground + Bore up his branching head; scarce from his mould + Behemoth, biggest born of earth, upheaved + His vastness; fleeced the flocks and bleating rose + As plants; ambiguous between sea and land, + The river-horse and scaly crocodile. + At once came forth whatever creeps the ground, + Insect or worm." + +There is no doubt as to the meaning of this statement, nor as to what a +man of Milton's genius expected would have been actually visible to an +eye-witness of this mode of origination of living things. + +The third hypothesis, or the hypothesis of evolution, supposes that, at +any comparatively late period of past time, our imaginary spectator +would meet with a state of things very similar to that which now +obtains; but that the likeness of the past to the present would +gradually become less and less, in proportion to the remoteness of his +period of observation from the present day; that the existing +distribution of mountains and plains, of rivers and seas, would show +itself to be the product of a slow process of natural change operating +upon more and more widely different antecedent conditions of the mineral +framework of the earth; until, at length, in place of that framework, he +would behold only a vast nebulous mass, representing the constituents of +the sun and of the planetary bodies. Preceding the forms of life which +now exist, our observer would see animals and plants not identical with +them, but like them; increasing their differences with their antiquity +and, at the same time, becoming simpler and simpler; until, finally, the +world of life would present nothing but that undifferentiated +protoplasmic matter which, so far as our present knowledge goes, is the +common foundation of all vital activity. + +The hypothesis of evolution supposes that in all this vast progression +there would be no breach of continuity, no point at which we could say +"This a natural process," and "This is not a natural process;" but that +the whole might be compared to that wonderful process of development +which may be seen going on every day under our eyes, in virtue of which +there arises, out of the semi-fluid, comparatively homogeneous substance +which we call an egg, the complicated organization of one of the higher +animals. That, in a few words, is what is meant by the hypothesis of +evolution. + + * * * * * + +I have already suggested that in dealing with these three hypotheses, in +endeavouring to form a judgment as to which of them is the more worthy +of belief, or whether none is worthy of belief--in which case our +condition of mind should be that suspension of judgment which is so +difficult to all but trained intellects--we should be indifferent to all +_a priori_ considerations. The question is a question of historical +fact. The universe has come into existence somehow or other, and the +problem is, whether it came into existence in one fashion, or whether it +came into existence in another; and, as an essential preliminary to +further discussion, permit me to say two or three words as to the nature +and the kinds of historical evidence. + +The evidence as to the occurrence of any event in past time may be +ranged under two heads which, for convenience' sake, I will speak of as +testimonial evidence and as circumstantial evidence. By testimonial +evidence I mean human testimony; and by circumstantial evidence I mean +evidence which is not human testimony. Let me illustrate by a familiar +example what I understand by these two kinds of evidence, and what is to +be said respecting their value. + +Suppose that a man tells you that he saw a person strike another and +kill him; that is testimonial evidence of the fact of murder. But it is +possible to have circumstantial evidence of the fact of murder; that is +to say, you may find a man dying with a wound upon his head having +exactly the form and character of the wound which is made by an axe, +and, with due care in taking surrounding circumstances into account, you +may conclude with the utmost certainty that the man has been murdered; +that his death is the consequence of a blow inflicted by another man +with that implement. We are very much in the habit of considering +circumstantial evidence as of less value than testimonial evidence, and +it may be that, where the circumstances are not perfectly clear and +intelligible, it is a dangerous and unsafe kind of evidence; but it must +not be forgotten that, in many cases, circumstantial is quite as +conclusive as testimonial evidence, and that, not unfrequently, it is a +great deal weightier than testimonial evidence. For example, take the +case to which I referred just now. The circumstantial evidence may be +better and more convincing than the testimonial evidence; for it may be +impossible, under the conditions that I have defined, to suppose that +the man met his death from any cause but the violent blow of an axe +wielded by another man. The circumstantial evidence in favour of a +murder having been committed, in that case, is as complete and as +convincing as evidence can be. It is evidence which is open to no doubt +and to no falsification. But the testimony of a witness is open to +multitudinous doubts. He may have been mistaken. He may have been +actuated by malice. It has constantly happened that even an accurate man +has declared that a thing has happened in this, that, or the other way, +when a careful analysis of the circumstantial evidence has shown that it +did not happen in that way, but in some other way. + +We may now consider the evidence in favour of or against the three +hypotheses. Let me first direct your attention to what is to be said +about the hypothesis of the eternity of the state of things in which we +now live. What will first strike you is, that it is a hypothesis which, +whether true or false, is not capable of verification by any evidence. +For, in order to obtain either circumstantial or testimonial evidence +sufficient to prove the eternity of duration of the present state of +nature, you must have an eternity of witnesses or an infinity of +circumstances, and neither of these is attainable. It is utterly +impossible that such evidence should be carried beyond a certain point +of time; and all that could be said, at most, would be, that so far as +the evidence could be traced, there was nothing to contradict the +hypothesis. But when you look, not to the testimonial evidence--which, +considering the relative insignificance of the antiquity of human +records, might not be good for much in this case--but to the +circumstantial evidence, then you find that this hypothesis is +absolutely incompatible with such evidence as we have; which is of so +plain and so simple a character that it is impossible in any way to +escape from the conclusions which it forces upon us. + +You are, doubtless, all aware that the outer substance of the earth, +which alone is accessible to direct observation, is not of a homogeneous +character, but that it is made up of a number of layers or strata, the +titles of the principal groups of which are placed upon the accompanying +diagram. Each of these groups represents a number of beds of sand, of +stone, of clay, of slate, and of various other materials. + +[Illustration: FIG. 1.--IDEAL SECTION OF THE CRUST OF THE EARTH.] + +On careful examination, it is found that the materials of which each of +these layers of more or less hard rock are composed are, for the most +part, of the same nature as those which are at present being formed +under known conditions on the surface of the earth. For example, the +chalk, which constitutes a great part of the Cretaceous formation in +some parts of the world, is practically identical in its physical and +chemical characters with a substance which is now being formed at the +bottom of the Atlantic Ocean, and covers an enormous area; other beds of +rock are comparable with the sands which are being formed upon +sea-shores, packed together, and so on. Thus, omitting rocks of igneous +origin, it is demonstrable that all these beds of stone, of which a +total of not less than seventy thousand feet is known, have been formed +by natural agencies, either out of the waste and washing of the dry +land, or else by the accumulation of the exuviae of plants and animals. +Many of these strata are full of such exuviae--the so-called "fossils." +Remains of thousands of species of animals and plants, as perfectly +recognisable as those of existing forms of life which you meet with in +museums, or as the shells which you pick up upon the sea-beech, have +been imbedded in the ancient sands, or muds, or limestones, just as they +are being imbedded now, in sandy, or clayey, or calcareous subaqueous +deposits. They furnish us with a record, the general nature of which +cannot be misinterpreted, of the kinds of things that have lived upon +the surface of the earth during the time that is registered by this +great thickness of stratified rocks. But even a superficial study of +these fossils shows us that the animals and plants which live at the +present time have had only a temporary duration; for the remains of such +modern forms of life are met with, for the most part, only in the +uppermost or latest tertiaries, and their number rapidly diminishes in +the lower deposits of that epoch. In the older tertiaries, the places of +existing animals and plants are taken by other forms, as numerous and +diversified as those which live now in the same localities, but more or +less different from them; in the mesozoic rocks, these are replaced by +others yet more divergent from modern types; and in the palaeozoic +formations the contrast is still more marked. Thus the circumstantial +evidence absolutely negatives the conception of the eternity of the +present condition of things. We can say with certainty that the present +condition of things has existed for a comparatively short period; and +that, so far as animal and vegetable nature are concerned, it has been +preceded by a different condition. We can pursue this evidence until we +reach the lowest of the stratified rocks, in which we lose the +indications of life altogether. The hypothesis of the eternity of the +present state of nature may therefore be put out of court. + +We now come to what I will term Milton's hypothesis--the hypothesis that +the present condition of things has endured for a comparatively short +time; and, at the commencement of that time, came into existence within +the course of six days. I doubt not that it may have excited some +surprise in your minds that I should have spoken of this as Milton's +hypothesis, rather than that I should have chosen the terms which are +more customary, such as "the doctrine of creation," or "the Biblical +doctrine," or "the doctrine of Moses," all of which denominations, as +applied to the hypothesis to which I have just referred, are certainly +much more familiar to you than the title of the Miltonic hypothesis. But +I have had what I cannot but think are very weighty reasons for taking +the course which I have pursued. In the first place, I have discarded +the title of the "doctrine of creation," because my present business is +not with the question why the objects which constitute Nature came into +existence, but when they came into existence, and in what order. This is +as strictly a historical question as the question when the Angles and +the Jutes invaded England, and whether they preceded or followed the +Romans. But the question about creation is a philosophical problem, and +one which cannot be solved, or even approached, by the historical +method. What we want to learn is, whether the facts, so far as they are +known, afford evidence that things arose in the way described by Milton, +or whether they do not; and, when that question is settled, it will be +time enough to inquire into the causes of their origination. + +In the second place, I have not spoken of this doctrine as the Biblical +doctrine. It is quite true that persons as diverse in their general +views as Milton the Protestant and the celebrated Jesuit Father Suarez, +each put upon the first chapter of Genesis the interpretation embodied +in Milton's poem. It is quite true that this interpretation is that +which has been instilled into every one of us in our childhood; but I do +not for one moment venture to say that it can properly be called the +Biblical doctrine. It is not my business, and does not lie within my +competency, to say what the Hebrew text does, and what it does not +signify; moreover, were I to affirm that this is the Biblical doctrine, +I should be met by the authority of many eminent scholars, to say +nothing of men of science, who, at various times, have absolutely denied +that any such doctrine is to be found in Genesis. If we are to listen to +many expositors of no mean authority, we must believe that what seems so +clearly defined in Genesis--as if very great pains had been taken that +there should be no possibility of mistake--is not the meaning of the +text at all. The account is divided into periods that we may make just +as long or as short as convenience requires. We are also to understand +that it is consistent with the original text to believe that the most +complex plants and animals may have been evolved by natural processes, +lasting for millions of years, out of structureless rudiments. A person +who is not a Hebrew scholar can only stand aside and admire the +marvellous flexibility of a language which admits of such diverse +interpretations. But assuredly, in the face of such contradictions of +authority upon matters respecting which he is incompetent to form any +judgment, he will abstain, as I do, from giving any opinion. + +In the third place, I have carefully abstained from speaking of this as +the Mosaic doctrine, because we are now assured upon the authority of +the highest critics, and even of dignitaries of the Church, that there +is no evidence that Moses wrote the Book of Genesis, or knew anything +about it. You will understand that I give no judgment--it would be an +impertinence upon my part to volunteer even a suggestion--upon such a +subject. But, that being the state of opinion among the scholars and the +clergy, it is well for the unlearned in Hebrew lore, and for the laity, +to avoid entangling themselves in such a vexed question. Happily, Milton +leaves us no excuse for doubting what he means, and I shall therefore be +safe in speaking of the opinion in question as the Miltonic hypothesis. + +Now we have to test that hypothesis. For my part, I have no prejudice +one way or the other. If there is evidence in favour of this view, I am +burdened by no theoretical difficulties in the way of accepting it; but +there must be evidence. Scientific men get an awkward habit--no, I won't +call it that, for it is a valuable habit--of believing nothing unless +there is evidence for it; and they have a way of looking upon belief +which is not based upon evidence, not only as illogical, but as immoral. +We will, if you please, test this view by the circumstantial evidence +alone; for, from what I have said, you will understand that I do not +propose to discuss the question of what testimonial evidence is to be +adduced in favour of it. If those whose business it is to judge are not +at one as to the authenticity of the only evidence of that kind which is +offered, nor as to the facts to which it bears witness, the discussion +of such evidence is superfluous. + +But I may be permitted to regret this necessity of rejecting the +testimonial evidence the less, because the examination of the +circumstantial evidence leads to the conclusion, not only that it is +incompetent to justify the hypothesis, but that, so far as it goes, it +is contrary to the hypothesis. + +The considerations upon which I base this conclusion are of the simplest +possible character. The Miltonic hypothesis contains assertions of a +very definite character relating to the succession of living forms. It +is stated that plants, for example, made their appearance upon the third +day, and not before. And you will understand that what the poet means by +plants are such plants as now live, the ancestors, in the ordinary way +of propagation of like by like, of the trees and shrubs which flourish +in the present world. It must needs be so; for, if they were different, +either the existing plants have been the result of a separate +origination since that described by Milton, of which we have no record, +nor any ground for supposition that such an occurrence has taken place; +or else they have arisen by a process of evolution from the original +stocks. + +In the second place, it is clear that there was no animal life before +the fifth day, and that, on the fifth day, aquatic animals and birds +appeared. And it is further clear that terrestrial living things, other +than birds, made their appearance upon the sixth day, and not before. +Hence, it follows that, if, in the large mass of circumstantial evidence +as to what really has happened in the past history of the globe we find +indications of the existence of terrestrial animals, other than birds, +at a certain period, it is perfectly certain that all that has taken +place since that time must be referred to the sixth day. + +In the great Carboniferous formation, whence America derives so vast a +proportion of her actual and potential wealth, in the beds of coal which +have been formed from the vegetation of that period, we find abundant +evidence of the existence of terrestrial animals. They have been +described, not only by European but by your own naturalists. There are +to be found numerous insects allied to our cockroaches. There are to be +found spiders and scorpions of large size, the latter so similar to +existing scorpions that it requires the practised eye of the naturalist +to distinguish them. Inasmuch as these animals can be proved to have +been alive in the Carboniferous epoch, it is perfectly clear that, if +the Miltonic account is to be accepted, the huge mass of rocks extending +from the middle of the Palaeozoic formations to the uppermost members of +the series, must belong to the day which is termed by Milton the sixth. +But, further, it is expressly stated that aquatic animals took their +origin upon the fifth day, and not before; hence, all formations in +which remains of aquatic animals can be proved to exist, and which +therefore testify that such animals lived at the time when these +formations were in course of deposition, must have been deposited during +or since the period which Milton speaks of as the fifth day. But there +is absolutely no fossiliferous formation in which the remains of aquatic +animals are absent. The oldest fossils in the Silurian rocks are exuviae +of marine animals; and if the view which is entertained by Principal +Dawson and Dr. Carpenter respecting the nature of the _Eozooen_ be well +founded, aquatic animals existed at a period as far antecedent to the +deposition of the coal as the coal is from us; inasmuch as the _Eozooen_ +is met with in those Laurentian strata which lie at the bottom of the +series of stratified rocks. Hence it follows, plainly enough, that the +whole series of stratified rocks, if they are to be brought into harmony +with Milton, must be referred to the fifth and sixth days, and that we +cannot hope to find the slightest trace of the products of the earlier +days in the geological record. When we consider these simple facts, we +see how absolutely futile are the attempts that have been made to draw a +parallel between the story told by so much of the crust of the earth as +is known to us and the story which Milton tells. The whole series of +fossiliferous stratified rocks must be referred to the last two days; +and neither the Carboniferous, nor any other, formation can afford +evidence of the work of the third day. + +Not only is there this objection to any attempt to establish a harmony +between the Miltonic account and the facts recorded in the fossiliferous +rocks, but there is a further difficulty. According to the Miltonic +account, the order in which animals should have made their appearance in +the stratified rocks would be this: Fishes, including the great whales, +and birds; after them, all varieties of terrestrial animals except +birds. Nothing could be further from the facts as we find them; we know +of not the slightest evidence of the existence of birds before the +Jurassic, or perhaps the Triassic, formation; while terrestrial animals, +as we have just seen, occur in the Carboniferous rocks. + +If there were any harmony between the Miltonic account and the +circumstantial evidence, we ought to have abundant evidence of the +existence of birds in the Carboniferous, the Devonian, and the Silurian +rocks. I need hardly say that this is not the case, and that not a trace +of birds makes its appearance until the far later period which I have +mentioned. + +And again, if it be true that all varieties of fishes and the great +whales, and the like, made their appearance on the fifth day, we ought +to find the remains of these animals in the older rocks--in those which +were deposited before the Carboniferous epoch. Fishes we do find, in +considerable number and variety; but the great whales are absent, and +the fishes are not such as now live. Not one solitary species of fish +now in existence is to be found in the Devonian or Silurian formations. +Hence we are introduced afresh to the dilemma which I have already +placed before you: either the animals which came into existence on the +fifth day were not such as those which are found at present, are not the +direct and immediate ancestors of those which now exist; in which case +either fresh creations of which nothing is said; or a process of +evolution must have occurred; or else the whole story must be given up, +as not only devoid of any circumstantial evidence, but contrary to such +evidence as exists. + +I placed before you in a few words, some little time ago, a statement of +the sum and substance of Milton's hypothesis. Let me now try to state as +briefly, the effect of the circumstantial evidence bearing upon the past +history of the earth which is furnished, without the possibility of +mistake, with no chance of error as to its chief features, by the +stratified rocks. What we find is, that the great series of formations +represents a period of time of which our human chronologies hardly +afford us a unit of measure. I will not pretend to say how we ought to +estimate this time, in millions or in billions of years. For my purpose, +the determination of its absolute duration is wholly unessential. But +that the time was enormous there can be no question. + +It results from the simplest methods of interpretation, that leaving out +of view certain patches of metamorphosed rocks, and certain volcanic +products, all that is now dry land has once been at the bottom of the +waters. It is perfectly certain that, at a comparatively recent period +of the world's history--the Cretaceous epoch--none of the great physical +features which at present mark the surface of the globe existed. It is +certain that the Rocky Mountains were not. It is certain that the +Himalaya Mountains were not. It is certain that the Alps and the +Pyrenees had no existence. The evidence is of the plainest possible +character, and is simply this:--We find raised up on the flanks of these +mountains, elevated by the forces of upheaval which have given rise to +them, masses of Cretaceous rock which formed the bottom of the sea +before those mountains existed. It is therefore clear that the elevatory +forces which gave rise to the mountains operated subsequently to the +Cretaceous epoch; and that the mountains themselves are largely made up +of the materials deposited in the sea which once occupied their place. +As we go back in time, we meet with constant alternations of sea and +land, of estuary and open ocean; and, in correspondence with these +alternations, we observe the changes in the fauna and flora to which I +have referred. + +But the inspection of these changes give us no right to believe that +there has been any discontinuity in natural processes. There is no trace +of general cataclysms, of universal deluges, or sudden destructions of a +whole fauna or flora. The appearances which were formerly interpreted in +that way have all been shown to be delusive, as our knowledge has +increased and as the blanks which formerly appeared to exist between the +different formations have been filled up. That there is no absolute +break between formation and formation, that there has been no sudden +disappearance of all the forms of life and replacement of them by +others, but that changes have gone on slowly and gradually, that one +type has died out and another has taken its place, and that thus, by +insensible degrees, one fauna has been replaced by another, are +conclusions strengthened by constantly increasing evidence. So that +within the whole of the immense period indicated by the fossiliferous +stratified rocks, there is assuredly not the slightest proof of any +break in the uniformity of Nature's operations, no indication that +events have followed other than a clear and orderly sequence. + +That, I say, is the natural and obvious teaching of the circumstantial +evidence contained in the stratified rocks. I leave you to consider how +far, by any ingenuity of interpretation, by any stretching of the +meaning of language, it can be brought into harmony with the Miltonic +hypothesis. + +There remains the third hypothesis, that of which I have spoken as the +hypothesis of evolution; and I purpose that, in lectures to come, we +should discuss it as carefully as we have considered the other two +hypotheses. I need not say that it is quite hopeless to look for +testimonial evidence of evolution. The very nature of the case precludes +the possibility of such evidence, for the human race can no more be +expected to testify to its own origin, than a child can be tendered as a +witness of its own birth. Our sole inquiry is, what foundation +circumstantial evidence lends to the hypothesis, or whether it lends +none, or whether it controverts the hypothesis. I shall deal with the +matter entirely as a question of history. I shall not indulge in the +discussion of any speculative probabilities. I shall not attempt to show +that Nature is unintelligible unless we adopt some such hypothesis. For +anything I know about the matter, it may be the way of Nature to be +unintelligible; she is often puzzling, and I have no reason to suppose +that she is bound to fit herself to our notions. + +I shall place before you three kinds of evidence entirely based upon +what is known of the forms of animal life which are contained in the +series of stratified rocks. I shall endeavour to show you that there is +one kind of evidence which is neutral, which neither helps evolution nor +is inconsistent with it. I shall then bring forward a second kind of +evidence which indicates a strong probability in favour of evolution, +but does not prove it; and, lastly, I shall adduce a third kind of +evidence which, being as complete as any evidence which we can hope to +obtain upon such a subject, and being wholly and strikingly in favour of +evolution, may fairly be called demonstrative evidence of its +occurrence. + + + + +LECTURE II. + +THE HYPOTHESIS OF EVOLUTION. THE NEUTRAL AND THE FAVOURABLE EVIDENCE. + + +In the preceding lecture I pointed out that there are three hypotheses +which may be entertained, and which have been entertained, respecting +the past history of life upon the globe. According to the first of these +hypotheses, living beings, such as now exist, have existed from all +eternity upon this earth. We tested that hypothesis by the +circumstantial evidence, as I called it, which is furnished by the +fossil remains contained in the earth's crust, and we found that it was +obviously untenable. I then proceeded to consider the second hypothesis, +which I termed the Miltonic hypothesis, not because it is of any +particular consequence to me whether John Milton seriously entertained +it or not, but because it is stated in a clear and unmistakable manner +in his great poem. I pointed out to you that the evidence at our command +as completely and fully negatives that hypothesis as it did the +preceding one. And I confess that I had too much respect for your +intelligence to think it necessary to add that the negation was equally +clear and equally valid, whatever the source from which that hypothesis +might be derived, or whatever the authority by which it might be +supported. I further stated that, according to the third hypothesis, or +that of evolution, the existing state of things is the last term of a +long series of states, which, when traced back, would be found to show +no interruption and no breach in the continuity of natural causation. I +propose, in the present, and the following lecture, to test this +hypothesis rigorously by the evidence at command, and to inquire how far +that evidence can be said to be indifferent to it, how far it can be +said to be favourable to it, and, finally, how far it can be said to be +demonstrative. + +From almost the origin of the discussions about the existing condition +of the animal and vegetable worlds and the causes which have determined +that condition, an argument has been put forward as an objection to +evolution, which we shall have to consider very seriously. It is an +argument which was first clearly stated by Cuvier in his criticism of +the doctrines propounded by his great contemporary, Lamarck. The French +expedition to Egypt had called the attention of learned men to the +wonderful store of antiquities in that country, and there had been +brought back to France numerous mummified corpses of the animals which +the ancient Egyptians revered and preserved, and which, at a reasonable +computation, must have lived not less than three or four thousand years +before the time at which they were thus brought to light. Cuvier +endeavoured to test the hypothesis that animals have undergone gradual +and progressive modifications of structure, by comparing the skeletons +and such other parts of the mummies as were in a fitting state of +preservation, with the corresponding parts of the representatives of the +same species now living in Egypt. He arrived at the conviction that no +appreciable change had taken place in these animals in the course of +this considerable lapse of time, and the justice of his conclusion is +not disputed. + +It is obvious that, if it can be proved that animals have endured, +without undergoing any demonstrable change of structure, for so long a +period as four thousand years, no form of the hypothesis of evolution +which assumes that animals undergo a constant and necessary progressive +change can be tenable; unless, indeed, it be further assumed that four +thousand years is too short a time for the production of a change +sufficiently great to be detected. + +But it is no less plain that if the process of evolution of animals is +not independent of surrounding conditions; if it may be indefinitely +hastened or retarded by variations in these conditions; or if evolution +is simply a process of accommodation to varying conditions; the argument +against the hypothesis of evolution based on the unchanged character of +the Egyptian fauna is worthless. For the monuments which are coeval with +the mummies testify as strongly to the absence of change in the physical +geography and the general conditions of the land of Egypt, for the time +in question, as the mummies do to the unvarying characters of its living +population. + +The progress of research since Cuvier's time has supplied far more +striking examples of the long duration of specific forms of life than +those which are furnished by the mummified Ibises and Crocodiles of +Egypt. A remarkable case is to be found in your own country, in the +neighbourhood of the falls of Niagara. In the immediate vicinity of the +whirlpool, and again upon Goat Island, in the superficial deposits which +cover the surface of the rocky subsoil in those regions, there are found +remains of animals in perfect preservation, and among them, shells +belonging to exactly the same species as those which at present inhabit +the still waters of Lake Erie. It is evident, from the structure of the +country, that these animal remains were deposited in the beds in which +they occur at a time when the lake extended over the region in which +they are found. This involves the conclusion that they lived and died +before the falls had cut their way back through the gorge of Niagara; +and, indeed, it has been determined that, when these animals lived, the +falls of Niagara must have been at least six miles further down the +river than they are at present. Many computations have been made of the +rate at which the falls are thus cutting their way back. Those +computations have varied greatly, but I believe I am speaking within the +bounds of prudence, if I assume that the falls of Niagara have not +retreated at a greater pace than about a foot a year. Six miles, +speaking roughly, are 30,000 feet; 30,000 feet, at a foot a year, gives +30,000 years; and thus we are fairly justified in concluding that no +less a period than this has passed since the shell-fish, whose remains +are left in the beds to which I have referred, were living creatures. + +But there is still stronger evidence of the long duration of certain +types. I have already stated that, as we work our way through the great +series of the Tertiary formations, we find many species of animals +identical with those which live at the present day, diminishing in +numbers, it is true, but still existing, in a certain proportion, in the +oldest of the Tertiary rocks. Furthermore, when we examine the rocks of +the Cretaceous epoch, we find the remains of some animals which the +closest scrutiny cannot show to be, in any important respect, different +from those which live at the present time. That is the case with one of +the cretaceous lamp-shells (_Terebratula_), which has continued to exist +unchanged, or with insignificant variations, down to the present day. +Such is the case with the _Globigerinae_, the skeletons of which, +aggregated together, form a large proportion of our English chalk. Those +_Globigerinae_ can be traced down to the _Globigerinae_ which live at the +surface of the present great oceans, and the remains of which, falling +to the bottom of the sea, give rise to a chalky mud. Hence it must be +admitted that certain existing species of animals show no distinct sign +of modification, or transformation, in the course of a lapse of time as +great as that which carries us back to the Cretaceous period; and which, +whatever its absolute measure, is certainly vastly greater than thirty +thousand years. + +There are groups of species so closely allied together that it needs the +eye of a naturalist to distinguish them one from another. If we +disregard the small differences which separate these forms and consider +all the species of such groups as modifications of one type, we shall +find that, even among the higher animals, some types have had a +marvellous duration. In the chalk, for example, there is found a fish +belonging to the highest and the most differentiated group of osseous +fishes, which goes by the name of _Beryx_. The remains of that fish are +among the most beautiful and well preserved of the fossils found in our +English chalk. It can be studied anatomically, so far as the hard parts +are concerned, almost as well as if it were a recent fish. But the genus +_Beryx_ is represented, at the present day, by very closely allied +species which are living in the Pacific and Atlantic Oceans. We may go +still farther back. I have already referred to the fact that the +Carboniferous formations, in Europe and in America, contain the remains +of scorpions in an admirable state of preservation, and that those +scorpions are hardly distinguishable from such as now live. I do not +mean to say that they are not different, but close scrutiny is needed in +order to distinguish them from modern scorpions. + +More than this. At the very bottom of the Silurian series, in beds which +are by some authorities referred to the Cambrian formation, where the +signs of life begin to fail us--even there, among the few and scanty +animal remains which are discoverable, we find species of molluscous +animals which are so closely allied to existing forms that, at one time, +they were grouped under the same generic name. I refer to the well-known +_Lingula_ of the _Lingula_ flags, lately, in consequence of some slight +differences, placed in the new genus _Lingulella_. Practically, it +belongs to the same great generic group as the _Lingula_, which is to be +found at the present day upon your own shores and those of many other +parts of the world. + +The same truth is exemplified if we turn to certain great periods of the +earth's history--as, for example, the Mesozoic epoch. There are groups +of reptiles, such as the _Ichthyosauria_ and the _Plesiosauria_, which +appear shortly after the commencement of this epoch, and they occur in +vast numbers. They disappear with the chalk and, throughout the whole of +the great series of Mesozoic rocks, they present no such modifications +as can safely be considered evidence of progressive modification. + +Facts of this kind are undoubtedly fatal to any form of the doctrine of +evolution which postulates the supposition that there is an intrinsic +necessity, on the part of animal forms which have once come into +existence, to undergo continual modification; and they are as distinctly +opposed to any view which involves the belief, that such modification as +may occur, must take place, at the same rate, in all the different types +of animal or vegetable life. The facts, as I have placed them before +you, obviously directly contradict any form of the hypothesis of +evolution which stands in need of these two postulates. + +But, one great service that has been rendered by Mr. Darwin to the +doctrine of evolution in general is this: he has shown that there are +two chief factors in the process of evolution: one of them is the +tendency to vary, the existence of which in all living forms may be +proved by observation; the other is the influence of surrounding +conditions upon what I may call the parent form and the variations which +are thus evolved from it. The cause of the production of variations is a +matter not at all properly understood at present. Whether variation +depends upon some intricate machinery--if I may use the phrase--of the +living organism itself, or whether it arises through the influence of +conditions upon that form, is not certain, and the question may, for the +present, be left open. But the important point is that, granting the +existence of the tendency to the production of variations; then, whether +the variations which are produced shall survive and supplant the parent, +or whether the parent form shall survive and supplant the variations, is +a matter which depends entirely on those conditions which give rise to +the struggle for existence. If the surrounding conditions are such that +the parent form is more competent to deal with them and flourish in +them, than the derived forms, then, in the struggle for existence, the +parent form will maintain itself and the derived forms will be +exterminated. But if, on the contrary, the conditions are such as to be +more favourable to a derived than to the parent form, the parent form +will be extirpated and the derived form will take its place. In the +first case, there will be no progression, no change of structure, +through any imaginable series of ages; in the second place, there will +be modification and change of form. + +Thus the existence of these persistent types, as I have termed them, is +no real obstacle in the way of the theory of evolution. Take the case of +the scorpions to which I have just referred. No doubt, since the +Carboniferous epoch, conditions have always obtained, such as existed +when the scorpions of that epoch flourished; conditions in which +scorpions find themselves better off, more competent to deal with the +difficulties in their way, than any variation from the scorpion type +which they may have produced; and, for that reason, the scorpion type +has persisted, and has not been supplanted by any other form. And there +is no reason, in the nature of things, why, as long as this world +exists, if there be conditions more favourable to scorpions than to any +variation which may arise from them, these forms of life should not +persist. + +Therefore, the stock objection to the hypothesis of evolution, based on +the long duration of certain animal and vegetable types, is no objection +at all. The facts of this character--and they are numerous--belong to +that class of evidence which I have called indifferent. That is to say, +they may afford no direct support to the doctrine of evolution, but they +are capable of being interpreted in perfect consistency with it. + +There is another order of facts belonging to the class of negative or +indifferent evidence. The great group of Lizards, which abound in the +present world, extends through the whole series of formations as far +back as the Permian, or latest Palaeozoic, epoch. These Permian lizards +differ astonishingly little from the lizards which exist at the present +day. Comparing the amount of the differences between them and modern +lizards, with the prodigious lapse of time between the Permian epoch and +the present age, it may be said that the amount of change is +insignificant. But, when we carry our researches farther back in time, +we find no trace of lizards, nor of any true reptile whatever, in the +whole mass of formations beneath the Permian. + +Now, it is perfectly clear that if our palaeontological collections are +to be taken, even approximately, as an adequate representation of all +the forms of animals and plants that have ever lived; and if the record +furnished by the known series of beds of stratified rock, covers the +whole series of events which constitute the history of life on the +globe, such a fact as this directly contravenes the hypothesis of +evolution; because this hypothesis postulates that the existence of +every form must have been preceded by that of some form little different +from it. Here, however, we have to take into consideration that +important truth so well insisted upon by Lyell and by Darwin--the +imperfection of the geological record. It can be demonstrated that the +geological record must be incomplete, that it can only preserve remains +found in certain favourable localities and under particular conditions; +that it must be destroyed by processes of denudation, and obliterated by +processes of metamorphosis. Beds of rock of any thickness, crammed full +of organic remains, may yet, either by the percolation of water through +them, or by the influence of subterranean heat, lose all trace of these +remains, and present the appearance of beds of rock formed under +conditions in which living forms were absent. Such metamorphic rocks +occur in formations of all ages; and, in various cases, there are very +good grounds for the belief that they have contained organic remains, +and that those remains have been absolutely obliterated. + +I insist upon the defects of the geological record the more because +those who have not attended to these matters are apt to say, "It is all +very well, but when you get into a difficulty with your theory of +evolution, you appeal to the incompleteness and the imperfection of the +geological record;" and I want to make it perfectly clear to you that +this imperfection is a great fact, which must be taken into account in +all our speculations, or we shall constantly be going wrong. + +[Illustration: FIG. 2.--TRACKS OF BRONTOZOUM.] + +You see the singular series of footmarks, drawn of its natural size in +the large diagram hanging up here (Fig. 2), which I owe to the kindness +of my friend Professor Marsh, with whom I had the opportunity recently +of visiting the precise locality in Massachusetts in which these tracks +occur. I am, therefore, able to give you my own testimony, if needed, +that the diagram accurately represents what we saw. The valley of the +Connecticut is classical ground for the geologist. It contains great +beds of sandstone, covering many square miles, which have evidently +formed a part of an ancient sea-shore, or, it may be, lake-shore. For a +certain period of time after their deposition, these beds have remained +sufficiently soft to receive the impressions of the feet of whatever +animals walked over them, and to preserve them afterwards, in exactly +the same way as such impressions are at this hour preserved on the +shores of the Bay of Fundy and elsewhere. The diagram represents the +track of some gigantic animal, which walked on its hind legs. You see +the series of marks made alternately by the right and by the left foot; +so that, from one impression to the other of the three-toed foot on the +same side, is one stride, and that stride, as we measured it, is six +feet nine inches. I leave you, therefore, to form an impression of the +magnitude of the creature which, as it walked along the ancient shore, +made these impressions. + +Of such impressions there are untold thousands upon these sandstones. +Fifty or sixty different kinds have been discovered, and they cover vast +areas. But, up to this present time, not a bone, not a fragment, of any +one of the animals which left these great footmarks has been found; in +fact, the only animal remains which have been met with in all these +deposits, from the time of their discovery to the present day--though +they have been carefully hunted over--is a fragmentary skeleton of one +of the smaller forms. What has become of the bones of all these animals? +You see we are not dealing with little creatures, but with animals that +make a step of six feet nine inches; and their remains must have been +left somewhere. The probability is, that they been dissolved away, and +absolutely lost. + +I have had occasion to work out the nature of fossil remains, of which +there was nothing left except casts of the bones, the solid material of +the skeleton having been dissolved out by percolating water. It was a +chance, in this case, that the sandstone happened to be of such a +constitution as to set, and to allow the bones to be afterward dissolved +out, leaving cavities of the exact shape of the bones. Had that +constitution been other than what it was, the bones would have been +dissolved, the layers of sandstone would have fallen together into one +mass, and not the slightest indication that the animal had existed would +have been discoverable. + +I know of no more striking evidence than these facts afford, of the +caution which should be used in drawing the conclusion, from the absence +of organic remains in a deposit, that animals or plants did not exist at +the time it was formed. I believe that, with a right understanding of +the doctrine of evolution on the one hand, and a just estimation of the +importance of the imperfection of the geological record on the other, +all difficulty is removed from the kind of evidence to which I have +adverted; and that we are justified in believing that all such cases are +examples of what I have designated negative or indifferent +evidence--that is to say, they in no way directly advance the hypothesis +of evolution, but they are not to be regarded as obstacles in the way of +our belief in that doctrine. + +I now pass on to the consideration of those cases which, for reasons +which I will point out to you by and by, are not to be regarded as +demonstrative of the truth of evolution, but which are such as must +exist if evolution be true, and which therefore are, upon the whole, +evidence in favour of the doctrine. If the doctrine of evolution be +true, it follows, that, however diverse the different groups of animals +and of plants may be, they must all, at one time or other, have been +connected by gradational forms; so that, from the highest animals, +whatever they may be, down to the lowest speck of protoplasmic matter in +which life can be manifested, a series of gradations, leading from one +end of the series to the other, either exists or has existed. +Undoubtedly that is a necessary postulate of the doctrine of evolution. +But when we look upon living Nature as it is, we find a totally +different state of things. We find that animals and plants fall into +groups, the different members of which are pretty closely allied +together, but which are separated by definite, larger or smaller, breaks +from other groups. In other words, no intermediate forms which bridge +over these gaps or intervals are, at present, to be met with. + +To illustrate what I mean: Let me call your attention to those +vertebrate animals which are most familiar to you, such as mammals, +birds, and reptiles. At the present day, these groups of animals are +perfectly well defined from one another. We know of no animal now living +which, in any sense, is intermediate between the mammal and the bird, or +between the bird and the reptile; but, on the contrary, there are many +very distinct anatomical peculiarities, well-defined marks, by which the +mammal is separated from the bird, and the bird from the reptile. The +distinctions are obvious and striking if you compare the definitions of +these great groups as they now exist. + +The same may be said of many of the subordinate groups, or orders, into +which these great classes are divided. At the present time, for example, +there are numerous forms of non-ruminant pachyderms, or what we may call +broadly, the pig tribe, and many varieties of ruminants. These latter +have their definite characteristics, and the former have their +distinguishing peculiarities. But there is nothing that fills up the gap +between the ruminants and the pig tribe. The two are distinct. Such also +is the case in respect of the minor groups of the class of reptiles. The +existing fauna shows us crocodiles, lizards, snakes, and tortoises; but +no connecting link between the crocodile and lizard, nor between the +lizard and snake, nor between the snake and the crocodile, nor between +any two of these groups. They are separated by absolute breaks. If, +then, it could be shown that this state of things had always existed, +the fact would be fatal to the doctrine of evolution. If the +intermediate gradations, which the doctrine of evolution requires to +have existed between these groups, are not to be found anywhere in the +records of the past history of the globe, their absence is a strong and +weighty negative argument against evolution; while, on the other hand, +if such intermediate forms are to be found, that is so much to the good +of evolution; although, for reasons which I will lay before you by and +by, we must be cautious in our estimate of the evidential cogency of +facts of this kind. + +It is a very remarkable circumstance that, from the commencement of the +serious study of fossil remains; in fact, from the time when Cuvier +began his brilliant researches upon those found in the quarries of +Montmartre, palaeontology has shown what she was going to do in this +matter, and what kind of evidence it lay in her power to produce. + +I said just now that, in the existing Fauna, the group of pig-like +animals and the group of ruminants are entirely distinct; but one of the +first of Cuvier's discoveries was an animal which he called the +_Anoplotherium_, and which proved to be, in a great many important +respects, intermediate in character between the pigs, on the one hand, +and the ruminants on the other. Thus research into the history of the +past did, to a certain extent, tend to fill up the breach between the +group of ruminants and the group of pigs. Another remarkable animal +restored by the great French palaeontologist, the _Palaeotherium_, +similarly tended to connect together animals to all appearance so +different as the rhinoceros, the horse, and the tapir. Subsequent +research has brought to light multitudes of facts of the same order; +and, at the present day, the investigations of such anatomists as +Ruetimeyer and Gaudry have tended to fill up, more and more, the gaps in +our existing series of mammals, and to connect groups formerly thought +to be distinct. + +But I think it may have an especial interest if, instead of dealing with +these examples, which would require a great deal of tedious osteological +detail, I take the case of birds and reptiles; groups which, at the +present day, are so clearly distinguished from one another that there +are perhaps no classes of animals which, in popular apprehension, are +more completely separated. Existing birds, as you are aware, are covered +with feathers; their anterior extremities, specially and peculiarly +modified, are converted into wings, by the aid of which most of them are +able to fly; they walk upright upon two legs; and these limbs, when they +are considered anatomically, present a great number of exceedingly +remarkable peculiarities, to which I may have occasion to advert +incidentally as I go on, and which are not met with, even approximately, +in any existing forms of reptiles. On the other hand, existing reptiles +have no feathers. They may have naked skins, or be covered with horny +scales, or bony plates, or with both. They possess no wings; they +neither fly by means of their fore-limbs, nor habitually walk upright +upon their hind-limbs; and the bones of their legs present no such +modifications as we find in birds. It is impossible to imagine any two +groups more definitely and distinctly separated, notwithstanding certain +characters which they possess in common. + +As we trace the history of birds back in time, we find their remains, +sometimes in great abundance, throughout the whole extent of the +tertiary rocks; but, so far as our present knowledge goes, the birds of +the tertiary rocks retain the same essential characters as the birds of +the present day. In other words, the tertiary birds come within the +definition of the class constituted by existing birds, and are as much +separated from reptiles as existing birds are. Not very long ago no +remains of birds had been found below the tertiary rocks, and I am not +sure but that some persons were prepared to demonstrate that they could +not have existed at an earlier period. But in the course of the last few +years, such remains have been discovered in England; though, +unfortunately, in so imperfect and fragmentary a condition, that it is +impossible to say whether they differed from existing birds in any +essential character or not. In your country the development of the +cretaceous series of rocks is enormous; the conditions under which the +later cretaceous strata have been deposited are highly favourable to the +preservation of organic remains; and the researches, full of labour and +risk, which have been carried on by Professor Marsh in these cretaceous +rocks of Western America, have rewarded him with the discovery of forms +of birds of which we had hitherto no conception. By his kindness, I am +enabled to place before you a restoration of one of these extraordinary +birds, every part of which can be thoroughly justified by the more or +less complete skeletons, in a very perfect state of preservation, which +he has discovered. This _Hesperornis_ (Fig. 3), which measured between +five and six feet in length, is astonishingly like our existing divers +or grebes in a great many respects; so like them indeed that, had the +skeleton of _Hesperornis_ been found in a museum without its skull, it +probably would have been placed in the same group of birds as the divers +and grebes of the present day.[1] + +[Illustration: FIG. 3.--HESPERORNIS REGALIS (Marsh).] + +But _Hesperornis_ differs from all existing birds, and so far resembles +reptiles, in one important particular--it is provided with teeth. The +long jaws are armed with teeth which have curved crowns and thick roots +(Fig. 4), and are not set in distinct sockets, but are lodged in a +groove. In possessing true teeth, the _Hesperornis_ differs from every +existing bird, and from every bird yet discovered in the tertiary +formations, the tooth-like serrations of the jaws in the _Odontopteryx_ +of the London clay being mere processes of the bony substance of the +jaws, and not teeth in the proper sense of the word. In view of the +characteristics of this bird we are therefore obliged to modify the +definitions of the classes of birds and reptiles. Before the discovery +of _Hesperornis_, the definition of the class Aves based upon our +knowledge of existing birds, might have been extended to all birds; it +might have been said that the absence of teeth was characteristic of the +class of birds; but the discovery of an animal which, in every part of +its skeleton, closely agrees with existing birds, and yet possesses +teeth, shows that there were ancient birds which, in respect of +possessing teeth, approached reptiles more nearly than any existing bird +does, and, to that extent, diminishes the _hiatus_ between the two +classes. + +[Illustration: FIG. 4.--HESPERORNIS REGALIS (Marsh). + +(Side and upper views of half the lower jaw; side and end views of a +vertebra and a separate tooth.)] + +The same formation has yielded another bird _Ichthyornis_ (Fig. 5), +which also possesses teeth; but the teeth are situated in distinct +sockets, while those of _Hesperornis_ are not so lodged. The latter also +has such very small, almost rudimentary, wings, that it must have been +chiefly a swimmer and a diver, like a Penguin; while _Ichthyornis_ has +strong wings and no doubt possessed corresponding powers of flight. +_Ichthyornis_ also differed in the fact that its vertebrae have not the +peculiar characters of the vertebrae of existing and of all known +tertiary birds, but were concave at each end. This discovery leads us to +make a further modification in the definition of the group of birds, and +to part with another of the characters by which almost all existing +birds are distinguished from reptiles. + +[Illustration: FIG. 5.--ICHTHYORNIS DISPAR (Marsh). + +(Side and upper views of half the lower jaw; and side and end views of a +vertebra.)] + +Apart from the few fragmentary remains from the English greensand, to +which I have referred, the mesozoic rocks, older than those in which +_Hesperornis_ and _Ichthyornis_ have been discovered have afforded no +certain evidence of birds, with the remarkable exception of the +Solenhofen slates. These so-called slates are composed of a fine grained +calcareous mud which has hardened into lithographic stone, and in which +organic remains are almost as well preserved as they would be if they +had been imbedded in so much plaster of Paris. They have yielded the +_Archaeopteryx_, the existence of which was first made known by the +finding of a fossil feather, or rather of the impression of one. It is +wonderful enough that such a perishable thing as a feather, and nothing +more, should be discovered; yet, for a long time, nothing was known of +this bird except its feather. But, by and by a solitary skeleton was +discovered, which is now in the British Museum. The skull of this +solitary specimen is unfortunately wanting, and it is therefore +uncertain whether the _Archaeopteryx_ possessed teeth or not. But the +remainder of the skeleton is so well preserved as to leave no doubt +respecting the main features of the animal, which are very singular. The +feet are not only altogether bird-like, but have the special characters +of the feet of perching birds, while the body had a clothing of true +feathers. Nevertheless, in some other respects, _Archaeopteryx_ is unlike +a bird and like a reptile. There is a long tail composed of many +vertebrae. The structure of the wing differs in some very remarkable +respects from that which it presents in a true bird. In the latter, the +end of the wing answers to the thumb and two fingers of my hand; but the +metacarpal bones, or those which answer to the bones of the fingers +which lie in the palm of the hand, are fused together into one mass; and +the whole apparatus, except the last joints of the thumb, is bound up in +a sheath of integument, while the edge of the hand carries the principal +quill-feathers. In the _Archaeopteryx_, the upper-arm bone is like that +of a bird; and the two bones of the fore-arm are more or less like those +of a bird, but the fingers are not bound together--they are free. What +their number may have been is uncertain; but several, if not all, of +them were terminated by strong curved claws, not like such as are +sometimes found in birds, but such as reptiles possess; so that, in the +_Archaeopteryx_, we have an animal which, to a certain extent, occupies a +midway place between a bird and a reptile. It is a bird so far as its +foot and sundry other parts of its skeleton are concerned; it is +essentially and thoroughly a bird by its feathers; but it is much more +properly a reptile in the fact that the region which represents the hand +has separate bones, with claws resembling those which terminate the +fore-limb of a reptile. Moreover, it had a long reptile-like tail with a +fringe of feathers on each side; while, in all true birds hitherto +known, the tail is relatively short, and the vertebrae which constitute +its skeleton are generally peculiarly modified. + +Like the _Anoplotherium_ and the _Palaeotherium_, therefore, +_Archaeopteryx_ tends to fill up the interval between groups which, in +the existing world, are widely separated, and to destroy the value of +the definitions of zoological groups based upon our knowledge of +existing forms. And such cases as these constitute evidence in favour of +evolution, in so far as they prove that, in former periods of the +world's history, there were animals which overstepped the bounds of +existing groups, and tended to merge them into larger assemblages. They +show that animal organisation is more flexible than our knowledge of +recent forms might have led us to believe; and that many structural +permutations and combinations, of which the present world gives us no +indication, may nevertheless have existed. + +But it by no means follows, because the _Palaeotherium_ has much in +common with the Horse, on the one hand, and with the Rhinoceros on the +other, that it is the intermediate form through which Rhinoceroses have +passed to become Horses, or _vice versa_; on the contrary, any such +supposition would certainly be erroneous. Nor do I think it likely that +the transition from the reptile to the bird has been effected by such a +form as _Archaeopteryx_. And it is convenient to distinguish these +intermediate forms between two groups, which do not represent the actual +passage from the one group to the other, as _intercalary_ types, from +those _linear_ types which, more or less approximately, indicate the +nature of the steps by which the transition from one group to the other +was effected. + +I conceive that such linear forms, constituting a series of natural +gradations between the reptile and the bird, and enabling us to +understand the manner in which the reptilian has been metamorphosed into +the bird type, are really to be found among a group of ancient and +extinct terrestrial reptiles known as the _Ornithoscelida_. The remains +of these animals occur throughout the series of mesozoic formations, +from the Trias to the Chalk, and there are indications of their +existence even in the later Palaeozoic strata. + +Most of these reptiles at present known are of great size, some having +attained a length of forty feet or perhaps more. The majority resembled +lizards and crocodiles in their general form, and many of them were, +like crocodiles, protected by an armour of heavy bony plates. But, in +others, the hind limbs elongate and the fore limbs shorten, until their +relative proportions approach those which are observed in the +short-winged, flightless, ostrich tribe among birds. + +The skull is relatively light, and in some cases the jaws, though +bearing teeth, are beak-like at their extremities and appear to have +been enveloped in a horny sheath. In the part of the vertebral column +which lies between the haunch bones and is called the sacrum, a number +of vertebrae may unite together into one whole, and in this respect, as +in some details of its structure, the sacrum of these reptiles +approaches that of birds. + +But it is in the structure of the pelvis and of the hind limb that some +of these ancient reptiles present the most remarkable approximation to +birds, and clearly indicate the way by which the most specialized and +characteristic features of the bird may have been evolved from the +corresponding parts in the reptile. + +In Fig. 6, the pelvis and hind limbs of a crocodile, a three-toed bird, +and an ornithoscelidan are represented side by side; and, for facility +of comparison, in corresponding positions; but it must be recollected +that, while the position of the bird's limb is natural, that of the +crocodile is not so. In the bird, the thigh-bone lies close to the body, +and the metatarsal bones of the foot (ii., iii., iv., Fig. 6) are, +ordinarily, raised into a more or less vertical position; in the +crocodile, the thigh-bone stands out at an angle from the body, and the +metatarsal bones (i., ii., iii., iv., Fig. 6) lie flat on the ground. +Hence, in the crocodile, the body usually lies squat between the legs, +while, in the bird, it is raised upon the hind legs, as upon pillars. + +In the crocodile, the pelvis is obviously composed of three bones on +each side: the ilium (Il.), the pubis (Pb.), and the ischium (Is.). In +the adult bird there appears to be but one bone on each side. The +examination of the pelvis of a chick, however, shows that each half is +made up of three bones, which answer to those which remain distinct +throughout life, in the crocodile. There is, therefore, a fundamental +identity of plan in the construction of the pelvis of both bird and +reptile; though the differences in form, relative size, and direction of +the corresponding bones in the two cases are very great. + +But the most striking contrast between the two lies in the bones of the +leg and of that part of the foot termed the tarsus, which follows upon +the leg. In the crocodile, the fibula (F) is relatively large and its +lower end is complete. The tibia (T) has no marked crest at its upper +end, and its lower end is narrow and not pulley-shaped. There are two +rows of separate tarsal bones (As., Ca., &c.) and four distinct +metatarsal bones, with a rudiment of a fifth. + +In the bird, the fibula is small and its lower end diminishes to a +point. The tibia has a strong crest at its upper end and its lower +extremity passes into a broad pulley. There seem at first to be no +tarsal bones; and only one bone, divided at the end into three heads for +the three toes which are attached to it, appears in the place of the +metatarsus. + +In a young bird, however, the pulley-shaped apparent end of the tibia is +a distinct bone, which represents the bones marked As., Ca., in the +crocodile; while the apparently single metatarsal bone consists of three +bones, which early unite with one another and with an additional bone, +which represents the lower row of bones in the tarsus of the crocodile. + +In other words, it can be shown by the study of development that the +bird's pelvis and hind limb are simply extreme modifications of the same +fundamental plan as that upon which these parts are modelled in +reptiles. + +[Illustration: FIG. 6.--BIRD. ORNITHOSCELIDAN. CROCODILE. + +(The letters have the same signification in all the figures. Il., +Ilium; a, anterior end; b, posterior end; Is., ischium; Pb., +pubis; T, tibia; F, fibula; As., astragalus; Ca., calcaneum; 1, +distal portion of the tarsus; i., ii., iii., iv.; metatarsal bones.)] + +On comparing the pelvis and hind limb of the ornithoscelidan with that +of the crocodile, on the one side, and that of the bird, on the other +(Fig. 6), it is obvious that it represents a middle term between the +two. The pelvic bones approach the form of those of the birds, and the +direction of the pubis and ischium is nearly that which is +characteristic of birds; the thigh bone, from the direction of its head, +must have lain close to the body; the tibia has a great crest; and, +immovably fitted on to its lower end, there is a pulley-shaped bone, +like that of the bird, but remaining distinct. The lower end of the +fibula is much more slender, proportionally, than in the crocodile. The +metatarsal bones have such a form that they fit together immovably, +though they do not enter into bony union; the third toe is, as in the +bird, longest and strongest. In fact, the ornithoscelidan limb is +comparable to that of an unhatched chick. + +Taking all these facts together, it is obvious that the view, which was +entertained by Mantell and the probability of which was demonstrated by +your own distinguished anatomist, Leidy, while much additional evidence +in the same direction has been furnished by Professor Cope, that some of +these animals may have walked upon their hind legs, as birds do, +acquires great weight. In fact, there can be no reasonable doubt that +one of the smaller forms of the _Ornithoscelida_, _Compsognathus_, the +almost entire skeleton of which has been discovered in the Solenhofen +slates, was a bipedal animal. The parts of this skeleton are somewhat +twisted out of their natural relations, but the accompanying figure +gives a just view of the general form of _Compsognathus_ and of the +proportions of its limbs; which, in some respects, are more completely +bird-like than those of other _Ornithoscelida_. + +[Illustration: FIG. 7.--RESTORATION OF COMPSOGNATHUS LONGIPES.] + +We have had to stretch the definition of the class of birds so as to +include birds with teeth and birds with paw-like fore-limbs and long +tails. There is no evidence that _Compsognathus_ possessed feathers; +but, if it did, it would be hard indeed to say whether it should be +called a reptilian bird or an avian reptile. + +As _Compsognathus_ walked upon its hind legs, it must have made tracks +like those of birds. And as the structure of the limbs of several of the +gigantic _Ornithoscelida_, such as _Iguandon_, leads to the conclusion +that they also may have constantly, or occasionally, assumed the same +attitude, a peculiar interest attaches to the fact that, in the Wealden +strata of England, there are to be found gigantic footsteps, arranged in +order like those of the _Brontozoum_, and which there can be no +reasonable doubt were made by some of the _Ornithoscelida_, the remains +of which are found in the same rocks. And, knowing that reptiles that +walked upon their hind legs and shared many of the anatomical characters +of birds did once exist, it becomes a very important question whether +the tracks in the Trias of Massachusetts, to which I referred some time +ago, and which formerly used to be unhesitatingly ascribed to birds, may +not all have been made by Ornithoscelidan reptiles; and whether, if we +could obtain the skeletons of the animals which made these tracks, we +should not find in them the actual steps of the evolutional process by +which reptiles gave rise to birds. + +The evidential value of the facts I have brought forward in this Lecture +must be neither over nor under estimated. It is not historical proof of +the occurrence of the evolution of birds from reptiles, for we have no +safe ground for assuming that true birds had not made their appearance +at the commencement of the Mesozoic epoch. It is, in fact, quite +possible that all these more or less avi-form reptiles of the Mesozoic +epoch are not terms in the series of progression from birds to reptiles +at all but simply the more or less modified descendants of Palaeozoic +forms through which that transition was actually effected. + +We are not in a position to say that the known _Ornithoscelida_ are +intermediate in the order of their appearance on the earth between +reptiles and birds. All that can be said is that, if independent +evidence of the actual occurrence of evolution is producible, then these +intercalary forms remove every difficulty in the way of understanding +what the actual steps of the process, in the case of birds, may have +been. + +That intercalary forms should have existed in ancient times is a +necessary consequence of the truth of the hypothesis of evolution; and, +hence, the evidence I have laid before you in proof of the existence of +such forms, is, so far as it goes, in favour of that hypothesis. + +There is another series of extinct reptiles, which may be said to be +intercalary between reptiles and birds, in so far as they combine some +of the characters of both these groups; and, which, as they possessed +the power of flight, may seem, at first sight, to be nearer +representatives of the forms by which the transition from the reptile to +the bird was effected, than the _Ornithoscelida_. + +[Illustration: FIG. 8.--PTERODACTYLUS SPECTABILIS (Von Meyer).] + +These are the _Pterosauria_, or Pterodactyles, the remains of which are +met with throughout the series of Mesozoic rocks, from the lias to the +chalk, and some of which attained a great size, their wings having a +span of eighteen or twenty feet. These animals, in the form and +proportions of the head and neck relatively to the body, and in the fact +that the ends of the jaws were often, if not always, more or less +extensively ensheathed in horny beaks, remind us of birds. Moreover, +their bones contained air cavities, rendering them specifically lighter, +as is the case in most birds. The breast-bone was large and keeled, as in +most birds and in bats, and the shoulder girdle is strikingly similar to +that of ordinary birds. But, it seems to me, that the special +resemblance of pterodactyles to birds ends here, unless I may add the +entire absence of teeth which characterizes the great pterodactyles +(_Pteranodon_), discovered by Professor Marsh. All other known +pterodactyles have teeth lodged in sockets. In the vertebral column and +the hind limbs there are no special resemblances to birds, and when we +turn to the wings they are found to be constructed on a totally +different principle from those of birds. + +There are four fingers. These four fingers are large, and three of them, +those which answer to the thumb and two following fingers in my +hand--are terminated by claws, while the fourth is enormously prolonged +and converted into a great jointed style. You see at once, from what I +have stated about a bird's wing, that there could be nothing less like a +bird's wing than this is. It concluded by general reasoning that this +finger had the office of supporting a web which extended between it and +the body. An existing specimen proves that such was really the case, and +that the pterodactyles were devoid of feathers, but that the fingers +supported a vast web like that of a bat's wing; in fact, there can be no +doubt that this ancient reptile flew after the fashion of a bat. + +Thus though the pterodactyle is a reptile which has become modified in +such a manner as to enable it to fly, and therefore, as might be +expected, presents some points of resemblance to other animals which +fly; it has, so to speak, gone off the line which leads directly from +reptiles to birds, and has become disqualified for the changes which +lead to the characteristic organization of the latter class. Therefore, +viewed in relation to the classes of reptiles and birds, the +pterodactyles appear to me to be, in a limited sense, intercalary forms; +but they are not even approximately linear, in the sense of exemplifying +those modifications of structure through which the passage from the +reptile to the bird took place. + + + + +LECTURE III. + +THE DEMONSTRATIVE EVIDENCE OF EVOLUTION. + + +The occurrence of historical facts is said to be demonstrated, when the +evidence that they happened is of such a character as to render the +assumption that they did not happen in the highest degree improbable; +and the question I now have to deal with is, whether evidence in favour +of the evolution of animals of this degree of cogency is, or is not, +obtainable from the record of the succession of living forms which is +presented to us by fossil remains. + +Those who have attended to the progress of palaeontology are aware that +evidence of the character which I have defined has been produced in +considerable and continually-increasing quantity during the last few +years. Indeed, the amount and the satisfactory nature of that evidence +are somewhat surprising, when we consider the conditions under which +alone we can hope to obtain it. + +It is obviously useless to seek for such evidence except in localities +in which the physical conditions have been such as to permit of the +deposit of an unbroken, or but rarely interrupted, series of strata +through a long period of time; in which the group of animals to be +investigated has existed in such abundance as to furnish the requisite +supply of remains; and in which, finally, the materials composing the +strata are such as to ensure the preservation of these remains in a +tolerably perfect and undisturbed state. + +It so happens that the case which, at present, most nearly fulfils all +these conditions is that of the series of extinct animals which +culminates in the Horses; by which term I mean to denote not merely the +domestic animals with which we are all so well acquainted, but their +allies, the ass, zebra, quagga, and the like. In short, I use "horses" +as the equivalent of the technical name _Equidae_, which is applied to +the whole group of existing equine animals. + +The horse is in many ways a remarkable animal; not least so in the fact +that it presents us with an example of one of the most perfect pieces of +machinery in the living world. In truth, among the works of human +ingenuity it cannot be said that there is any locomotive so perfectly +adapted to its purposes, doing so much work with so small a quantity of +fuel, as this machine of nature's manufacture--the horse. And, as a +necessary consequence of any sort of perfection, of mechanical +perfection as of others, you find that the horse is a beautiful +creature, one of the most beautiful of all land-animals. Look at the +perfect balance of its form, and the rhythm and force of its action. The +locomotive machinery is, as you are aware, resident in its slender fore +and hind limbs; they are flexible and elastic levers, capable of being +moved by very powerful muscles; and, in order to supply the engines +which work these levers with the force which they expend, the horse is +provided with a very perfect apparatus for grinding its food and +extracting therefrom the requisite fuel. + +Without attempting to take you very far into the region of osteological +detail, I must nevertheless trouble you with some statements respecting +the anatomical structure of the horse; and, more especially, will it be +needful to obtain a general conception of the structure of its fore and +hind limbs, and of its teeth. But I shall only touch upon those points +which are absolutely essential to our inquiry. + +Let us turn in the first place to the fore-limb. In most quadrupeds, as +in ourselves, the fore-arm contains distinct bones called the radius and +the ulna. The corresponding region in the Horse seem at first to possess +but one bone. Careful observation, however, enables us to distinguish in +this bone a part which clearly answers to the upper end of the ulna. +This is closely united with the chief mass of the bone which represents +the radius, and runs out into a slender shaft which may be traced for +some distance downwards upon the back of the radius, and then in most +cases thins out and vanishes. It takes still more trouble to make sure +of what is nevertheless the fact, that a small part of the lower end of +the bone of the horse's fore-arm, which is only distinct in a very young +foal, is really the lower extremity of the ulna. + +What is commonly called the knee of a horse is its wrist. The "cannon +bone" answers to the middle bone of the five metacarpal bones, which +support the palm of the hand in ourselves. The "pastern," "coronary," +and "coffin" bones of veterinarians answer to the joints of our middle +fingers, while the hoof is simply a greatly enlarged and thickened nail. +But if what lies below the horse's "knee" thus corresponds to the middle +finger in ourselves, what has become of the four other fingers or +digits? We find in the places of the second and fourth digits only two +slender splint-like bones, about two-thirds as long as the cannon bone, +which gradually taper to their lower ends and bear no finger joints, or, +as they are termed, phalanges. Sometimes, small bony or gristly nodules +are to be found at the bases of these two metacarpal splints, and it is +probable that these represent rudiments of the first and fifth toes. +Thus, the part of the horse's skeleton, which corresponds with that of +the human hand, contains one overgrown middle digit, and at least two +imperfect lateral digits; and these answer, respectively, to the third, +the second, and the fourth fingers in man. + +Corresponding modifications are found in the hind limb. In ourselves, +and in most quadrupeds, the leg contains two distinct bones, a large +bone, the tibia, and a smaller and more slender bone, the fibula. But, +in the horse, the fibula seems, at first, to be reduced to its upper +end; a short slender bone united with the tibia, and ending in a point +below, occupying its place. Examination of the lower end of a young +foal's shin-bone, however, shows a distinct portion of osseous matter, +which is the lower end of the fibula; so that the, apparently single, +lower end of the shin-bone is really made up of the coalesced ends of +the tibia and fibula, just as the, apparently single, lower end of the +fore-arm bone is composed of the coalesced radius and ulna. + +The heel of the horse is the part commonly known as the hock. The hinder +cannon bone answers to the middle metatarsal bone of the human foot, the +pastern, coronary, and coffin bones, to the middle toe bones; the hind +hoof to the nail; as in the fore-foot. And, as in the fore-foot, there +are merely two splints to represent the second and the fourth toes. +Sometimes a rudiment of a fifth toe appears to be traceable. + +The teeth of a horse are not less peculiar than its limbs. The living +engine, like all others, must be well stoked if it is to do its work; +and the horse, if it is to make good its wear and tear, and to exert the +enormous amount of force required for its propulsion, must be well and +rapidly fed. To this end, good cutting instruments and powerful and +lasting crushers are needful. Accordingly, the twelve cutting teeth of a +horse are close-set and concentrated in the fore part of its mouth, like +so many adzes or chisels. The grinders or molars are large, and have an +extremely complicated structure, being composed of a number of different +substances of unequal hardness. The consequence of this is that they +wear away at different rates; and, hence, the surface of each grinder is +always as uneven as that of a good millstone. + +I have said that the structure of the grinding teeth is very +complicated, the harder and the softer parts being, as it were, +interlaced with one another. The result of this is that, as the tooth +wears, the crown presents a peculiar pattern, the nature of which is not +very easily deciphered at first; but which it is important we should +understand clearly. Each grinding tooth of the upper jaw has an _outer +wall_ so shaped that, on the worn crown, it exhibits the form of two +crescents, one in front and one behind, with their concave sides turned +outwards. From the inner side of the front crescent, a crescentic _front +ridge_ passes inwards and backwards, and its inner face enlarges into a +strong longitudinal fold or _pillar_. From the front part of the hinder +crescent, a _back ridge_ takes a like direction, and also has its +_pillar_. + +The deep interspaces or _valleys_ between these ridges and the outer +wall are filled by bony substance, which is called _cement_, and coats +the whole tooth. + +The pattern of the worn face of each grinding tooth of the lower jaw is +quite different. It appears to be formed of two crescent-shaped ridges, +the convexities of which are turned outwards. The free extremity of each +crescent has a _pillar_, and there is a large double _pillar_ where the +two crescents meet. The whole structure is, as it were, imbedded in +cement, which fills up the valleys, as in the upper grinders. + +If the grinding faces of an upper and of a lower molar of the same side +are applied together, it will be seen that the apposed ridges are +nowhere parallel, but that they frequently cross; and that thus, in the +act of mastication, a hard surface in the one is constantly applied to a +soft surface in the other, and _vice versa_. They thus constitute a +grinding apparatus of great efficiency, and one which is repaired as +fast as it wears, owing to the long-continued growth of the teeth. + +Some other peculiarities of the dentition of the horse must be noticed, +as they bear upon what I shall have to say by and by. Thus the crowns of +the cutting teeth have a peculiar deep pit, which gives rise to the +well-known "mark" of the horse. There is a large space between the outer +incisors and the front grinder. In this space the adult male horse +presents, near the incisors on each side, above and below, a canine or +"tush," which is commonly absent in mares. In a young horse, moreover, +there is not unfrequently to be seen in front of the first grinder, a +very small tooth, which soon falls out. If this small tooth be counted +as one, it will be found that there are seven teeth behind the canine on +each side; namely, the small tooth in question, and the six great +grinders, among which, by an unusual peculiarity, the foremost tooth is +rather larger than those which follow it. + +I have now enumerated those characteristic structures of the horse which +are of most importance for the purpose we have in view. + +To any one who is acquainted with the morphology of vertebrated animals, +they show that the horse deviates widely from the general structure of +mammals; and that the horse type is, in many respects, an extreme +modification of the general mammalian plan. The least modified mammals, +in fact, have the radius and ulna, the tibia and fibula, distinct and +separate. They have five distinct and complete digits on each foot, and +no one of these digits is very much larger than the rest. Moreover, in +the least modified mammals, the total number of the teeth is very +generally forty-four, while in horses, the usual number is forty, and in +the absence of the canines, it may be reduced to thirty-six; the incisor +teeth are devoid of the fold seen in those of the horse: the grinders +regularly diminish in size from the middle of the series to its front +end; while their crowns are short, early attain their full length, and +exhibit simple ridges or tubercles, in place of the complex foldings of +the horse's grinders. + +Hence the general principles of the hypothesis of evolution lead to the +conclusion that the horse must have been derived from some quadruped +which possessed five complete digits on each foot; which had the bones +of the fore-arm and of the leg complete and separate; and which +possessed forty-four teeth, among which the crowns of the incisors and +grinders had a simple structure; while the latter gradually increased in +size from before backwards, at any rate in the anterior part of the +series, and had short crowns. + +And if the horse has been thus evolved, and the remains of the different +stages of its evolution have been preserved, they ought to present us +with a series of forms in which the number of the digits becomes +reduced; the bones of the fore-arm and leg gradually take on the equine +condition; and the form and arrangement of the teeth successively +approximate to those which obtain in existing horses. + +Let us turn to the facts, and see how far they fulfil these requirements +of the doctrine of evolution. + +In Europe abundant remains of horses are found in the Quaternary and +later Tertiary strata as far as the Pliocene formation. But these +horses, which are so common in the cave-deposits and in the gravels of +Europe, are in all essential respects like existing horses. And that is +true of all the horses of the latter part of the Pliocene epoch. But, in +deposits which belong to the earlier Pliocene and later Miocene epochs, +and which occur in Britain, in France, in Germany, in Greece, in India, +we find animals which are extremely like horses--which, in fact, are so +similar to horses, that you may follow descriptions given in works upon +the anatomy of the horse upon the skeletons of these animals--but which +differ in some important particulars. For example, the structure of +their fore and hind limbs is somewhat different. The bones which, in the +horse, are represented by two splints, imperfect below, are as long as +the middle metacarpal and metatarsal bones; and, attached to the +extremity of each, is a digit with three joints of the same general +character as those of the middle digit, only very much smaller. These +small digits are so disposed that they could have had but very little +functional importance, and they must have been rather of the nature of +the dew-claws, such as are to be found in many ruminant animals. The +_Hipparion_, as the extinct European three-toed horse is called, in +fact, presents a foot similar to that of the American _Protohippus_ +(Fig. 9), except that, in the _Hipparion_, the smaller digits are +situated farther back, and are of smaller proportional size, than in the +_Protohippus_. + +The ulna is slightly more distinct than in the horse; and the whole +length of it, as a very slender shaft, intimately united with the +radius, is completely traceable. The fibula appears to be in the same +condition as in the horse. The teeth of the _Hipparion_ are essentially +similar to those of the horse, but the pattern of the grinders is in +some respects a little more complex, and there is a depression on the +face of the skull in front of the orbit, which is not seen in existing +horses. + +In the earlier Miocene, and perhaps the later Eocene deposits of some +parts of Europe, another extinct animal has been discovered, which +Cuvier, who first described some fragments of it, considered to be a +_Palaeotherium_. But as further discoveries threw new light upon its +structure, it was recognised as a distinct genus, under the name of +_Anchitherium_. + +In its general characters, the skeleton of _Anchitherium_ is very +similar to that of the horse. In fact, Lartet and De Blainville called +it _Palaeotherium equinum_ or _hippoides_; and De Christol, in 1847, said +that it differed from _Hipparion_ in little more than the characters of +its teeth, and gave it the name of _Hipparitherium_. Each foot possesses +three complete toes; while the lateral toes are much larger in +proportion to the middle toe than in _Hipparion_, and doubtless rested +on the ground in ordinary locomotion. + +The ulna is complete and quite distinct from the radius, though firmly +united with the latter. The fibula seems also to have been complete. Its +lower end, though intimately united with that of the tibia, is clearly +marked off from the latter bone. + +There are forty-four teeth. The incisors have no strong pit. The canines +seem to have been well developed in both sexes. The first of the seven +grinders, which, as I have said, is frequently absent, and, when it does +exist, is small in the horse, is a good-sized and permanent tooth, while +the grinder which follows it is but little larger than the hinder ones. +The crowns of the grinders are short, and though the fundamental pattern +of the horse-tooth is discernible, the front and back ridges are less +curved, the accessory pillars are wanting, and the valleys, much +shallower, are not filled up with cement. + +Seven years ago, when I happened to be looking critically into the +bearing of palaeontological facts upon the doctrine of evolution, it +appeared to me that the _Anchitherium_, the _Hipparion_, and the modern +horses, constitute a series in which the modifications of structure +coincide with the order of chronological occurrence, in the manner in +which they must coincide, if the modern horses really are the result of +the gradual metamorphosis, in the course of the Tertiary epoch, of a +less specialised ancestral form. And I found by correspondence with the +late eminent French anatomist and palaeontologist, M. Lartet, that he had +arrived at the same conclusion from the same data. + +That the _Anchitherium_ type had become metamorphosed into the +_Hipparion_ type, and the latter into the _Equine_ type, in the course +of that period of time which is represented by the latter half of the +Tertiary deposits, seemed to me to be the only explanation of the facts +for which there was even a shadow of probability.[2] + +And, hence, I have ever since held that these facts afford evidence of +the occurrence of evolution, which, in the sense already defined, may be +termed demonstrative. + +All who have occupied themselves with the structure of _Anchitherium_, +from Cuvier onwards, have acknowledged its many points of likeness to a +well-known genus of extinct Eocene mammals, _Palaeotherium_. Indeed, as +we have seen, Cuvier regarded his remains of _Anchitherium_ as those of +a species of _Palaeotherium_. Hence, in attempting to trace the pedigree +of the horse beyond the Miocene epoch and the Anchitheroid form, I +naturally sought among the various species of Palaeotheroid animals for +its nearest ally, and I was led to conclude that the _Palaeotherium +minus (Plagiolophus)_ represented the next step more nearly than any +form then known. + +I think that this opinion was fully justifiable; but the progress of +investigation has thrown an unexpected light on the question, and has +brought us much nearer than could have been anticipated to a knowledge +of the true series of the progenitors of the horse. + +You are all aware that, when your country was first discovered by +Europeans, there were no traces of the existence of the horse in any +part of the American Continent. The accounts of the conquest of Mexico +dwell upon the astonishment of the natives of that country when they +first became acquainted with that astounding phenomenon--a man seated +upon a horse. Nevertheless, the investigations of American geologists +have proved that the remains of horses occur in the most superficial +deposits of both North and South America, just as they do in Europe. +Therefore, for some reason or other--no feasible suggestion on that +subject, so far as I know, has been made--the horse must have died out +on this continent at some period preceding the discovery of America. Of +late years there has been discovered in your Western Territories that +marvellous accumulation of deposits, admirably adapted for the +preservation of organic remains, to which I referred the other evening, +and which furnishes us with a consecutive series of records of the fauna +of the older half of the Tertiary epoch, for which we have no parallel +in Europe. They have yielded fossils in an excellent state of +conservation and in unexampled number and variety. The researches of +Leidy and others have shown that forms allied to the _Hipparion_ and the +_Anchitherium_ are to be found among these remains. But it is only +recently that the admirably conceived and most thoroughly and patiently +worked-out investigations of Professor Marsh have given us a just idea +of the vast fossil wealth, and of the scientific importance, of these +deposits. I have had the advantage of glancing over the collections in +Yale Museum; and I can truly say that, so far as my knowledge extends, +there is no collection from any one region and series of strata +comparable, for extent, or for the care with which the remains have been +got together, or for their scientific importance, to the series of +fossils which he has deposited there. This vast collection has yielded +evidence bearing upon the question of the pedigree of the horse of the +most striking character. It tends to show that we must look to America, +rather than to Europe, for the original seat of the equine series; and +that the archaic forms and successive modifications of the horse's +ancestry are far better preserved here than in Europe. + +Professor Marsh's kindness has enabled me to put before you a diagram, +every figure in which is an actual representation of some specimen which +is to be seen at Yale at this present time (Fig. 9). + +[Illustration: FIG. 9.] + +The succession of forms which he has brought together carries us from +the top to the bottom of the Tertiaries. Firstly, there is the true +horse. Next we have the American Pliocene form of the horse +(_Pliohippus_); in the conformation of its limbs it presents some very +slight deviations from the ordinary horse, and the crowns of the +grinding teeth are shorter. Then comes the _Protohippus_, which +represents the European _Hipparion_, having one large digit and two +small ones on each foot, and the general characters of the fore-arm and +leg to which I have referred. But it is more valuable than the European +_Hipparion_ for the reason that it is devoid of some of the +peculiarities of that form--peculiarities which tend to show that the +European _Hipparion_ is rather a member of a collateral branch, than a +form in the direct line of succession. Next, in the backward order in +time, is the _Miohippus_, which corresponds pretty nearly with the +_Anchitherium_ of Europe. It presents three complete toes--one large +median and two smaller lateral ones; and there is a rudiment of that +digit, which answers to the little finger of the human hand. + +The European record of the pedigree of the horse stops here; in the +American Tertiaries, on the contrary, the series of ancestral equine +forms is continued into the Eocene formations. An older Miocene form, +termed _Mesohippus_, has three toes in front, with a large splint-like +rudiment representing the little finger; and three toes behind. The +radius and ulna, the tibia and the fibula, are distinct, and the short +crowned molar teeth are anchitherioid in pattern. + +But the most important discovery of all is the _Orohippus_, which comes +from the Eocene formation, and is the oldest member of the equine +series, as yet known. Here we find four complete toes on the front-limb, +three toes on the hind-limb, a well-developed ulna, a well-developed +fibula, and short-crowned grinders of simple pattern. + +Thus, thanks to these important researches, it has become evident that, +so far as our present knowledge extends, the history of the horse-type +is exactly and precisely that which could have been predicted from a +knowledge of the principles of evolution. And the knowledge we now +possess justifies us completely in the anticipation, that when the still +lower Eocene deposits, and those which belong to the Cretaceous epoch, +have yielded up their remains of ancestral equine animals, we shall +find, first, a form with four complete toes and a rudiment of the +innermost or first digit in front, with, probably, a rudiment of the +fifth digit in the hind foot;[3] while, in still older forms, the series +of the digits will be more and more complete, until we come to the +five-toed animals, in which, if the doctrine of evolution is well +founded, the whole series must have taken its origin. + + * * * * * + +That is what I mean by demonstrative evidence of evolution. An inductive +hypothesis is said to be demonstrated when the facts are shown to be in +entire accordance with it. If that is not scientific proof, there are no +merely inductive conclusions which can be said to be proved. And the +doctrine of evolution, at the present time, rests upon exactly as secure +a foundation as the Copernican theory of the motions of the heavenly +bodies did at the time of its promulgation. Its logical basis is +precisely of the same character--the coincidence of the observed facts +with theoretical requirements. + +The only way of escape, if it be a way of escape, from the conclusions +which I have just indicated, is the supposition that all these different +equine forms have been created separately at separate epochs of time; +and, I repeat, that of such an hypothesis as this there neither is, nor +can be, any scientific evidence; and, assuredly, so far as I know, there +is none which is supported, or pretends to be supported, by evidence or +authority of any other kind. I can but think that the time will come +when such suggestions as these, such obvious attempts to escape the +force of demonstration, will be put upon the same footing as the +supposition made by some writers, who are, I believe, not completely +extinct at present, that fossils are mere simulacra, are no indications +of the former existence of the animals to which they seem to belong; but +that they are either sports of Nature, or special creations, +intended--as I heard suggested the other day--to test our faith. + +In fact, the whole evidence is in favour of evolution, and there is none +against it. And I say this, although perfectly well aware of the seeming +difficulties which have been built up upon what appears to the +uninformed to be a solid foundation. I meet constantly with the argument +that the doctrine of evolution cannot be well founded, because it +requires the lapse of a very vast period of time; the duration of life +upon the earth, thus implied, is inconsistent with the conclusions +arrived at by the astronomer and the physicist. I may venture to say +that I am familiar with those conclusions, inasmuch as some years ago, +when President of the Geological Society of London, I took the liberty +of criticising them, and of showing in what respects, as it appeared to +me, they lacked complete and thorough demonstration. But, putting that +point aside, suppose that, as the astronomers, or some of them, and some +physical philosophers, tell us, it is impossible that life could have +endured upon the earth for as long a period as is required by the +doctrine of evolution--supposing that to be proved--I desire to be +informed, what is the foundation for the statement that evolution does +require so great a time? The biologist knows nothing whatever of the +amount of time which may be required for the process of evolution. It is +a matter of fact that the equine forms which I have described to you +occur, in the order stated, in the Tertiary formations. But I have not +the slightest means of guessing whether it took a million of years, or +ten millions, or a hundred millions, or a thousand millions of years, to +give rise to that series of changes. A biologist has no means of +arriving at any conclusion as to the amount of time which may be needed +for a certain quantity of organic change. He takes his time from the +geologist. The geologist, considering the rate at which deposits are +formed and the rate at which denudation goes on upon the surface of the +earth, arrives at more or less justifiable conclusions as to the time +which is required for the deposit of a certain thickness of rocks; and +if he tells me that the Tertiary formations required 500,000,000 years +for their deposit, I suppose he has good ground for what he says, and I +take that as a measure of the duration of the evolution of the horse +from the _Orohippus_ up to its present condition. And, if he is right, +undoubtedly evolution is a very slow process, and requires a great deal +of time. But suppose, now, that an astronomer or a physicist--for +instance, my friend Sir William Thomson--tells me that my geological +authority is quite wrong; and that he has weighty evidence to show that +life could not possibly have existed upon the surface of the earth +500,000,000 years ago, because the earth would have then been too hot to +allow of life, my reply is: "That is not my affair; settle that with the +geologist, and when you have come to an agreement among yourselves I +will adopt your conclusion." We take our time from the geologists and +physicists; and it is monstrous that, having taken our time from the +physical philosopher's clock, the physical philosopher should turn round +upon us, and say we are too fast or too slow. What we desire to know is, +is it a fact that evolution took place? As to the amount of time which +evolution may have occupied, we are in the hands of the physicist and +the astronomer, whose business it is to deal with those questions. + + * * * * * + +I have now, ladies and gentlemen, arrived at the conclusion of the task +which I set before myself when I undertook to deliver these lectures. My +purpose has been, not to enable those among you who have paid no +attention to these subjects before, to leave this room in a condition to +decide upon the validity or the invalidity of the hypothesis of +evolution; but I have desired to put before you the principles upon +which all hypotheses respecting the history of Nature must be judged; +and furthermore, to make apparent the nature of the evidence and the +amount of cogency which is to be expected and may be obtained from it. +To this end, I have not hesitated to regard you as genuine students and +persons desirous of knowing the truth. I have not shrunk from taking you +through long discussions, that I fear may have sometimes tried your +patience; and I have inflicted upon you details which were +indispensable, but which may well have been wearisome. But I shall +rejoice--I shall consider that I have done you the greatest service, +which it was in my power to do--if I have thus convinced you that the +great question which we have been discussing is not one to be dealt with +by rhetorical flourishes, or by loose and superficial talk; but that it +requires the keen attention of the trained intellect and the patience of +the accurate observer. + +When I commenced this series of lectures, I did not think it necessary +to preface them with a prologue, such as might be expected from a +stranger and a foreigner; for during my brief stay in your country, I +have found it very hard to believe that a stranger could be possessed of +so many friends, and almost harder that a foreigner could express +himself in your language in such a way as to be, to all appearance, so +readily intelligible. So far as I can judge, that most intelligent, and, +perhaps, I may add, most singularly active and enterprising body, your +press reporters, do not seem to have been deterred by my accent from +giving the fullest account of everything that I happen to have said. + +But the vessel in which I take my departure to-morrow morning is even +now ready to slip her moorings; I awake from my delusion that I am other +than a stranger and a foreigner. I am ready to go back to my place and +country; but, before doing so, let me, by way of epilogue, tender to you +my most hearty thanks for the kind and cordial reception which you have +accorded to me; and let me thank you still more for that which is the +greatest compliment which can be afforded to any person in my +position--the continuous and undisturbed attention which you have +bestowed upon the long argument which I have had the honour to lay +before you. + + + [1] The absence of any keel on the breast-bone and some other + osteological peculiarities, observed by Professor Marsh, + however, suggest that _Hesperornis_ may be a modification of a + less specialised group of birds than that to which these + existing aquatic birds belong. + + + [2] I use the word "type" because it is highly probable that many + forms of _Anchitherium_-like and _Hipparion_-like animals + existed in the Miocene and Pliocene epochs, just as many species + of the horse tribe exist now; and it is highly improbable that + the particular species of _Anchitherium_ or _Hipparion_, which + happen to have been discovered, should be precisely those which + have formed part of the direct line of the horse's pedigree. + + [3] Since this lecture was delivered, Professor Marsh has discovered + a new genus of equine mammals (_Eohippus_) from the lowest + Eocene deposits of the West, which corresponds very nearly to + this description.--_American Journal of Science_, November, + 1876. + + + + +BALTIMORE. + +ADDRESS ON UNIVERSITY EDUCATION.[1] + + +The actual work of the University founded in this city by the +well-considered munificence of Johns Hopkins commences to-morrow, and +among the many marks of confidence and good-will which have been +bestowed upon me in the United States, there is none which I value more +highly than that conferred by the authorities of the University when +they invited me to deliver an address on such an occasion. + +For the event which has brought us together is, in many respects, +unique. A vast property is handed over to an administrative body, +hampered by no conditions save these;--That the principal shall not be +employed in building: that the funds shall be appropriated, in equal +proportions, to the promotion of natural knowledge and to the +alleviation of the bodily sufferings of mankind; and, finally, that +neither political nor ecclesiastical sectarianism shall be permitted to +disturb the impartial distribution of the testator's benefactions. + +In my experience of life a truth which sounds very much like a paradox +has often asserted itself; namely, that a man's worst difficulties begin +when he is able to do as he likes. So long as a man is struggling with +obstacles he has an excuse for failure or shortcoming; but when fortune +removes them all and gives him the power of doing as he thinks best, +then comes the time of trial. There is but one right, and the +possibilities of wrong are infinite. I doubt not that the trustees of +the Johns Hopkins University felt the full force of this truth when they +entered on the administration of their trust a year and a half ago; and +I can but admire the activity and resolution which have enabled them, +aided by the able president whom they have selected, to lay down the +great outlines of their plan, and carry it thus far into execution. It +is impossible to study that plan without perceiving that great care, +forethought, and sagacity, have been bestowed upon it, and that it +demands the most respectful consideration. I have been endeavouring to +ascertain how far the principles which underlie it are in accordance +with those which have been established in my own mind by much and +long-continued thought upon educational questions. Permit me to place +before you the result of my reflections. + +Under one aspect a university is a particular kind of educational +institution, and the views which we may take of the proper nature of a +university are corollaries from those which we hold respecting education +in general. I think it must be admitted that the school should prepare +for the university, and that the university should crown the edifice, +the foundations of which are laid in the school. University education +should not be something distinct from elementary education, but should +be the natural outgrowth and development of the latter. Now I have a +very clear conviction as to what elementary education ought to be; what +it really may be, when properly organised; and what I think it will be, +before many years have passed over our heads, in England and in America. +Such education should enable an average boy of fifteen or sixteen to +read and write his own language with ease and accuracy, and with a sense +of literary excellence derived from the study of our classic writers: to +have a general acquaintance with the history of his own country and with +the great laws of social existence; to have acquired the rudiments of +the physical and psychological sciences, and a fair knowledge of +elementary arithmetic and geometry. He should have obtained an +acquaintance with logic rather by example than by precept; while the +acquirement of the elements of music and drawing should have been +pleasure rather than work. + +It may sound strange to many ears if I venture to maintain the +proposition that a young person, educated thus far, has had a liberal, +though perhaps not a full, education. But it seems to me that such +training as that to which I have referred may be termed liberal, in both +the senses in which that word is employed, with perfect accuracy. In the +first place, it is liberal in breadth. It extends over the whole ground +of things to be known and of faculties to be trained, and it gives equal +importance to the two great sides of human activity--art and science. In +the second place, it is liberal in the sense of being an education +fitted for free men; for men to whom every career is open, and from whom +their country may demand that they should be fitted to perform the +duties of any career. I cannot too strongly impress upon you the fact +that, with such a primary education as this, and with no more than is to +be obtained by building strictly upon its lines, a man of ability may +become a great writer or speaker, a statesman, a lawyer, a man of +science, painter, sculptor, architect, or musician. That even +development of all a man's faculties, which is what properly constitutes +culture, may be effected by such an education, while it opens the way +for the indefinite strengthening of any special capabilities with which +he may be gifted. + +In a country like this, where most men have to carve out their own +fortunes and devote themselves early to the practical affairs of life, +comparatively few can hope to pursue their studies up to, still less +beyond, the age of manhood. But it is of vital importance to the welfare +of the community that those who are relieved from the need of making a +livelihood, and still more, those who are stirred by the divine impulses +of intellectual thirst or artistic genius, should be enabled to devote +themselves to the higher service of their kind, as centres of +intelligence, interpreters of nature, or creators of new forms of +beauty. And it is the function of a university to furnish such men with +the means of becoming that which it is their privilege and duty to be. +To this end the university need cover no ground foreign to that occupied +by the elementary school. Indeed it cannot; for the elementary +instruction which I have referred to embraces all the kinds of real +knowledge and mental activity possible to man. The university can add no +new departments of knowledge, can offer no new fields of mental +activity; but what it can do is to intensify and specialise the +instruction in each department. Thus literature and philology, +represented in the elementary school by English alone, in the university +will extend over the ancient and modern languages. History, which, like +charity, best begins at home, but, like charity, should not end there, +will ramify into anthropology, archaeology, political history, and +geography, with the history of the growth of the human mind and of its +products in the shape of philosophy, science, and art. And the +university will present to the student libraries, museums of +antiquities, collections of coins, and the like, which will efficiently +subserve these studies. Instruction in the elements of social economy, a +most essential, but hitherto sadly-neglected part of elementary +education, will develop in the university into political economy, +sociology, and law. Physical science will have its great divisions of +physical geography, with geology and astronomy; physics; chemistry and +biology; represented not merely by professors and their lectures, but by +laboratories, in which the students, under guidance of demonstrators, +will work out facts for themselves and come into that direct contact +with reality which constitutes the fundamental distinction of scientific +education. Mathematics will soar into its highest regions; while the +high peaks of philosophy may be scaled by those whose aptitude for +abstract thought has been awakened by elementary logic. Finally, schools +of pictorial and plastic art, of architecture, and of music, will offer +a thorough discipline in the principles and practice of art to those in +whom lies nascent the rare faculty of aesthetic representation, or the +still rarer powers of creative genius. + +The primary school and the university are the alpha and omega of +education. Whether institutions intermediate between these (so-called +secondary schools) should exist, appears to me to be a question of +practical convenience. If such schools are established, the important +thing is that they should be true intermediaries between the primary +school and the university, keeping on the wide track of general culture, +and not sacrificing one branch of knowledge for another. + +Such appear to me to be the broad outlines of the relations which the +university, regarded as a place of education, ought to bear to the +school, but a number of points of detail require some consideration, +however briefly and imperfectly I can deal with them. In the first +place, there is the important question of the limitations which should +be fixed to the entrance into the university; or, what qualifications +should be required of those who propose to take advantage of the higher +training offered by the university. On the one hand, it is obviously +desirable that the time and opportunities of the university should not +be wasted in conferring such elementary instruction as can be obtained +elsewhere; while, on the other hand, it is no less desirable that the +higher instruction of the university should be made accessible to every +one who can take advantage of it, although he may not have been able to +go through any very extended course of education. My own feeling is +distinctly against any absolute and defined preliminary examination, the +passing of which shall be an essential condition of admission to the +university. I would admit to the university any one who could be +reasonably expected to profit by the instruction offered to him; and I +should be inclined, on the whole, to test the fitness of the student, +not by examination before he enters the university, but at the end of +his first term of study. If, on examination in the branches of knowledge +to which he has devoted himself, he show himself deficient in industry +or in capacity, it will be best for the university and best for himself, +to prevent him from pursuing a vocation for which he is obviously unfit. +And I hardly know of any other method than this by which his fitness or +unfitness can be safely ascertained, though no doubt a good deal may be +done, not by formal cut and dried examination, but by judicious +questioning, at the outset of his career. + +Another very important and difficult practical question is, whether a +definite course of study shall be laid down for those who enter the +university; whether a curriculum shall be prescribed; or whether the +student shall be allowed to range at will among the subjects which are +open to him. And this question is inseparably connected with another, +namely, the conferring of degrees. It is obviously impossible that any +student should pass through the whole of the series of courses of +instruction offered by a university. If a degree is to be conferred as a +mark of proficiency in knowledge, it must be given on the ground that +the candidate is proficient in a certain fraction of those studies; and +then will arise the necessity of insuring an equivalency of degrees, so +that the course by which a degree is obtained shall mark approximately +an equal amount of labour and of acquirements, in all cases. But this +equivalency can hardly be secured in any other way than by prescribing a +series of definite lines of study. This is a matter which will require +grave consideration. The important points to bear in mind, I think, are +that there should not be too many subjects in the curriculum, and that +the aim should be the attainment of thorough and sound knowledge of +each. + +One half of the Johns Hopkins bequest is devoted to the establishment of +a hospital, and it was the desire of the testator that the university +and the hospital should co-operate in the promotion of medical +education. The trustees will unquestionably take the best advice that is +to be had as to the construction and administration of the hospital. In +respect to the former point, they will doubtless remember that a +hospital may be so arranged as to kill more than it cures; and, in +regard to the latter, that a hospital may spread the spirit of pauperism +among the well-to-do, as well as relieve the sufferings of the +destitute. It is not for me to speak on these topics--rather let me +confine myself to the one matter on which my experience as a student of +medicine, and an examiner of long standing, who has taken a great +interest in the subject of medical education, may entitle me to a +hearing. I mean the nature of medical education itself, and the +co-operation of the university in its promotion. + +What is the object of medical education? It is to enable the +practitioner, on the one hand, to prevent disease by his knowledge of +hygiene; on the other hand, to divine its nature, and to alleviate or +cure it, by his knowledge of pathology, therapeutics, and practical +medicine. That is his business in life, and if he has not a thorough and +practical knowledge of the conditions of health, of the causes which +tend to the establishment of disease, of the meaning of symptoms, and of +the uses of medicines and operative appliances, he is incompetent, even +if he were the best anatomist, or physiologist, or chemist, that ever +took a gold medal or won a prize certificate. This is one great truth +respecting medical education. Another is, that all practice in medicine +is based upon theory of some sort or other; and therefore, that it is +desirable to have such theory in the closest possible accordance with +fact. The veriest empiric who gives a drug in one case because he has +seen it do good in another of apparently the same sort, acts upon the +theory that similarity of superficial symptoms means similarity of +lesions; which, by the way, is perhaps as wild an hypothesis as could be +invented. To understand the nature of disease we must understand health, +and the understanding of the healthy body means the having a knowledge +of its structure and of the way in which its manifold actions are +performed, which is what is technically termed human anatomy and human +physiology. The physiologist again must needs possess an acquaintance +with physics and chemistry, inasmuch as physiology is, to a great +extent, applied physics and chemistry. For ordinary purposes a limited +amount of such knowledge is all that is needful; but for the pursuit of +the higher branches of physiology no knowledge of these branches of +science can be too extensive, or too profound. Again, what we call +therapeutics, which has to do with the action of drugs and medicines on +the living organism, is, strictly speaking, a branch of experimental +physiology, and is daily receiving a greater and greater experimental +development. + +The third great fact which is to be taken into consideration in dealing +with medical education, is that the practical necessities of life do +not, as a rule, allow aspirants to medical practice to give more than +three, or it may be four years to their studies. Let us put it at four +years, and then reflect that, in the course of this time, a young man +fresh from school has to acquaint himself with medicine, surgery, +obstetrics, therapeutics, pathology, hygiene, as well as with the +anatomy and the physiology of the human body; and that his knowledge +should be of such a character that it can be relied upon in any +emergency, and always ready for practical application. Consider, in +addition, that the medical practitioner may be called upon, at any +moment, to give evidence in a court of justice in a criminal case; and +that it is therefore well that he should know something of the laws of +evidence, and of what we call medical jurisprudence. On a medical +certificate, a man may be taken from his home and from his business and +confined in a lunatic asylum; surely, therefore, it is desirable that +the medical practitioner should have some rational and clear conceptions +as to the nature and symptoms of mental disease. Bearing in mind all +these requirements of medical education, you will admit that the burden +on the young aspirant for the medical profession is somewhat of the +heaviest, and that it needs some care to prevent his intellectual back +from being broken. + +Those who are acquainted with the existing systems of medical education +will observe that, long as is the catalogue of studies which I have +enumerated, I have omitted to mention several that enter into the usual +medical curriculum of the present day. I have said not a word about +zoology, comparative anatomy, botany, or materia medica. Assuredly this +is from no light estimate of the value or importance of such studies in +themselves. It may be taken for granted that I should be the last person +in the world to object to the teaching of zoology, or comparative +anatomy, in themselves; but I have the strongest feeling that, +considering the number and the gravity of those studies through which a +medical man must pass, if he is to be competent to discharge the serious +duties which devolve upon him, subjects which lie so remote as these do +from his practical pursuits should be rigorously excluded. The young +man, who has enough to do in order to acquire such familiarity with the +structure of the human body as will enable him to perform the operations +of surgery, ought not, in my judgment, to be occupied with +investigations into the anatomy of crabs and starfishes. Undoubtedly the +doctor should know the common poisonous plants of his own country when +he sees them; but that knowledge may be obtained by a few hours devoted +to the examination of specimens of such plants, and the desirableness of +such knowledge is no justification, to my mind, for spending three +months over the study of systematic botany. Again, materia medica, so +far as it is a knowledge of drugs, is the business of the druggist. In +all other callings the necessity of the division of labour is fully +recognised, and it is absurd to require of the medical man that he +should not avail himself of the special knowledge of those whose +business it is to deal in the drugs which he uses. It is all very well +that the physician should know that castor oil comes from a plant, and +castoreum from an animal, and how they are to be prepared; but for all +the practical purposes of his profession that knowledge is not of one +whit more value, has no more relevancy, than the knowledge of how the +steel of his scalpel is made. + +All knowledge is good. It is impossible to say that any fragment of +knowledge, however insignificant or remote from one's ordinary pursuits, +may not some day be turned to account. But in medical education, above +all things, it is to be recollected that, in order to know a little +well, one must be content to be ignorant of a great deal. + +Let it not be supposed that I am proposing to narrow medical education, +or, as the cry is, to lower the standard of the profession. Depend upon +it there is only one way of really ennobling any calling, and that is to +make those who pursue it real masters of their craft, men who can truly +do that which they profess to be able to do, and which they are credited +with being able to do by the public. And there is no position so ignoble +as that of the so-called "liberally-educated practitioner," who, as +Talleyrand said of his physician, "Knows everything, even a little +physic;" who may be able to read Galen in the original; who knows all +the plants, from the cedar of Lebanon to the hyssop upon the wall; but +who finds himself, with the issues of life and death in his hands, +ignorant, blundering, and bewildered, because of his ignorance of the +essential and fundamental truths upon which practice must be based. +Moreover, I venture to say, that any man who has seriously studied all +the essential branches of medical knowledge; who has the needful +acquaintance with the elements of physical science; who has been brought +by medical jurisprudence into contact with law; whose study of insanity +has taken him into the fields of psychology; has _ipso facto_ received a +liberal education. + +Having lightened the medical curriculum by culling out of it everything +which is unessential, we may next consider whether something may not be +done to aid the medical student toward the acquirement of real knowledge +by modifying the system of examination. In England, within my +recollection, it was the practice to require of the medical student +attendance on lectures upon the most diverse topics during three years; +so that it often happened that he would have to listen, in the course of +a day, to four or five lectures upon totally different subjects, in +addition to the hours given to dissection and to hospital practice: and +he was required to keep all the knowledge he could pick up, in this +distracting fashion, at examination point, until, at the end of three +years, he was set down to a table and questioned pell-mell upon all the +different matters with which he had been striving to make acquaintance. +A worse system and one more calculated to obstruct the acquisition of +sound knowledge and to give full play to the "crammer" and the "grinder" +could hardly have been devised by human ingenuity. Of late years great +reforms have taken place. Examinations have been divided so as to +diminish the number of subjects among which the attention has to be +distributed. Practical examination has been largely introduced; but +there still remains, even under the present system, too much of the old +evil inseparable from the contemporaneous pursuit of a multiplicity of +diverse studies. + +Proposals have recently been made to get rid of general examinations +altogether, to permit the student to be examined in each subject at the +end of his attendance on the class; and then, in case of the result +being satisfactory, to allow him to have done with it; and I may say +that this method has been pursued for many years in the Royal School of +Mines in London, and has been found to work very well. It allows the +student to concentrate his mind upon what he is about for the time +being, and then to dismiss it. Those who are occupied in intellectual +work, will, I think, agree with me that it is important, not so much to +know a thing, as to have known it, and known it thoroughly. If you have +once known a thing in this way it is easy to renew your knowledge when +you have forgotten it; and when you begin to take the subject up again, +it slides back upon the familiar grooves with great facility. + +Lastly comes the question as to how the university may co-operate in +advancing medical education. A medical school is strictly a technical +school--a school in which a practical profession is taught--while a +university ought to be a place in which knowledge is obtained without +direct reference to professional purposes. It is clear, therefore, that +a university and its antecedent, the school, may best co-operate with +the medical school by making due provision for the study of those +branches of knowledge which lie at the foundation of medicine. + +At present, young men come to the medical schools without a conception +of even the elements of physical science; they learn, for the first +time, that there are such sciences as physics, chemistry, and +physiology, and are introduced to anatomy as a new thing. It may be +safely said that, with a large proportion of medical students, much of +the first session is wasted in learning how to learn--in familiarising +themselves with utterly strange conceptions, and in awakening their +dormant and wholly untrained powers of observation and of manipulation. +It is difficult to overestimate the magnitude of the obstacles which are +thrown in the way of scientific training by the existing system of +school education. Not only are men trained in mere book-work, ignorant +of what observation means, but the habit of learning from books alone +begets a disgust of observation. The book-learned student will rather +trust to what he sees in a book than to the witness of his own eyes. + +There is not the least reason why this should be so, and, in fact, when +elementary education becomes that which I have assumed it ought to be, +this state of things will no longer exist. There is not the slightest +difficulty in giving sound elementary instruction in physics, in +chemistry, and in the elements of human physiology, in ordinary schools. +In other words, there is no reason why the student should not come to +the medical school, provided with as much knowledge of these several +sciences as he ordinarily picks up, in the course of his first year of +attendance, at the medical school. + +I am not saying this without full practical justification for the +statement. For the last eighteen years we have had in England a system +of elementary science teaching carried out under the auspices of the +Science and Art Department, by which elementary scientific instruction +is made readily accessible to the scholars of all the elementary schools +in the country. Commencing with small beginnings, carefully developed +and improved, that system now brings up for examination as many as seven +thousand scholars in the subject of human physiology alone. I can say +that, out of that number, a large proportion have acquired a fair amount +of substantial knowledge; and that no inconsiderable percentage show as +good an acquaintance with human physiology as used to be exhibited by +the average candidates for medical degrees in the University of London, +when I was first an examiner there twenty years ago; and quite as much +knowledge as is possessed by the ordinary student of medicine at the +present day. I am justified, therefore, in looking forward to the time +when the student who proposes to devote himself to medicine will come, +not absolutely raw and inexperienced as he is at present, but in a +certain state of preparation for further study; and I look to the +university to help him still further forward in that stage of +preparation, through the organisation of its biological department. Here +the student will find means of acquainting himself with the phenomena of +life in their broadest acceptation. He will study not botany and +zoology, which, as I have said, would take him too far away from his +ultimate goal; but, by duly arranged instruction, combined with work in +the laboratory upon the leading types of animal and vegetable life, he +will lay a broad, and at the same time solid, foundation of biological +knowledge; he will come to his medical studies with a comprehension of +the great truths of morphology and of physiology, with his hands trained +to dissect and his eyes taught to see. I have no hesitation in saying +that such preparation is worth a full year added on to the medical +curriculum. In other words, it will set free that much time for +attention to those studies which bear directly upon the student's most +grave and serious duties as a medical practitioner. + +Up to this point I have considered only the teaching aspect of your +great foundation, that function of the university in virtue of which it +plays the part of a reservoir of ascertained truth, so far as our +symbols can ever interpret nature. All can learn; all can drink of this +lake. It is given to few to add to the store of knowledge, to strike new +springs of thought, or to shape new forms of beauty. But so sure as it +is that men live not by bread, but by ideas, so sure is it that the +future of the world lies in the hands of those who are able to carry the +interpretation of nature a step further than their predecessors; so +certain is it that the highest function of a university is to seek out +those men, cherish them, and give their ability to serve their kind full +play. + +I rejoice to observe that the encouragement of research occupies so +prominent a place in your official documents, and in the wise and +liberal inaugural address of your president. This subject of the +encouragement, or, as it is sometimes called, the endowment of research, +has of late years greatly exercised the minds of men in England. It was +one of the main topics of discussion by the members of the Royal +Commission of whom I was one, and who not long since issued their +report, after five years' labour. Many seem to think that this question +is mainly one of money; that you can go into the market and buy +research, and that supply will follow demand, as in the ordinary course +of commerce. This view does not commend itself to my mind. I know of no +more difficult practical problem than the discovery of a method of +encouraging and supporting the original investigator without opening the +door to nepotism and jobbery. My own conviction is admirably summed up +in the passage of your president's address, "that the best investigators +are usually those who have also the responsibilities of instruction, +gaining thus the incitement of colleagues, the encouragement of pupils, +and the observation of the public." + +At the commencement of this address I ventured to assume that I might, +if I thought fit, criticise the arrangements which have been made by the +board of trustees, but I confess that I have little to do but to applaud +them. Most wise and sagacious seems to me the determination not to build +for the present. It has been my fate to see great educational funds +fossilise into mere bricks and mortar, in the petrifying springs of +architecture, with nothing left to work the institution they were +intended to support. A great warrior is said to have made a desert and +called it peace. Administrators of educational funds have sometimes made +a palace and called it a university. If I may venture to give advice in +a matter which lies out of my proper competency, I would say that +whenever you do build, get an honest bricklayer, and make him build you +just such rooms as you really want, leaving ample space for expansion. +And a century hence, when the Baltimore and Ohio shares are at one +thousand premium, and you have endowed all the professors you need, and +built all the laboratories that are wanted, and have the best museum and +the finest library that can be imagined; then, if you have a few hundred +thousand dollars you don't know what to do with, send for an architect +and tell him to put up a facade. If American is similar to English +experience, any other course will probably lead you into having some +stately structure, good for your architect's fame, but not in the least +what you want. + +It appears to me that what I have ventured to lay down as the principles +which should govern the relations of a university to education in +general, are entirely in accordance with the measures you have adopted. +You have set no restrictions upon access to the instruction you propose +to give; you have provided that such instruction, either as given by the +university or by associated institutions, should cover the field of +human intellectual activity. You have recognised the importance of +encouraging research. You propose to provide means by which young men, +who may be full of zeal for a literary or for a scientific career, but +who also may have mistaken aspiration for inspiration, may bring their +capacities to a test, and give their powers a fair trial. If such a one +fail, his endowment terminates, and there is no harm done. If he +succeed, you may give power of flight to the genius of a Davy or a +Faraday, a Carlyle or a Locke, whose influence on the future of his +fellow-men shall be absolutely incalculable. + +You have enunciated the principle that "the glory of the university +should rest upon the character of the teachers and scholars, and not +upon their numbers or buildings constructed for their use." And I look +upon it as an essential and most important feature of your plan that the +income of the professors and teachers shall be independent of the number +of students whom they can attract. In this way you provide against the +danger, patent elsewhere, of finding attempts at improvement obstructed +by vested interests; and, in the department of medical education +especially, you are free of the temptation to set loose upon the world +men utterly incompetent to perform the serious and responsible duties of +their profession. + +It is a delicate matter for a stranger to the practical working of your +institutions, like myself, to pretend to give an opinion as to the +organisation of your governing power. I can conceive nothing better than +that it should remain as it is, if you can secure a succession of wise, +liberal, honest, and conscientious men to fill the vacancies that occur +among you. I do not greatly believe in the efficacy of any kind of +machinery for securing such a result; but I would venture to suggest +that the exclusive adoption of the method of co-optation for filling the +vacancies which must occur in your body, appears to me to be somewhat +like a tempting of Providence. Doubtless there are grave practical +objections to the appointment of persons outside of your body and not +directly interested in the welfare of the university; but might it not +be well if there were an understanding that your academic staff should +be officially represented on the board, perhaps even the heads of one or +two independent learned bodies, so that academic opinion and the views +of the outside world might have a certain influence in that most +important matter, the appointment of your professors? I throw out these +suggestions, as I have said, in ignorance of the practical difficulties +that may lie in the way of carrying them into effect, on the general +ground that personal and local influences are very subtle, and often +unconscious, while the future greatness and efficiency of the noble +institution which now commences its work must largely depend upon its +freedom from them. + + * * * * * + +I constantly hear Americans speak of the charm which our old mother +country has for them, of the delight with which they wander through the +streets of ancient towns, or climb the battlements of mediaeval +strongholds, the names of which are indissolubly associated with the +great epochs of that noble literature which is our common inheritance; +or with the blood-stained steps of that secular progress, by which the +descendants of the savage Britons and of the wild pirates of the North +Sea have become converted into warriors of order and champions of +peaceful freedom, exhausting what still remains of the old Berserk +spirit in subduing nature, and turning the wilderness into a garden. But +anticipation has no less charm than retrospect, and to an Englishman +landing upon your shores for the first time, travelling for hundreds of +miles through strings of great and well-ordered cities, seeing your +enormous actual, and almost infinite potential, wealth in all +commodities, and in the energy and ability which turn wealth to account, +there is something sublime in the vista of the future. Do not suppose +that I am pandering to what is commonly understood by national pride. I +cannot say that I am in the slightest degree impressed by your bigness, +or your material resources, as such. Size is not grandeur, and territory +does not make a nation. The great issue, about which hangs a true +sublimity, and the terror of overhanging fate, is what are you going to +do with all these things? What is to be the end to which these are to be +the means? You are making a novel experiment in politics on the greatest +scale which the world has yet seen. Forty millions at your first +centenary, it is reasonably to be expected that, at the second, these +states will be occupied by two hundred millions of English-speaking +people, spread over an area as large as that of Europe, and with +climates and interests as diverse as those of Spain and Scandinavia, +England and Russia. You and your descendants have to ascertain whether +this great mass will hold together under the forms of a republic, and +the despotic reality of universal suffrage; whether state rights will +hold out against centralisation, without separation; whether +centralisation will get the better, without actual or disguised +monarchy; whether shifting corruption is better than a permanent +bureaucracy; and as population thickens in your great cities, and the +pressure of want is felt, the gaunt spectre of pauperism will stalk +among you, and communism and socialism will claim to be heard. Truly +America has a great future before her; great in toil, in care, and in +responsibility; great in true glory if she be guided in wisdom and +righteousness; great in shame if she fail. I cannot understand why other +nations should envy you, or be blind to the fact that it is for the +highest interest of mankind that you should succeed; but the one +condition of success, your sole safeguard, is the moral worth and +intellectual clearness of the individual citizen. Education cannot give +these, but it may cherish them and bring them to the front in whatever +station of society they are to be found; and the universities ought to +be, and may be, the fortresses of the higher life of the nation. + +May the university which commences its practical activity to-morrow +abundantly fulfil its high purpose; may its renown as a seat of true +learning, a centre of free inquiry, a focus of intellectual light, +increase year by year, until men wander hither from all parts of the +earth, as of old they sought Bologna, or Paris, or Oxford. + +And it is pleasant to me to fancy that, among the English students who +are drawn to you at that time, there may linger a dim tradition that a +countryman of theirs was permitted to address you as he has done to-day, +and to feel as if your hopes were his hopes and your success his joy. + + + [1] Delivered at the formal opening of the Johns Hopkins University + at Baltimore, U.S., September 12. The total amount bequeathed by + Johns Hopkins is more than 7,000,000 dollars. The sum of + 3,500,000 dollars is appropriated to a university, a like sum to + a hospital, and the rest to local institutions of education and + charity. + + + + +LONDON. + +LECTURE ON THE STUDY OF BIOLOGY. + + +It is my duty to-night to speak about the study of Biology, and while it +may be that there are many of my audience who are quite familiar with +that study, yet as a lecturer of some standing, it would, I know by +experience, be very bad policy on my part to suppose such to be +extensively the case. On the contrary, I must imagine that there are +many of you who would like to know what Biology is; that there are +others who have that amount of information, but would nevertheless +gladly hear why it should be worth their while to study Biology; and yet +others, again, to whom these two points are clear, but who desire to +learn how they had best study it, and, finally, when they had best study +it. + +I shall, therefore, address myself to the endeavour to give you some +answer to these four questions--what Biology is; why it should be +studied; how it should be studied; and when it should be studied. + +In the first place, in respect to what Biology is, there are, I believe, +some persons who imagine that the term "Biology" is simply a new-fangled +denomination, a neologism in short, for what used to be known under the +title of "Natural History;" but I shall try to show you, on the +contrary, that the word is the expression of the growth of science +during the last 200 years, and came into existence half a century ago. + +At the revival of learning, knowledge was divided into two kinds--the +knowledge of nature and the knowledge of man; for it was the current +idea then (and a great deal of that ancient conception still remains) +that there was a sort of essential antithesis, not to say antagonism, +between nature and man; and that the two had not very much to do with +one another, except that the one was oftentimes exceedingly troublesome +to the other. Though it is one of the salient merits of our great +philosophers of the seventeenth century, that they recognised but one +scientific method, applicable alike to man and to nature, we find this +notion of the existence of a broad distinction between nature and man in +the writings both of Bacon and of Hobbes of Malmesbury; and I have +brought with me that famous work which is now so little known, greatly +as it deserves to be studied, "The Leviathan," in order that I may put +to you in the wonderfully terse and clear language of Thomas Hobbes, +what was his view of the matter. He says:-- + + "The register of knowledge of fact is called history. Whereof there + be two sorts, one called natural history; which is the history of + such facts or effects of nature as have no dependence on man's + will; such as are the histories of metals, plants, animals, + regions, and the like. The other is civil history; which is the + history of the voluntary actions of men in commonwealths." + +So that all history of fact was divided into these two great groups of +natural and of civil history. The Royal Society was in course of +foundation about the time that Hobbes was writing this book, which was +published in 1651; and that Society was termed a "Society for the +Improvement of Natural Knowledge," which was then nearly the same thing +as a "Society for the Improvement of Natural History." As time went on, +and the various branches of human knowledge became more distinctly +developed and separated from one another, it was found that some were +much more susceptible of precise mathematical treatment than others. The +publication of the "Principia" of Newton, which probably gave a greater +stimulus to physical science than any work ever published before, or +which is likely to be published hereafter, showed that precise +mathematical methods were applicable to those branches of science such +as astronomy, and what we now call physics, which occupy a very large +portion of the domain of what the older writers understood by natural +history. And inasmuch as the partly deductive and partly experimental +methods of treatment to which Newton and others subjected these branches +of human knowledge, showed that the phenomena of nature which belonged +to them were susceptible of explanation, and thereby came within the +reach of what was called "philosophy" in those days; so much of this +kind of knowledge as was not included under astronomy came to be spoken +of as "natural philosophy"--a term which Bacon had employed in a much +wider sense. Time went on, and yet other branches of science developed +themselves. Chemistry took a definite shape; and since all these +sciences, such as astronomy, natural philosophy, and chemistry, were +susceptible either of mathematical treatment or of experimental +treatment, or of both, a broad distinction was drawn between the +experimental branches of what had previously been called natural history +and the observational branches--those in which experiment was (or +appeared to be) of doubtful use, and where, at that time, mathematical +methods were inapplicable. Under these circumstances the old name of +"Natural History" stuck by the residuum, by those phenomena which were +not, at that time, susceptible of mathematical or experimental +treatment; that is to say, those phenomena of nature which come now +under the general heads of physical geography, geology, mineralogy, the +history of plants, and the history of animals. It was in this sense that +the term was understood by the great writers of the middle of the last +century--Buffon and Linnaeus--by Buffon in his great work, the "Histoire +Naturelle Generale," and by Linnaeus in his splendid achievement, the +"Systema Naturae." The subjects they deal with are spoken of as "Natural +History," and they called themselves and were called "Naturalists." But +you will observe that this was not the original meaning of these terms; +but that they had, by this time, acquired a signification widely +different from that which they possessed primitively. + +The sense in which "Natural History" was used at the time I am now +speaking of has, to a certain extent, endured to the present day. There +are now in existence in some of our northern universities, chairs of +"Civil and Natural History," in which "Natural History" is used to +indicate exactly what Hobbes and Bacon meant by that term. The unhappy +incumbent of the chair of Natural History is, or was, supposed to cover +the whole ground of geology, mineralogy, and zoology, perhaps even +botany, in his lectures. + +But as science made the marvellous progress which it did make at the +latter end of the last and the beginning of the present century, +thinking men began to discern that under this title of "Natural History" +there were included very heterogeneous constituents--that, for example, +geology and mineralogy were, in many respects, widely different from +botany and zoology; that a man might obtain an extensive knowledge of +the structure and functions of plants and animals, without having need +to enter upon the study of geology or mineralogy, and _vice versa_; and, +further as knowledge advanced, it became clear that there was a great +analogy, a very close alliance, between those two sciences of botany and +zoology which deal with living beings, while they are much more widely +separated from all other studies. It is due to Buffon to remark that he +clearly recognised this great fact. He says: "Ces deux genres d'etres +organises [les animaux et les vegetaux] ont beaucoup plus de proprietes +communes que de differences reelles." Therefore, it is not wonderful +that, at the beginning of the present century, in two different +countries, and so far as I know, without any intercommunication, two +famous men clearly conceived the notion of uniting the sciences which +deal with living matter into one whole, and of dealing with them as one +discipline. In fact, I may say there were three men to whom this idea +occurred contemporaneously, although there were but two who carried it +into effect, and only one who worked it out completely. The persons to +whom I refer were the eminent physiologist Bichat, and the great +naturalist Lamarck, in France; and a distinguished German, Treviranus. +Bichat[1] assumed the existence of a special group of "physiological" +sciences. Lamarck, in a work published in 1801,[2] for the first time +made use of the name "Biologie" from the two Greek words which signify a +discourse upon life and living things. About the same time it occurred +to Treviranus, that all those sciences which deal with living matter are +essentially and fundamentally one, and ought to be treated as a whole; +and, in the year 1802, he published the first volume of what he also +called "Biologie." Treviranus's great merit lies in this, that he worked +out his idea, and wrote the very remarkable book to which I refer. It +consists of six volumes, and occupied its author for twenty years--from +1802 to 1822. + +That is the origin of the term "Biology;" and that is how it has come +about that all clear thinkers and lovers of consistent nomenclature have +substituted for the old confusing name of "Natural History," which has +conveyed so many meanings, the term "Biology" which denotes the whole of +the sciences which deal with living things, whether they be animals or +whether they be plants. Some little time ago--in the course of this +year, I think--I was favoured by a learned classic, Dr. Field of +Norwich, with a disquisition, in which he endeavoured to prove that, +from a philological point of view, neither Treviranus nor Lamarck had +any right to coin this new word "Biology" for their purpose; that, in +fact, the Greek word "Bios" had relation only to human life and human +affairs, and that a different word was employed by the Greeks when they +wished to speak of the life of animals and plants. So Dr. Field tells us +we are all wrong in using the term biology, and that we ought to employ +another; only he is not quite sure about the propriety of that which he +proposes as a substitute. It is a somewhat hard one--"zootocology." I am +sorry we are wrong, because we are likely to continue so. In these +matters we must have some sort of "Statute of Limitations." When a name +has been employed for half-a-century, persons of authority[3] have been +using it, and its sense has become well understood, I am afraid that +people will go on using it, whatever the weight of philological +objection. + +Now that we have arrived at the origin of this word "Biology," the next +point to consider is: What ground does it cover? I have said that, in +its strict technical sense, it denotes all the phenomena which are +exhibited by living things, as distinguished from those which are not +living; but while that is all very well, so long as we confine ourselves +to the lower animals and to plants, it lands us in considerable +difficulties when we reach the higher forms of living things. For +whatever view we may entertain about the nature of man, one thing is +perfectly certain, that he is a living creature. Hence, if our +definition is to be interpreted strictly, we must include man and all +his ways and works under the head of Biology; in which case, we should +find that psychology, politics, and political economy would be absorbed +into the province of Biology. In fact, civil history would be merged in +natural history. In strict logic it may be hard to object to this +course, because no one can doubt that the rudiments and outlines of our +own mental phenomena are traceable among the lower animals. They have +their economy and their polity, and if, as is always admitted, the +polity of bees and the commonwealth of wolves fall within the purview of +the biologist proper, it becomes hard to say why we should not include +therein human affairs, which in so many cases resemble those of the bees +in zealous getting, and are not without a certain parity in the +proceedings of the wolves. The real fact is that we biologists are a +self-sacrificing people; and inasmuch as, on a moderate estimate, there +are about a quarter of a million different species of animals and plants +to know about already, we feel that we have more than sufficient +territory. There has been a sort of practical convention by which we +give up to a different branch of science what Bacon and Hobbes would +have called "Civil History." That branch of science has constituted +itself under the head of Sociology. I may use phraseology which, at +present, will be well understood and say that we have allowed that +province of Biology to become autonomous; but I should like you to +recollect that that is a sacrifice, and that you should not be surprised +if it occasionally happens that you see a biologist apparently +trespassing in the region of philosophy or politics; or meddling with +human education; because, after all, that is a part of his kingdom which +he has only voluntarily forsaken. + +Having now defined the meaning of the word Biology, and having indicated +the general scope of Biological Science, I turn to my second question, +which is--Why should we study Biology? Possibly the time may come when +that will seem a very odd question. That we, living creatures, should +not feel a certain amount of interest in what it is that constitutes our +life will eventually, under altered ideas of the fittest objects of +human inquiry, appear to be a singular phenomenon; but, at present, +judging by the practice of teachers and educators, Biology would seem to +be a topic that does not concern us at all. I propose to put before you +a few considerations with which I dare say many will be familiar +already, but which will suffice to show--not fully, because to +demonstrate this point fully would take a great many lectures--that +there are some very good and substantial reasons why it may be advisable +that we should know something about this branch of human learning. + +I myself entirely agree with another sentiment of the philosopher of +Malmesbury, "that the scope of all speculation is the performance of +some action or thing to be done," and I have not any very great respect +for, or interest in, mere knowing as such. I judge of the value of human +pursuits by their bearing upon human interests; in other words, by their +utility; but I should like that we should quite clearly understand what +it is that we mean by this word "utility." In an Englishman's mouth it +generally means that by which we get pudding or praise, or both. I have +no doubt that is one meaning of the word utility, but it by no means +includes all I mean by utility. I think that knowledge of every kind is +useful in proportion as it tends to give people right ideas, which are +essential to the foundation of right practice, and to remove wrong +ideas, which are the no less essential foundations and fertile mothers +of every description of error in practice. And inasmuch as, whatever +practical people may say, this world is, after all, absolutely governed +by ideas, and very often by the wildest and most hypothetical ideas, it +is a matter of the very greatest importance that our theories of things, +and even of things that seem a long way apart from our daily lives, +should be as far as possible true, and as far as possible removed from +error. It is not only in the coarser practical sense of the word +"utility," but in this higher and broader sense, that I measure the +value of the study of biology by its utility; and I shall try to point +out to you that you will feel the need of some knowledge of biology at a +great many turns of this present nineteenth century life of ours. For +example, most of us attach great importance to the conception which we +entertain of the position of man in this universe and his relation to +the rest of nature. We have almost all been told, and most of us hold by +the tradition, that man occupies an isolated and peculiar position in +nature; that though he is in the world he is not of the world; that his +relations to things about him are of a remote character; that his origin +is recent, his duration likely to be short, and that he is the great +central figure round which other things in this world revolve. But this +is not what the biologist tells us. + +At the present moment you will be kind enough to separate me from them, +because it is in no way essential to my present argument that I should +advocate their views. Don't suppose that I am saying this for the +purpose of escaping the responsibility of their beliefs; indeed, at +other times and in other places, I do not think that point has been left +doubtful; but I want clearly to point out to you that for my present +argument they may all be wrong; and, nevertheless, my argument will hold +good. The biologists tell us that all this is an entire mistake. They +turn to the physical organisation of man. They examine his whole +structure, his bony frame and all that clothes it. They resolve him into +the finest particles into which the microscope will enable them to break +him up. They consider the performance of his various functions and +activities, and they look at the manner in which he occurs on the +surface of the world. Then they turn to other animals, and taking the +first handy domestic animal--say a dog--they profess to be able to +demonstrate that the analysis of the dog leads them, in gross, to +precisely the same results as the analysis of the man; that they find +almost identically the same bones, having the same relations; that they +can name the muscles of the dog by the names of the muscles of the man, +and the nerves of the dog by those of the nerves of the man, and that, +such structures and organs of sense as we find in the man such also we +find in the dog; they analyse the brain and spinal cord, and they find +that the nomenclature which fits the one answers for the other. They +carry their microscopic inquiries in the case of the dog as far as they +can, and they find that his body is resolvable into the same elements as +those of the man. Moreover, they trace back the dog's and the man's +development, and they find that, at a certain stage of their existence, +the two creatures are not distinguishable the one from the other; they +find that the dog and his kind have a certain distribution over the +surface of the world, comparable in its way to the distribution of the +human species. What is true of the dog they tell us is true of all the +higher animals; and they assert that they can lay down a common plan for +the whole of these creatures, and regard the man and the dog, the horse +and the ox as minor modifications of one great fundamental unity. +Moreover, the investigations of the last three-quarters of a century +have proved, they tell us, that similar inquiries, carried out through +all the different kinds of animals which are met with in nature, will +lead us, not in one straight series, but by many roads, step by step, +gradation by gradation, from man, at the summit, to specks of animated +jelly at the bottom of the series. So that the idea of Leibnitz, and of +Bonnet, that animals form a great scale of being, in which there are a +series of gradations from the most complicated form to the lowest and +simplest; that idea, though not exactly in the form in which it was +propounded by those philosophers, turns out to be substantially correct. +More than this, when biologists pursue their investigations into the +vegetable world, they find that they can, in the same way, follow out +the structure of the plant, from the most gigantic and complicated trees +down through a similar series of gradations, until they arrive at specks +of animated jelly, which they are puzzled to distinguish from those +specks which they reached by the animal road. + +Thus, biologists have arrived at the conclusion that a fundamental +uniformity of structure pervades the animal and vegetable worlds, and +that plants and animals differ from one another simply as diverse +modifications of the same great general plan. + +Again, they tell us the same story in regard to the study of function. +They admit the large and important interval which, at the present time, +separates the manifestations of the mental faculties observable in the +higher forms of mankind, and even in the lower forms, such as we know +them, from those exhibited by other animals; but, at the same time, they +tell us that the foundations, or rudiments, of almost all the faculties +of man are to be met with in the lower animals; that there is a unity of +mental faculty as well as of bodily structure, and that, here also, the +difference is a difference of degree and not of kind. I said "almost +all," for a reason. Among the many distinctions which have been drawn +between the lower creatures and ourselves, there is one which is hardly +ever insisted on,[4] but which may be very fitly spoken of in a place so +largely devoted to Art as that in which we are assembled. It is this, +that while, among various kinds of animals, it is possible to discover +traces of all the other faculties of man, especially the faculty of +mimicry, yet that particular form of mimicry which shows itself in the +imitation of form, either by modelling or by drawing, is not to be met +with. As far as I know, there is no sculpture or modelling, and +decidedly no painting or drawing, of animal origin, I mention the fact, +in order that such comfort may be derived therefrom as artists may feel +inclined to take. + +If what the biologists tell us is true, it will be needful to get rid of +our erroneous conceptions of man, and of his place in nature, and to +substitute right ones for them. But it is impossible to form any +judgment as to whether the biologists are right or wrong, unless we are +able to appreciate the nature of the arguments which they have to offer. + +One would almost think this to be a self-evident proposition. I wonder +what a scholar would say to the man who should undertake to criticise a +difficult passage in a Greek play, but who obviously had not acquainted +himself with the rudiments of Greek grammar. And yet, before giving +positive opinions about these high questions of Biology, people not only +do not seem to think it necessary to be acquainted with the grammar of +the subject, but they have not even mastered the alphabet. You find +criticism and denunciation showered about by persons, who, not only have +not attempted to go through the discipline necessary to enable them to +be judges, but who have not even reached that stage of emergence from +ignorance in which the knowledge that such a discipline is necessary +dawns upon the mind. I have had to watch with some attention--in fact I +have been favoured with a good deal of it myself--the sort of criticism +with which biologists and biological teachings are visited. I am told +every now and then that there is a "brilliant article"[5] in so-and-so, +in which we are all demolished. I used to read these things once, but I +am getting old now, and I have ceased to attend very much to this cry of +"wolf." When one does read any of these productions, what one finds +generally, on the face of it, is that the brilliant critic is devoid of +even the elements of biological knowledge, and that his brilliancy is +like the light given out by the crackling of thorns under a pot of which +Solomon speaks. So far as I recollect, Solomon makes use of the image +for purposes of comparison; but I will not proceed further into that +matter. + +Two things must be obvious: in the first place, that every man who has +the interests of truth at heart must earnestly desire that every +well-founded and just criticism that can be made should be made; but +that, in the second place, it is essential to anybody's being able to +benefit by criticism, that the critic should know what he is talking +about, and be in a position to form a mental image of the facts +symbolised by the words he uses. If not, it is as obvious in the case of +a biological argument, as it is in that of a historical or philological +discussion, that such criticism is a mere waste of time on the part of +its author, and wholly undeserving of attention on the part of those who +are criticised. Take it then as an illustration of the importance of +biological study, that thereby alone are men able to form something like +a rational conception of what constitutes valuable criticism of the +teachings of biologists.[6] + +Next, I may mention another bearing of biological knowledge--a more +practical one in the ordinary sense of the word. Consider the theory of +infectious disease. Surely that is of interest to all of us. Now the +theory of infectious disease is rapidly being elucidated by biological +study. It is possible to produce, from among the lower animals, examples +of devastating diseases which spread in the same manner as our +infectious disorders, and which are certainly and unmistakably caused by +living organisms. This fact renders it possible, at any rate, that that +doctrine of the causation of infectious disease which is known under the +name of "the germ theory" may be well-founded; and, if so, it must needs +lead to the most important practical measures in dealing with those +terrible visitations. It may be well that the general, as well as the +professional, public should have a sufficient knowledge of biological +truths to be able to take a rational interest in the discussion of such +problems, and to see, what I think they may hope to see, that, to those +who possess a sufficient elementary knowledge of Biology, they are not +all quite open questions. + +Let me mention another important practical illustration of the value of +biological study. Within the last forty years the theory of agriculture +has been revolutionised. The researches of Liebig, and those of our own +Lawes and Gilbert, have had a bearing upon that branch of industry the +importance of which cannot be overestimated; but the whole of these new +views have grown out of the better explanation of certain processes +which go on in plants; and which, of course, form a part of the +subject-matter of Biology. + +I might go on multiplying these examples, but I see that the clock won't +wait for me, and I must therefore pass to the third question to which I +referred: Granted that Biology is something worth studying, what is the +best way of studying it? Here I must point out that, since Biology is a +physical science, the method of studying it must needs be analogous to +that which is followed in the other physical sciences. It has now long +been recognised that, if a man wishes to be a chemist, it is not only +necessary that he should read chemical books and attend chemical +lectures, but that he should actually perform the fundamental +experiments in the laboratory for himself, and thus learn exactly what +the words which he finds in his books and hears from his teachers, mean. +If he does not do so, he may read till the crack of doom, but he will +never know much about chemistry. That is what every chemist will tell +you, and the physicist will do the same for his branch of science. The +great changes and improvements in physical and chemical scientific +education, which have taken place of late, have all resulted from the +combination of practical teaching with the reading of books and with the +hearing of lectures. The same thing is true in Biology. Nobody will ever +know anything about Biology except in a dilettante "paper-philosopher" +way, who contents himself with reading books on botany, zoology, and the +like; and the reason of this is simple and easy to understand. It is +that all language is merely symbolical of the things of which it treats; +the more complicated the things, the more bare is the symbol, and the +more its verbal definition requires to be supplemented by the +information derived directly from the handling, and the seeing, and the +touching of the thing symbolised:--that is really what is at the bottom +of the whole matter. It is plain common sense, as all truth, in the long +run, is only common sense clarified. If you want a man to be a tea +merchant, you don't tell him to read books about China or about tea, but +you put him into a tea-merchant's office where he has the handling, the +smelling, and the tasting of tea. Without the sort of knowledge which +can be gained only in this practical way, his exploits as a tea merchant +will soon come to a bankrupt termination. The "paper-philosophers" are +under the delusion that physical science can be mastered as literary +accomplishments are acquired, but unfortunately it is not so. You may +read any quantity of books, and you may be almost as ignorant as you +were at starting, if you don't have, at the back of your minds, the +change for words in definite images which can only be acquired through +the operation of your observing faculties on the phenomena of nature. + +It may be said:--"That is all very well, but you told us just now that +there are probably something like a quarter of a million different kinds +of living and extinct animals and plants, and a human life could not +suffice for the examination of one-fiftieth part of all these." That is +true, but then comes the great convenience of the way things are +arranged; which is, that although there are these immense numbers of +different kinds of living things in existence, yet they are built up, +after all, upon marvellously few plans. + +There are certainly more than 100,000 species of insects, and yet +anybody who knows one insect--if a properly chosen one--will be able to +have a very fair conception of the structure of the whole. I do not mean +to say he will know that structure thoroughly, or as well as it is +desirable he should know it; but he will have enough real knowledge to +enable him to understand what he reads, to have genuine images in his +mind of those structures which become so variously modified in all the +forms of insects he has not seen. In fact, there are such things as +types of form among animals and vegetables, and for the purpose of +getting a definite knowledge of what constitutes the leading +modifications of animal and plant life, it is not needful to examine +more than a comparatively small number of animals and plants. + +Let me tell you what we do in the biological laboratory which is lodged +in a building adjacent to this. There I lecture to a class of students +daily for about four-and-a-half months, and my class have, of course, +their text-books; but the essential part of the whole teaching, and that +which I regard as really the most important part of it, is a laboratory +for practical work, which is simply a room with all the appliances +needed for ordinary dissection. We have tables properly arranged in +regard to light, microscopes, and dissecting instruments, and we work +through the structure of a certain number of animals and plants. As, for +example, among the plants, we take a yeast plant, a _Protococcus_, a +common mould, a _Chara_, a fern, and some flowering plant; among animals +we examine such things as an _Amoeba_, a _Vorticella_, and a +fresh-water polype. We dissect a star-fish, an earth-worm, a snail, a +squid, and a fresh-water mussel. We examine a lobster and a cray-fish, +and a black beetle. We go on to a common skate, a cod-fish, a frog, a +tortoise, a pigeon, and a rabbit, and that takes us about all the time +we have to give. The purpose of this course is not to make skilled +dissectors, but to give every student a clear and definite conception, +by means of sense-images, of the characteristic structure of each of the +leading modifications of the animal kingdom; and that is perfectly +possible, by going no further than the length of that list of forms +which I have enumerated. If a man knows the structure of the animals I +have mentioned, he has a clear and exact, however limited, apprehension +of the essential features of the organisation of all those great +divisions of the animal and vegetable kingdoms to which the forms I have +mentioned severally belong. And it then becomes possible for him to read +with profit; because every time he meets with the name of a structure, +he has a definite image in his mind of what the name means in the +particular creature he is reading about, and therefore the reading is +not mere reading. It is not mere repetition of words; but every term +employed in the description, we will say, of a horse, or of an elephant, +will call up the image of the things he had seen in the rabbit, and he +is able to form a distinct conception of that which he has not seen, as +a modification of that which he has seen. + +I find this system to yield excellent results; and I have no hesitation +whatever in saying, that any one who has gone through such a course, +attentively, is in a better position to form a conception of the great +truths of Biology, especially of morphology (which is what we chiefly +deal with), than if he had merely read all the books on that topic put +together. + +The connection of this discourse with the Loan Collection of Scientific +Apparatus arises out of the exhibition in that collection of certain +aids to our laboratory work. Such of you as have visited that very +interesting collection may have noticed a series of diagrams and of +preparations illustrating the structure of a frog. Those diagrams and +preparations have been made for the use of the students in the +biological laboratory. Similar diagrams and preparations illustrating +the structure of all the other forms of life we examine, are either made +or in course of preparation. Thus the student has before him, first, a +picture of the structure he ought to see; secondly, the structure itself +worked out; and if with these aids, and such needful explanations and +practical hints as a demonstrator can supply, he cannot make out the +facts for himself in the materials supplied to him, he had better take +to some other pursuit than that of biological science. + +I should have been glad to have said a few words about the use of +museums in the study of Biology, but I see that my time is becoming +short, and I have yet another question to answer. Nevertheless I must, +at the risk of wearying you, say a word or two upon the important +subject of museums. Without doubt there are no helps to the study of +Biology, or rather to some branches of it, which are, or may be, more +important than natural history museums; but, in order to take this place +in regard to Biology, they must be museums of the future. The museums of +the present do not, by any means, do so much for us as they might do. I +do not wish to particularise, but I dare say many of you, seeking +knowledge, or in the laudable desire to employ a holiday usefully, have +visited some great natural history museum. You have walked through a +quarter of a mile of animals, more or less well stuffed, with their long +names written out underneath them; and, unless your experience is very +different from that of most people, the upshot of it all is that you +leave that splendid pile with sore feet, a bad headache, and a general +idea that the animal kingdom is a "mighty maze without a plan." I do not +think that a museum which brings about this result does all that may be +reasonably expected from such an institution. What is needed in a +collection of natural history is that it should be made as accessible +and as useful as possible, on the one hand to the general public, and on +the other to scientific workers. That need is not met by constructing a +sort of happy hunting-ground of miles of glass cases; and, under the +pretence of exhibiting everything, putting the maximum amount of +obstacle in the way of those who wish properly to see anything. + +What the public want is easy and unhindered access to such a collection +as they can understand and appreciate; and what the men of science want +is similar access to the materials of science. To this end the vast mass +of objects of natural history should be divided into two parts--one open +to the public, the other to men of science, every day. The former +division should exemplify all the more important and interesting forms +of life. Explanatory tablets should be attached to them, and catalogues +containing clearly-written popular expositions of the general +significance of the objects exhibited should be provided. The latter +should contain, packed into a comparatively small space, in rooms +adapted for working purposes, the objects of purely scientific interest. +For example, we will say I am an ornithologist. I go to examine a +collection of birds. It is a positive nuisance to have them stuffed. It +is not only sheer waste, but I have to reckon with the ideas of the +bird-stuffer, while, if I have the skin and nobody has interfered with +it, I can form my own judgment as to what the bird was like. For +ornithological purposes, what is needed is not glass cases full of +stuffed birds on perches, but convenient drawers into each of which a +great quantity of skins will go. They occupy no great space and do not +require any expenditure beyond their original cost. But for the +edification of the public, who want to learn indeed, but do not seek for +minute and technical knowledge, the case is different. What one of the +general public walking into a collection of birds desires to see is not +all the birds that can be got together. He does not want to compare a +hundred species of the sparrow tribe side by side; but he wishes to know +what a bird is, and what are the great modifications of bird structure, +and to be able to get at that knowledge easily. What will best serve his +purpose is a comparatively small number of birds carefully selected, and +artistically, as well as accurately, set up; with their different ages, +their nests, their young, their eggs, and their skeletons side by side; +and in accordance with the admirable plan which is pursued in this +museum, a tablet, telling the spectator in legible characters what they +are and what they mean. For the instruction and recreation of the public +such a typical collection would be of far greater value than any +many-acred imitation of Noah's ark. + +Lastly comes the question as to when biological study may best be +pursued. I do not see any valid reason why it should not be made, to a +certain extent, a part of ordinary school training. I have long +advocated this view, and I am perfectly certain that it can be carried +out with ease, and not only with ease, but with very considerable profit +to those who are taught; but then such instruction must be adapted to +the minds and needs of the scholars. They used to have a very odd way of +teaching the classical languages when I was a boy. The first task set +you was to learn the rules of the Latin grammar in the Latin +language--that being the language you were going to learn! I thought +then that this was an odd way of learning a language, but did not +venture to rebel against the judgment of my superiors. Now, perhaps, I +am not so modest as I was then, and I allow myself to think that it was +a very absurd fashion. But it would be no less absurd, if we were to set +about teaching Biology by putting into the hands of boys a series of +definitions of the classes and orders of the animal kingdom, and making +them repeat them by heart. That is so very favourite a method of +teaching, that I sometimes fancy the spirit of the old classical system +has entered into the new scientific system, in which case I would much +rather that any pretence at scientific teaching were abolished +altogether. What really has to be done is to get into the young mind +some notion of what animal and vegetable life is. In this matter, you +have to consider practical convenience as well as other things. There +are difficulties in the way of a lot of boys making messes with slugs +and snails; it might not work in practice. But there is a very +convenient and handy animal which everybody has at hand, and that is +himself; and it is a very easy and simple matter to obtain common +plants. Hence the general truths of anatomy and physiology can be taught +to young people in a very real fashion by dealing with the broad facts +of human structure. Such viscera as they cannot very well examine in +themselves, such as hearts, lungs, and livers, may be obtained from the +nearest butcher's shop. In respect to teaching something about the +biology of plants, there is no practical difficulty, because almost any +of the common plants will do, and plants do not make a mess--at least +they do not make an unpleasant mess; so that, in my judgment, the best +form of Biology for teaching to very young people is elementary human +physiology on the one hand, and the elements of botany on the other; +beyond that I do not think it will be feasible to advance for some time +to come. But then I see no reason why, in secondary schools, and in the +Science Classes which are under the control of the Science and Art +Department--and which I may say, in passing, have, in my judgment, done +so very much for the diffusion of a knowledge of science over the +country--we should not hope to see instruction in the elements of +Biology carried out, not perhaps to the same extent, but still upon +somewhat the same principle as here. There is no difficulty, when you +have to deal with students of the ages of 15 or 16, in practising a +little dissection and in getting a notion of, at any rate, the four or +five great modifications of the animal form; and the like is true in +regard to the higher anatomy of plants. + +While, lastly, to all those who are studying biological science with a +view to their own edification merely, or with the intention of becoming +zoologists or botanists; to all those who intend to pursue +physiology--and especially to those who propose to employ the working +years of their lives in the practice of medicine--I say that there is no +training so fitted, or which may be of such important service to them, +as the discipline in practical biological work which I have sketched out +as being pursued in the laboratory hard by. + + * * * * * + +I may add that, beyond all these different classes of persons who may +profit by the study of Biology, there is yet one other. I remember, a +number of years ago, that a gentleman who was a vehement opponent of Mr. +Darwin's views and had written some terrible articles against them, +applied to me to know what was the best way in which he could acquaint +himself with the strongest arguments in favour of evolution. I wrote +back, in all good faith and simplicity, recommending him to go through a +course of comparative anatomy and physiology, and then to study +development. I am sorry to say he was very much displeased, as people +often are with good advice. Notwithstanding this discouraging result, I +venture, as a parting word, to repeat the suggestion, and to say to all +the more or less acute lay and clerical "paper-philosophers"[7] who +venture into the regions of biological controversy--Get a little sound, +thorough, practical, elementary instruction in biology. + + + [1] See the distinction between the "sciences physiques" and the + "sciences physiologiques" in the "Anatomic Generale," 1801. + + + [2] "Hydrogeologie," an. x. (1801). + + + [3] "The term _Biology_, which means exactly what we wish to + express, _the Science of Life_, has often been used, and has of + late become not uncommon, among good writers."--Whewell, + "Philosophy of the Inductive Sciences," vol. i. p. 544 (edition + of 1847). + + + [4] I think that my friend Professor Allman was the first to draw + attention to it. + + + [5] Galileo was troubled by a sort of people whom he called "paper + philosophers," because they fancied that the true reading of + nature was to be detected by the collation of texts. The race is + not extinct, but, as of old, brings forth its "winds of + doctrine" by which the weathercock heads among us are much + exercised. + + + [6] Some critics do not even take the trouble to read. I have + recently been adjured with much solemnity, to state publicly why + I have "changed my opinion" as to the value of the + palaeontological evidence of the occurrence of evolution. + + To this my reply is, Why should I, when that statement was made + seven years ago? An address delivered from the Presidential + Chair of the Geological Society, in 1870, may be said to be a + public document, inasmuch as it not only appeared in the + _Journal_ of that learned body, but was re-published, in 1873, + in a volume of "Critiques and Addresses," to which my name is + attached. Therein will be found a pretty full statement of my + reasons for enunciating two propositions: (1) that "when we turn + to the higher _Vertebrata_, the results of recent + investigations, however we may sift and criticise them, seem to + me to leave a clear balance in favour of the evolution of living + forms one from another;" and (2) that the case of the horse is + one which "will stand rigorous criticism." + + Thus I do not see clearly in what way I can be said to have + changed my opinion, except in the way of intensifying it, when + in consequence of the accumulation of similar evidence since + 1870, I recently spoke of the denial of evolution as not worth + serious consideration. + + + [7] Writers of this stamp are fond of talking about the Baconian + method. I beg them therefore to lay to heart these two weighty + sayings of the herald of Modern Science:-- + + "Syllogismus ex propositionibus constat, propositiones ex + verbis, verba notionum tesserae sunt. Itaque si notiones ipsae + (_id quod basis rei est_) confusae sint et temere a rebus + abstractae, nihil in iis quae superstruuntur est + firmitudinis."--"Novum Organon," ii. 14. + + "Huic autem vanitati nonnulli ex modernis summa levitate ita + indulserunt, ut in primo capitulo Geneseos et in libro Job + et aliis scripturis sacris, philosophiam naturalem fundare + conati sint; _inter vivos quaerentes mortua_."--_Ibid._, 65. + + + +***END OF THE PROJECT GUTENBERG EBOOK AMERICAN ADDRESSES, WITH A LECTURE +ON THE STUDY OF BIOLOGY*** + + +******* This file should be named 16136.txt or 16136.zip ******* + + +This and all associated files of various formats will be found in: +https://www.gutenberg.org/dirs/1/6/1/3/16136 + + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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