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 Darwiniana :essays /by Thomas H. Huxley. 
 
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DARWIN lANA 
 
 E-^^SAYS 
 
 BY 
 
 THOMAS H. HUXLEY 
 
 NEW YORK 
 
 D. APPLETON AND COMPANY 
 
 1894 
 
Authorized Edition. 
 
PKEFACE 
 
 I HAVE entitled this volume "Darwiniana" 
 because the pieces republished in it either treat of 
 the ancient doctrine of Evolution, rehabilitated and 
 placed upon a sound scientific foundation, since 
 and in consequence of, the publication of the 
 " Origin of Species ; " or they attempt to meet the 
 more weighty of the unsparing criticisms with 
 which that great work was visited for several years 
 after its appearance ; or they record the impression 
 left by the personality of Mr, Darwin on one who 
 had the privilege and the happiness of enjoying his 
 friendship for some thirty years ; or they endeavour 
 to sum up his work and indicate its enduring 
 influence on the course of scientific thought. 
 
 Those who take the trouble to read the first 
 two essays, published in 1859 and 1860, will, I 
 think, do me the justice to admit that my zeal to 
 secure fair play for Mr. Darwin, did not drive me 
 into the position of a mere advocate ; and that, 
 while doing justice to the greatness of the argu- 
 
Vi PKEFACE 
 
 ment I did not fail to indicate its weak points. I 
 have never seen any reason for departing from the 
 position which I took up in these two essays ; and 
 the assertion which I sometimes meet with nowa- 
 days, that I have " recanted " or changed my 
 opinions about Mr. Darwin's views, is quite unin- 
 teUigible to me. 
 
 As I have said in the seveuth essay, the fact of 
 evokition is to my mind sufficiently evidenced by 
 palaeontology ; and I remain of the opinion ex- 
 pressed in the second, that until selective breeding 
 is definitely proved to give rise to varieties infertile 
 with one another, the logical foundation of the 
 theory of natural selection is incomplete. We still 
 remain very much in the dark about the causes of 
 variation ; the apparent inheritance of acquired 
 characters in some cases; and the struggle for 
 existence within the organism, which probably 
 lies at the bottom of both of these phenomena. 
 
 Some apology is due to the reader for the repro- 
 duction of the " Lectures to Working Men " in 
 their original state. They were taken down in 
 shorthand by Mr. J. Aldous Mays, who requested 
 me to allow him to print them. I was very much 
 pressed with work at the time ; and, as I could not 
 revise the reports, which I imagined, moreover, 
 would be of little or no interest to any but my 
 auditors, I stipulated that a notice should be pre- 
 fixed to that effect. This was done ; but it did not 
 
PREFACE. vii 
 
 prevent a considerable diffusion of the little book 
 in this country and in the United States, nor its 
 translation into more than one foreign languasre. 
 Moreover Mr, Darwin often urged me to revise and 
 expand the lectures into a systematic popular 
 exposition of the topics of which they treat. I 
 have more than ores set about the task : but the 
 proverb about spoiling a horn and not making a 
 spoon, is particularly applicable to attempts to 
 remodel a piece of work which may have served its 
 immediate purpose well enough. 
 
 So I have reprinted the lectures as they stand, 
 
 with all their imperfections on their heads. It 
 
 would seem that many people must have found 
 
 them useful thirty years ago ; and, though the 
 
 sixties appear now to be reckoned by many of the 
 
 rising generation as a part of the dark ages, I am 
 
 not without some grounds for suspecting that 
 
 there yet remains a fair sprinkling even of 
 
 " philosophic thinkers " to whom it may be a 
 
 profitable, perhaps even a novel, task to descend 
 
 from the heights of speculation and go over the 
 
 A B C of the great biological problem as it was 
 
 set before a body of shrewd artisans at that remote 
 
 epoch. 
 
 T. H. H. 
 
 HODESLEA, EaSTBOTJENE, 
 
 April 7th, 1893. 
 
CONTENTS 
 
 I 
 
 PAGE 
 THE DARWINIAN HYPOTHESIS [1859] 1 
 
 II 
 
 THE OHIGIN OF SPECIES [1860] 22 
 
 CRITICISMS ON " THE OEIGIN OF SPECIES " [1864] ... 80 
 
 IV 
 
 THE GENEALOGT OF ANIMALS [1869] 107 
 
 V 
 
 MR. dabwin's critics [1871] 120 
 
 VI 
 
 EVOLUTION IN BIOLOGY [1878] 187 
 
X CONTENTS 
 
 VII 
 
 PAOH 
 THE COMING OF AGE OF "THE OEIGIN OF SPECIES " 
 
 [1880] 227 
 
 VIII 
 
 OHAELES DARWIN [1882] 244 
 
 IX 
 
 THE DARWIN MEMORIAL [1885] 248 
 
 X 
 OBITUARY [1888] .....*" 253 
 
 XI 
 
 six lectures to working men " on our knowledge 
 of the causes of the phenomena op organic 
 nature" [1863] 803 
 
I 
 
 THE DARWINIAN HYPOTHESIS 
 
 [1859] 
 
 The hypothesis of which the present work of 
 Mr. Darwin is but the prehminary outline, may 
 be stated in his own language as follows : — 
 " Species originated by means of natural selection, 
 or through the preservation of the favoured races 
 in the struggle for life." To render this thesis 
 intelligible, it is necessary to interpret its terms. 
 In the first place, what is a species ? The question 
 is a simple one, but the right answer to it is hard 
 to find, even if we appeal to those who should 
 know most about it. It is all those animals or 
 plants which have descended from a single pair of 
 parents ; it is the smallest distinctly definable 
 group of living organisms ; it is an eternal and 
 immutable entity ; it is a mere abstraction of the 
 human intellect having no existence in nature. 
 Such are a few of the significations attached to 
 
2 THE DARWINIAN HYPOTHESIS I 
 
 this simple word which may be culled from 
 authoritative sources; and if, leaving terms and 
 theoretical subtleties aside, we turn to facts and 
 endeavour to gather a meaning for ourselves, by- 
 studying the things to which, in practice, the 
 name of species is applied, it profits us little. For 
 practice varies as much as theory. Let two 
 botanists or two zoologists examine and describe 
 the productions of a country, and one will pretty 
 certainly disagree with the other as to the number, 
 limits, and definitions of the species into which he 
 groups the very same things. In these islands, we 
 are in the habit of regarding mankind as of one 
 species, but a fortnight's steam will land us in a 
 coimtry where divines and savants, for once in 
 agreement, vie with one another in loudness of 
 assertion, if not in cogency of proof, that men are 
 of different species; and, more particularly, that 
 the species negro is so distinct from our own that 
 the Ten Commandments have actually no reference 
 to him. Even in the calm region of entomology, 
 where, if anywhere in this sinful world, passion 
 and prejudice should fail to stir the mind, one 
 learned coleopterist will fill ten attractive volumes 
 with descriptions of species of beetles, nine-tenths 
 of which are immediately declared by his brother 
 beetle-mongers to be no species at all. 
 
 The truth is that the number of distinguishable 
 living creatures almost surpasses imagination. At 
 least 100,000 such kinds of insects alone have been 
 
I THE DARWINIAN HYPOTHESIS 3 
 
 described and may be identified in collections, and 
 the number of separable kinds of living things is 
 under-estimated at half a million. Seeing that 
 most of these obvious kinds have their accidental 
 varieties, and that they often shade into others 
 by imperceptible degrees, it may well be 
 imagined that the task of distinguishing be- 
 tween what is permanent and what fleeting, 
 what is a species and what a mere variety, 
 is sufficiently formidable. 
 
 But is it not possible to apply a test whereby a 
 true species may be known from a mere variety ? 
 Is there no criterion of species ? Great authori- 
 ties affirm that there is — that the unions of 
 members of the same species are always fertile, 
 while those of distinct species are either sterile, 
 or their offspring, called hybrids, are so. It is 
 affirmed not only that this is an experimental 
 fact, but that it is a provision for the preservation 
 of the purity of species. Such a criterion as this 
 would be invaluable ; but, unfortunately, not only 
 is it not obvious how to apply it in the great 
 majority of cases in which its aid is needed, but 
 its general validity is stoutly denied. The Hon. 
 and Rev. Mr. Herbert, a most trustworthy authority, 
 not only asserts as the result of his own observa- 
 tions and experiments that many hybrids are 
 quite as fertile as the parent species, but he goes 
 so far as to assert that the particular plant Crinum 
 capense is much more fertile when crossed by a 
 
4s THE DARWINIAN HYPOTHESIS I 
 
 distinct species than when fertilised by its proper 
 pollen ! On the other hand, the famous Gaertner, 
 though he took the greatest pains to cross the 
 Primrose and the Cowslip, succeeded only once or 
 twice in several years ; and yet it is a well- 
 established fact that the Primrose and the Cow- 
 slip are only varieties of the same kind of plant. 
 Again, such cases as the following are well estab- 
 lished. The female of species A, if crossed with 
 the male of species B, is fertile ; but, if the female 
 of B is crossed with the male of A, she remains 
 barren. Facts of this kind destroy the value of 
 the supposed criterion. 
 
 If, weary of the endless difficulties involved in 
 the determination of species, the investigator, 
 contenting himself with the rough practical 
 distinction of separable kinds, endeavours to 
 study them as they occur in nature — to ascertain 
 their relations to the conditions which surround 
 them, their mutual harmonies and discordancies of 
 structure, the bond of union of their present and 
 their past history, he finds himself, according to 
 the received notions, in a mighty maze, and with, 
 at most, the dimmest adumbration of a plan. 
 If he starts with any one clear conviction, it is 
 that every part of a living creature is cunningly 
 adapted to some special use in its life. Has not 
 his Paley told him that that seemingly useless 
 organ, the spleen, is beautifully adjusted as so 
 much packing between the other organs ? And 
 
1 THE DARWINIAN HYPOTHESIS 5 
 
 yet, at the outset of his studies, he finds that no 
 adaptive reason whatsoever can be given for one- 
 half of the peculiarities of vegetable structure. 
 He also discovers rudimentary teeth, which are 
 never used, in the gums of the young calf and in 
 those of the foetal whale ; insects which never 
 bite have rudimental jaws, and others which 
 never fly have rudimental wings ; naturally blind 
 creatures have rudimental eyes ; and the halt 
 have rudimentary limbs. So, again, no animal or 
 plant puts on its perfect form at once, but all have 
 to start from the same point, however various the 
 course which each has to pursue. Not only men 
 and horses, and cats and dogs, lobsters and 
 beetles, periwinkles and mussels, but even the 
 very sponges and animalcules commence their 
 existence under forms which are essentially 
 undistinguishable ; and this is true of all the 
 infinite variety of plants. Nay, more, all living 
 beings march, side by side, along the high road of 
 development, and separate the later the more likei 
 they are ; like people leaving church, who all gd 
 down the aisle, but having reached the door, somJ 
 turn into the parsonage, others go down thq 
 village, and others part only in the next parish.? 
 A man in his development runs for a little while 
 parallel with, though never passing through, the 
 form of the meanest worm, then travels for a 
 space beside the fish, then journeys along with 
 the bird and the reptile for his fellow travellers ; 
 
6 THE DARWINIAN HYPOTHESIS I 
 
 and only at last, after a brief companionship with 
 the highest of the four-footed and four-handed 
 world, rises into the dignity of pure manhood. No 
 competent thinker of the present day dreams of 
 explaining these indubitable facts by the notion 
 of the existence of unknown and undiscoverable 
 adaptations to purpose. And we would remind 
 those who, ignorant of the facts, must be moved 
 by authority, that no one has asserted the incom- 
 petence of the doctrine of final causes, in its 
 application to physiology and anatomy, more 
 strongly than our own eminent anatomist. 
 Professor Owen, who, speaking of such cases, says 
 ("On the Nature of Limbs," pp. 39, 40)— " I 
 think it will be obvious that the principle of final 
 adaptations fails to satisfy all the conditions of 
 the problem." 
 
 Butjif the^doctrine of fin al causes will n ot 
 help us to comprehend the anomalies ^pf living 
 structure, the principleof_ad^MitiQli- must surely 
 lead' us to understand why certai n liv ing beings are 
 found in certain regions of jdie_jwqrld and not in 
 others,^ The Palm, as we know, will not grow in 
 our climate, nor the Oak in Greenland. The 
 white bear cannot live where the tiger thrives, 
 nor vice versd, and the more the natural habits of 
 animal and vegetable species are examined, the 
 more do they seem, on the whole, limited to 
 particular provinces. But when we look into the 
 facts established by the study of the geographical 
 
I THE DARWINIAN HYPOTHESIS 7 
 
 distribution of animals and plants it seems 
 utterly hopeless to attempt to understand the 
 strange and apparently capricious relations which 
 they exhibit. O ne would be- -inHinetLl o suppose 
 a . yriori that every country must be naturally 
 peoj)le(lby_those a.n,iTT ;ia1s t.hai. -a.ra_fittpatj;2_li^ 
 and thrive in it. And yet how, on this hypothesis, 
 are we to account for the'^bsence of cattle in the 
 Pampa s of South America,, when those parts of 
 the New Wor ld were discovere d ? Iji_is_notthat 
 they were unfit for cat tle, for millions of cattle 
 now run wild there ;~and the like., holds good of 
 Australia and^ ^e w Zealand. It is a curious 
 circumstance", m tact, that the animals and plants 
 of the Northern Hemisphere are not only as well 
 adapted to live in the Southern Hemisphere as 
 its own autochthones, but are, in many cases, 
 absolutely better adapted, and so overrun and 
 extirpate the aborigines. Clearly, therefore, the 
 species which naturally inhabit a country are not 
 necessarily the best adapted to its climate and 
 other conditions. The inhabitants of islands are 
 often distinct from .^any other ¥nown ^Jpec^§._ of 
 an imal or ^^nts, (wit^qg^ our recent examples 
 froin the ^work of Sir EmersoTr~Tennent, on 
 Ceylon), and yet they have almost always a sort 
 of general family resemblance to the animals and 
 plauta uf — tAre-jaeaa-e gtr iSamland ^ Un the other 
 hand, there is hardly a species of fish, shell, or 
 crab common to the opposite sides of the narrow 
 SO 
 
8 THE DARWINIAN HYPOTHESIS I 
 
 isthmus of Panama.^ Wlierever_ws_Ji>J3k,_then, 
 living nature_offCTS_us-iiiMks-iD£-.difficuK 
 "'irwe'~sup£ose_tJiat-JV-hat_5Ke ^ee is all that can 
 
 be~lmo55uo£-*fer- . 
 
 Vat our knowledge of life is not confined to the 
 existing world. Whatever their minor differences, 
 seologists are agreed as to the vast thickness of the 
 accumulated strata which compose the visible part 
 of our earth, and the inconceivable immensity of 
 the time the lapse of Avhich they are the imperfect 
 but the only accessible witnesses. Now, through- 
 out the greater part of this long series of stratified 
 rocks are scattered, sometimes very abundantly, 
 multitudes of organic remains, the fossilised 
 exuviae of animals and plants which lived and 
 died while the mud of which the rocks are formed 
 Avas yet soft ooze, and could receive and bury 
 them. It would be a great error to suppose that 
 these organic remains were fragmentary relics. 
 Our museums exhibit fossil shells of immeasurable 
 antiquity, as perfect as the day they were formed ; 
 whole skeletons without a limb disturbed ; nay, 
 the changed flesh, the developing embryos, and 
 even the very footsteps of primaeval organisms. 
 Thus the naturalist finds in the bowels of the earth 
 species as well defined as, and in some groups 
 of animals more numerous than, those which 
 breathe the upper air. But, singularly enough, 
 the majority of these entombed species are wholly 
 1 [See page 60 Note] 
 
I THE DARWINIAN HYPOTHESIS 9 
 
 distinct from those that now live. Nor is this un- 
 l ikeness~without i^ rule~anc r ordel\ ~ As a bro ad ' 
 fa^ L the further w e go bacFln t |me_thgjftss Jjtp._ 
 buried sg ecies are like existing forms ; and, the fur- 
 the r apart the se ts "f ftYtiruvt-. creaturesare, the less 
 they are like one another. ._ In lO^^er words, there 
 has been a regular succession of living beings, each 
 younger set, being in a very broad and general 
 sense, somewhat more like those which now live. 
 
 It was once supposed that this succession had 
 been the result of vast successive catastrophes, 
 destructions, and re-creations en masse ; but 
 catastrophes are now almost eliminated from 
 geological, or at least palseontological speculation ; 
 and it is admitted, on all hands, that the seeming 
 breaks in the chain of being are not absolute, but 
 only relative to our imperfect knowledge ; that 
 species have replaced species, not in assemblages, 
 but one by one ; and that, if it were possible to 
 have all the phenomena of the past presented to 
 us, the convenient epochs and formations of the 
 geologist, though having a certain distinctness, 
 would fade into one another with limits as 
 undefinable as those of the distinct and yet 
 separable colours of the solar spectrum. 
 
 Such is a brief summary of the main truths 
 which have been established concerning species. 
 Are these truths ultimate and irresolvable facts, 
 or are their complexities and perplexities the 
 mere expressions of a higher law ? 
 
10 THE DARWINIAN HYPOTHESIS 1 
 
 A large number of persons practically assume 
 the former position to be correct. They believe 
 that the writer of the Pentateuch was empowered 
 and commissioned to teach us scientific as well as 
 other truth, that the account we find there of the 
 creation of living things is simply and literally 
 correct, and that anything which seems to con- 
 tradict it is, by the nature of the case, false. All 
 the phenomena which have been detailed are, on 
 this view, the immediate product of a creative 
 fiat and, consequently, are out of the domain of 
 science altogether. 
 
 Whether this view prove ultimately to be true 
 or false, it is, at any rate, not at present sup- 
 ported by what is commonly regarded as logical 
 proof, even if it be capable of discussion by 
 reason ; and hence we consider ourselves at liberty 
 to pass it by, and to turn to those views which 
 profess to rest on a scientific basis only, and there- 
 fore admit of being argued to their consequences. 
 And we do this with the less hesitation as it so 
 happens that those persons who are practically 
 conversant with the facts of the case (plainly a 
 considerable advantage) have always thought fit 
 to range themselves under the latter category. 
 
 The majority of these competent persons have 
 up to the present time maintained two positions — 
 the first, that every species, is, within certain de- 
 fined limits, fixed and incapable of modification; 
 the second, that every species was originally pro- 
 
I THE DARWINIAN HYPOTHESIS 11 
 
 duced by a distinct creative act. The second 
 position is obviously incapable of proof or disproof, 
 the direct operations of the Creator not being 
 subjects of science ; and it must therefore be 
 regarded as a corollary from the first, the truth 
 or falsehood of which is a matter of evidence. 
 Most persons imagine that the arguments in 
 favour of it are overwhelming ; but to some few 
 minds, and these, it must be confessed, intellects 
 of no small power and grasp of knowledge, they 
 have not brought conviction. Among these 
 minds, that of the famous naturalist Lamarck, 
 who possessed a greater acquaintance with the 
 lower forms of life than any man of his day, 
 Cuvier not excepted, and was a good botanist to 
 boot, occupies a prominent place. 
 
 Two facts appear to have strongly affected the 
 course of thought of this remarkable man — the 
 one, that finer or stronger links of affinity connect 
 all living beings with one another, and that thus 
 the highest creature grades by multitudinous 
 steps into the lowest ; the other, that an organ 
 may be developed in particular directions by 
 exerting itself in particular ways, and that modi- 
 fications once induced may be transmitted and 
 become hereditary. Putting these facts together, 
 Lamarck endeavoured to account for the first by 
 the operation of the second. Place an animal in 
 new circumstances, says he, and its needs will be 
 altered ; the new needs will create new desires, and 
 
12 THE DAEWINIAN HYPOTHESIS I 
 
 the attempt to gratify such desires will result in an 
 appropriate modification of the organs exerted. 
 Make a man a blacksmith, and his brachial muscles 
 will develop in accordance with the demands made 
 upon them, and in like manner, says Lamarck, 
 "the efforts of some short-necked bird to catch 
 fish without wetting himself have, with time and 
 perseverance, given rise to all our herons and 
 long-necked waders." 
 
 The Lamarckian hypothesis has long since been 
 justly condemned, and it is the established prac- 
 tice for every tyro to raise his heel against the 
 carcase of the dead lion. But it is rarely either 
 wise or instructive to treat even the errors of a 
 really great man with mere ridicule, and in the 
 present case the logical form of the doctrine stands 
 on a very different footing from its substance. 
 
 If species have really arisen by the operation 
 of natural conditions, we ought to be able to find 
 those conditions now at work ; we ought to be 
 able to discover in nature some power adequate 
 to modify any given kind of animal or plant in 
 such a manner as to give rise to another kind, 
 which would be admitted by naturalists as a 
 distinct species. Lamarck imagined that he had 
 discovered this vera ccm^a in the admitted facts 
 that some organs may be modified by exercise ; 
 and that modifications, once produced, are capable 
 of hereditary transmission. It does not seem to 
 have occurred to him to inquire whether there is 
 
I THE DARWINIAN HYPOTHESIS 13 
 
 any reason to believe that there are any limits to 
 the amount of modification producible, or to ask 
 how long an animal is likely to endeavour to 
 gratify an impossible desire. The bird, in our 
 example, would surely have renounced fish dinners 
 long before it had produced the least effect on leg 
 or neck. 
 
 Since Lamarck's time, almost all competent 
 naturalists have left speculations on the origin of 
 species to such dreamers as the author of the 
 " Vestiges," by whose well-intentioned efforts the 
 Lamarckian theory received its final condemnation 
 in the minds of all sound thinkers. Notwith- 
 standing this silence, however, the transmutation 
 theory, as it has been called, has been a " skeleton 
 in the closet" to many an honest zoologist and 
 botanist who had a soul above the mere naming of 
 dried plants and skins. Surely, has such an one 
 thought, nature is a mighty and consistent whole, 
 and the providential order established in the 
 world of life must, if we could only see it rightly. 
 be consistent with that dominant over the multi- 
 form shapes of brute matter. But what is the 
 history of astronomy, of all the branches of physics, 
 of chemistry, of medicine, but a narration of the 
 steps by which the human mind has been com- 
 pelled, often sorely against its will, to recognise 
 the operation of secondary causes in events where 
 ignorance beheld an immediate intervention of a 
 higher power ? And when we know that living 
 
14 THE DAEWINIAN HYPOTHESIS 
 
 thin-s are formed of the same elements as the 
 thmgs are lor ^^^^^ ^^ 
 
 inorsanic world, that tnej' ^ ^ ^ . . 
 
 bound by a thousand ties of natural piety is r 
 probable: nay is it possible, that they, and the^ 
 alone should have no order m their seemmc 
 disorder, no unity in their seeming multiplicity 
 should suffer no explanation by the discover} 
 of some central and sublime law of mutua 
 connection ? 
 
 Questions of this kind have assuredly often arisen 
 but it might have been long before they receivec 
 such expression as would have commanded th( 
 respect and attention of the scientific world, hac 
 it not been for the publication of the work which 
 prompted this article. Its author, Mr. Darwin 
 inheritor of a once celebrated name, won his spurs 
 in science when most of those now distinguishec 
 were young men, and has for the last twentj 
 years held a place in the front ranks of Britist 
 philosophers. After a circumnavigatory voyage 
 undertaken solely for the love of his science, Mr 
 Darwin published a series of researches which al 
 once arrested the attention of naturalists anc 
 geologists ; his generalisations have since received 
 ample confirmation and now command universa 
 assent, nor is it questionable that they have hac 
 the most important influence on the progress o: 
 science. More recently Mr. Darwin, with i. 
 versatility which is among the rarest of gifts 
 turned his attention to a most difficult question o: 
 
I THE DARWINIAN HYPOTHESIS 15 
 
 zoology and minute anatomy ; and no living 
 naturalist and anatomist has published a better 
 monograph than that which resulted from his 
 labours. Such a man, at all events, has not 
 entered the sanctuary with unwashed hands, and 
 when he lays before us the results of twenty 
 years' investigation and reflection we must listen 
 even though we be disposed to strike. But, in 
 reading his work, it must be confessed that the 
 attention which might at first be dutifully, soon 
 becomes willingly, given, so clear is the author's 
 thought, so outspoken his conviction, so honest 
 and fair the candid expression of his doubts. 
 Those who would judge the book must read it : 
 we shall endeavour only to make its line of argu- 
 ment and its philosophical position intelligible to 
 the general reader in our own way. 
 
 The Baker Street Bazaar has just been exhibit- 
 ing its familiar annual spectacle. Straight-backed, 
 small-headed, big-barrelled oxen, as dissimilar 
 from any wild species as can well be imagined, 
 contended for attention and praise with sheep of 
 half-a-dozen different breeds and styes of bloated 
 preposterous pigs, no more like a wild boar or sow 
 than a city alderman is like an ourang-outang. 
 The cattle show has been, and perhaps may again 
 be, succeeded by a poultry show, of whose crowing 
 and clucking prodigies it can only be certainly 
 predicated that they will be very unlike the 
 aboriginal Phasianus gallus. If the seeker after 
 
16 THE DARWINIAN HYPOTHESIS I 
 
 animal anomalies is not satisfied, a turn or two in 
 Seven Dials will convince him that the breeds of 
 pigeons are quite as extraordinary and unlike one 
 another and their parent stock, while the Horti- 
 cultural Society will provide him with any number 
 of corresponding vegetable aberrations from 
 nature's types. He will learn with no little 
 surprise, too, in the course of his travels, that the 
 proprietors and producers of these animal and 
 vegetable anomalies regard them as distinct 
 species, with a firm belief, the strength of which 
 is exactly proportioned to their ignorance of 
 scientific biology, and which is the more remark- 
 able as they are all proud of their skill in origmat- 
 ing such " species/' 
 
 On careful inquiry it is found that all these, and 
 the many other artificial breeds or races of animals 
 and plants, have been produced by one method. 
 The breeder — and a skilful one must be a person 
 of much sagacity and natural or acquired perceptive 
 faculty — notes some slight difference, arising he 
 knows not how, in some individuals of his stock. 
 If he wish to perpetuate the difference, to form a 
 breed with the peculiarity in question strongly 
 marked, he selects such male and female indi- 
 viduals as exhibit the desired character, and breeds 
 from them. Their offspring are then carefully 
 examined, and those which exhibit the peculiarity 
 the most distinctly are selected for breeding ; and 
 this operation is repeated until the desired amount 
 
I THE DARWINIAN HYPOTHESIS 17 
 
 of divergence from the primitive stock is reached. 
 It is then found that by continuing the process of 
 selection — always breeding, that is, from well- 
 marked forms, and allowing no impure crosses to 
 interfere — a race may be formed, the tendency of 
 which to reproduce itself is exceedingly strong ; 
 nor is the limit to the amount of divergence which 
 may be thus produced known ; but one -thing is 
 certain, that, if certain breeds of dogs, or of pigeons, 
 or of horses, were known only in a fossil state, no 
 naturalist would hesitate in regarding them as 
 distinct species. 
 
 But in all these cases we have human interfer- 
 ence. Without the breeder there would be no 
 selection, and without the selection no race. 
 Before admitting the possibility of natural species 
 having originated in any similar way, it must be 
 proved that there is in Nature some power which 
 takes the place of man, and performs a selection 
 sua sponte. I t is the cla im of Mr. Darwin tha,t h e 
 pro fesses to have disco" TOreTlhe existence and th e 
 modusoperwnM^^g(_^^\&'l natural selec tion," as he 
 terms it ; and, if he be right, the process is per- 
 fectly gimpla and "(JOfHpr^hensible, and irresistibly 
 (Jedllcilble from very~1amLlIaf but well nigh_for- 
 g otten TaHs. 
 
 ^WhoTTor^nstance, has duly reflected upon all 
 the consequences of the marvellous struggle for 
 existence which is daily and hourly going on 
 among living beings ? Not only does every animal 
 
18 THE DARWINIAN HYPOTHESIS 1 
 
 live at the expense of some other animal or plant, 
 but the very plants are at war. The ground is 
 full of seeds that cannot rise into seedlings ; the 
 seedlings rob one another of air, light and water, 
 the strongest robber winning the day, and ex- 
 tinguishing his competitors. Year after year, the 
 wild animals with which man never interferes are, 
 on the average, neither more nor less numerous 
 than they were ; and yet we know that the annual 
 produce of every pair is from one to perhaps a 
 million young; so that it is mathematically certain 
 that, on the average, as many are killed by natural 
 causes as are born every year, and those only escape 
 which happen to be a little better fitted to resist 
 destruction than those which die. The individuals 
 of a species are like the crew of a foundered ship, 
 and none but good swimmers have a chance of 
 reaching the land. 
 
 Such being unquestionably the necessary con- 
 ditions under which living creatures exist, Mr. 
 Darwin discovers in them the instrument of natural 
 selection. Suppose that in the midst of this in- 
 cessant competition some individuals of a species 
 (A) present accidental variations which happen to 
 fit them a little better than their fellows for the 
 struggle in which they are engaged, then the 
 chances are in favour, not only of these individuals 
 being better nourished than the others, but of 
 their predominating over their fellows in other 
 ways, and of having a better chance of leavino- 
 
I THE DAEWINIAN HYPOTHESIS 19 
 
 offspring, which will of course tend to reproduce 
 the peculiarities of their parents. Their offspring 
 will, by a parity of reasoning, tend to predominate 
 over their contemporaries, and there being (sup- 
 pose) no room for more than one species such as 
 A, the weaker variety will eventually be destroyed 
 by the new destructive influence which is thrown 
 into the scale, and the stronger will take its place. 
 Surrounding conditions remaining unchanged, the 
 new variety (which we may call B) — supposed, for 
 argument's sake, to be the best adapted for these 
 conditions which can be got out of the original 
 stock — will remain unchanged, all accidental devia- 
 tions from the type becoming at once extinguished, 
 as less fit for their post than B itself. The tend- 
 ency of B to persist jvill grow with its persistence 
 through successive generations, and it will acquire 
 all the characters of a new species. 
 
 But, on the other hand, if the conditions of life 
 change in any degree, however slight, B may no 
 longer be that form which is best adapted to with- 
 stand their destructive, and profit by their sus- 
 taining, influence ; in which case if it should give 
 rise to a more competent variety (C), this will take 
 its place and become a new species ; and thus, by 
 natural selection, the species B and C will be suc- 
 cessively derived from A. 
 
 That this most ingenious hypothesis enables us 
 to give a reason for many apparent anomalies in 
 the distribution of living beings in time and space^ 
 
20 THE DARWINIAN HYPOTHESIS I 
 
 and that it is not contradicted by the main phen- 
 omena of life and organisation appear to ns to be 
 unquestionable ; and, so far, it must be admitted to 
 have an immense advantage over any of its prede- 
 cessors. But it is quite another matter to affirm 
 absolutely either the truth or falsehood of Mr. 
 Darwin's views at the present stage of the inquiry. 
 Goethe has an excellent aphorism defining that 
 state of mind which he calls " Tluitige Skepsis " 
 — active doubt. It is doubt which so loves truth 
 that it neither dares rest in doubting, nor extin- 
 guish itself by unjustified belief ; and we commend 
 this state of mind to students of species, with 
 respect to Mr. Darwin's or any other hypothesis, 
 as to their origin. The combined investigations 
 of another twenty years may, perhaps, enable 
 naturalists to say whether the modifying causes 
 and the selective power, which Mr. Darwin has 
 satisfactorily shown to exist in Nature, are com- 
 petent to produce all the effects he ascribes to 
 them ^jij^whether, on the other hand, he has been 
 led t(^^«^^imatg.the value of the principle of 
 natural selectroir,-~-as!lffr5a;tly. as Lamarck over- 
 estimated his vera causa ofm^diAcation by exercise. 
 But there is, at all events, one advantage pos- 
 sessed by the more recent writer over his pre- 
 decessor. Mr. Darwin abhors mere speculation as 
 nature abhors a vacuum. He is as greedy of cases 
 and precedents as any constitutional lawyer, and 
 all the principles he lays down are capable of being 
 
I THE DARWINIAN HYPOTHESIS 21 
 
 brought to the test of observation and experiment. 
 The path he bids us follow professes to be, not a 
 mere airy track, fabricated of ideal cobwebs, but a 
 solid and broad bridge of facts. If it be so, it 
 will carry us safely over many a chasm in our 
 knowledge, and lead us to a region free from the 
 snares of those fascinating but barren virgins, the 
 Final Causes, against whom a high authority has so 
 justly warned us. " My sons, dig in the vineyard," 
 were the last words of the old man in the fable : 
 and, though the sons found no treasure, they made 
 their fortunes by the grapes. 
 
II 
 
 THE ORIGIN OF SPECIES 
 
 [1860] 
 
 Mr. Darwin's long-standing and well-earned 
 scientific eminence probably renders him indiffer- 
 ent to that social notoriety which passes by the 
 name of success ; but if the calm spirit of the 
 philosopher have not yet wholly superseded the 
 ambition and the vanity of the carnal man within 
 him, he must be well satisfied with the results of 
 his venture in publishing the " Origin of Species." 
 Overflowing the narrow bounds of purely scientific 
 circles, the " species question " divides with Italy 
 and the Volunteers the attention of general 
 society. Everybody has read Mr. Darwin's book, 
 or, at least, has given an opinion upon its merits 
 or demerits ; pietists, whether lay or ecclesiastic, 
 decry it with the mild railing which sounds so 
 charitable ; bigots denounce it with ignorant 
 invective ; old ladies of both sexes consider it a 
 
II THE ORIGIN OF SPECIES 23 
 
 decidedly dangerous book, and even savants, who 
 have no better mud to throw, quote antiquated 
 writers to show that its author is no better than 
 an ape himself ; while every philosophical thinker 
 hails it as a veritable Whitworth gun in the 
 armoury of liberalism ; and all competent natural- 
 ists and physiologists, whatever their opinions as. 
 to the ultimate fate of the doctrines put forth, 
 acknowledge that the work in which they are 
 embodied is a solid contribution to knowledge 
 and inaugurates a new epoch in natural history. 
 
 Nor has the discussion of the subject been 
 restrained within the limits of conversation. 
 When the public is eager and interested, reviewers 
 must minister to its wants ; and the genuine 
 littdrateur is too much in the habit of acquiring 
 his knowledge from the book he judges — as the 
 Abyssinian is said to provide himself with steaks 
 from the ox which carries him — to be withheld 
 from criticism of a profound scientific work by 
 the mere want of the requisite preliminary scien- 
 tific acquirement ; while, on the other hand, the 
 men of science who wish well to the new views, 
 no less than those who dispute their validity, have 
 naturally sought opportunities of expressing their 
 opinions. Hence it is not surprising that almost 
 all the critical journals have noticed Mr. Darwin's 
 work at greater or less length ; and so many dis- 
 quisitions, of every degree of excellence, from the 
 poor product of ignorance, too often stimulated by 
 
 31 
 
24 THE ORIGIN OF SPECIES II 
 
 prejudice, to the fair and thoughtful essay of the 
 candid student of Nature, have appeared, that it 
 seems an ahiiost hopeless task to attempt to say 
 anything neAv upon the question. 
 
 But it may be doubted if the knowledge and 
 acumen of prejudged scientific opponents, and the 
 subtlety of orthodox special pleaders, have yet 
 exerted their full force in mystifying the real issues 
 of the great controversy which has been set afoot, 
 and whose end is hardly likely to be seen by this 
 generation ; so tliat, at this eleventh hour, and even 
 failing anything new, it may be useful to state 
 afresh that which is true, and to put the funda- 
 mental positions advocated by Mr. Darwin in such 
 a form that they may be grasped by those whose 
 special studies lie in other directions. And the 
 adoption of this course may be the more advisable, 
 because, notwithstanding its great deserts, and 
 indeed partly on account of them, the " Origin of 
 Species " is by no means an easy book to read — if 
 by reading is implied the full comprehension of an 
 author's meanincr. 
 
 We do not speak jestingly in saying that it is 
 Mr. Darwin's misfortune to know more about the 
 question he has taken up than any man livino-. 
 Personally and practically exercised in zoology, in 
 minute anatomy, in geology ; a student of geogra- 
 phical distribution, not on maps and in museimis 
 only, but by long voyages and laborious collection ; 
 having largely advanced each of these branches of 
 
II THE ORIGIN OF SPECIES 25 
 
 science, and having spent many years in gathering 
 and sifting materials for his present work, the 
 store of accurately registered facts upon which the 
 author of the " Origin of Species " is able to draw 
 at will is prodigious. 
 
 But this very superabundance of matter must 
 have been embarrassing to a writer who, for the 
 present, can only put forward an abstract of his 
 views ; and thence it arises, perhaps, that notwith- 
 standing the clearness of the style, those who 
 attempt fairly to digest the book find much of it 
 a sort of intellectual pemmican — a mass of facts 
 crushed and pounded into shape, rather than held 
 together by the ordinary medium of an obvious 
 logical bond ; due attention will, without doubt, 
 discover this bond, but it is often hard to find. 
 
 Again, from sheer want of room, much has to 
 be taken for granted which might readily enough 
 be proved ; and hence, while the adept, who can 
 supply the missing links in the evidence from his 
 own knowledge, discovers fresh proof of the singu- 
 lar thoroughness with which all difficulties have 
 been considered and all unjustifiable suppositions 
 avoided, at every reperusal of Mr. Darwin's preg- 
 nant paragraphs, the novice in biology is apt to 
 complain of the frequency of what he fancies is 
 gratuitous assumption. 
 
 Thus while it may be doubted if, for some years, 
 any one is likely to be competent to pronounce 
 judgment on all the issues raised by Mr. Darwin, 
 
26 THE ORIGIN OF SPECIES « 
 
 there is assuredly abundant room for him, who, 
 assuming the humbler, though perhaps as useful, 
 office of an interpreter between the " Origin of 
 Species " and the public, contents himself with 
 endeavouring to point out the nature of the prob- 
 lems which it discusses ; to distinguish between 
 the ascertained facts and the theoretical views 
 which it contains ; and finally, to show the extent 
 to which the explanation it offers satisfies the re- 
 quirements of scientific logic. At any rate, it is 
 this office which we purpose to undertake in the 
 following pages. 
 
 It may be safely assumed that our readers have 
 a general conception of the nature of the objects 
 to which the word " species " is applied ; but it 
 has, perhaps, occurred to a few, even to those who 
 are naturalists ex professo, to reflect, that, as com- 
 monly employed, the term has a double sense and 
 denotes two very different orders of relations. 
 When we call _a_group__of animals^-or-of-jjlants, a 
 species, we may imply thereby, e ither that aj j, 
 these animals ofplants havesome common peculij^ 
 arity of form &r struc ture ; or, we may mean^at 
 they possess some common_functional character. 
 That part of biological science which deals w^th 
 form and structure is called Morphology — that 
 which concerns itself wi^h^jfu notion, Physiqlogy — 
 so that we may conveniently speak of these two 
 senses, or aspects, of " species "—the one as mor- 
 phological, the other as physiological. Eegarded 
 
II THE ORIGIN OF SPECIES 27 
 
 from the former point of view, a species is nothing 
 more than a kind of animal or plant, which is 
 distinctly definable from all others, by certain 
 constant, and not merely sexual, morphological 
 peculiarities. Thus horses form a species, because 
 the group of animals to which that name is applied 
 is distinguished from all others in the world by 
 the following constantly associated characters. 
 They have — 1, A vertebral column ; 2, Mammas ; 
 3, A placental embryo ; 4, Four legs ; 5, A single 
 well-developed toe in each foot provided with a 
 hoof; 6, A bushy tail; and 7, Callosities on the 
 inner sides of both the fore and the hind legs. 
 The asses, again, form a distinct species, because, 
 with the same characters, as far as the fifth in the 
 above list, all asses have tufted tails, and have 
 callosities only on the inner side of the fore-legs. 
 If animals were discovered having the general 
 characters of the horse, but sometimes with cal- 
 losities only on the fore-legs, and more or less 
 tufted tails ; or animals having the general char- 
 acters of the ass, but with more or less bushy 
 tails, and sometimes with callosities on both pairs 
 of legs, besides beinof intermediate in other re- 
 spects — the two species would have to be merged 
 into one. They could no longer be regarded as 
 morphologically distinct species, for they would 
 not be distinctly definable one from the other. 
 
 However bare and simple this definition of 
 species may appear to be, we confidently appeal to 
 
28 THE ORIGIN OF SPECIES H 
 
 all practical naturalists, -whether zoologists, botan- 
 ists, or pateontologists, to say if, in the vast 
 majority of cases, they know, or mean to affirm, 
 anything more of the group of animals or plants 
 they so denominate than what has just been stated. 
 Even the most decided advocates of the received 
 doctrines respecting species admit this. 
 
 " I apprehend," says Professor Owen, ' " that few naturalists 
 nowadays, in describing and proposing a name for what they 
 call ' a new species,' use that term to signify what was meant by 
 it twenty or thirty years ago ; that is, an originally distinct 
 creation, maintaining its primitive distinction by obstructive 
 generative peculiarities. The proposer of the new species now 
 intends to state no more than he actually knows ; as, for 
 example, that the diffia-ences on which he founds the specific 
 character are constant in individuals of both sexes, so far as 
 observation has reached ; and that they are not due to domes- 
 tication or to artificially superinduced external circumstances, or 
 to any outward influence within his cognizance ; that the species 
 is wild, or is such as it appears by Nature." 
 
 If we consider, in fact, that by far the largest 
 
 proportion of recorded existing species are known 
 
 only by the study of their skins, or bones, or other 
 
 lifeless exuviae ; that we are acquainted with none, 
 
 or next to none, of their physiological peculiarities, 
 
 beyond those which can be deduced from their 
 
 structure, or are open to cursory observation ; and 
 
 that we cannot hope to learn more of any of those 
 
 extinct forms of life which now constitute no 
 
 inconsiderable proportion of the known Flora and 
 
 * " On tho Osteology of the Chimpanzees and Orangs "; 
 Transactions of the Zoological Society, 1858. 
 
II THE ORIGIN OF SPECIES 29 
 
 Fauna of the world : it is obvious that the defini- 
 tions of these species can be only of a purely 
 structural, or morphological, character. It is 
 probable that naturalists would have avoided 
 much confusion of ideas if they had more fre- 
 quently borne the necessary limitations of our 
 knowledge in mind. But while it may safely be 
 admitted that we are acquainted with only the 
 morphological characters of the vast majority of 
 species — the functional or physiological, peculiari- 
 ties of a few have been carefully investigated, and 
 the result of that stu(]y forms a large and most 
 interesting portion of the j)hysiology of reproduc- 
 tion. 
 
 The student of Nature wonders the more and is 
 astonished the less, the more conversant he becomes 
 with her operations ; but of all the perennial 
 miracles she offers to his inspection, perhaps the 
 most worthy of admiration is the development of 
 a plant or of an animal from its embryo. Examine 
 the recently laid egg of some common animal, 
 such as a salamander or newt. It is a minute 
 spheroid in which the best microscope will reveal 
 nothing but a structureless sac, enclosing a glairy 
 fluid, holding granules in suspension.^ But strange 
 possibilities lie dormant in that semi-fluid globule. 
 Let a moderate supply of warmth reach its watery 
 cradle, and the plastic matter undergoes changes 
 
 1 [When this sentence was %\Titten, it was generally believed 
 that the original nucleus of the egg (the germinal vesicle) 
 disappeared, 1893.] 
 
30 THE ORIGIN OF SPECIES II 
 
 SO rapid, yet so steady and purposelike in their 
 succession, that one can only compare them to 
 those operated by a skilled modeller uiaon a form- 
 less lump of clay. As with an invisible trowel, 
 the mass is divided and subdivided into smaller 
 and smaller portions, until it is reduced to an 
 aggregation of granules not too large to build withal 
 the finest fabrics of the nascent organism. And, 
 then, it is as if a delicate finger traced out the line 
 to be occupied by the spinal column, and moulded 
 the contour of the body ; pinching up the head 
 at one end, the tail at the other, and fashioning 
 flank and limb into due salamandrine proportions, 
 in so artistic a way, that, after watching the process 
 hour by hour, one is almost involuntarily possessed 
 bv the notion, that some more subtle aid to vision 
 than an achromatic, would show the hidden artist, 
 with his plan before him, striving with skilful 
 manipulation to jjerfect his work. 
 
 As life advances, and the young amphibian 
 ranges the waters, the terror of his insect con- 
 temporaries, not only are the nutritious jjarticles 
 supplied by its prey, by the addition of which to 
 its frame, growth takes place, laid down, each in 
 its proper spot, and in such due proportion to the 
 rest, as to reproduce the form, the colour, and the 
 size, characteristic of the parental stock ; but even 
 the wonderful powers of reproducing lost parts 
 possessed by these animals are controlled by the 
 same governing tendency. Cut off the legs, the 
 
II THE ORIGIN OF SPECIES 31 
 
 tail, the jaws, separately or all together, and, as 
 Spallanzani showed long ago, these parts not only 
 grow again, but the redintegrated limb is formed 
 on the same type as those which were lost. The 
 new jaw, or leg, is a newt's, and never by any 
 accident more like that of a frog. What is true 
 of the newt is true of every animal and of every 
 plant ; the acorn tends to build itself up again 
 into a woodland giant such as that from whose 
 twig it fell ; the spore of the humblest lichen 
 reproduces the green or brown incrustation which 
 gave it birth ; and at the other end of the scale of 
 life, the child that resembled neither the paternal 
 nor the maternal side of the house would be 
 regarded as a kind of monster. 
 
 So that the one end to which, in all living 
 beings, the formative impulse is tending — the one 
 scheme which the Archgeus of the old speculators 
 strives to carry out, seems to be to mould the 
 offspring into the likeness of the parent. It is 
 the first gi-eat law of reproduction, that th e 
 o8'spring_tgnda_ta.resem ble its p arent or parents, 
 more closely than anything else. ._ 
 
 Science will some day show us how this law is a 
 necessary consequence of the more general laws 
 which govern matter ; but, for the present, more 
 can hardly be said than that it appears to be iu 
 harmony with them. We know that the phae- 
 nomena of vitality are not something apart from 
 other physical phsenomena, but one with them ; 
 
32 THE ORIGIN OF SPECIES II 
 
 and matter and force are the two names of the 
 one artist who fashions the living as well as the 
 lifeless. Hence living bodies should obey the 
 same great laws as other matter— nor, throughout 
 Nature, is there a law of wider application than 
 this, that a body impelled by two forces takes the 
 direction of their resultant. But living bodies 
 may be regarded as nothing but extremely complex 
 bundles of forces held in a mass of matter, as the 
 complex forces of a magnet are held in the steel 
 by its coercive force ; and, since the differences 
 of sex are comparatively slight, or, in other words, 
 the sum of the forces in each has a very similar 
 tendency, their resultant, the offspring, may reason- 
 ably be expected to deviate but little from a course 
 parallel to either, or to both. 
 
 Represent the reason of the law to ourselves by 
 what physical metaphor or analogy we will, how- 
 ever, the great matter is to apprehend its existence 
 and the importance of the consequences deducible 
 from it. For^hiu gs whi ch are like to the same 
 are like to one another ; and if, in a great series of 
 generationsr''every~oHspring is like its parent, it 
 follows that all the offspring and all the parents 
 must be like one another; and that, given an 
 original parental stock, with the opportunity of 
 undisturbed multiplication, the law in question 
 necessitates the production, in course of time, of 
 an indefinitely large group, the whole of the mem- 
 bers of which are at once very similar and are blood 
 
ir THE ORIGIN OF SPECIES S3 
 
 relations, having descended from the same parent, 
 or pair of parents. The proof that all the members 
 of any given group of animals, or plants, had thus 
 descended, would be ordinarily considered sufficient 
 to entitle them to the rank of physiological species, 
 for most physiologists consider species to be de- 
 finable as "the offspring of a single primitive 
 stock." 
 
 But though it is quite true that all those 
 groups we call species viay, according to the 
 known laws of reproduction, have descended from 
 a single stock, and though it is very likely they 
 really have done so, yet this conclusion rests on 
 deduction and can hardly hope to establish itself 
 upon a basis of observation. And the primitive- 
 ness of the supposed single stock, which, after all, 
 is the essential part of the matter, is not only a 
 hypothesis, but one which has not a shadow of 
 foundation, if by " primitive " be meant " indepen- 
 dent of any other living being." A scientific 
 definition, of which an unwarrantable hypothesis 
 forms an essential part, carries its condemnation 
 within itself; but, even supposing such a 
 definition were, in form, tenable, the physiologist 
 who should attempt to apply it in Nature would 
 soon find himself involved in great, if not in- 
 extricable, difficulties. As we have said, it is 
 indubitable that offspring tend to resemble the 
 parental organism, but it is equally true that the 
 similarity attained never amounts to identity 
 
34 THE ORIGIN OF SPECIES II 
 
 either in form or in structure. There is always a 
 certain amount of deviation, not only from the 
 precise characters of a single parent, but when, as 
 in most animals and many plants, the sexes are 
 lodged in distinct individuals, from an exact mean 
 between the two parents. And indeed, on 
 general principles, this slight deviation seems as 
 intelligible as the general similarity, if we reflect 
 how complex the co-operating " bundles of forces " 
 are, and how improbable it is that, in any case, 
 their true resultant shall coincide with any mean 
 between the more obvious characters of the two 
 parents. Whatever be~^s cause, however, the 
 co-existence of this tendency to minor variation 
 with the tendency to general similarity, is of vast 
 importance in its bearing on the question of the 
 origin of species. 
 
 As a general rule, the extent to which an 
 ofiFspring~3ifieFsTfom its parent Is^slight eno ugh ; 
 but, occasionally, the ainount of diperence is much 
 more strongly marked, and then the divergen±_ 
 offspf irjif recei-^s_the "nami^^ora^''Variety. Multi- 
 tudes, of what there is every reason to believe are 
 such varieties, are known, but the origin of very 
 few has been accurately recorded, and of these we 
 will select two as more especially illustrative of 
 the main features of variation. The first of them 
 is that of the "Ancon" or "Otter" sheep, of 
 which a careful account is given by Colonel 
 David Humphreys, F.R.S., in a letter to Sir 
 
ir THE ORIGIN OF SPECIES 35 
 
 Joseph Banks, published in the " Philosophical 
 Transactions " for 1813. It appears that one Seth 
 Wright, the proprietor of a farm on the banks 
 of the Charles River, in Massachusetts, possessed 
 a flock of fifteen ewes and a ram of the ordinary 
 kind. In the year 1791, one of the ewes 
 presented her owner with a male lamb, differing, 
 for no assignable reason, from its parents by a 
 proportionally long body and short bandy legs, 
 whence it was unable to emulate its relatives in 
 those sportive leaps over the neighbours' fences, 
 in which they were in the habit of indulging, 
 much to the good farmer's vexation. 
 
 The second case is that detailed by a no less 
 unexceptionable authority than Reaumur, in his 
 "Art de faire eclore les Poulets." A Maltese 
 couple, named Kelleia, whose hands and feet were 
 constructed upon the ordinary human model, had 
 born to them a son, Gratio, who possessed six per- 
 fectly movable fingers on each hand, and six toes, 
 not quite so well formed, on each foot. No cause 
 could be assigned for the appearance of this unusual 
 variety of the human species. 
 
 Two circumstances are well worthy of remark in 
 both these cases. In each, the variety appears to 
 have arisen in full force, and, as it were, per saltum ; 
 a wide and definite difference appearing, at once, 
 between the Ancon ram and the ordinary sheep ; 
 between the six-fingered and six-toed Gratio Kelleia 
 and ordinary men. In neither case is it possible 
 
36 THE ORIGIN OF SPECIES n 
 
 to point out any obvious reason for the appearance 
 of the variety. Doubtless there were determining 
 causes for these as for all other jjhsenomena ; but 
 they do not appear, and we can be tolerably certain 
 that what are ordinarily understood as changes in 
 physical conditions, as in climate, in food, or the 
 like, did not take place and had nothing to do with 
 the matter. It was no case of what is commonly 
 called adaptation to circumstances ; but, to use a 
 conveniently erroneous phrase, the variations ai'ose 
 spontaneously. The fruitless search after final 
 causes leads their pursuers a long way ; but even 
 those hardy teleologists, who are ready to break 
 through all the laws of physics in chase of their 
 favourite will-o'-the-wisp, may be puzzled to dis- 
 cover what purpose could be attained by the stunted 
 legs of Seth Wright's ram or the hexadactyle 
 members of Gratio Kelleia. 
 
 Varieties then arise we know not why ; and it is 
 more than probable that the majority of varieties 
 have arisen in this " spontaneous '' manner, though 
 we are, of course, far from denying that they may 
 be traced, in some cases, to distinct external in- 
 fluences ; which are assuredly competent to alter 
 the character of the tegumentary covering, to 
 change colour, to increase or diminish the size of 
 muscles, to modify constitution, and, among plants, 
 to give rise to the metamorphosis of stamens into 
 petals, and so forth. But however they may have 
 arisen, what especially interests us at present is, to 
 
II 
 
 THE ORIGIN OF SPECIES 37 
 
 remark that, once in existence, many varieties obey 
 the fundamental law of reproduction that like tends 
 to produce like; and their offspring exemplify it by 
 tending to exhibit the same deviation from the 
 parental stock as themselves. Indeed, there seems 
 to be, in many instances, a prepotent influence 
 about a newly-arisen variety which gives it what 
 one may call an unfair advantage over the normal 
 descendants from the same stock. This is strik- 
 ingly exemplified by the case of Gratio Kelleia, 
 who married a woman with the ordinary penta- 
 dactyle extremities, and had by her four children, 
 Salvator, George, Andr^, and Marie. Of these 
 children Salvator, the eldest boy, had six fingers 
 and six toes, like his father ; the second and third, 
 also boys, had five fingers and five toes, like their 
 mother, though the hands and feet of George 
 were slightly deformed. The last, a girl, had five 
 fingers and five toes, but the thumbs were slightly 
 deformed. The variety thus reproduced itself 
 purely in the eldest, while the normal type 
 reproduced itself purely in the third, and almost 
 purely in the second and last : so that it would 
 seem, at first, as if the normal type were more 
 powerful than the variety. But all these children 
 grew up and intermarried with normal wives and 
 husband, and then, note what took place : Salvator 
 had four children, three of whom exhibited the 
 hexadactyle members of their grandfather and 
 father, while the youngest had the pentadactyle 
 
38 THE ORIGIN OF SPECIES " 
 
 limbs of the mother and grandmother; so that 
 here, notwithstanding a double pentadactyle 
 dilution of the blood, the hexadactyle variety had 
 the best of it. The same pre-potency of the 
 variety was still more markedly exemplified in the 
 progeny of two of the other children, Marie and 
 George. Marie (whose thumbs only were de- 
 formed) gave birth to a boy with six toes, and 
 three other normally formed children ; but George, 
 who was not quite so pure a pentadactyle, begot, 
 first, two girls, each of whom had six fingers and 
 toes ; then a girl with six fingers on each hand and 
 six toes on the right foot, but only five toes on 
 the left ; and lastly, a boy with only five fingers 
 and toes. In these instances, therefore, the 
 variety, as it were, leaped over one generation to 
 reproduce itself in full force in the next. Finally, 
 the purely pentadactyle Andre was the father of 
 many children, not one of whom departed from 
 the normal parental type. 
 
 If a variation which approaches the nature of a 
 monstrosity can strive thus forcibly to reproduce 
 itself, it is not wonderful that less aberrant 
 modifications should tend to be preserved even 
 more strongly ; and the history of the Ancon sheep 
 is, in this respect, particularly instructive. With 
 the " 'cuteness " characteristic of their nation, the 
 neighbours of the Massachusetts farmer imagined 
 it would be an excellent thing if all his sheep 
 were imbued with the stay-at-home tendencies 
 
II THE ORIGIN OF SrECIES 39 
 
 enforced by Nature upon the newly-arrived ram ; 
 and they advised Wright to kill the old patriarch 
 of his fold, and install the Ancon ram in his place. 
 The result justified their sagacious anticipations, 
 and coincided very nearly with what occurred to 
 the progeny of Gratio Kelleia. The young lambs 
 were almost always either pure Ancons, or pure 
 ordinary sheep.^ But when sufficient Ancon 
 sheep were obtained to interbreed with one 
 another, it was found that the offspring was 
 always pure Ancon. Colonel Humphreys, in fact, 
 states that he was acquainted with only " one 
 questionable case of a contrary nature.'' Here, 
 then, is a remarkable and well-established 
 instance, not only of a very distinct race being 
 established per saltiovi, but of that race breeding 
 " true " at once, and showing no mixed forms, 
 even when crossed with another breed. 
 
 By taking care to select Ancons of both sexes, 
 for breeding from, it thus became easy to establish 
 an extremely well-marked race ; so peculiar that, 
 
 ^ Colonel Humphreys' statements are exceedingly explicit on 
 this point ; — " When an Ancon ewe is impregnated by a com- 
 niou ram, the increase resembles wholly either the ewe or the 
 ram. The increase of the common ewe impregnated by an 
 Ancon ram follows entirely the one or the other, without 
 blending any of the distinguishing and essential peculiarities 
 of both. Frequent instances have happened where common 
 ewes have had twins by Ancon rams, when one exhibited the 
 complete marks and features of the ewe, the other of the ram. 
 The contrast has been rendered singularly striking, when one 
 short-legged and one long-lfgged lamb, protluced at a birth, 
 have been seen sucking the dam at the same time." — Philoso- 
 phical Transaclions, 1813, Pt. I. pp. 89, 90. 
 32 
 
40 THE ORIGIN OF SPECIES n 
 
 even when herded with other sheep, it was noted 
 that the An cons kept together. And there is 
 every reason to believe that the existence of this 
 breed might have been indefinitely protracted ; 
 but the introduction of the Merino sheep, which 
 were not only very superior to the Ancons in wool 
 and meat, but quite as quiet and orderly, led to 
 the complete neglect of the new breed, so that, in 
 1813, Colonel Humphreys found it difficult to 
 obtain the specimen, the skeleton of which was 
 presented to Sir Joseph Banks. We believe that, 
 for many years, no remnant of it has existed in 
 the United States. 
 
 Gratio Kelleia was not the progenitor of a race 
 of six-fingered men, as Seth Wright's ram became 
 a nation of Ancon sheep, though the tendency of 
 the variety to perpetuate itself appears to have 
 been fully as strong in the one case as in the 
 other. And the reason of the difference is not 
 far to seek. Seth Wright took care not to weaken 
 the Ancon blood by matching his Ancon ewes 
 with any but males of the same variety, while 
 Gratio Kelleia's sons were too far removed from 
 the patriarchal times to intermarry with their 
 sisters ; and his grand -children seem not to have 
 been attracted by their six-fingered cousins. In 
 other words, in the one example a race was pro- 
 duced, because, for several generations, care was 
 taken to select both parents of the breedino- stock 
 from animals exhibiting a tendency to vary in the 
 
11 THE ORIGIN OF SPECIES 41 
 
 same direction ; while, lu ^. ^ other, no race was 
 evolved, because no such selecii. • was exercised. 
 A race is a propagated variety ; and ajs, by the laws 
 of repro7nrcti on,""o5spr]ng tMd~~to~assume~ the 
 parehiEar.fofins, they will..j3.e. iff ore-likely— to-pro- 
 pagate a variation exhibited, by botTTpafSfits than 
 .jfchat possessed by only .one. "~ 
 
 There is no organ of the body of an animal 
 which may not, and does not, occasionally, vary 
 more or less from the normal type ; and there is no 
 variation which may not be transmitted and which, 
 if selectivel}^ transmitted, may not become the 
 foundation of a race. This great truth, sometimes 
 forgotten by philosophers, has long been familiar 
 to practical agriculturists and breeders ; and upon 
 it rest all the methods of improving the breeds of 
 domestic animals, which, for the last century, have 
 been followed with so much success in England. 
 Colour, form, size, texture of hair or wool, pro- 
 portions of various parts, strength or weakness of 
 constitution, tendency to fatten or to remain lean, 
 to give much or little milk, speed, strength, tem- 
 per, intelligence, special instincts ; there is not one 
 of these characters the transmission of which is not 
 an every-day occurrence within the experience of 
 cattle-breeders, stock-farmers, horse-dealers, and 
 dog and poultry fanciers. Nay, it is only the other 
 day that an eminent physiologist. Dr. Brown- 
 Sequard, communicated to the Royal Society his 
 discovery that epilepsy, artificially produced in 
 
42 THE ORIGIN OF SPECIES 11 
 
 guinea-pigs, by a r^-^Jtls which he has discovered, 
 is transmitted + ^.^'their offspring.^ 
 
 But a race, once produced, is no more a fixed 
 and immutable entity than the stock -whence it 
 sprang ; variations arise among its mernbers, and 
 as these variations are transmitted Uke any others, 
 new races may be developed out of the pre-exist- 
 ing one ad infinituvi, or, at least, within any limit 
 at present determined. Giyen^sufiScient jtime-and 
 sufficiently careful selection, and the multitude of 
 races which may arise from a common stock is.,a3 
 astonishing as are the extreme structural differ- 
 ences which they may present. A remarkable 
 example of this is to be found in the rock-pigeon, 
 which Mr. Darwin has, in our opinion, satisfactorily 
 demonstrated to be the progenitor of all our 
 domestic pigeons, of which there are certainly 
 more than a hundred well-marked races. The 
 most noteworthy of these races are, the four great 
 stocks known to the " fancy " as tumblers, pouters, 
 carriers, and fantails ; birds which not only differ 
 most singularly in size, colour, and habits, but in the 
 form of the beak and of the skull : in the pro- 
 portions of the beak to the skull ; in the number 
 of tail-feathers ; in the absolute and relative size of 
 the feet ; in the presence or absence of the uropygial 
 gland ; in the number of vertebrje in the back ; 
 in short, in precisely those characters in which 
 
 1 [Compare "Weismann's Essays Upon Eeredily, p. 310, et scq. 
 1893.] 
 
II THE ORIGIN OF SPECIES 43 
 
 the genera and species of birds differ from one 
 another. 
 
 And it is most remarkable and instructive to 
 observe, that none of these races can be shown to 
 have been originated by the action of changes in 
 what are commonly called external circumstances, 
 upon the wild rock-pigeon. On the contrary, 
 from time immemorial pigeon -fanciers have had 
 essentially similar methods of treating their pets, 
 which have been housed, fed, protected and cared 
 for in much the same way in all pigeonries. In 
 fact, there is no case better adapted than that of 
 the pigeons to refute the doctrine which one sees 
 put forth on high authority, that " no other 
 characters than those founded on the development 
 of bone for the attachment of mxiscles" »are 
 capable of variation. In precise contradiction of 
 this hasty assertion, Mr. Darwin's researches 
 prove that the skeleton of the wings in domestic 
 pigeons has hardly varied at all from that of the 
 wild type ; while, on the other hand, it is in exactly 
 those respects, such as the relative length of the 
 beak and skull, the number of the vertebrae, and 
 the number of the tail-feathers, in which muscular 
 exertion can have no important influence, that 
 the utmost amount of variation has taken place. 
 
 We have said that the following out of the 
 properties exhibited by physiological species would 
 lead us into difficulties, and at this point they begin 
 
44 THE ORIGIN OF SPECIES " 
 
 to be obvious ; for if, as the result of spontaneous 
 variation and of selective breeding, the progeny of 
 a common stock may become separated into groups 
 distinguished from one another by constant, not 
 sexual, morphological characters, it is clear that 
 the physiological definition of species is likely to 
 clash with the morphological definition. No one 
 would hesitate to describe the pouter and the 
 tumbler as distinct species,if they were found fossil, 
 or if their skins and skeletons were imported, as 
 those of exotic wild birds commonly are — and with- 
 out doubt, if considered alone, they are good and 
 distinct morphological species. On the other hand, 
 they are not physiological species, for they are 
 descended from a common stock, the rock-pigeon. 
 
 Under these circumstances, as it is admitted on 
 all sides that races occur in Nature, how are we to 
 know whether any apparently distinct animals are 
 really of different physiological species, or not, 
 seeing that the amount of morphological difference 
 is no safe guide ? Is there any test of a physio- 
 logical species ? The usual answer of physiologists 
 is in the affirmative. It is said that such a test is 
 to be found in the phasnoraena of hybridisation — 
 in the results of crossing races, as compared with 
 the results of crossing species. 
 
 So far as the evidence goes at present, in- 
 dividuals, of what are certainly known to be mere 
 races produced by selection, however distinct they 
 may appear to be, not only breed freely together, 
 
II THE ORIGIN OF SPECIES 45 
 
 but the offspring of such crossed races are perfectly 
 fertile with one another. Thus, the spaniel and 
 the greyhound, the dray-horse and the Arab, the 
 pouter and the tiimbler, breed together with perfect 
 freedom, and their mongrels, if matched with other 
 mongrels of the same kind, are equally fertile. 
 
 On the other hand, there can be no doubt that 
 the individuals of many natural species are either 
 absolutely infertile if crossed with individuals of 
 other species, or, if they give rise to hybrid 
 offspring, the hybrids so produced are infertile 
 when paired together. The horse and the ass, 
 for instance, if so crossed, give rise to the mule, 
 and there is no certain evidence of offspring ever 
 having been produced by a male and female 
 mule. The unions of the rock-pigeon and the 
 ring-pigeon appear to be equally barren of result. 
 Here, then, says the physiologist, we have a means 
 
 nf riist.inguishing- n.ny_tw o true specie s from any 
 two varietie s. If a male and_a female, s"elec ted: 
 irom pf),rJL -group, produce offspring, and that off- 
 spring is fertile with others produced in the s ame 
 ■yyay^ tlip prrQnpg are racos and not species. If, on 
 the other ha.nd.^np result ensues, or if the offspring 
 are infertile with others jrodliceJ in the same 
 way, they are tru^_physiological species. The 
 test would be an admirable one, if, in the first 
 place, it were always practicable to apply it, and 
 if, in the second, it always yielded results suscep- 
 tible of a definite interpretation. Unfortunately, 
 
\_f i.l,J.VJ J.J.1 KJ±: MA JJJVjXJLLikJ 
 
 in the great majority of cases, this touchstone for 
 species is wholly inapplicable. 
 
 The constitution of many wild animals is so 
 altered by confinement that they will not breed 
 even with their own females, so that the negative 
 results obtained from crosses are of no value ; and 
 the antipathy of wild animals of different species 
 for one another, or even of wild and tame members 
 of the same species, is ordinarily so great, that it 
 is hopeless to look for such unions in Nature. 
 The hermaphrodism of most plants, the difficulty 
 in the way of insuring the absence of their own 
 or the proper working of other pollen, are obsta- 
 cles of no less magnitude in applying the test to 
 them. And, in both animals and plants, is super- 
 added the further difficulty, that experiments 
 must be continued over a long time for the purpose 
 of ascertaining the fertility of the mongrel or 
 hybrid progeny, as well as of the first crosses from 
 which they spring. 
 
 Not only do these great practical difficulties lie 
 in the way of applying the hybridisation test, but 
 even wTien this oracle can be questioned, its replies 
 are sometimes as doubtful as those of Delphi. 
 For example, cases are cited by Mr. Darwin, of 
 plants which are more fertile with the pollen of 
 another species than with their own ; and there 
 are others, such as certain Fuci, the male element 
 of which will fertilise the ovule of a plant of 
 distinct species, while the males of the latter 
 
n THE ORIGIN OF SPECIES 47 
 
 species are ineffective with the females of the 
 first. So that, in the last-named instance, a 
 physiologist, who should cross the two species in 
 one way, would decide that they were true species; 
 while another, who should cross them in the 
 reverse way, would, with equal justice, according 
 to the rule, pronounce them to be mere races. 
 Several plants,' which there is great reason to 
 believe are mere varieties, are almost sterile when 
 crossed ; while both animals and plants, which 
 have always been regarded by naturalists as of 
 distinct species, turn out, when the test is applied, 
 to be perfectly fertile. Again, the sterility or 
 fertility of crosses seems to bear no relation to the 
 stjuctural resemblances or differences of the 
 members of any two groups. 
 
 Mr. Darwin has discussed this question with 
 singular ability and circumspection, and his con- 
 clusions are summed up as follows, at page 276 of 
 his work : — 
 
 ' ' First crosses between forms sufficiently distinct to be ranked 
 as species, and their hybrids, are very generally, but not 
 universally, sterile. The sterility is of all degrees, and is often 
 so slight that the two most careful experimentalists who have 
 ever lived have come to diametrically opposite conclusions in 
 ranking forms by this test. The sterility is innately variable 
 in individuals of the same species, and is eminently susceptible 
 of favourable and unfavourable conditions. The degree of 
 sterility' does not strictly follow systematic affinity, but is 
 governed by several curious and complex laws. It is generally 
 different and sometimes widely dilTerent, in reciprocal crosses 
 
48 THE ORIGIN OF SPECIES " 
 
 between the same two species. It is not always equal in degree 
 iiL a first cross, and in tlie hybrid produced from this cross. 
 
 " In the same manner as in grafting trees, the capacity of 
 one species or variety to take on another is incidental on 
 generally unknown diiferences in their vegetative systems ; so 
 in crossing, the greater or less facility of one species to unite 
 with another is incidental on unknown differences in their 
 reproductive systems. There is no more reason to think that 
 species have been specially endowed with various degrees of 
 sterility to prevent them crossing and breeding in Nature, than 
 to think that trees have been specially endowed with various 
 and somewhat analogous degrees of difficulty in being grafted 
 together, in order to prevent them becoming inarched in our 
 forests. 
 
 ' ' The sterility of first crosses between pure species, which 
 have their reproductive systems perfect, seems to depend on 
 several circumstances ; in some cases largely on the early death of 
 the embryo. The sterility of hybrids which have their repro- 
 ductive systems imperfect, and which have had this system 
 and tlieir whole organisation disturbed by being compounded 
 of two distinct species, seems closely allied to that sterility 
 which so fiequently affects ])ure species when their natural con- 
 ditions of life have been disturbed. This view is supported by 
 a parallelism of another kind : namely, that the crossing of 
 forms, only slightly different, is favourable to the vigour and 
 fertility of the offspring ; and that slight changes in the con- 
 ditions of life are apparently favotiralde to the vigour and 
 fertility of all organic beings. It is not surprising that the 
 degree of difficulty in uniting two species, and the degree of 
 sterility of their hybrid offspring, should generally correspond, 
 thoiigh due to distinct causes ; for both depend on the amount 
 of difference of some kind between the species which are crossed. 
 Nor is it surprising that the facility of effecting a first cross, 
 the fertility of hybrids produced from it, and the capacity of 
 being grafted together — though this latter capacity evidently 
 depends on widely different circumstances — should all run to a 
 certain extent parallel with the systematic affinity of the forms 
 which are subjected to experiment ; for systematic affinity 
 
H THE ORIGIN OF SPECIES 49 
 
 attempts to express all kinds of resemblance between all 
 species. 
 
 "First crosses between forms known to be varieties, or 
 sufficiently alike to be considered as varieties, and their mon- 
 grel offspring, are very generally, but not quite universally, 
 fertile. Nor is tliis nearly general and perfect fertility sur- 
 prising, when we remember bow liable we are to argue in a 
 circle with respect to varieties in a state of Nature ; and when 
 we remember that the greater number of varieties have been 
 produced under domestication by the selection of mere external 
 differences, and not of differences in the reproductive system. 
 In all other respects, excluding fertility, there is a close general 
 resemblance between h)'brids and mongrels." — Pp. 276 — 8. 
 
 We fully agree with the general tenor of this 
 weighty passage ; but forcible as are these argu- 
 ments, and little as the value of fertility or 
 infertility as a test of species may be, it jniist_not 
 be forgotten that the__reallyJ.mportant fact, so far 
 as the inquiry into the origin of species goes, i.s" 
 t hat there are suchTKings in Nature7as groups of 
 amhials and of plants, the members ot^wh jc hare in~ 
 c apableof fertile uniaD^mth -tbiosarofQjiier-. groups ; 
 and thajLtkej:£_iu:a_auaE!SuJD^SLas.'^^ 
 a re absolutely steri le when crossed, .with othe r 
 hybrids . For, if such plisenomena as these were 
 exhibited by only two of those assemblages of 
 living objects, to which the name of species 
 (whether it be used in its physiological or in its 
 morphological sense) is given, it would have to be 
 accounted for by any theory of the origin of 
 species, and every theory which could not account 
 for it would be, so far, imperfect. 
 
50 THE ORIGIN OF SPECIES H 
 
 Up to this point, we have been dealing with 
 matters of fact, and the statements which we 
 have laid before the reader would, to the best of 
 our knowledge, be admitted to contain a fair 
 exposition of what is at present known respecting 
 the essential properties of species, by all who 
 have studied the question. And wha.tever may- 
 be his theoretical views, no naturalist will prob- 
 ably be disposed to demur to the following 
 summary of that exposition : — 
 
 Livino- beings, whether animals or plants, are 
 divisible into multitudes of distinctly definable 
 kinds, which are morphological species. They are 
 also divisible into groups of individuals, which 
 breed freely together, tending to reproduce their 
 like, and are physiological species. Normally 
 resembling their parents, the offspring of members 
 of these species are still liable to vary ; and the 
 variation may be perpetuated by selection, as a 
 race, which race, in many cases, presents all the 
 characteristics of a morphological species. But 
 it is not as yet proved that a race ever exhibits, 
 when crossed with another race of the same 
 species, those phisnomena of hybridisation which 
 are exhibited by many species when crossed with 
 other species. On the other hand, not only is it 
 not proved that all species give rise to hybrids 
 infertile inter se, but there is much reason to 
 believe that, in crossing, species exhibit every 
 gradation from perfect sterility to perfect fertility. 
 
II THE ORIGIN OF SPECIES 51 
 
 Such are the most essential characteristics of 
 species. Even were man not one of them — a 
 member of the same system and subject to the 
 same laws — -the question of their origin, their 
 causal connexion, that is, with the other ph<Eno- 
 mena of the universe, must have attracted his 
 attention, as soon as his intelligence had raised 
 itself above the level of his daily wants. 
 
 Indeed history relates that such was the case, 
 and has embalmed for us the speculations upon 
 the origin of living beings, which were among the 
 earliest products of the dawning intellectual activity 
 of man. In those early days positive knowledge 
 was not to be had, but the craving after it needed, 
 at all hazards, to be satisfied, and according to the 
 country, or the turn of thought, of the speculator, 
 the suggestion that all living things arose from the 
 mud of the Nile, from a primeval egg, or from some 
 more anthropomorphic agency, afforded a sufficient 
 resting-place for his curiosity. The myths of 
 Paganism are as dead as Osiris or Zeus, and the 
 man who should revive them, in opposition to the 
 knowledge of our time, would be justly laughed to 
 scorn : but the coeval imaginations current among 
 the rude inhabitants of Palestine, recorded by 
 writers whose very name and age are admitted by 
 every scholar to be unknown, have unfortunately 
 not yet shared their fate, but, even at this day, are 
 regarded by nine-tenths of the civilised world as 
 the authoritative standard of fact and the criterion 
 
5iJ THE OBIGIN OF SPECIES II 
 
 of the justice of scientific conclusions, in all that 
 relates to the origin of things, and, among them, 
 of species. In this nineteenth century, as at the 
 dawn of modern physical science, the cosmogony 
 of the semi-barbarous Hebrew is the incubus of 
 the philosopher and the opprobrium of the ortho- 
 dox. Who shall number the patient and earnest 
 seekers after truth, from the days of Galileo until 
 now, whose lives have been embittered and their 
 good name blasted by the mistaken zeal of Biblio- 
 laters ? Who shall count the host of weaker men 
 whose sense of truth has been destroyed in the efifort 
 to harmonise impossibilities — whose life has been 
 wasted in the attempt to force the generous new 
 wine of Science into the old bottles of Judaism, com- 
 pelled by the outcry of the same strong party ? 
 
 It is true that if philosophers have suffered, their 
 cause has been amply avenged. ''Extinguished 
 theologians lie about the cradle of every science as 
 the strangled snakes beside that of Hepcules ; and 
 history records that whenever science and ortho- 
 doxy have been fairly opposed, the latter has been 
 forced to retire from the lists, bleeding and crushed 
 if not annihilated ; scotched, if not slain. But 
 orthodoxy is the Bourbon of the world of thought. 
 It learns not, neither can it forget; and though, 
 at present, bewildered and afraid to move, it is as 
 willing as ever to insist that the first chapter of 
 Genesis contains the beginning and the end of 
 sound science; and to visit, with such petty 
 
n THE ORIGIN OF SPECIES 53 
 
 thunderbolts as its half-paralysed hands can hurl, 
 those who refuse to degrade Nature to the level of 
 primitive Judaism. 
 
 Philosophers, on the other hand, have no such 
 aggressive tendencies. With eyes fixed on the 
 noble goal to which " per aspera et ardua " they 
 tend, they may, now and then, be stirred to 
 momentary wrath by the unnecessary obstacles 
 with which the ignorant, or the malicious, encum- 
 ber, if they cannot bar, the difficult path ; but why 
 should their souls be deeply vexed ? The majesty 
 of Fact is on their side, and the elemental forces 
 of Nature are working for them. Not a star comes 
 to the meridian at its calculated time but testifies 
 to the justice of their methods — their beliefs are 
 " one with the falling rain and with the growing 
 corn." By doubt they are established, and open 
 inquiry is their bosom friend. Such men have no 
 fear of traditions however venerable, and no respect 
 for them when they become mischievous and 
 obstructive ; but they have better than mere anti- 
 quarian business in hand, and if dogmas, which 
 ought to be fossil but are not, are not forced upon 
 their notice, they are too happy to treat them as 
 non-existent. 
 
 The hypotheses respecting the origin of species 
 which profess to stand upon a scientific basis, and, 
 as such, alone demand serious attention, are of two 
 kinds. The one, the " special creation " hypothesis. 
 
54 THE ORIGIN OF SPECIES II 
 
 presumes every species to have originated from one 
 or more stocks, these not being the result of the 
 modificationof any other form of living matter — or 
 arising by natural agencies— but being produced, 
 as such, by a supernatural creative act. 
 
 The_ ,other, the so-called "transmutation" 
 hypothesis, considers that all existing species^ are 
 the result of the modification of pre-existing I 
 species, and Ihose of their predecessors, by^ agencies 
 similar to those which at the present_day„prciduce 
 varieties and races, and therefore in an altosrether 
 natural way pandT it is "a probabje, though not a 
 Tie'cessary consequence of this hypothesis, that~ all 
 living beings have arisen from a single stock. 
 With respect to the origin of this primitive ^tock, 
 or stocks, the doctrine of the origin of species is 
 obviously not necessai'ily concerned. The trans- 
 mutation hypothesis, for example, is perfectly 
 consistent either with the conception of a special 
 creation of the primitive germ, or with the 
 supposition of its having arisen, as a modification 
 of inorganic matter, by natural causes. i 
 
 The doctrine of special creation owes its exist- 
 ence very largely to the supposed necessity of 
 making science accord with the Hebrew cos- 
 mogony ; but it is curious to observe that, as the 
 doctrine is at present maintained by men of 
 science, it is as hopelessly inconsistent with the 
 Hebrew view as any other hypothesis. 
 
 If there be any result which has come more 
 
ir THE ORIGIN OF SPECIES 55 
 
 clearly out of geological investigation than another, 
 
 it is, that the vast series of extinct animals and 
 
 plants is not divisible, as it was once supposed to 
 
 be, into distinct groups, separated bj sharply- 
 
 markeJ boundaries. There are no great gulfs 
 
 between epochs and formations — no successive 
 
 periods marked bytlie appearance of plants, of 
 
 water animals, and^of land animals, enjmasse. 
 
 Every year adds to the list of links between 
 
 what the older geologists supposed to be widely 
 
 separated epochs : witness the crags linking the 
 
 drift with older tertiaries ; the Maestricht beds 
 
 linking the tertiaries with the chalk; the St. 
 
 Cassian beds exhibiting an abundant fauna of 
 
 mixed mesozoic and palaeozoic types, in rocks of an 
 
 epoch once supposed to be eminently poor in life ; 
 
 witness, lastly, the incessant disputes as to whether 
 
 a given stratum shall be reckoned devonian or 
 
 carboniferous, silurian or devonian, cambrian or 
 
 Silurian. 
 
 This truth is further illustrated in a most 
 interesting manner by the impartial and highly 
 competent testimony of M. Pictet, from whose 
 calculations of what percentage of the genera of 
 animals, existing in any formation, lived during 
 the preceding formation, it results that in no case 
 is the proportion less than one-third, or 33 per 
 cent. It is the triassic formation, or the com- 
 mencement of the mesozoic epoch, which has 
 received the smallest inheritance from preceding 
 S3 
 
5G THE ORIGIN OF SPECIES U 
 
 ages. The other formations not uncommonly 
 exhibit 60, 80, or even 94 per cent, of genera in 
 common with those whose remains are imbedded 
 in their predecessor. Not only is this true, but 
 the subdivisions of each formation exhibit new 
 species characteristic of, and found only in, them ; 
 and, in many cases, as in the lias for example, the 
 separate beds of these subdivisions are distin- 
 guished by well-marked and peculiar forms of life. 
 A section, a hundred feet thick, will exhibit, at 
 different heights, a dozen species of ammonite, 
 none of which passes beyond its particular zone 
 of limestone, or clay, into the zone below it or into 
 that above it ; so that those who adopt the doc- 
 trine of special creation must be prepared to admit, 
 that at intervals of time, corresponding with the 
 thickness of these beds, the Creator thought fit 
 to interfere with the natural course of events for 
 the purpose of making a new ammonite. It is 
 not easy to transplant oneself into the frame of 
 mind of those who can accept such a conclusion 
 as this, on any evidence short of absolute demon- 
 stration ; and it is difficult to see wliat is to be 
 gained by so doing, since, as we have said, it is 
 obvious that such a view of the oriein of livino- 
 beings is utterly opposed to the Hebrew cos- 
 mogony. Deserving no aid from the powerful 
 arm of Bibliolatry, then, does the received form of 
 the hypothesis of special creation derive any 
 support from science or sound logic ? Assuredly 
 
II 
 
 THE ORIGIN OF SPECIES 57 
 
 Bot much. The arguments brought forward in its 
 favour all take one form : If species were not 
 supernaturally created, we cannot understand the 
 facts X, or y, or z\ we cannot understand the 
 structure of arii .mals or plants, unless we suppose 
 they were contrived fo r specialend s ; wejcfuinot 
 understand the structure of the eye, except by 
 supposing it to have, been mg-dft to se.e ^witTTTwe 
 cannot_j.mdei^ts!jidL„in^tiKcts, unless we -Supp,Qse 
 animals t o have been mirac ulous ly endowed with 
 ihena^ 
 
 As a question of dialectics, it must be admitted 
 that this sort of reasoning is not very formidable 
 to those who are not to be frightened by conse- 
 quences. It is an argumentum ad ignurantiam — 
 take this explanation or be ignorant. But suppose 
 we prefer, to admit our ignorance rather than 
 adopt a hypothesis at variance with all the teach- 
 ings of Nature ? Or, suppose for a moment we 
 admit the explanation, and then seriously ask 
 ourselves how much the wiser are we ; what does 
 the explanation explain ? Is it any more than a 
 grandiloquent way of announcing the fact, that we 
 really know nothing about the matter ? A 
 phsenomenon is explained when it is shown to be 
 a case of some general law of Nature ; but the 
 supernatural interposition of the Creator can, by 
 the nature of the case, exemplify no law, and if 
 species have really arisen in this way, it is absurd 
 to attempt to discuss their origin. 
 
58 THE OKIGIN OF SPECIES H 
 
 Or, lastly, let us ask ourselves whether any 
 amount of evidence which the nature of our 
 faculties permits us to attain, can justify us in 
 asserting that any phaenomenon is out of the reach 
 of natural causation. To this end it is obviously 
 necessary that we should know all the con- 
 sequences to which all possible combinations, 
 continued through unlimited time, can give rise. 
 If we knew these, and found none competent to 
 originate species, we should have good ground for 
 denying their origin by natural causation. Till 
 we know them, any hypothesis is better than one 
 which involves us in such miserable presumption. 
 
 But the hypothesis of special creation is not 
 only a mere specious mask for our ignorance ; its 
 existence in Biology marks the youth and imper- 
 fection of the science. For what is the history of 
 every science but the history of the elimination 
 of the notion of creative, or other .^ijiterferences, 
 witlT'the natural orcTerof the phsenomena which 
 are the subject-matter of that science ? When 
 Astronomy was young " the morning stars sang 
 together for joy," and the planets were guided 
 in their courses by celestial hands. Now, the 
 harmony of the stars has resolved itself into 
 gravitation^ccordingjtojthe inverse squares of the 
 distances, and the orbits of the planets are dedu- 
 cible from the laws of the forces which allow a 
 schoolboy's stone to break a window. The light- 
 ning was the angel of the Lord ; but it has pleased 
 
IT THE ORIGIN OF SPECIES 59 
 
 Providence, in these modem times, that science 
 should make it the humble messenger of man, and 
 we know that every flash that shimmers about 
 the horizon on a summer's evening is determined 
 by ascertainable conditions, and that its direction 
 and brightness might, if our knowledge of these 
 were great enough, have been calculated. 
 
 The solvency of great mercantile companies 
 
 rests on the validity of the laws which have been 
 
 ascertained to govern the seeming irregularity of 
 
 that human life which the moralist bewails as the 
 
 most uncertain of things ; plague, pestilence, and 
 
 famine are admitted, by all but fools, to be the 
 
 natural result of causes for the most part fully 
 
 within human control, and not the unavoidable 
 
 tortures inflicted by wrathful Omnipotence upon 
 
 His helpless handiwork. 
 
 Harmonious order governing eternally continu- 
 ous progress — the web and woof of matter and 
 force interweaving by slow degrees^^jaitbout a 
 broken thread, that "VeiL wlriliinTes between us 
 and the Infinite — that univer§.e— wlw«lr aluiiy we 
 know or can knoWT'^ucn is the ^jictiixe which 
 science draws of the world, and in proportion as 
 any part of that picture is in unison with the rest, 
 so may we feel sure that it is rightly painted. 
 Shall Biology alone remain out of harmony with 
 her sister sciences ? 
 
 Such arguments against the hypothesis of the 
 direct creation of species as these sre plainly 
 
60 THE ORIGIN OF SPECIES II 
 
 enough deducible from general considerations ; but 
 there are, in addition, phsenomena exhibited by 
 species themselves, and yet not so much a part of 
 their very essence as to have required earlier 
 mention, which are in the highest degree per- 
 plexing, if we adopt the popularly accepted 
 hypothesis. Such are the facts of distribution in 
 space and in time ; the singular phsenomena 
 brought to light by the study of development ; 
 the structural relations of species upon which our 
 systems of classification are founded ; the great 
 doctrines of philosophical anatomy, such as 
 that of homology, or of the community of 
 structural plan exhibited by large groups of 
 species differing very widely in their habits and 
 functions. 
 
 The species of animals which inhabit the sea on 
 opposite sides of the isthmus of Panama are 
 wholly distinct ; ^ the animals and plants which 
 inhabit islands are comnaonly distinct from those 
 of the neighbouring mainlands, and yet have a 
 similarity of aspect. The mammals of the latest 
 tertiary epoch in the Old and New Worlds belong 
 to the same genera, or family groups, as those 
 which now inhabit the same great geographical 
 area. The crocodilian reptiles which existed in the 
 earliest secondary epoch were similar in general 
 structure to those now living, but exhibit slight 
 
 ^ Eecent investigations tend to show that this statement is 
 not strictly accin-ate. — 1870. 
 
II THE ORIGIN OF SPECIES 61 
 
 differences in their vertebrae, nasal passages, and 
 one or two other points. The guinea-pig has 
 teeth which are shed before it is born, and hence 
 can never subserve the masticatory purpose for 
 which they seem contrived, and, in like manner, 
 the female duo^onoc has tusks which never cut the 
 gum. All the members of the same great group 
 run through similar conditions in their develop- 
 ment, and all their parts, in the adult state, are 
 arranged according to the same plan. Man is 
 more like a crorilla than a grorilla is like a lemur. 
 Such are a few, taken at random, among the 
 multitudes of similar facts which modem research 
 has established ; but when the student seeks for 
 an explanation of them from the supporters of 
 the received hypothesis of the origin of species, 
 the reply he receives is, in substance, of Oriental 
 simplicity and brevity — " Mashallah ! it so pleases 
 God ! " There are different species on opposite 
 sides of the isthmus of Panama, because they were 
 created different on the two sides. The pliocene 
 mammals are like the existing ones, because such 
 was the plan of creation ; and we find rudimental 
 organs and similarity of plan, because it has 
 pleased the Creator to set before Himself a 
 " divine exemplar or archetype," and to copy it in 
 His works ; and somewhat ill, those who hold this 
 view imply, in some of them. That such verbal 
 hocus-pocus should be received as science will one 
 day be regarded as evidence of the low state of 
 
62 THE ORIGIN OF SPECIES li 
 
 intelligence in the nineteenth century, just as 
 we amuse ourselves with the phraseology about 
 Nature's abhorrence of a vacuum, wherewith 
 Torricelli s compatriots were satisfied to explain 
 the rise of water in a pump. And be it recol- 
 lected that this sort of satisfaction works not only 
 negative but positive ill, by discouraging inquiry, 
 and so depriving man of the usufruct of one of the 
 most fertile fields of his great patrimony, Nature. 
 The objections to the doctrine of the origin of 
 s^pecies by special creation which have been 
 detaired7 must have occurred-, -wirth-more_Qr_less 
 force, to the mind of every one who has seriously 
 and independently considered the subject. It is 
 therefore no wonder that^~TromTi'ffiS~'^~ttme, this 
 hypothesis should have been met by counter 
 hypotheses, all as well, and some better founded 
 than itself ; and it is curious to remark that the 
 inventors of the opposing views seem to have been 
 led into them as much by their knowledge of 
 geology, as by their acquaintance with biology. 
 In fact, when the mind,has once -admitted the 
 conception of the gradual production of the present 
 physical state of our globe, by natural causes 
 operating through long ages of time, it will be 
 little disposed to allow that living beings have 
 made their appearance in another way, and the 
 speculations of De Maillet and his successors are 
 the natural complement of Scilla's demonstration 
 of the true nature of fossils. 
 
n THE ORIGIN OF SPECIES G3 
 
 A contemporary of Newton and of Leibnitz, 
 
 sharing therefore in the intellectual activity of tliu 
 
 remarkable age which witnessed the birth of 
 
 modern physical science, Benoit de Maillet spent 
 
 a lonar life as a consular asrent of the French Gov- 
 
 ernmeut in various Mediterranean ports. For 
 
 sixteen years, in fact, he held the office of Consul- 
 
 General in Egypt, and the wonderful phenomena 
 
 offered by the valley of the Nile appear to have 
 
 strongly impressed his mind, to have directed his 
 
 attention to all facts of a similar order which came 
 
 within his observation, and to have led him to 
 
 speculate on the origin of the present condition of 
 
 our globe and of its inhabitants. But, with all 
 
 his ardour for science, De Maillet seems to have 
 
 hesitated to publish views which, notwithstanding 
 
 the ingenious attempts to reconcile them with the 
 
 Hebrew hypothesis contained in the preface to 
 
 " Telliamed," were hardly likely to be received 
 
 witlrfavour by his contemporaries. 
 
 But a short time had elapsed since more than 
 one of the great anatomists and physicists of the 
 Italian school had paid dearly for their endeavours 
 to dissipate some of the prevalent errors ; and 
 their illustrious pupil, Harvey, the founder of 
 modern physiology, had not fared so well, in a 
 country less oppressed by the benumbing in- 
 fluences of theology, as to tempt any man to follow 
 his example. Probably not uninfluenced by these 
 considerations, his Catholic majesty's Consul- 
 
64 THE ORIGIN OF SPECIES n 
 
 General for Egypt kept his theories to himself 
 throughout a long life, for " Telliamed," the only 
 scientific work which is known to have proceeded 
 from his pen, was not printed till 1735, when its 
 author had reached the ripe age of seventy-nine ; 
 and though De Maillot lived three years longer, 
 his book was not given to the world before 1748. 
 Even then it was anonymous to those who were 
 not in the secret of the anacjrammatic character 
 of its title ; and the preface and dedication are so 
 worded as, in case of necessity, to give the printer 
 a fair chance of falling back on the excuse that 
 the work was intended for a mere jcu d! esprit. 
 
 The speculations of the suppositious Indian 
 sage, though quite as sound as those of many a 
 " Mosaic Geology,'' which sells exceedingly well, 
 have no great value if we consider them by the 
 light of modern science. The waters are supposed 
 to have originally covered the whole globe ; to 
 have deposited the rocky masses which compose 
 its mountains by processes comparable to those 
 which are now forming mud, sand, and shingle ; 
 and then to have gradually lowered their level, 
 leaving the spoils of their animal and vegetable 
 inhabitants embedded in the strata. As the dry 
 land appeared, certain of the aquatic animals are 
 supposed to have taken to it, and to have become 
 gradually adapted to terrestrial and aerial modes 
 of existence. But if we regard the general tenor 
 r.nd style of the reasoning in relation to the state 
 
II THE OEIGIN OF SPECIES 65 
 
 of knowledge of tlie day, two circumstances 
 appear very well worthy of remark. The first, 
 that De Maillet had a notion of the modifiability 
 of living forms (though without any precise 
 information on the subject), and how such modi- 
 fiability might account for the origin of species ; 
 the second, that he very clearly apprehended the 
 great modem geological doctrine, so strongly 
 insisted upon by Hutton, and so ably and 
 comprehensively expounded by Lyell, that we 
 must look to existing causes for the explanation 
 of past geological events. Indeed, the following 
 passage of the preface, in which De Maillet is 
 supposed to speak of the Indian philosopher 
 Telliamed, his alter ego, might have been written 
 by the most philosophical uniformitarian of the 
 present day : — 
 
 ' ' Ce qu'il y a d'etonnant, est que pour arriver k ces connois- 
 sances il semble avoir perverti Tordre nature!, puisqu'au lieu de 
 s'attacher d'abord a rechercher Torigine de notre globe il a 
 commence par travailler a s'instruire de la nature. Mais h, 
 I'entendre, ce renversement de I'ordre a ete pour lui Tcffet d'un 
 genie favorable qui I'a conduit pas a pas et comme par la main 
 aux decouvertes les plus sublimes. C'est en decomposant la 
 substance de ce globe par une anatomie exacte de toutes ses 
 parties qu'il a premierement appris de quelles matieres il etait 
 compose et quels arrangemens ces memes matieres observaient 
 entre elles. Ces lumieres jointes a I'esprit de comparaison 
 toujoms necessaire k quiconque entreprend de percer les voiles 
 dont la nature aime a se cacher, ont servi de guide h, notre 
 philosophe potir parvenir k des connoissances plus interessantes. 
 Par la matiere et I'arrangement de c<^s compositions il pretend 
 
66 THE ORIGIN OF SPECIES H 
 
 avoir reconnu quelle est la veritable origine dece globe que nous 
 habitons, comment et par qui il a ete forme."— Pp. xix. xx. 
 
 But De Maillet was before his age, and as could 
 hardly fail to happen to one who speculated on a 
 zoological and botanical question before Linnaeus, 
 and on a physiological problem before Haller, he 
 fell into great errors here and there ; and hence, 
 perhaps, the general neglect of his work. Kobinet's 
 speculations are rather behind, than in advance 
 of, those of De Maillet ; and though Linnaeus 
 may have played with the hypothesis of trans- 
 mutation, it obtained no serious support until 
 Lamarck adopted it, and advocated it with great 
 ability in his " Philosophie Zoologique." 
 
 Impelled towards the hypothesis of the 
 transmutation of species, partly by his general 
 cosmological and geological views ; partly by the 
 conception of a graduated, though irregularly 
 branching, scale of being, which had arisen out of 
 his profound study of plants and of the lower 
 forms of animal life, Lamarck, whose general line 
 of thought often closely resembles that of De 
 Maillet, made a great advance upon the crude 
 and merely speculative manner in which that writer 
 deals with the qiiestion of the origin of living 
 beings, by endeavouring to find physical causes 
 competent to effect that change of one species 
 into another, which De Maillet had only supposed 
 to occur. And Lamarck conceived that he had 
 found in Nature such causes, amj)ly sufficient for 
 
II THE ORIGIN OF SPECIES 67 
 
 the purpose in view. It is a physiological fact, 
 he^^say;s^ that organs are increased in size by 
 
 ac tion, at ro phied, by inaction; it is another 
 
 physiological fact that modifications produced are 
 transmissible to offspring. Change the actions of 
 aaLajmnal^_Jhere|orej_ar^ chang e its 
 
 structure, by increasing_the development of the 
 parts neAvlyJhrDUght into use and by the diminu- 
 t.inn nf thoRP. ]fis s used ; but by altering the 
 circumstances which surround it you will alter its 
 actions,^ aim~Hence, m the long run, change of 
 circumstance must^produce change of organisation. 
 All the species of animals, therefore, are, in 
 Lamarck's view, the result of the i^irect action 
 of^ changes of circumstance, upon those primitive 
 germs which he co nsidered to have originally 
 arisen, by spontaneous generation, within the 
 waters of the globe. It is curious, however, that 
 Lam^irck should'Tiisist so strongly ^ as he has done, 
 that circumstances never in any degi'ee directly 
 modify the form or the organisation of animals, 
 but only operate by changing their wants and 
 consequently their actions ; for he thereby brings 
 upon himself the obvious question. How, then, do 
 plants, which cannot be said to have wants or 
 actions, become modified ? To this he replies, 
 that they are modified by the changes in their 
 nutritive processes, which are effected by changing 
 circumstances ; and it does not seem to have 
 
 '^ See Phil. Zoologique, vol. i. p. 222, et seq. 
 
68 THE ORIGIN OF SPECIES H 
 
 occurred to him that such changes might be as 
 well supposed to take place among animals. 
 
 When we have said that Lamarck felt that 
 mere speculation was not the way to arrive at the 
 origin of species, but that it was necessary, in 
 order to the establishment of any sound theory 
 on the subject, to discover by observation or 
 otherwise, some vera causa, competent to give rise 
 to them ; that he affirmed the true order of 
 classification to coincide with the order of their 
 development one from another; that he insisted 
 on the necessity of allowing sufficient time, very 
 strongly ; and that all the varieties of instinct and 
 reason were traced back by him to the same 
 cause as that which has given rise to species, we 
 have enumerated his chief contributions to the 
 advance of the question. On the other hand, 
 from his ignorance of any power in Nature 
 competent to modify the structure of animals, 
 except the development of parts, or atrophy of 
 them, in consequence of a change of needs, 
 Lamarck was led to attach infinitely greater 
 weight than it deserves to this agency, and the 
 absurdities into which he was led have met with 
 deserved condemnation. Of the struggle for 
 existence, on which, as we shall see, Mr. Darwin 
 lays such great stress, he had no conception ; 
 indeed, he doubts whether there really are such 
 things as extinct species, unless they be such large 
 animals as may have met their death at the 
 
II THE ORIGIN OF SPECIES 69 
 
 hands of man ; and so little does he dream of 
 
 there being any other destructive causes at work, 
 
 that, in discussing the possible existence of fossil 
 
 shells, he asks, "Pourquoi d'ailleurs seroient-ils 
 
 perdues des que rhomme n'a pu op^rer leur 
 
 destruction ? " (" Phil. Zool.," vol. i. p. 77.) Of 
 
 the influence of selection Lamarck has as little 
 
 notion, and he makes no use of the wonderful 
 
 phaenomena which are exhibited by domesticated 
 
 animals, and illustrate its powers. The vast 
 
 influence of Cuvier was employed against the 
 
 Lamarckian views, and, as the untenability of 
 
 some of his conclusions was easily shown, his 
 
 doctrines sank under the opprobrium of scientific, 
 
 as well as of theological, heterodoxy. Nor have 
 
 the efforts made of late years to revive them 
 
 tended to re-establish their credit in the minds of 
 
 sound thinkers acquainted with the facts of the 
 
 case ; indeed it may be doubted whether Lamarck 
 
 has not suffered more from his friends than from 
 
 his foes. 
 
 Two years ago, in fact, though we venture to 
 question if even the strongest supporters of the 
 special creation hypothesis had not, now and then, 
 an uneasy consciousness that all was not right, 
 their position seemed more impregnable than ever, 
 if not by its own inherent strength, at any rate by 
 the obvious failure of all the attempts which had 
 been made to carry it. On the other hand, how- 
 ever much the few, who thought deeply on the 
 
70 THE ORIGIN OF SPECIES II 
 
 question of species, might be repelled hy the 
 generally received dogmas, they saw no way of 
 escaping from them save by the adoption of 
 suppositions so little justified by experiment 
 or by observation as to be at least equally dis- 
 tasteful. 
 
 The choice lay between two absurdities and a 
 middle condition of uneasy scepticism ; which 
 last, however unpleasant and unsatisfactory, was 
 obviously the only justifiable state of mind 
 under the circumstances. 
 
 Such being the general ferment in the minds of 
 naturalists, it is no wonder that they mustered 
 strong in the rooms of the Linngean Society, on 
 the 1st of July of the year 1858, to hear two 
 papers by authors living on opposite sides of the 
 globe, working out their results independently, 
 and yet professing to have discovered one and the 
 same solution of all the problems connected with 
 species. The one of these authors was an able 
 naturalist, Mr. Wallace, who had been employed 
 for some years in studying the productions of the 
 islands of the Indian Archipelago, and who had 
 forwarded a n.emoir embodying his views to Mr. 
 Darwin, for communication to the Linntean Society. 
 On perusing the essay, Mr. Darwin was not a little 
 surprised to find that it embodied some of the 
 leading ideas of a great work which he had been 
 preparing for twenty years, and parts of which, 
 containing a development of the very same views, 
 
II THE ORIGIN OP SPECIES 71 
 
 had been perused by his private friends fifteen or 
 sixteen years before. Perplexed in what manner 
 to do full justice both to his friend and to himself, 
 Mr. Darwin placed the matter in the hands of 
 Dr. Hooker and Sir Charles Lyell, by whose advice 
 he communicated a brief abstract of his own views 
 to the Linnaean Society, at the same time that 
 Mr. Wallace's paper was read. Of that abstract, 
 the work on the " Origin of Species " is an enlarge- 
 ment ; but a complete statement of Mr. Darwin's 
 doctrine is looked for in the large and well- 
 illustrated work which he is said to be preparing 
 for publication. 
 
 The Darwinian hypothesis has themerit^^f 
 being eminently simple and comprehensible in 
 principle, and its essential positions may be stated 
 in a veiry few words : all species have been pro- 
 duced_by the development of varieties from 
 common stocks ; by the conversion of JhgfeT'first 
 into permanent races and then into new species, 
 by the-process of natural selection, which process 
 is essentially- ideaticaLwitL that artificial selectioja 
 by which man has origi nated the races of domestic 
 anino^Js^the ^txMg4{l£....^£caL^x istence ta king "the 
 place of man, and exerting, in^the case of natural 
 selection, that selective action which he performs 
 i n artificial selecti oji. 
 
 The evidence brought forward by Mr. Darwin in 
 support of his hypothesis is of three kinds. First, 
 U 
 
Y2 THE OKIGIN OF SPECIES II 
 
 he endeavours to prove that species may be 
 originated by selection ; secondly, he attempts to 
 show that natural causes are competent to exert 
 selection ; and thirdly, he tries to prove that the 
 most remarkable and apparently anomalous 
 phfenomena exhibited by the distribution, 
 development, and mutual relations of species, 
 can be shown to be deducible from the general 
 doctrine of their origin, which he propounds, 
 combined with the known facts of geological 
 change ; and that, even if all these pheenomena 
 are not at present explicable by it, none are 
 necessarily inconsistent with it. 
 
 There cannot be a doubt that the method of 
 inquiry which Mr. Darwin has adopted is not only 
 rigorously in accordance with the canons of 
 scientific logic, but that it is the only adequate 
 method. Critics exchisively trained in classics or 
 in mathematics, who have never determined a 
 scientific fact in their lives by induction from 
 experiment or observation, prate learnedly about 
 Mr. Darwin's method, which is not inductive 
 enough, not Baconian enough, forsooth, for them. 
 But even if practical acquaintance with the process 
 of scientific investigation is denied them, they may 
 learn, by the perusal of Mr. Mill's admirable 
 chapter " On the Deductive Method," that there 
 are multitudes of scientific inquiries in which the 
 method of pure induction helps the investigator 
 but a very little way. 
 
n THE ORIGIN OF SPECIES 73 
 
 "The mode of investigation," says Mr. Mill, "which, from 
 the proved inapplicability of direct methods of observation and 
 experiment, remains to us as the main source of the knowledge 
 we possess, or can acquire, respecting the conditions and laws of 
 recurrence of the more complex phcenomena, is called, in its 
 most general expression, the deductive method, and consists of 
 three operations : the first, one of direct induction ; the second, 
 of ratiocination ; and the third, of verification. " 
 
 Now, the conditions which have determined the 
 existence of species are not only exceedingly com- 
 plex, but, so far as the great majority of them are 
 concerned, are necessarily beyond our cognisance. 
 But what Mr. Darwin has attempted to do is in 
 exact accordance with the rule laid down by Mr. 
 Mill ; he has endeavoured to determine certain 
 great facts inductively, by observation and experi- 
 ment ; he has then reasoned from the data thus 
 furnished ; and lastly, he has tested the validity of 
 his ratiocination by comparing his deductions with 
 the observed facts of Nature. Inductively, Mr. 
 Darwin endeavours to prove that species arise in 
 a given way. Deductively, he desires to show 
 that, if they arise in that way, the facts of distri- 
 bution, development, classification, &c., may be 
 accounted for, i.e. may be deduced from their mode 
 of origin, combined with admitted changes in 
 physical geography and climate, during an inde- 
 finite period. And this explanation, or coinci- 
 dence of observed with deduced facts, is, so far as 
 it extends, a verification of the Darwinian view. 
 
 There is no fault to be found with Mr. Darwin's 
 
74 THE ORIGIN OF SPECIES il 
 
 method, then ; but it is another question whether 
 he has fulfilled all the conditions imposed by that 
 method. Is it satisfactorily proved, in fact, that 
 species may be originated by selection ? that there 
 is such a thing as natural selection ? that none 
 of the phsenomena exhibited by species are incon- 
 sistent with the origin of species in this way ? If 
 these questions can be answered in the affirmative, 
 Mr. Darwin's view steps out of the rank of hypo- 
 theses into those of proved theories ; but, so long 
 as the evidence at present adduced falls short of 
 enforcing that affirmation, so long, to our minds, 
 must the new doctrine be content to remain among 
 the former — an extremely valuable, and in the 
 highest degree probable, doctrine, indeed the only 
 extant hypothesis which is worth anything in a 
 scientific point of view ; but still a hypothesis, and 
 not yet the theory of species. 
 
 After much consideration, and with assuredly 
 no bias against Mr. Darwin's views, it is our clear 
 conviction that, as the evidence stands, it is not 
 absolutely proven that a group of animals, having 
 all the characters exhibited by species in Nature, 
 has ever been originated by selection, whether 
 artificial or natural. Groups having the morpho- 
 logical character of species — distinctand permanent 
 races in fact — have been so produced over and over 
 again ; but there is no positive evidence, at present, 
 that any group of animals has^ by variation and 
 selective breeding, given rise to another group 
 
II THE ORIGIN OF SPECIES 75 
 
 "which was, even in the least degree, infertile with 
 the first. Mr. Darwin is perfectly, aware of this 
 weak point, and brings forward a multitude of 
 ingenious and important arguments to diminish 
 the force of the objection. We admit the value of 
 these arguments to their fullest extent ; nay, we 
 will go so far as to express our belief that experi- 
 ments, conducted by a skilful physiologist, would very 
 probably obtain the desired production of mutually 
 more or less infertile breeds from a common stock, 
 in a comparatively few years ; but still, as the case 
 stands at present, this " little rift within the lute " 
 is not to be disguised nor overlooked. 
 
 In the remainder of Mr. Darwin's argument our 
 own private ingenuity has not hitherto enabled us 
 to pick holes of any great importance ; and judging 
 by what we hear and read, other adventurers in 
 the same field do not seem to have been much 
 more fortunate. It has been urged, for instance, 
 that in his chapters on the struggle for existence 
 and on natural selection, Mr. Darwin does not so 
 much prove that natural selection does occur, as 
 that it must occur ; but, in fact, no other sort of 
 demonstration is attainable. A race does not 
 attract our attention in Nature until it has, in all 
 probability, existed for a considerable time, and 
 then it is too late to inquire into the conditions of 
 its origin. Again, it is said that there is no real 
 analogy between the selection which takes place 
 under domestication, by human influence, and any 
 
76 THE ORIGIN OF SPECIES II 
 
 operation which can be effected by Nature, for man 
 interferes intelligently. Reduced to its elements, 
 this argument implies that an effect produced with 
 trouble by an intelligent agent must, a fortiori, be 
 more troublesome, if not impossible, to an unin- 
 telligent agent. Even putting aside the question 
 whether Nature, acting as she does according to 
 definite and invariable laws, can be rightly called 
 an unintelligent agent, such a position as this is 
 wholly untenable. Mix salt and sand, and it shall 
 puzzle the wisest of men, with his mere natural 
 appliances, to separate all the grains of sand from 
 all the grains of salt ; but a shoAver of rain will 
 effect the same object in ten" minutes. And so, 
 while man may find it tax all his intelligence to 
 separate any variety which arises, and to breed 
 selectively from it, the destructive agencies inces- 
 santly at work in Nature, if they find one variety 
 to be more soluble in circumstances than the other, 
 will inevitably, in the long run, eliminate it. 
 
 A frequent and a just objection to the Lamarckian 
 hypothesis of the transmutation of species is based 
 upon the absence of transitional forms between 
 many species. But against the Darwinian hypo- 
 thesis this argument has no force. Indeed, one of 
 the most valuable and suggestive parts of Mr. 
 Darwin's work is that in which he proves, that 
 the frequent absence of transitions is a necessary 
 consequence of his doctrine, and that the stock 
 whence two or more species have sprung, need in 
 
II '' THE ORIGIN OF SPECIES 77 
 
 no respect be intermediate between these species. 
 If any two species have arisen from a common 
 stock in the same way as the carrier and the 
 pouter, say, have arisen from the rock-oigeon, 
 then the common stock of these two species need 
 be no more intermediate between the two than 
 the rock-pigeon is between the carrier and 
 pouter. Clearly appreciate the force of this 
 analogy, and all the arguments against the origin 
 of species by selection, based on the absence of 
 transitional forms, fall to the ground. And Mr. 
 Darwin's position might, we think, have been 
 even stronger than it is if he had not embarrassed 
 himself with the aphorism, " Naiura non facit 
 saltum," which turns up so often in his pages. 
 We believe, as we have said above, that Nature 
 does make jumps now and then, and a recognition 
 of the fact is of no small importance in disposing 
 of many minor objections to the doctrine of trans- 
 mutation. 
 
 But we must pause. The discussion of Mr. 
 Darwin's arguments in detail would lead us far 
 beyond the limits within which we proposed, at 
 starting, to confine this article. Our object has 
 been attained if we have given an intelligible, 
 however brief, account of the established facts 
 connected with species, and of the relation of the 
 explanation of those facts offered by Mr. Darwin to 
 the theoretical views held by his predecessors and 
 his contemporaries, and, above all, to the require- 
 
78 THE ORIGIN OF SPECIES II 
 
 ments of scientific logic. We have ventured to 
 point out that it does not, as yet, satisfy all those 
 requirements ; but we do not hesitate to assert 
 that it is as superior to any preceding or con- 
 temporary hypothesis, in the extent of observa- 
 tional and experiTnental basis on which it rests, in 
 its rigorously scientific method, and in its power of 
 explaining biological phsenomena, as was the 
 hypothesis of Copernicus to the speculations of 
 Ptolemy. But the planetary orbits turned out to 
 be not quite circular after all, and, grand as was 
 the service Copernicus rendered to science, Kepler 
 and Newton had to come after him. What if the 
 orbit of Darwinism should be a little too circular ? 
 What if species should offer residual phsenomena, 
 here and there, not explicable by natural selection ? 
 Twenty years hence naturalists may be in a 
 position to say whether this is, or is not, the case ; 
 but in either event they will owe the author of 
 " The Origin of Species " an immense debt of 
 gratitude. We should leave a very wrong im- 
 pression on the reader's mind if we permitted him 
 to suppose that the value of that work depends 
 wholly on the ultimate justification of the 
 theoretical views which it contains. On the con- 
 trary, if they were disproved to-morrow, the book 
 would still be the best of its kind — the most 
 compendious statement of well-sifted facts bearing 
 on the doctrine of species that has ever appeared. 
 The chapters on Variation, on the Struo-o-le for 
 
II THE ORIGIN OF SPECIES 79 
 
 Existence, on Instinct, on Hybridism, on the Imper- 
 fection of the Geological Record, on Geographical 
 Distribution, have not only no equals, but, so far 
 as our knowledge goes, no competitors, within the 
 range of biological literature. And viewed as a 
 whole, we do not believe that, since the publica- 
 tion of Von Baer's " Researches on Development," 
 thirty years ago, any work has appeared calculated 
 to exert so large an influence, not only on the 
 future of Biology, but in extending the domination 
 of Science over recjions of thought into which she 
 has, as yet, hardly penetrated. 
 
Ill 
 
 CRITICISMS ON "THE ORIGIN OF 
 SPECIES" 
 
 [1864] 
 
 1. UeBER die DaRWIn'sCHE SCHOrFTTNGSTHEORIE ; EIN 
 
 VoETRAG, VON A. KoLLiKER. Leipzig, 1864. 
 
 2. Examination du Livre de M. Darwin sur l'Origine 
 
 DES EspfecES. Par P. Floure.ns. Paris, 1864. 
 
 In the course of the present year several foreign 
 commentaries upon Mr. Darwin's great work have 
 made their appearance. Those who have perused 
 that remarkable chapter of the " Antiquity of 
 Man," in which Sir Charles Lyell draws a parallel 
 between the development of species and that of 
 languages, will be glad to hear that one of the 
 most eminent philologers of Germany, Professor 
 Schleicher, has, independently, published a most 
 instructive and philosophical pamphlet (an ex- 
 cellent notice of which is to be found in the 
 
m CRITICISMS ON " THE ORIGIN OF SPECIES " 81 
 
 Reader, for February 27tli of this year) supporting 
 similar views with all the weight of his special 
 knowledge and established authority as a linguist. 
 Professor Haeckel, to whom Schleicher addresses 
 himself, previously took occasion, in his splendid 
 monograph on the Badiolaria} to express his high 
 appreciation of, and general concordance with, Mr. 
 Darwin's views. 
 
 But the most elaborate criticisms of the " Origin 
 of Species " which have appeared are two works of 
 very widely different merit, the one by Professor 
 Kolliker, the well-known anatomist and histolo- 
 gist of Wiirzburg; the other by M. Flourens, 
 Perpetual Secretary of the French Academy of 
 Sciences. 
 
 Professor Kolliker's critical essay " Upon the 
 Darwinian Theory " is, like all that proceeds from 
 the pen of that thoughtful and accomplished 
 writer, worthy of the most careful consideration. 
 It comprises a brief but clear sketch of Darwin's 
 views, followed by an enumeration of the leading 
 difficulties in the way of their acceptance ; diffi- 
 culties which would appear to be insurmountable 
 to Professor Kolliker, inasmuch as he proposes to 
 replace Mr. Darwin's Theory by one which he 
 terms the " Theory of Heterogeneous Generation." 
 We shall proceed to consider first the destructive, 
 and secondly, the constructive portion of the 
 essay, 
 
 1 Die Badiolarien : eine Monographie, p. 231. 
 
82 CRITICISMS ON " THE ORIGIN OF SPECIES " in 
 
 We regret to find ourselves compelled to dissent 
 very widely from many of Professor Kolliker's 
 remarks; and from none more thoroughly than 
 from those in which he seeks to define what 
 we may term the philosophical position of Dar- 
 winism. 
 
 " Darwin," says Professor Kolliker, "is, in the fullest sense of 
 the word, a Teleologist. He says quite distinctly (First Edition, 
 pp. 199, 200) that every particular in the structure of an animal 
 has been created for its benefit, and he regards the whole series 
 of animal forms only from this point of view." 
 
 And again : 
 
 "7. The teleological general conception adopted by Darwin 
 is a mistaken one. 
 
 "Varieties arise irrespectively of the notion of purpose, or 
 of utility, according to general laws of Nature, and may be 
 either useful, or hurtful, or inditt'erent. 
 
 " The assumption that an organism exists only on account of 
 some definite end in view, and represents something more than 
 the incorporation of a general idea, or law, implies a one-sided 
 conception of the universe. Assuredly, every organ has, and 
 every organism fulfils, its end, but its purpose is not the condition 
 of its existence. Every organism is also sufficiently perfect for 
 the purpose it serves, and in that, at least, it is useless to seek 
 for a cause of its improvement. " 
 
 It is singular how differently one and the same 
 book will impress different minds. That which 
 struck the present writer most forcibly on his first 
 perusal of the " Origin of Species " was the con- 
 viction that Teleology, as commonly understood, 
 had received its deathblow at Mr. Darwin's hands. 
 For the teleological argument runs thus : an organ 
 
Ill CRITICISMS ON " THE ORIGIN OF SPECIES " 83 
 
 or organism (A) is precisely fitted to perform a 
 function or purpose (B) ; therefore it was specially 
 constructed to perform that function. In Paley's 
 famous illustration, the adaptation of all the parts 
 of the watch to the function, or purpose, of showing 
 the time, is held to be evidence that the watch 
 was specially contrived to that end ; on the ground, 
 that the only cause we know of, competent to 
 produce such an efifect as a watch which shall keep 
 time, is a contriving intelligence adapting the 
 means directly to that end. 
 
 Suppose, however, that any one had been able 
 to show that the watch had not been made directly 
 by any person, but that it was the result of the 
 modification of another watch which kept time but 
 poorly ; and that this again had proceeded from a 
 structure which could hardly be called a watch 
 at all — seeing that it had no figures on the dial 
 and the hands were nidimentary ; and that going 
 back and back in time we came at last to a re- 
 volving barrel as the earliest traceable rudiment 
 of the whole fabric. And imagine that it had 
 been possible to show that all these changes 
 had resulted, first, from a tendency of the structure 
 to vary indefinitely ; and secondly, from something 
 in the surrounding world which helped all variations 
 in the direction of an accurate time-keeper, and 
 checked all those in other directions ; then it is 
 obvious that the force of Paley's argument would 
 be gone. For it would be demonstrated that an 
 
84 CRITICISMS ON " THE ORIGIN OF SPECIES m 
 
 apparatus thoroughly well adapted to a particular 
 purpose might be the result of a method of trial 
 and error Avorked by unintelligent agents, as well 
 as of the direct application of the means appro- 
 priate to that end, by an intelligent agent. 
 
 Now it appears to us that what we have here, 
 for illustration's sake, supposed to be done with 
 the watch, is exactly what the establishment of 
 Darwin's Theory will do for the organic world. 
 For the notion that every organism has been 
 created as it is and launched straight at a purpose, 
 Mr. Darwin substitutes the conception of some- 
 thing which may fairly be termed a method of 
 trial and error. Organisms vary incessantly ; of 
 these variations the few meet with surroundincp 
 conditions which suit them and thrive ; the many 
 are unsuited and become extinguished, 
 ' According to Teleology, each organism is like a 
 rifle bullet fired straight at a mark ; according to 
 Darwin, organisms are like grapeshot of which one 
 hits something and the rest fall wide. 
 
 For the teleologist an organism exists because 
 it was made for the conditions in which it is found ; 
 for the Darwinian an organism exists because, out 
 of many of its kind, it is the only one which has 
 been able to persist in the conditions in which it 
 is found. 
 
 Teleology implies that the organs of every 
 organism are perfect and cannot be improved ; the 
 Darwinian theory simply affirms that they work 
 
in CKITICISMS ON " THE ORIGIN OF SPECIES " 85 
 
 well enough to enable the organism to hold its 
 own against such competitors as it has met with, 
 but admits the possibility of indefinite improve- 
 ment. But an example may bring into clearer 
 light the profound opposition between the ordinary 
 teleological, and the Darwinian, conception. 
 
 Cats catch mice, small birds and the like, very 
 well. Teleology tells us that they do so because 
 they were expressly constructed for so doing — that 
 they are perfect mousing apparatuses, so perfect 
 and so delicately adjusted that no one of their or- 
 gans could be altered, without the change involving 
 the alteration of all the rest. Darwinism affirms 
 on the contrary, that there was no express con- 
 struction concerned in the matter ; but that among 
 the multitudinous variations of the Feline stock, 
 many of which died out from want of power to 
 resist opposing influences, some, the cats, were 
 better fitted to catch mice than others, whence 
 they throve and 'persisted, in proportion to the 
 advantage over their fellows thus offered to them. 
 
 Far from imagining that cats exist in order to 
 catch mice well, Darwinism supposes that cats exist 
 hecmtse they catch mice well — mousing being not 
 the end, but the condition, of their existence. And 
 if the cat type has long persisted as we know it, 
 the interpretation of the fact upon Darwinian 
 principles would be, not that the cats have re- 
 mained invariable, but that such varieties as have 
 incessantly occurred have been, on the whole, less 
 
86 CRITICISMS ON " THE ORIGIN OF SPECIES " iii 
 
 fitted to get on in the world than the existing 
 stock. 
 
 If we apprehend the spirit of the " Origin of 
 Species " rightly, then, nothing can be more en- 
 tirely and absolutely opposed to Teleology, as it is 
 commonly understood, than the Darwinian Theory. 
 So far from beinof a " Teleologist in the fullest sense 
 of the word," we should deny that he is a 
 Teleologist in the ordinary sense at all ; and we 
 should say that, apart from his merits as a na- 
 turalist, he has rendered a most remarkable service 
 to philosophical thought by enabling the student 
 of Nature to recognise, to their fullest extent, those 
 adaptations to purpose which are so striking in the 
 organic world, and which Teleology has done good 
 service in keeping before our minds, without being 
 false to the fundamental principles of a scientific 
 conception of the universe. The apparently diverg- 
 ing teachings of the Teleologist and of the Morpho- 
 logist are reconciled by the Darwinian hypothesis. 
 
 But leaving our own impressions of the " Origin 
 of Species," and turning to those jDassages especially 
 cited by Professor Kolliker, we cannot admit that 
 they bear the interpretation he puts upon them. 
 Darwin, if we read him rightly, does not affirm that 
 every detail in the structure of an animal has been 
 created for its benefit. His words are (p. 199) : — 
 
 " The foregoing remarks lead me to say a few words on the 
 protest lately made by some naturalists against the utilitarian 
 doctrine that every detail of structure has been produced for the 
 
in CRITICISMS ON " THE ORIGIN OF SPECIES " 87 
 
 good of its possessor. They believe that very many stmcliires 
 have been created for beauty in the eyes of man, or for mere 
 variety. This doctrine, if true, would be absolutely fatal to my 
 theory— yet I fully admit that many structures are of no direct 
 use to their possessor." 
 
 And after sundry illustrations and qualifications, 
 he concludes (p. 200) : — 
 
 "Hence every detail of structure in eveiy living creature 
 (making some little allowance for tlie direct action of physical 
 conditions) may be viewed either as having been of special use 
 to some ancestral form, or as being now of special use to the 
 descendants of this form — either directly, or indirectly, through 
 the complex laws of growth." 
 
 But it is one thing to say, Darwinically, that 
 every detail observed in an animal's structure is 
 of use to it, or has been of use to its ancestors ; 
 and quite another to affirm, teleologically, that 
 every detailof an animal's structure has been 
 created for its benefit. Oa the former hypothesis, 
 for example, the teeth of the foetal Halccna have a 
 meaning ; on tha latter, none. So far as we are 
 aware, there is not a phrase in the " Origin of 
 Species " inconsistent with Professor Kolliker's 
 position, that " varieties arise irrespectively of the 
 notion of purpose, or of utility, according to general 
 laws of Nature, and may be either useful, or hurt- 
 ful, or indifferent." 
 
 On the contrary, Mr. Darwin writes (Summary 
 of Chap. V.) :— 
 
 " Our ignorance of the laws of variation is profound. Not in 
 one case out of a hundred can we pretend to assign any reason 
 wliy this or that part varies more or less from the same part in 
 35 
 
88 CKITICISMS ON " THE ORIGIN OF SPECIES " in 
 
 the parents. . . The external conditions of life, as climate and 
 food, &c., seem to have induced some slight modifications. 
 Habit, in producing constitutional differences, and use, in 
 strengthening, and disuse, in weakening and diminishing organs, 
 seem to have been more potent in their effects.'' 
 
 And finally, as if to prevent all possible miscon- 
 ception, Mr. Darwin concludes his Chapter on 
 Variation with these pregnant "vvords : — 
 
 ' ' Whatever the cause may be of each slight difference in the 
 offspring from their parents — and a cause for each must exist — 
 it is the steady accumulation, through natural selection of such 
 differences, when beneficial to the individual, that gives rise to 
 all the more important modifications of stmcture, by whiclx the 
 innumerable beings on the face of the earth are enabled to 
 struggle with each other, and the best adapted to survive." 
 
 We have dwelt at length upon this subject, be- 
 cause of its great general importance, and because 
 we believe that Professor Kolliker's criticisms on 
 this head are based upon a misapprehension of Mr. 
 Darwin's views — substantially they appear to us 
 to coincide with his own. The other objections 
 which Professor Kolliker enumerates and discusses 
 are the following : ^ — 
 
 "1. No transitional forms between existing species are 
 known ; and known varieties, whether selected or spontaneous, 
 never go so far as to establish new species." 
 
 To this Professor Kolliker appears to attach 
 some weight. He makes the suggestion that the 
 
 1 Space will not allow us to give Professor KtSUiker's argu- 
 ments in detail ; our readers will find a full and accurate versfon 
 of them in the Header for August 13th and 20th, 1864, 
 
m CEITICISMS ON " THE ORIGIN OF SPECIES " 89 
 
 short-faced tumbler pigeon may be a pathological 
 
 product. 
 
 "2. IN"© transitional forms of animals are met witli among the 
 organic reiaaiiis of earlier epoclis. " 
 
 Upon this, Professor KoUiker remarks that the 
 absence of transitional forms in the fossil world, 
 though not necessarily fatal to Darwin's views, 
 weakens his case. 
 
 "3. Tlie struggle for existence does not take place." 
 
 To this objection, urged by Pelzeln, Kolliker, 
 very justly, attaches no weight. 
 
 "4. A tendency of organisms to give rise to useful varieties, 
 and a natural selection, do not exist. 
 
 "The varieties which are found arise in consequence of 
 manifold external influences, and it is not obvious why they all, 
 or partially, should be particularly useful. Each animal suffices 
 for its own ends, is perfect of its kind, and needs no further 
 development. Should, however, a variety be useful and even 
 maintain itself, there is no obvious reason why it should change 
 any further. The whole conception of the imperfection of 
 organisms and the necessity of their becoming perfected is 
 plainly the weakest .side of Darwin's Theory, and a pis alter 
 (Nothbehelf) because Darwin could think of no other principle 
 by which to explain the metamorphoses which, as I also believe, 
 have occurred." 
 
 Here again we must venture to dissent com- 
 pletely from Professor Kolliker's couception of Mr. 
 Darwin's hypothesis. It appears to us to be one 
 of the many peculiar merits of that hypothesis that 
 it involves no belief in a necessary and continual 
 progress of organisms. 
 
 Again, Mr. Darwin, if we read him aright. 
 
90 CRITICISMS ON " THE ORIGIN OF SPECIES " in 
 
 assumes no special tendency of organisms to give 
 rise to useful varieties, and knows nothing of needs 
 of development, or necessity of perfection. What 
 he says is, in substance : All organisms vary. It 
 is in the highest degree improbable that any given 
 variety should have exactly the same relations to 
 surrounding conditions as the parent stock. In 
 that case it is either better fitted (when the varia- 
 tion may be called useful), or worse fitted, to cope 
 with them. If better, it will tend to supplant the 
 parent stock ; if worse, it will tend to be extin- 
 guished by the parent stock. 
 
 If (as is hardly conceivable) the new variety is 
 so perfectly adapted to the conditions that no 
 improvement upon it is possible, — it will persist, 
 because, though it does not cease to vary, the 
 varieties will be inferior to itself. 
 
 If, as is more probable, the new variety is by no 
 means perfectly adapted to its conditions, but only 
 fairly well adapted to them, it will persist, so long 
 as none of the varieties wliich it throws off are 
 better adapted than itself. 
 
 On the other hand, as soon as it vanes in a 
 useful way, i.e. when the variation is such as to 
 adapt it more perfectly to its conditions, the fresh 
 variety will tend to supplant the former. 
 
 So far from a gradual progress towards perfection 
 forming any necessary part of the Darwinian 
 creed, it appears to us that it is perfectly consistent 
 with indefinite persistence in one state, or with 
 
Ill CniTICISMS ON "THE ORIGIN OF SPECIES " 91 
 
 a gradual retrogression. Suppose, for example, a 
 return of the glacial epoch and a spread of polar 
 climatal conditions over the whole globe. The 
 operation of natural selection under these circum- 
 stances would tend, on the whole, to the weeding 
 out of the higher organisms and the cherishing of 
 the lower forms of life. Cryptogamic vegetation 
 would have the advantage over Phanerogamic ; 
 ITydrozoa over Corals ; Griistacea over Insecta, and 
 Amphipoda and Isopoda over the higher Crustacea ; 
 Cetaceans and Seals over the Primates ; the 
 civilisation of the Esquimaux over that of the 
 European. 
 
 " 5. Pelzeln has also objected that if the later organisms have 
 proceeded from the earlier, the whole developmental series, from 
 the simplest to the highest, could not now exist ; in such a caso 
 the simpler organisms must have disappeared." 
 
 To this Professor Kolliker replies, with perfect 
 justice, that the conclusion drawn by Pelzeln does 
 not really follow from Darwin's premises, and that, 
 if we take the facts of Palaeontology as they 
 stand, they rather support than oppose Darwin's 
 theory. 
 
 " 6. Great weight must be attached to the objection brought 
 forward by Huxley, otherwise a warm supporter of Darwin's 
 hypothesis, that we know of no varieties which are sterile with 
 one another, as is the rule among sharply distinguished animal 
 forms. 
 
 " If DaiTvin is right, it must be demonstrated that forms may 
 be produced by selection, which, like the present sharply dis- 
 tinguished animal foims, are infertile, when coupled with one 
 another, and this has not been done." 
 
92 CRITICISMS ON " THE ORIGIN OF SPECIES " m 
 
 The weight of this objection is obvious ; but our 
 ignorance of the conditions of fertility and sterility, 
 the want of carefully conducted experiments 
 extending over long series of years, and the 
 strange anomalies presented by the results of the 
 cross-fertilisation of many plants, should all, as 
 Mr. Darwin has urged, be taken into account in 
 considering it. 
 
 The seventh objection is that we have already 
 discussed (supra p. 82). 
 
 The eighth and last stands as follows : — 
 
 "8. The developmental theory of Darwin is not needed to 
 enable us to understand the regular harmonious progress of the 
 complete series of organic forms from the simpler to the more 
 perfect. 
 
 "The existence of general laws of Nature explains this 
 harmony, even if we assume that all beings have arisen separately 
 and independent of one another. Darwin forgets that inorganic 
 nature, in which there can be no thought of genetic connexion 
 of forms, exhibits the same regular plan, the same harmony, as 
 the organic world ; and that, to cite only one example, there is 
 as much a natural system of minerals as of plants and 
 animals. " 
 
 We do not feel quite sure that we seize 
 Professor Kolliker's meaning here, but he appears 
 to suggest that the observation of the general order 
 and harmony which pervade inorganic nature, 
 would lead us to anticipate a similar order and 
 harmony in the organic world. And this is no 
 doubt true, but it by no means follows that the 
 particular order and harmony observed among 
 them should be that which we see. Surely the 
 
Ill CRITICISMS ON " THE ORIGIN OF SPECIES " 93 
 
 stripes of dun horses, and the teeth of the foetal 
 Balcena, are not explained by the " existence of 
 general laws of Nature." Mr. Darwin endeavours 
 to explain the exact order of organic nature 
 which exists ; not the mere fact that there is 
 some order. 
 
 And with regard to the existence of a natural 
 system of minerals ; the obvious reply is that 
 there may be a natural classification of any 
 objects — of stones on a sea-beach, or of works of 
 art; a natural classification being simply an 
 assemblage of objects in groups, so as to express 
 their most important and fundamental resem- 
 blances and difi"erences. No doubt Mr. Darwin 
 believes that those resemblances and differences 
 upon which our natural systems or classifications 
 of animals and plants are based, are resemblances 
 and differences which have been produced gene- 
 tically, but we can discover no reason for suppos- 
 ing that he denies the existence of natural classi- 
 fications of other kinds. 
 
 And, after all, is it quite so certain that a 
 genetic relation may not underlie the classification 
 of minerals ? The inorganic world has not always 
 been what we see it. It has certainly had its 
 metamorphoses, and, very probably, a long 
 " Entwickelungsgeschichte " out of a nebular 
 blastema. Who knows how far that amount of 
 likeness among sets of minerals, in virtue of which 
 they are now grouped into families and orders, 
 
94 CRITICISMS ON " THE ORIGIN OF SPECIES iii 
 
 may not be the expression of the common condi- 
 tions to which that particular patch of nebulous 
 fog, which may have been constituted by their 
 atoms, and of which they may be, in the strictest 
 sense, the descendants, was subjected ? 
 
 It will be obvious from what has preceded, that 
 we do not agree with Professor Kolliker in think- 
 ing th% objections which he brings forward so 
 weighty as to be fatal to Darwin's view. But even 
 if the case were otherwise, we should be unable to 
 accept the " Theory of Heterogeneous Generation " 
 which is offered as a substitute. That theory is 
 thus stated : — 
 
 "The fundamental conception of this hypothesis is, that, 
 under the influence of a general law of development, the germs 
 of organisms produce others different from themselves. 
 This njight happen (1) by the fecundated ova passing, in the 
 course of their development, under particular circumstances, into 
 higher forms ; (2) by the primitive and later organisms produc- 
 ing other organisms without fecundation, out of germs or eggs 
 (Parthenogenesis)." 
 
 In favour of this hypothesis, Professor Kolliker 
 
 adduces the well-known facts of Agamogenesis, or 
 
 " alternate generation " ; the extreme dissimilarity 
 
 of the males and females of many animals ; and of 
 
 the males, females, and neuters of those insects 
 
 which live in colonies : and he defines its relations 
 
 to the Darwinian theory as follows : — 
 
 " It is obvious that my hypothesis is apparently very similar 
 to Darwin's, inasmuch as I also consider that the various forms 
 of animals have proceeded directly from one another. My 
 hypothesis of the creation of organisms by heterogeneous genera- 
 
m CRITICISMS ON " THE ORIGIN OF SPECIES " 95 
 
 tion, however, is distinguished very essentially from Darwiu's 
 by the entire absence of the principle of useful variations and 
 their natural selection : and my fundamental conception is this, 
 that a great plan of development lies at the foundation of the 
 origin of the whole organic world, impelling the simpler forms 
 to more and more complex developments. How this law 
 operates, what influences determine the development of the 
 eggs and germs, and impel them to assume constantly new 
 forms, I naturally cannot pretend to say ; but I can at least 
 adduce the great analogy of the alternation of generations. If 
 a Bipinnaria, a Brachiolaria, a Plutcus, is competent to produce 
 the Echinoderm, which is so widely different from it ; if a 
 hydroid polype can produce the higher Medusa ; if the vermiform 
 Trematode ' nurse ' can develop within itself the very unlike 
 Cercaria, it will not appear impossible that the egg, or ciliated 
 embryo, of a sponge, for once, under special conditions, might 
 become a hydroid polype, or the embryo of a Medusa, an 
 Echinoderm." 
 
 It is obvious, from these extracts, that Pro- 
 fessor KoUiker's hypothesis is based, upon the 
 supposed existence of a close analogy between the 
 phsenomena of Agamogenesis and the production 
 of new species from pre-existing ones. But is the 
 analogy a real one ? We think that it is not, and, 
 by the hypothesis cannot be, 
 
 For what are the phsenomena of Agamogenesis, 
 stated generally ? An impregnated egg develops 
 into a sexless form, A ; this gives rise, non-sexually, 
 to a second form or forms, B, more or less different 
 from A. B may multiply non-sexually again ; in 
 the simpler cases, however, it does not, but, acquir- 
 ing sexual characters, produces impregnated eggs 
 from whence A, once more, arises. 
 
96 CRITICISMS ON " THE ORIGIN OF SPECIES " ill 
 
 No case of Agamogenesis is known in Avhicn 
 when A differs widely from B, it is itself capable of 
 sexual propagation. ISTo case -whatever is known 
 in which the progeny of B, by sexual generation, 
 is other than a reproduction of A. 
 
 But if this be a true statement of the nature of 
 the process of Agamogenesis, how can it enable us 
 to comprehend the production of new species from 
 already existing ones ? Let us suppose Hyaenas 
 to have preceded Dogs, and to have produced the 
 latter in this way. Then the Hyasna will represent 
 A, and the Dog, B. The first difficulty that pre- 
 sents itself is that the Hyasna must be non-sexual, 
 or the process will be wholly without analogy in 
 the world of Agamogenesis. But passing over this 
 difficulty, and supposing a male and female Dog to 
 be produced at the same time from the Hyaena 
 stock, the progeny of the pair, if the analogy of 
 the simpler kinds of Agamogenesis ^ is to be fol- 
 lowed, should be a litter, not of puppies, but of 
 young Hyaenas. For the Agamogenetic series is 
 
 ^ If, on the contrary, we follow tlie analogy of the more com- 
 plex forms of Agamogenesis, such as that exliibited by some 
 Trcmatoda and by the Aphides, the Hyaena must [iroduce, non- 
 sexually, a brood of sexless Dogs, from which other sexless 
 Dogs must proceed. At the end of a certain number of terms 
 of the series, the Dogs would acquire sexes and generate young ; 
 but these young would be, not Dogs, hut Hyaenas In fact, we 
 have demonstrated, in Agamogenetic phaenomena, that inevitable 
 recurrence to the original type, which is asserted to be true of 
 variations in general, by Mr. Darwin's opponents; and which, 
 if the assertion could be changed into a demonstration, would, 
 in fact, be fatal to his hypothesis. 
 
Ill CRITICISMS ON " THE ORIGIN OF SPECIES " 97 
 
 always, as we have seen, A : B : A : B, &c, ; whereas, 
 for the production of a new species, the series must 
 he A : B : B : B, &c. The production of new species, 
 or genera, is the extreme permanent divergence 
 from the primitive stock. All known Agamo- 
 genetic processes, on the other hand, end in a conj- 
 plete return to the primitive stock. How then is 
 the production of new species to be rendered 
 intelhgible by the analogy of Agamogenesis ? 
 
 The other alternative put by Professor Kolliker 
 — ^the passage of fecundated ova in the course of 
 their development into higher forms — would, if it 
 occurred, be merely an extreme case of variation in 
 the Darwinian sense, greater in degree than, but 
 perfectly similar in kind to, that which occurred 
 when the well-known Ancon Ram was developed 
 from an ordinary Ewe's ovum. Indeed we have 
 always thought that Mr. Darwin has unnecessarily 
 hampered himself by adhering so strictly to his 
 favourite " Natura non facit saltum." We greatly 
 suspect that she does make considerable jumps in 
 the way of variation now and then, and that these 
 saltations give rise to some of the gaps which ap- 
 pear to exist in the series of known forms. 
 
 Strongly and freely as we have ventured to 
 disagree with Professor Kolliker, we have always 
 done^ so with regret, and we trust without violating 
 that respect which is due, not only to his scientific 
 eminence and to the careful study which he has 
 
98 CRITICISMS ON " THE ORIGIN OF SPECIES " m 
 
 devoted to the subject, but to the perfect fairness 
 of his argumentation, and the generous appreciation 
 of the worth of Mr. Darwin's labours which he 
 always displays. It would be satisfactory to be 
 able to say as much for M. Flourens. 
 
 But the Perpetual Secretary of the French 
 Academy of Sciences deals with Mr. Darwin as the 
 first Napoleon would have treated an " ideologue ; " 
 and while displaying a painful weakness of logic 
 and shallowness of information, assumes a tone of 
 authority, which always touches upon the ludicrous, 
 and sometimes passes the limits of good breeding. 
 
 For example (p. 56) : — 
 
 " M. Darwin continue : ' Aucune distinction absolue n'a ete 
 et ne pent etre etablie entre les especes et les varietes.' Je vous 
 ai dejh, dit que vous vous trompiez ; une distinction absolue 
 sepaie les varietes d'avec les especes." 
 
 " Jc votes ai ddja dit ; moi, M. le Secretaire per- 
 petuel de I'Academie des Sciences : et vous 
 
 " ' Qui n'etes rien, 
 
 Pas meme Academician ; ' 
 
 what do you mean by asserting the contrary ? " 
 Being devoid of the blessings of an Academy in 
 England, we are unaccustomed to see our ablest 
 men treated in this fashion, even by a " Perpetual 
 Secretary." 
 
 Or again, considering that if there is any one 
 quality of Mr. Darwin's work to which friends and 
 foes have alike borne witness, it is his candour and 
 
Ill CKITICISMS ON " THE ORIGIN OF SrECIES " 99 
 
 fairness in admitting and discussing objections, 
 what is to be thought of M, Flourens' assertion, 
 that 
 
 ' ' M. Darwin ne cite que les auteurs qui partagent ses 
 opinions." (P. 40.) 
 
 Once more (p. 65) : — 
 
 "Enfin rouvrage de M. Darwin a paru. On no peut qu'etre 
 frappe du talent de I'auteur. Mais que d'idees obscures, que 
 d'idees fausses ! Quel jargon metaphysique jete mal a propos 
 dans I'histoire naturelle, qui tombe dans le galimatias des qu'elle 
 sort des idees claires, des idees justes ! Quel langage pretentieux 
 ft vide ! Quelles personnifications pueriles et surannees ! O 
 lucidite ! solidite de I'esprit Fran^ais, que deveiiez-vous ? " 
 
 " Obscure ideas," " metaphysical jargon," " pre- 
 tentious and empty language," " puerile and 
 superannuated personifications." Mr. Darwin has 
 many and hot opponents on this side of the 
 Channel and in Germany, but we do not recollect 
 to have found precisely these sins in the long 
 catalogue of those hitherto laid to his charge. It 
 is worth while, therefore, to examine into these 
 discoveries effected solely by the aid of the 
 " lucidity and solidity " of the mind of M. 
 Flourens. 
 
 According to M. Flourens, Mr. Darwin's great 
 error is that he has personified Nature (p. 10), 
 and further that he has 
 
 "imagined a natural selection: he imagines afterwards that 
 this power of selecting {pouvoir d' 6lire) which he gives to Nature 
 is similar to the power of man. These two suppositions ad- 
 
100 CRITICISMS ON " THE ORIGIN OF SPECIES " m 
 
 mitted, nothing stops him : he plays with Nature as he likes, 
 and makes her do all he pleases." (P. 6.) 
 
 And this is the way M. Flourens extinguishes 
 natural selection : 
 
 "Voyonsdonc encore une fois, ce qii'il pent y avoir de fonde 
 dans ce qu'on nomme Ucction naturelle. 
 
 " L election naturelle n'est sous un autre nom que la nature. 
 Pour un etre organise, la nature n'est que I'organisation, ni plus 
 ni moins. 
 
 " II faudra done aussi personnifier V organisation, et dire que 
 T organisation choisit I'organisation. L'elc.ction natttrellc est 
 cette forinc substantielle dont on jouait autrefois avec tant de 
 facilite. Aristote disait que ' Si I'art de batir etait dans le bois, 
 cet art agirait comme la nature.' A la place de I'art de bdiir 
 M. Darwin met I'eleclion nat%irelle, et c'est tout un : I'un n'est 
 pas plus chimerique que I'autre. " (P. 31.) 
 
 And this is really all that M. Flourens can make 
 of Natural Selection. We have given the original, 
 in fear lest a translation should be regarded as a 
 travesty ; but with the original before the reader, 
 Ave nnay try to analyse the passage. " For an 
 organised being, Nature is only organisation, 
 neither more nor less." 
 
 Organised beings then have absolutely no 
 relation to inorganic nature : a plant does not 
 depend on soil or sunshine, climate, depth in the 
 ocean, height above it; the quantity of saline 
 matters in water have no influence upon animal 
 life ; the substitution of carbonic acid for oxygen 
 in our atmosphere would hurt nobody ! That 
 these are absurdities no one should know better 
 
Ill CRITICISMS ON " THE ORIGIN OF SPECIES " 101 
 
 than M. Flourens ; but they are logical deductions 
 from the assertion just quoted, and from the 
 further statement that natural selection means 
 only that " organisation chooses and selects 
 organisation." 
 
 For if it be once admitted (what no sane man 
 denies) that the chances of life of any given 
 organism are increased by certain conditions (A) 
 and diminished by their opposites (B), then it is 
 mathematically certain that any change of con- 
 ditions in the direction of (A) will exercise a 
 selective influence in favour of that organism, 
 tending to its increase and rnultiplication, while 
 any change in the direction of (B) will exercise a 
 selective influence against that organism, tending 
 to its decrease and extinction. 
 
 Or, on the other hand, conditions remaining the 
 same, let a given organism vary (and no one 
 doubts that they do vary) in two directions : into 
 one form {a) better fitted to cope with these con- 
 ditions than the original stock, and a second {h) 
 less well adapted to them. Then it is no less certain 
 that the conditions in question must exercise a 
 selective influence in favour of (a) and against (b), 
 so that (a) will tend to predominance, and (b) to 
 extirpation. 
 
 That M. Flourens should be unable to perceive 
 the logical necessity of these simple arguments, 
 which lie at the foundation of all Mr. Darwin's 
 reasoning ; that he should confound an irrefragable 
 
102 CRITICISMS ON "THE ORIGIN OF SPECIES III 
 
 deduction from the observed relations of organisms 
 to the conditions which lie around them, with a 
 metaphysical " forme substantielle," or a chimerical 
 personification of the powers of Nature, would be 
 incredible, were it not that other passages of his 
 work leave no room for doubt upon the subject. 
 
 "On imagine line Election naiurelle que, pour plus de menage- 
 ment, on me Jit etre inamseicnlc, sans s'apercevoirque le contre- 
 sens litteral est precisement la : election inconscienti." (P. 52.) 
 
 " J'ai deja Jit ce qu'il faut penser de Vilcction naturelle. Ou 
 Vilection naturelle n'est rien, ou c'est la nature : mais la nature 
 douee d'ilection, mais la nature personnifiee : dernieie erreur du 
 dernier siecle : Le xix" ne fait plus de personnifications." (P, 
 53.) 
 
 M. Flourens cannot imagine an unconscious 
 selection — it is for him a contradiction in terms. 
 Did M. Flourens ever visit one of the prettiest 
 watering-places of " la belle France," the Baie 
 d'Arcachon ? If so, he will probably have passed 
 through the district of the Landes, and will have 
 had an opportunity of observing the formation of 
 "dunes'"' on a grand scale. What are these 
 " dunes " ? The winds and waves of the Bay of 
 Biscay have not much consciousness, and yet they 
 have with great care " selected," from among an 
 infinity of masses of silex of all shapes and sizes, 
 which have been submitted to their action, all the 
 grains of sand below a certain size, and have 
 heaped them by themselves over a great area. 
 This sand has been " unconsciously selected " from 
 
in CRITICISMS ON " THE ORIGIN OF SPECIES " 103 
 
 amidst the gravel in which it first lay with as 
 much precision as if man had " consciously 
 selected " it by the aid of a sieve. Physical 
 Geology is full of such selections — of the picking 
 out of the soft from the hard, of the soluble from 
 the insoluble, of the fusible from the infusible, by 
 natural agencies to which we are certainly not in 
 the habit of ascribing consciousness. 
 
 But that which wind and sea are to a sandy 
 beach, the sum of influences, which we term the 
 " conditions of existence," is to living organisms. 
 The weak are sifted out from the strong. A frosty 
 night " selects " the hardy plants in a plantation 
 from among the tender ones as effectually as if it 
 were the wind, and they, the sand and pebbles, of 
 our illustration ; or, on the other hand, as if the 
 intelligence of a gardener had been operative in 
 cutting the weaker organisms down. The thistle, 
 which has spread over the Pampas, to the de- 
 struction of native plants, has been more effectually 
 " selected " by the unconscious operation of natural 
 conditions than if a thousand agriculturists had 
 spent their time in sowing it. 
 
 It is one of Mr. Darwin's many great services 
 to Biological science that he has demonstrated the 
 significance of these facts. He has shown that — 
 given variation and given change of conditions — 
 the inevitable result is the exercise of such an 
 influence upon organisms that one is helped and 
 another is impeded ; one tends to predominate, 
 36 
 
104 CRITICISMS ON "the ORIGIN OF SPECIES III 
 
 anotlier to disappear ; and thus the living world 
 bears within itself, and is surrounded by, impulses 
 towards incessant change. 
 
 But the truths just stated are as certain as any- 
 other physical laws, quite independently of the 
 truth, or falsehood, of the hypothesis which Mr. 
 Darwin has based upon them ; and that M. 
 Flourens, missing the substance and grasping at a 
 shadow, should be blind to the admirable exposi- 
 tion of them, which Mr. Darwin has given, and see 
 nothing there but a "derni^re erreur du dernier 
 siecle " — a personification of Nature — leads us 
 indeed, to cry with him : " lucidite ! solidite 
 de I'esprit Fran^ais, que devenez-vous ? " 
 
 M. Flourens has, in fact, utterly failed to com- 
 prehend the first principles of the doctrine which 
 he assails so rudely. His objections to details are 
 of the old sort, so battered and hackneyed on this 
 side of the Channel, that not even a Quarterly 
 Reviewer could be induced to pick them up for 
 the purpose of pelting Mr. Darwin over again. 
 We have Cuvier and the mummies ; M. Eoulin 
 and the domesticated animals of America; the 
 difficulties presented by hybridism and by Palaeon- 
 tology ; Darwinism a rifacciamento of De Maillet 
 and Lamarck ; Darwinism a system without a 
 commencement, and its author bound to believe in 
 M. Pouchet, &c. &c. How one knows it all by 
 heart, and with what relief one reads at p. 65 — 
 " Je laisse M. Daiwin 1 " 
 
Ill CEITICISMS ON " THE ORIGIN OF SPECIES " 105 
 
 But we cannot leave M. Flourens without calling 
 our readers' attention to his wonderful tenth 
 chapter, " De la Pr^existence des Germes et de 
 I'Epigenese," which opens thus : — • 
 
 " Spontaneous generation is only a chimsera. This point 
 established, two hypotheses remain : that of pre-existence and 
 that of epigencsis. The one of these hypotheses has as little 
 foundation as the other. " (P. 163.) 
 
 ' ' The doctrine of epigenesis is derived from Harvey : follow- 
 ing by ocular inspection the development of the new being in 
 the "Windsor does, he saw each part appear successively, and 
 taking the moment of appearance for the moment of formation 
 he imngined epigenesis." (P. 165.) 
 
 On the contrary, says M. Flourens (p. 167), 
 
 " The new being is formed at a stroke (lout d'un coup), as a 
 whole, instantaneously ; it is not formed part by part, and at 
 difierent times. It is formed at once at the single individual 
 moment at which the conjunction of the male and female 
 elements takes place." 
 
 It will he observed that M. Flourens uses 
 language which cannot be mistaken. For him, 
 the labours of Von Baer, of Rathke, of Coste, and 
 their contemporaries and successors in Germany, 
 France, and England, are non-existent : and, as 
 Darwin " imagina " natural selection, so Harvey 
 "imagina" that doctrine which gives him an even 
 greater claim to the veneration of posterity than 
 his better known discovery of the circulation of 
 the blood. 
 
 Language such as that we have quoted is, in 
 fact, so preposterous, so utterly incompatible with 
 
106 CRITICISMS ON " THE ORIGIN OF SPECIES III 
 
 anything but absolute ignorance of some of the 
 best established facts, that we should have passed 
 it over in silence had it not appeared to afford 
 some clue to M. Flourens' unhesitating, a priori, 
 repudiation of all forms of the doctrine of pro- 
 gressive modification of living beings. He whose 
 mind remains uninfluenced by an acquaintance 
 with the phagnomena of development, must indeed 
 lack one of the chief motives towards the 
 endeavour to trace a genetic relation between 
 the different existing forms of life. Those who 
 are ignorant of Geology, find no difficulty in 
 believing that the world was made as it is ; and 
 the shepherd, untutored in history, sees no reason 
 to regard the green mounds which indicate the 
 site of a Roman camp, as aught but part and 
 parcel of the primaeval hill -side. So M. Flourens, 
 who believes that embryos are formed " tout d'un 
 coup," naturally finds no difficulty in conceiving 
 that species came into existence in the same 
 way. 
 
IV 
 
 THE GENEALOGY OF ANIMALS i 
 
 [1869] 
 
 Considering that Germany now takes the lead of 
 the world in scientific investigation, and particu- 
 larly in biology, Mr. Darwin must be well pleased 
 at the rapid spread of his views among some of 
 the ablest and most laborious of German 
 naturalists. 
 
 Among these. Professor Haeckel, of Jena, is the 
 Coryphaeus. I know of no more solid and import- 
 ant contributions to biology in the past seven 
 years than Haeckel's work on the " Radiolaria," 
 and the researches of his distinguished colleague 
 Gegenbaur, in vertebrate anatomy; while in 
 Haeckel's " Generelle Morphologic " there is all 
 the force, suggestiveness, and, what I may term 
 
 ^ The Natural History of Creation. By Dr. Ernst Haeckel. 
 [Natiirlichc Schopfungs-Gfcschichte. — Von Dr. Ernst Haeckel, 
 Professor an der Universitiit Jena.] Berlin, 1868. 
 
108 THE GENEALOGY OF ANIMALS IV 
 
 the systematising poweT, of Oken, without his ex- 
 travagance. The " Generelle Morphologie " is, in 
 fact, an attempt to put the Doctrine of Evohition, 
 so far as it apphes to the living world, into a logical 
 form ; and to work out its practical applications to 
 their final results. The work before us, again, may- 
 be said to be an exposition of the "Generelle 
 Morphologie " for an educated public, consisting, 
 as it does, of the substance of a series of lectures 
 delivered before a mixed audience at Jena, in the 
 session 1867-8. 
 
 " The Natural History of Creation," — or, as 
 Professor Haeckel admits it would have been 
 better to call his work, " The History of the 
 Development or Evolution of Nature," — deals, in 
 the first six lectures, with the general and his- 
 torical aspects of the question and contains a very 
 interesting and lucid account of the views of Lin- 
 naeus, Cuvier, Agassiz, Goethe, Oken, Kant, 
 Lamarck, Lyell, and Darwin, and of the historical 
 filiation of these philosophers. 
 
 The next six lectures are occupied by a well- 
 digested statement of Mr. Darwin's views. The 
 
IV THE GENEALOGY OF ANIMALS 109 
 
 spontaneous generation, while admitting that there 
 is no experimental evidence in its favour. Professor 
 Haeckel denies the possibility of disproving it, and 
 points out that the assumption that it has occurred 
 is a necessary part of the doctrine of Evolution. 
 The fourteenth lecture, on " Schopfungs-Perioden 
 und Schopfungs-Urkunden," answers pretty much 
 to the famous disquisition on the " Imperfection 
 of the Geological Record " in the " Origin of 
 Species." 
 
 The following five lectures contain the most 
 original matter of any, being devoted to " Phylo- 
 geny," or the working out of the details of the 
 process of Evolution in the animal and vegetable 
 kingdoms, so as to prove the line of descent of 
 each group of living beings, and to furnish it 
 with its proper genealogical tree, or " phylum." 
 
 The last lecture considers objections and sums 
 up the evidence in favour of biological Evolution. 
 
 I shall best testify to my sense of the value of 
 the work thus briefly analysed if I now proceed to 
 note down some of the more important criticisms 
 which have been suggested to me by its perusal, 
 
 I. In more than one place. Professor Haeckel 
 enlarges upon the service which the " Origin of 
 Species " has done, in favouring what he terms 
 the " causal or mechanical " view of living nature 
 as opposed to the " teleological or vitalistic ' view. 
 And no doubt it is quite true that the doctrine of 
 Evolution is the most formidable opponent of all 
 
110 THE GENEALOGY OF ANIMALS IT 
 
 the commoner and coarser forms of Teleology. 
 But perhaps the most remarkable service to the 
 philosophy of Biology rendered by Mr. Darwin is 
 the reconciliation of Teleology and Morphology, 
 and the explanation of the facts of both which his 
 views offer. 
 
 The Teleology which supposes that the eye, 
 such as we see it in man or one of the higher Vcrte- 
 hrata, was made with the precise structure which 
 it exhibits, for the purpose of enabling the animal 
 which possesses it to see, has undoubtedly received 
 its death-blow. Nevertheless it is necessary to 
 remember that there is a wider Teleology, which 
 is not touched by the doctrine of Evolution, but is 
 actually based upon the fundamental proposition 
 of Evolution. That proposition is, that the whole 
 world, living and not living, in the result of the 
 mutual interaction, according to definite laws, of 
 the forces possessed by the molecules of which the 
 primitive nebulosity of the universe was composed. 
 If this be true, it is no less certain that the existing 
 world lay, potentially, in the cosmic vapour ; and 
 that a sufficient intelligence could, from a know- 
 ledge of the properties of the molecules of that 
 vapour, have predicted, say the state of the Fauna 
 of Britain in 1869, with as much certainty as one 
 can say what will happen to the vapour of the 
 breath in a cold winter's day. 
 
 Consider a kitchen clock, which ticks loudly, 
 shows the hours, minutes, and seconds, strikes. 
 
IV ' THE GENEALOGY OF ANIMALS 111 
 
 cries " cuckoo ! " and perhaps shows the phases of 
 the moon. When the clock is wound up, all the 
 phenomena which it exhibits are potentially con- 
 tained in its mechanism, and a clever clockmaker 
 could predict all it will do after an examination of 
 its structure. 
 
 If the evolution theory is correct, the mole- 
 cular structure of the cosmic gas stands in 
 the same relation to the phenomena of the 
 world as the structure of the clock to its pheno- 
 mena. 
 
 Now let us suppose a death-watch, living in the 
 clock-case, to be a learned and intelligent student 
 of its works. He might say, " I find here nothing 
 but matter and force and pure mechanism from 
 beginning to end," and he would be quite right. 
 But if he drew the conclusion that the clock was 
 not contrived for a purpose, he would be quite 
 wrong. On the other hand, imagine another 
 death-watch of a different turn of mind. He, 
 listening to the monotonous " tick ! tick ! " so 
 exactly like his own, might arrive at the conclusion 
 that the clock was itself a monstrous sort of 
 death-watch, and that its final cause and purpose 
 was to tick. How easy to point to the clear 
 relation of the whole mechanism to the pendulum, 
 to the fact that the one thing the clock did always 
 and without intermission was to tick, and that all 
 the rest of its phenomena were intermittent and 
 subordinate to ticking ! For all this, it is certain 
 
112 THE GENEALOGY OF ANIMALS IV 
 
 that kitchen clocks are not contrived for the 
 purpose of making a ticking noise. 
 
 Thus the teleological theorist would be as wrong 
 as the mechanical theorist, among our death- 
 watches ; and, probably, the only death-watch who 
 would be right would be the one who should 
 maintain that the sole thing death-watches could 
 be sure about was the nature of the clock-works 
 and the way they move ; and that the purpose of 
 the clock lay wholly beyond the purview of beetle 
 faculties. 
 
 Substitute "cosmic vapour" for "clock," and 
 " molecules " for " works," and the application 
 of the argument is obvious. The teleological 
 and the mechanical views of nature are not, 
 necessarily, mutually exclusive. On the contrary, 
 the more purely a mechanist the speculator is, the 
 more firmly does he assume a primordial mo- 
 lecular arrangement, of which all the phenomena 
 of the universe are the consequences ; and 
 the more completely is he thereby at the 
 mercy of the teleologist, who can always defy 
 him to disprove that this primordial molecular 
 arrangement was not intended to evolve 
 the phenomena of the universe. On the other 
 hand, if the teleologist assert that this, that, or 
 the other result of the working of any part of the 
 mechanism of the universe is its purpose and final 
 cause, the mechanist can always inquire how he 
 knows that it is more than an unessential incident 
 
IV THE GENEALOGY OF ANIMALS 113 
 
 — the mere ticking of the clock, which he mistakes 
 for its function. And there seems to be no reply 
 to this inquiry, any more than to the further, not 
 irrational, question, why trouble one's self about 
 matters which are out of reach, when the working 
 of the mechanism itself, which is of infinite 
 practical importance, affords scope for all our 
 energies ? 
 
 Professor Haeckel has invented a new and con- 
 venient name " Dysteleology," for the study of 
 the " purposelessnesses " which are observable in 
 living organisms — such as the multitudinous cases 
 of rudimentary and apparently useless structures. 
 I confess, however, that it has often appeared to 
 me that the facts of Dysteleology cut two ways. 
 If we are to assume, as evolutionists in general do, 
 that useless organs atrophy, such cases as the 
 existence of lateral rudiments of toes, in the foot 
 of a horse, place us in a dilemma. For, either 
 these rudiments are of no use to the animal, in 
 which case, considering that the horse has existed 
 in its present form since the Pliocene epoch, they 
 surely ought to have disappeared ; or they are of 
 some use to the animal, in which case they are of 
 no use as arguments against Teleology. A similar, 
 but still stronger, argument may be based upon 
 the existence of teats, and even functional mam- 
 mary glands, in male mammals. Numerous cases 
 of " Gynaecomasty," or functionally active breasts 
 in men, are on record, though there is no mam- 
 
114 THE GENEALOGY OF ANIMALS IT? 
 
 malian species whatever in which the male nor- 
 mally suckles the young. Thus, there can be 
 little doubt that the mammary gland was as 
 apparently useless in the remotest male mam- 
 malian ancestor of man as in living men, and yet 
 it has not disappeared. Is it then still profitable 
 to the male organism to retain it ? Possibly ; but 
 in that case its dysteleological value is gone.^ 
 
 II. Professor Haeckel looks upon the causes 
 which have led to the present diversity of living 
 nature as twofold. Living matter, he tells us, is 
 urged by two impulses : a centripetal, which tends 
 to preserve and transmit the specific form, and 
 which he identifies with heredity ; and a centri- 
 fugal, which results from the tendency of external 
 conditions to modify the organism and effect its 
 adaptation to themselves. The internal impulse 
 is conservative, and tends to the preservation oJ 
 specific, or individual, form ; the external impulse 
 is metamorphic, and tends to the modification ol 
 specific, or individual, form. 
 
 In developing his views upon this subject 
 Professor Haeckel introduces qualifications whicl 
 disarm some of the criticisms I should have beer 
 disposed to offer ; but I think that his method ol 
 stating the case has the inconvenience of tending 
 to leave out of sight the important fact — which is 
 a cardinal point in the Darwinian hypothesis — 
 
 1 [The recent discovery of the important part played by th( 
 Thyroid gland should be a warning to all speculators abou 
 useless organs. 1893.] 
 
XV THE GENEALOGY OF ANIMALS 115 
 
 that the tendency to vary, in a given organism, may 
 have nothing to do with the external conditions to 
 which that individual organism is exposed, but 
 may depend wholly upon internal conditions. No 
 one, I imagine, would dream of seeking for the 
 cause of the development of the sixth finger and 
 toe in the famous Maltese, in the direct influence 
 of the external conditions of his life. 
 
 I conceive that both hereditary transmission 
 and adaptation need to be analysed into their 
 constituent conditions by the further application 
 of the doctrine of the Struggle for Existence. It 
 is a probable hypothesis, that what the world is to 
 organisms in general, each organism is to the 
 molecules of which it is composed. Multitudes of 
 these, having diverse tendencies, are competing 
 with one another for opportunity to exist and 
 multiply ; and the organism, as a whole, is as 
 much the product of the molecules which are 
 victorious as the Fauna, or Flora, of a country is 
 the product of the victorious organic beings in it. 
 
 On this hypothesis, hereditary transmission is 
 the result of the victory of particular molecules 
 contained in the impregnated germ. Adaptation 
 to conditions is the result of the favouring of the 
 multiplication of those molecules whose organising 
 tendencies are most in harmony with such 
 conditions. In this view of the matter, conditions 
 are not actively productive, but are passively 
 permissive ; they do not cause variation in any 
 
116 THE GENEALOGY OF ANIMALS ly 
 
 given direction, but they permit and favour a 
 tendency in that direction which already exists. 
 
 It is true that, in the long run, the origin of 
 the organic molecules themselves, and of their 
 tendencies, is to be sought in the external world ; 
 but if we carry our inquiries as far back as this, 
 the distinction between internal and external 
 impulses vanishes. On the other hand, if we 
 confine ourselves to the consideration of a single 
 organism, I think it must be admitted that the 
 existence of an internal metamorphic tendency 
 must be as distinctly recognised as that of an 
 internal conservative tendency ; and that the 
 influence of conditions is mainly, if not wholly, 
 the result of the extent to which they favour the 
 one, or the other, of these tendencies. 
 
 III. There is only one point upon which I 
 fundamentally and entirely disagree with Professor 
 Haeckel, but that is the very important one of 
 his conception of geological time, and of the 
 meaning of the stratified rocks as records and 
 indications of that time. Conceiving that the 
 stratified rocks of an epoch indicate a period of 
 depression,, and that the intervals between the 
 epochs correspond with periods of elevation of 
 which we have no record, he intercalates between 
 the different epochs, or periods, intervals which he 
 terms "Ante-periods." Thus, instead of con- 
 sidering the Triassic, Jurassic, Cretaceous, and 
 Eocene periods, as continuously successive, he 
 
rv THE GENEALOGY OF ANIMALS 11 7 
 
 interposes a period before each, as an " Antetrias- 
 zeit," "Antejura-zeit," " Antecreta-zeit," "Anteo- 
 cenzeit," &c. And he conceives that the abrupt 
 changes between the Faunse of the different forma- 
 tions are due to the lapse of time, of which we have 
 no organic record, during their "Ante-periods." 
 
 The frequent occurrence of strata containing 
 assemblages of organic forms which are inter- 
 mediate between those of adjacent formations, is, 
 to my mind, fatal to this view. In the well- 
 known St. Cassian beds, for example, Palaeozoic 
 and Mesozoic forms are commingled, and, between 
 the Cretaceous and the Eocene formations, there 
 are similar transitional beds. On the other hand, 
 in the middle of the Silurian series, extensive 
 unconformity of the strata indicates the lapse of 
 vast intervals of time between the deposit of 
 successive beds, without any corresponding change 
 in the Fauna. 
 
 Professor Haeckel will, I fear, think me unreason- 
 able, if I say that he seems to be still ovei'shadowed 
 by geological superstitions ; and that he will have 
 to believe in the completeness of the geological 
 record far less than he does at present. He assumes, 
 for example, that there was no dry land, nor any 
 terrestrial life, before the end of the Silurian epoch, 
 simply because, up to the present time, no indica- 
 tions of fresh water, or terrestrial organisms, have 
 been found in rocks of older date. And, in 
 speculating upon the origin of a given group, he 
 
118 THE GENEALOGY OF ANIMALS IV 
 
 rarely goes further back than the " Ante-period," 
 which precedes that in which the remains of 
 animals belonging to that group are found. Thus, 
 as fossil remains of the majority of the groups of 
 Beptilia are first found in the Trias, they are 
 assumed to have originated in the "Antetriassic " 
 period, or between the Permian and Triassic 
 epochs. 
 
 I confess this is wholly incredible to me. The 
 Permian and the Triassic deposits pass completely 
 into one another ; there is no sort of discontinuity 
 answering to an unrecorded " Antetrias " ; and, 
 what is more, we have evidence of immensely 
 extensive dry land during the formation of these 
 deposits. We know that the dry land of the Trias 
 absolutely teemed with reptiles of all groups 
 except Pterodactyles, Snakes, and perhaps Tor- 
 toises ; there is every probability that true Birds 
 existed, and Mammalia certainly did. Of the in- 
 habitants of the Permian dry land, on the contrary, 
 all that have left a record are a few lizards. Is it 
 conceivable that these last should really represent 
 the whole terrestrial population of that time, and 
 that the development of Mammals, of Birds, and 
 of the highest forms of Reptiles, should have been 
 crowded into the time during which the Permian 
 conditions quietly passed away, and the Triassic 
 conditions began ? Does not any such supposition 
 become in the highest degree improbable, when, 
 in the terrestrial or fresh-water Labyrinthodonts, 
 
IV THE GENEALOGY OF ANIMALS 119 
 
 -(vhich lived on the land of the Carboniferous epoch, 
 as well as on that of the Trias, we have evidence 
 that one form of terrestrial life persisted, through- 
 out all these ages, with no important modification ? 
 For my part, having regard to the small amount 
 of modification (except in the way of extinction) 
 which the Crocodilian, Lacertilian, and Chelonian 
 Reptilia have undergone, from the older Mesozoic 
 times to the present day, I cannot but put the 
 existence of the common stock from which they 
 sprang far back in the Palaeozoic epoch ; and I 
 should apply a similar argumentation to all other 
 groups of animals, 
 
 [The remainder of this essay contains a discussion of questions 
 of taxonomy and phylogeny, which is now antiquated. I have 
 reprinted the considerations about the reconciliation of Teleology 
 with Morphology, about " Dysteleology," and about the struggle 
 for existence within the organism, because it has happened to 
 me to be charged with overlooking them. 
 
 In discussing Teleology, I ought to have pointed out, as I 
 have done elsewhere [Life and Letters of Charles Darwin, vol. ii. 
 p. 202), that Paley " proleptically accepted the modem doctrine 
 of Evolution," {Natural Theology, chap, xxiii.). 1893.] 
 
 SV 
 
MR. DARWIN'S CRITICS i 
 
 [1871] 
 
 The gradual lapse of time has now separated us by 
 more than a decade from the date of the publi- 
 cation of the " Origin of Species " — and whatever 
 may be thought or said about Mr. Darwin's doc- 
 trines, or the manner in which he has propounded 
 them, this much is certain, that, in a dozen years, 
 the " Origin of Species " has worked as complete a 
 revolution in biological science as the " Principia " 
 did in astronomy — and it has done so, because, in 
 the words of Helmholtz, it contains " an essentially 
 new creative thought."^ 
 
 And as time has slipped by, a happy change 
 
 ^ 1. Contributions to the Theory of Natural Selection. By 
 A. R. Wallace. 1870.— 2. The Genesis of Species. 'By &t. George 
 Mivart, F.R.S. Second Edition. 1S71.~Z. Darwin's £>esce7U 
 of Man. Quarterly Review, July 1371. 
 
 ^ Helmholtz : Ucbcr das Zicl und die Fortschritte der Natur- 
 wijiscn-schaft. Eiciffnungsvede fiir die Naturforscherversamm- 
 lujig zu Innsbruck. 1869. 
 
V MR. Darwin's critics 121 
 
 has come over Mr. Darwin's critics. The mixture 
 of ignorance and insolence which, at first, character- 
 ised a large proportion of the attacks with which 
 he was assailed, is no longer the sad distinction of 
 anti-Darwinian criticism. Instead of abusive non- 
 sense, which merely discredited its writers, we read 
 essays, which are, at worst, more or less intelligent 
 and appreciative ; while, sometimes, like that 
 which appeared in the " North British Review " for 
 1867, they have a real and permanent value. 
 
 The several publications of Mr. Wallace and Mr. 
 Mivart contain discussions of some of Mr. Darwin's 
 views, which are worthy of particular attention, not 
 only on account of the acknowledged scientific 
 competence of these writers, but because they ex- 
 hibit an attention to those philosophical questions 
 which underlie all physical science, which is as rare 
 as it is needful. And the same may be said of an 
 article in the " Quarterly Review " for July 1871, 
 the comparison of which with an article in the 
 same Review for July 1860, is perhaps the best 
 evidence which can be brought forward of the 
 change which has taken place in public opinion 
 on " Dai-winism." 
 
 The Quarterly Reviewer admits " the certainty 
 of the action of natural selection " (p. 49) ; and 
 further allows that there is an d priori probability 
 in favour of the evolution of man from some lower 
 animal form, if these lower animal forms them- 
 selves have arisen by evolution. 
 
122 ME. daewin's ceitics -v 
 
 Mr, Wallace and Mr. Mivart go much further 
 than this. They are as stout believers in evolution 
 as Mr. Darwin himself; but Mr. Wallace denies 
 that man can have been evolved from a lower 
 animal by that process of natural selection which 
 he, with Mr. Darwin, holds to have been sufficient 
 for the evolution of all animals below man ; while 
 Mr. Mivart, admitting that natural 5eje£±i on has 
 been one of the conditions of the evolution of the 
 animals below man, maintains that natural se- 
 lection must, even in their case, have been supple- 
 mented by " some other cause " — of the nature of, 
 which, unfortunately, he does not give us any idea. 
 Thus Mr. Mivart is less of a Darwinian than Mr. 
 Wallace, for he has less faith in the power of 
 natural selection. But he is more of an evolutionist 
 than Mr. Wallace, because Mr. Wallace thinks it 
 necessary to call in an intelligent agent — a sort of 
 supernatural Sir John Sebright — to produce even 
 the animal frame of man ; while Mr. Mivart re- 
 quires no Divine assistance till he comes to man's 
 soul. 
 
 Thus there is a considerable divergence between 
 Mr. Wallace and Mr. Mivart. On the other hand, 
 there are some curious similarities between Mr. 
 Mivart and the Quarterly Eeviewer, and these 
 are sometimes so close, that, if Mr. Mivart thought 
 it worth while, I think he might make out a 
 good case of plagiarism against the Reviewer, who 
 studiously abstains from quoting him. 
 
V MR. Darwin's critics 123 
 
 Both tlie Eeviewer and Mr. Mivart reproach Mr. 
 Darwin with being, " like so many other physic- 
 ists," entangled in a radically false metaphysical 
 system, and with setting at nought the first 
 principles of both philosophy and religion. Both 
 enlarge npon the necessity of a sound philo- 
 sophical basis, and both, I venture to add, make a 
 conspicuous exhibition of its absence. The 
 Quarterly Reviewer believes that man " diflFers 
 more from an elephant or a gorilla than do these 
 from the dust of the earth on which they tread," 
 and Mr. Mivart has expressed_the_opinion jthat 
 there is_more_diffe,ren.ce between man and an jipe 
 than there is between an ape and a piece of 
 fanitej_- 
 
 And even when Mr. Mivart (p. 86) trips in a 
 matter of anatomy, and creates a difficulty for Mr. 
 Darwin out of a supposed close similarity between 
 the eyes of fishes and cephalopods, which (as 
 Gegenbaur and others have clearly shown) does 
 not exist, the Quarterly Reviewer adopts the 
 argument without hesitation (p. 66). 
 
 There is another important point, however, in 
 which it is hard to say whether Mr. Mivart 
 diverges from the Quarterly Reviewer or not. 
 
 The Reviewer declares that Mr. Darwin has, 
 " with needless opposition, set at nought the first 
 principles of both philosophy and religion " (p. 
 90). 
 
 1 See the Tablet for Marcli 11, 1871. 
 
124 MR. Darwin's critics v 
 
 It looks, at first, as if this meant, that Mr. 
 Darwin's views being false, the opposition to 
 " religion " which flows from them must be need- 
 less. But I suspect this is not the right view of 
 the meaning of the passage, as Mr. Mivart, from 
 whom the Quarterly Reviewer plainly draws so 
 much inspiration, tells us that " the consequences 
 which have been drawn from evolution, whether 
 exclusively Darwinian or not, to the prejudice of 
 religion, by no means follow from it, and are in 
 fact illegitimate" (p. 5). 
 
 I may assume, then, that the Quarterly 
 Reviewer and Mr. Mivart admit that there is no 
 necessary opposition between " evolution whether 
 exclusively Darwinian or not,'' and religion. But 
 then, what do they mean by this last much- 
 abused term ? On this point the- Quarterly 
 Reviewer is silent. Mr. Mivart, on the contrary, 
 is perfectly explicit, and the whole tenor of his 
 remarks leaves no doubt that by "religion" he- 
 means theology ; and by theology, that particular 
 variety of the great Proteus, which is expounded 
 by the doctors of the Roman Catholic Church, ''ud 
 held by the members of that religious community 
 to be the sole form of absolute truth and of saving 
 faith. 
 
 According to Mr. Mivart, the greatest and most 
 orthodox authorities upon matters of Catholic 
 doctrine agree in distinctly asserting " derivative 
 creation " or evolution ; " and. thus their teachings 
 
V MR. Darwin's critics 125 
 
 harmonise with all Jthat niodem science can 
 
 possibly require " (p. 305). 
 
 I confess that this bold assertion interested me 
 more than anything else in Mr. Mivart's book. 
 What little knowledge I possessed of Catholic 
 doctrine, and of the influence exerted by Catholic 
 authority in former times, had not led me to 
 expect that modern science was likely to find 
 a warm welcome within the pale of the greatest 
 and most consistent of theological organisations. 
 
 And my astonishment reached its climax when 
 I found Mr. Mivart citing Father Suarez as his 
 chief witness in favour of the scientific freedom 
 enjoyedH3y-£!atholics — the popular repute of that 
 learfied theologian and subtle casuist not being such 
 as to make his works a hkely place of refuge for 
 liberahty of thought. But in these days, when 
 Judas Iscariot and Robespierre, Henry VIII. 
 and Catiline, have all been shown to be men of 
 admirable virtue, far in advance of their age, and 
 consequently the victims of vulgar prejudice, it 
 was obviously possible that Jesuit Suarez might 
 bftfin like case. And, spurred by Mr. Mivart's 
 unhesitating declaration, I hastened to acquaint 
 myself with such of the works of the great Catholic 
 divine as bore upon the question, hoping, not 
 merely to acquaint myself with the true teachings 
 of the infallible Church, and free myself of an 
 unjust prejudice ; but, haply, to enable myself, at 
 a pinch, to put some Protestant bibliolater to 
 
126 MR, DARWIN'S CRITICS V 
 
 shame, by the bright example of Catholic freedom 
 from the trammels of verbal inspiration. 
 
 I regret to say that my anticipations have been 
 cruelly disappointed. But the extent to which 
 my hopes have been crushed can only be fully 
 appreciated by citing, in the first place, those 
 passages of Mr. Mivart's work by which they were 
 excited. In his introductory chapter I find the 
 following passages : — 
 
 "The prevalence of this theory [of evolution] 
 need alarm no one, for it is, without any doubt, 
 perfectly consistent with the strictest and most 
 orthodox Christian ^ theology " (p. 5). 
 
 "Mr. Darwin and others may perhaps be 
 excused if they have not devoted much time to 
 the study of Christian philosophy ; but they have 
 no right to assume or accept without careful ex- 
 amination, as an unquestioned fact, that in that 
 philosophy there is a necessary antagonism 
 between the two ideas ' creation ' and ' evolution,* 
 as applied to organic forms. 
 
 " It is notorious and patent to all who choose to 
 seek, that many distinguished Christian thinkers 
 have accepted, and do accept, both ideas, i.e. both 
 ' creation ' and ' evolution,' 
 
 " As much as ten years ago an eminently 
 Christian writer observed : ' The creationist theory 
 does not necessitate the perpetual search after 
 
 1 It should be obsurvod that Mr. Mivart employs the term 
 " Christian" as if it were the equivalent of " Catholic." 
 
V MK. Darwin's critics 127 
 
 manifestations of miraculous power and perpetual 
 "catastrophes." Creation is not a miraculous 
 interference witli the laws of Nature, but the very 
 institution of those laws. Law and regularity, 
 not arbitrary intervention, was the patristic ideal 
 of creation. With this notion they admitted, 
 without diflflculty, the most surprising origin of 
 living creatures, provided it took place by law. 
 They held that when God said, " Let the waters 
 produce," " Let the earth produce," He conferred 
 forces on the elements of earth and water which 
 enabled them naturally to produce the various 
 species of organic beings. This power, they 
 thought, remains attached to the elements 
 throughout all time.' The same writer quotes 
 St. Augustin and St. Thomas Aquinas, to the 
 effect that, ' in the institution of Nature, we do not 
 look for miracles, but for the laws of Nature.' 
 And, again, St, Basil speaks of the continued 
 operation of natural laws in the production of all 
 organisms. 
 
 " So much for the writers of early and mediaeval 
 times. As to the present day, the author can 
 confidently affirm that there are many as well 
 versed in theology as Mr. Darwin is in his own 
 department of natural knowledge, who would not 
 be disturbed by the thorough demonstration of his 
 theory. Nay, they would not even be in the least 
 painfully affected at witnessing the generation of 
 animals of complex organisation by the skilful 
 
128 MR. Darwin's critics v 
 
 artificial arrangement of natural forces, and the 
 production, in the future, of a fish by means 
 analogous to those by which we now produce 
 urea. 
 
 " And this because they know that the possi- 
 bility of such phenomena, though by no means 
 actually foreseen, has yet been fully provided for 
 in the old philosophy centuries before Darwin, or 
 even centuries before Bacon, and that their place in 
 the system can be at once assigned them without 
 even disturbing its order or marring its harmony. 
 
 " Moreover, the old tradition in this respect has 
 never been abandoned, however much it may have 
 been ignored or neglected by some modern writers. 
 In proof of this, it may be observed that perhaps 
 no post-mediaeval theologian has a wider reception 
 amongst Christians throughout the world than 
 Suarez, who has a separate section ^ in opposition 
 to those who maintain the distinct creation of the 
 various kinds — or substantial forms — of organic 
 life " (pp. 19—21). 
 
 Still more distinctly does Mr. Mivart express 
 himself in the same sense, in his last chapter, 
 entitled " Theology and Evolution " (pp. 302-5). 
 
 " It appears, then, that Christian thinkers are 
 perfectly free to accept the general evolution 
 theory. But are there any theological authorities 
 to justify this view of the matter ? 
 
 1 Suarez, Mctaphyjica. Edition Yives. Paris, 1868, vol. i. 
 Disput. XV. § 2. 
 
V MR. DARWIN'S CRITICS 129 
 
 "Now, considering how extremely recent are 
 these biological speculations, it might hardly be 
 expected d, priori that writers of earlier ages 
 should have given expression to doctrines 
 harmonising in any degree with such very 
 modem views ; nevertheless, this is certainly 
 the case, and it would be easy to give numerous 
 examples. It will be better, however, to cite one 
 or two authorities of weight. Perhaps no writer 
 of the earlier Christian ages could be quoted whose 
 authority is more generally recognised than that 
 of St. Augustin. The same may be said of the 
 mediaeval period for St. Thomas Aquinas : and 
 since the movement of Luther, Suarez may 
 be taken as an authority, widely venerated, 
 and one whose orthodoxy has never been ques- 
 tioned. 
 
 " It must be borne in mind that for a consider- 
 able time even after the last of these writers no 
 one had disputed the generally received belief as 
 to the small age of the world, or at least of the 
 kinds of animals and plants inhabiting it. It 
 becomes, therefore, much more striking if views 
 formed under such a condition of opinion are 
 found to harmonise with modern ideas con- 
 cerning ' Creation ' and organic Life. 
 
 " Now St. Augustin insists in a very remarkable 
 manner on the merely derivative sense in which 
 God's creation of organic forms is to be under- 
 stood \ that is, that God created them by conferring 
 
130 MK. DARWIN'S CRITICS V 
 
 on the material world the power to evolve them 
 under suitable conditions." 
 
 Mr. Mivart then cites certain passages from St. 
 Augustin, St. Thomas Aquinas, and Cornelius k 
 Lapide, and finally adds : — 
 
 "As to Suarez, it will be enough to refer to Disp. xv. sec. 2, 
 No. 9, p. 508, t. i. edition Vives, Paris ; also Nos. 13 — 15. 
 Many other references to the same effect could easily be given, 
 but these may suffice. 
 
 "It is then evident that ancient and most venerable theo- 
 logical authorities distinctly assert derivative creation, and 
 thus their teachings harmonise with all that modern science 
 can possibly require." 
 
 It will be observed that Mr. Mivart refers solely 
 to Suarez's fifteenth Disputation, though he adds, 
 " Many other references to the same effect could 
 easily be given." I shall look anxiously for these 
 references in the third edition of the " Genesis of 
 Species." For tlie present, all I can say is, that 
 I have sought in vain, either in the fifteenth 
 Disputation, or elsewhere, for any passage in 
 Suarez's writings which, in the slightest degree, 
 bears out Mr. Mivart 's views as to his opinions.^ 
 
 The title of this fifteenth Disputation is " De 
 causa formal! substantial!," and the second section 
 of that Disputation (to which Mr, Mivart refers) 
 is headed, " Quomodo possit forma substantialis 
 fieri in materia et ex materia ? " 
 
 1 The edition of Suarez's Butpntationes from which the follow- 
 ing citations are given, is Birckmann's, in two volumes folio, 
 and is dated 1630. 
 
V ME. dakwin's critics 131 
 
 The problem which Suarez discusses in this 
 place may be popularly stated thus : According to 
 the scholastic philosophy every natural body has 
 two components — the one its " matter " {materia 
 prima), the other its " substantial form " (forma 
 suhstantialis). Of these the matter is everywhere 
 the same, the matter of one body being indis- 
 tinguishable from the matter of any other body. 
 That which diflferentiates any one natural body 
 from all others is its substantial form, which 
 inheres in the matter of that body, as the human 
 soul inheres in the matter of the frame of man, 
 and is the source of all the activities and other 
 properties of the body. 
 
 Thus, says Suarez, if water is heated, and the 
 source of heat is then removed, it cools again. 
 The reason of this is that there is a certain '' inti- 
 mius principium " in the water, which brings it 
 back to the cool condition when the external 
 impediment to the existence of that condition is 
 removed. This intimius principiicm is the " sub- 
 stantial form " of the water. And the substantial 
 form of the water is not only the cause (radix) of 
 the coolness of the water, but also of its moisture, 
 of its density, and of all its other properties. 
 
 It will thus be seen that " substantial forms " 
 play nearly the same part in the scholastic 
 philosophy as " forces " do in modern science ; the 
 general tendency of modern thought being to 
 conceive all bodies as resolvable into material 
 
132 ME. daewin's CEITICS V 
 
 particles and forces, in virtue of which last these 
 particles assume those dispositions and exercise 
 those powers which are characteristic of each 
 particular kind of matter. 
 
 But the Schoolmen distinguished two kinds of 
 substantial forms, the one spiritual and the other 
 material. The former division is represented by 
 the human soul, the anima rationalis ; and they 
 affirm as a matter, not merely of reason, but of 
 faith, that every human soul is created out of 
 nothing, and by this act of creation is endowed 
 with the power of existing for all eternity, apart 
 from the materia prima of which the corporeal 
 frame of man is composed. And the anima 
 rationalis, once united with the materia, prima of 
 the body, becomes its substantial form, and is the 
 source of all the powers and faculties of man — of 
 all the vital and sensitive phenomena which he 
 exhibits — ^just as the substantial form of water is 
 the source of all its qualities. 
 
 The " material substantial forms " are those 
 which inform all other natural bodies except that 
 of man ; and the object of Suarez in the present 
 Disputation, is to show that the axiom " ex nihilo 
 nihil fit," though not true of the substantial form 
 of man, is true of the substantial forms of all 
 other bodies, the endless mutations of which 
 constitute the ordinary course of nature. The 
 origin of the difficulty which he discusses is easily 
 comprehensible. Suppose a piece of bright iron 
 
V MR. DARWIN'S CRITICS 133 
 
 to be exposed to the air. The existence of the 
 iron depends on the presence within it of a sub- 
 stantial form, which is the cause of its properties, 
 e.g. brightness, hardness, weight. But, by degrees, 
 the iron becomes converted into a mass of rust, 
 which is dull, and soft, and light, and, in all other 
 respects, is quite different from the iron. As, in 
 the scholastic view, this difference is due to the 
 rust being informed by a new substantial form, 
 the grave problem arises, how did this new sub- 
 stantial form come into being ? Has it been 
 created ? or has it arisen by the power of natural 
 causation? If the former hypothesis is correct, 
 then the axiom, " ex nihilo nihil fit," is false, even 
 in relation to the ordinary course of nature, seeing 
 that such mutations of matter as imply the 
 continual origin of new substantial forms are 
 occurring every moment. But the harmonisation 
 of Aristotle with theology was as dear to the 
 Schoolmen, as the smoothing down the differences 
 between Moses and science is to our Broad Church- 
 men, and they were proportionably unwilling to 
 contradict one of Aristotle's fundamental proposi- 
 tions. Nor was their objection to flying in the face 
 of the Stagirite likely to be lessened by the fact 
 that such flight landed them in flat Pantheism. 
 
 So Father Suarez fights stoutly for the second 
 hypothesis ; and I quote the principal part of his 
 argumentation as an exquisite specimen of that 
 speech which is a " darkening of counsel." 
 
134 MR. DARWIN'S CRITICS V 
 
 "13. Secundo de omnibus aliis formis substantialibus [sc. 
 materialibus] diccndum est non fieri propria ex nihilo, sed ex 
 potentia praejaceutis mateiiae educi : ideoque in effectione harum 
 formanim nil fieri contra illud axioma, Ex nihilo nihil fit, si 
 recte intelligatur. Haec assertio sumitur ex Aristotele 1. Phy- 
 sicorum per totum et libro 7. Metaphyss. et ex aliis auctoribus, 
 quos statim referam. Et declaratur breviter, nam fieri ex 
 nihilo duo dicit, unum est fieri absolute et simpliciter, aliud est 
 quod talis effectio fit ex nihilo. Primum proprie dicitur de re 
 subsistente, quia ejus est fieri, cujus est esse : id autem proprie 
 quod subsistit et habet esse ; nam quod alteri adjacet, potius est 
 quo aliud est. Ex hac ergo parte, formee substantiales niate- 
 riales non fiunt ex nihilo, quia proprie non fiunt. Atque banc 
 rationem reddit Divus Thomas 1 parte, quajstione 45, articulo 
 8, et qusestione 90, articulo 2, et ex dicendismagisexplicabitur. 
 Sumendo ergo ipsum fien in hac proprietate et rigore, sic fieri 
 ex nihilo est fieri secundum se totum, id est nulla sui parte 
 prsesupposita, ex quo fiat. Et hac ratione res naturales dum de 
 novo fiunt, non fiunt ex nihilo, quia fiunt ex praesupposita 
 materia, ex qua componuntur, et ita non fiunt, secundum se 
 totse, sed secundum aliquid sui. Formae autem harum rerum, 
 quamvis revera totam suam entitatem de novo accipiant, quam 
 antea non habebant, quia vero ipsse non fiunt, ut dictum est, 
 ideo neque ex nihilo fiunt. Attamen, quia latiori modo sumendo 
 verbum illud fieri negari non potest : quin forma facta sit, eo 
 modo quo nunc est, et antea non erat, ut etiam probat ratio 
 dubitandi posita in principio sectionis, ideo addendum est, 
 sumpto fieri in hac amplitudine, fieri ex nihilo non tamen 
 negare habitudinem materialis caus£e intrinsece componentis id 
 quod fit, sed etiam habitudinem causae materialis per se causantis 
 et sustentantis formam quae fit, seu confit. Diximus enim in 
 superioribus materiam et esse causam compositi et formae 
 dependentis ab ilia : ut res ergo dicatur ex nihilo fieri uterque 
 modus causal itatis negari debet ; et eodem sensu accipiendum 
 est illud axioma, ut sit verum ; Ex nihilo nihil fit, scilicet 
 virtute agentis naturalis et finiti nihil fieri, nisi ex prsesupposito 
 subjecto per se concurrente, et ad compositum et ad formam, si 
 utrumque sue modo ab eodem agente fiat. Ex his ergo rectfe 
 
V MK. Darwin's critics 133 
 
 concluditur, formas substantiales materiales non fieri ex nihilo, 
 quia fiunt ex materia, qiioe in suo genero per se concurrit, et 
 influit ad esse, et fieri talium formarum ; quia, sicut esse non 
 possunt nisi affixae materia;, a qua sustententur in esse : ita nee 
 fieri possunt, nisi earum effectio et penetratio in eadem materia 
 sustentetur. Et hsec est propria et per se diflferentia inter 
 eflectionem ox nihilo, et ex aliquo, propter quarii, ut infra 
 ostendemus, prior modus efficiendi superat vim finitam natu- 
 raliam agentium, nou vero posterior. 
 
 "14. Ex his etiain constat, propria de his formis dici non 
 creari, sed educi de potentia materiae." ^ 
 
 If I may venture to interpret these hard say- 
 ings, Suarez conceives that the evolution of 
 substantial forms in the ordinary course of natxire, 
 is conditioned not only by the existence of the 
 materia prima, but also by a certain " concurrence 
 and influence " which that materia exerts ; and 
 every new substantial form being thus conditioned, 
 and in part, at any rate, caused, by a pre-existing 
 something, cannot be said to be created out of 
 nothing. 
 
 But as the whole tenor of the context shows, 
 Suarez applies this argumentation merely to the 
 evolution of material substantial forms in the 
 ordinary course of nature. How the substantial 
 forms of animals and plants primarily originated, 
 is a question to which, so far as I am able to 
 discover, he does not so much as allude in his 
 " Metaphysical Disputations." Nor was there any 
 necessity that he should do so, inasmuch as he 
 
 ^ Suarez, loc. cit. Disput. xv. § ii. 
 88 
 
136 MR Darwin's critics v 
 
 lias devoted a separate treatise of considerable 
 bulk to the discussion of all the problems which 
 arise out of the account of the Creation which is 
 given in the Book of Genesis. And it is a 
 matter of Avonderment to me that Mr. Mivart, 
 who somewhat sharply reproves " Mr. Darwin and 
 others " for not acquainting themselves with the 
 true teachings of his Church, should allow 
 himself to be indebted to a lieretic like myself 
 for a knowledge of the existence of that " Trac- 
 tatus de opere sex Dierum," ^ in which the learned 
 Father, of whom he justly sjDeaks, as " an 
 authority widely venerated, and whose orthodoxy 
 has never been questioned," directly opposes all 
 those opinions for which Mr. Mivart claims the 
 shelter of his authority. 
 
 In the tenth and eleventh chapters of the first 
 book of this treatise, Suarez inquires in what sense 
 the word " day," as employed in the first chapter 
 of Genesis, is to be taken. He discusses the 
 views of Philo and of Augustin on this question, 
 and rejects them. He suggests that the approval 
 of their allegorising interpretations by St. Thomas 
 Aquinas, merely arose out of St. Thomas's 
 modesty, and his desire not to seem openly to 
 controvert St. Augustin — " voluisse Divus Thomas 
 
 ^ Tractatus da oycic sex Dierum, scio de Universi Creatione, 
 quatemts sex dicbns pcrfeda esse, in lihro Genesis cap. i. refertur, 
 ct pncsirlim de produciiune hominis m sialic innocentioe, Ed. 
 Birckmann, 1622. 
 
V MR. DARWm'S CRITICS 137 
 
 pro sua modestia subterfugere vim argumenti 
 potius quam aperte Augustinum inconstantise 
 arguere." 
 
 Finally, Suarez decides that the writer of 
 Genesis meant that the term " day " should be 
 taken in its natural sense ; and he winds up the 
 discussion with the very just and natural remark 
 that " it is not probable that God, in inspiring 
 Moses to write a history of the Creation which 
 was to be believed by ordinary people, would 
 have made him use language, the true meaningf of 
 which it is hard to discover, and still harder to 
 believe." ^ 
 
 And in chapter xii. 3, Suarez further ob- 
 serves : — 
 
 " Ratio enim retinendi veram significationem diei naturalis 
 est ilia communis, quod verba Scripturse non sunt ad metaphoras 
 transferenda, nisi vel necessitas cogit, vul ex ipsa scriptura 
 constet, et maxime in historica nanatione ct ad instructioncm 
 fidei pertinente : sed hiec ratio non minus cogit ad intelligendum 
 proprie dienim numerum, quam diei qualitatem, quia non 
 
 MINUS UXO MODO QUAM ALIO DESTRUITUR SINCERITAS, IMO ET 
 
 VERITAS HiSTORiiE. Secundo hoc valde confirmant alia Scripturae 
 loca, in quibus hi sex dies tanquam veri, et inter se distinct! 
 commemorantur, ut Exod. 20 dicitur, Sex diebus operabis ct 
 facies omnia opera iua, scptimo autcm die Sabbatum Domini Dei 
 
 ^ " Propterhaec ergo sententia ilia Augustini et propter nimiam 
 obscuritatem et subtilitatem ejus ditflcilis creditu est : quia 
 verisimile non est Deum inspirasse Moysi, ut historian! de 
 creatione mundi ad fidem totius populi adeo necessariam per 
 nomiiia dierum explicaret, quorum significatio vix inveniri et 
 dilficillime ab aliquo credi posset." {Loc. cit. Lib. I. cap. xi. 
 42.) 
 
138 MR. DARWIN'S CRITICS V 
 
 tui est. Et infra ; Sex enim diehus fecit Bominus cmluin et 
 terram et mare et omnia qum in eis mint, et idem repetitur in 
 cap. 31. In quibus locis sermonis proprietas colligi potest turn 
 ex sequiparatione, nam cum dicitur : sex dicbus operabii, pro- 
 priissime intelligitur : turn quia non est verisimile, potuisse 
 populum intelligere verba ilia in alio sensu, et h contrario in- 
 credibile est, Deum in suis praeceptis tradendis illis verbis ad 
 populum fuisse loquutum, quibus deciperetur, falsum sensum 
 concipiendo, si Deus non per sex veros dies opera sua fecisset. " 
 
 These passages leave no doubt that this great 
 doctor of the Catholic Church, of unchallenged 
 authority and unspotted orthodoxy, not only 
 declares it to be Catholic doctrine that the work 
 of creation took place in the space of six natural 
 days ; but that he warmly repudiates, as inconsist- 
 ent with our knowledge of the Divine attributes, 
 the supposition that the language which Catholic 
 faith requires the believer to hold that God 
 inspired, was used in any other sense than that 
 which He knew it would convey to the minds of 
 those to whom it was addressed. 
 
 And I think that in this repudiation Father 
 Suarez will have the sympathy of every man of 
 common uprightness, to whom it is certainly 
 " incredible " that the Almighty should have acted 
 in a manner which He would esteem dishonest 
 and base in a man. 
 
 But the belief that the universe was created in 
 six natural days is hopelessly inconsistent with 
 the doctrine of evolution, in so far as it applies to 
 the stars and planetary bodies ; and it can be 
 
V MR. Darwin's critics 139 
 
 made to agree with a belief in the evolution of 
 living beings only by the supposition that the 
 plants and animals, which are said to have been 
 created on the third, fifth, and sixth days, were 
 merely the primordial forms, or rudiments, out of 
 which existing plants and animals have been 
 evolved; so that, on these days, plants and 
 animals were not created actually, but only 
 potentially. 
 
 The latter view is that held by Mr. Mivart, who 
 follows St. Augustin, and implies that he has the 
 sanction of Suarez. But, in point of fact, the 
 latter great light of orthodoxy takes no small 
 pains to give the most explicit and direct contra- 
 diction to all such imaoinations, as the folio vvincr 
 passages prove. In the first place, as regards 
 plants, Suarez discusses the problem : — 
 
 " Quomodo Jierba virens ct ccctera vegetabilia hoc [tcrtio] die 
 fMriTit produicta. ^ 
 
 " PrsBcipua enim difficultas hie est, quam attingit Div. Thomas 
 1, par. qu. 69, art. 2, an htec productio plantanim hoc die facta 
 intelligenda sit de productione ipsarum in proprio esse actuali et 
 formali .(ut sic rem explicerem) vel de productione tan turn in 
 semine et in potentia. Nam Divus Augustinus libro quinto Genes, 
 ad liter, cap. 4 et 5 et libro 8, cap. 3, posteriorem partem tradit, 
 dicens, terram in hoc die accepisse virtutem germinandi omnia 
 vegetabilia quasi concepto omnium illorum semine, non tamen 
 statim vegetabilia omnia produxisse. Quod primo suadet verbis 
 illis capitis secundi. In die quo fecit Dcus cmlum et terram et 
 
 ^ Loc. eit. Lib. II. cap. vii. et viii. 1, 32, 35. 
 
140 MR. DARWIN'S CRITICS V 
 
 omne virgultuin agri priusguam germinaret. Qiiomodo eniin 
 potuerunt virgiilta fieri antequam terra germinaret nisi quia 
 causaliter prius et quasi in radice, seu in semine facta sunt, et 
 postea in actu producta ? Secundo cnnfirmari potest, quia 
 vcrbum illud germinct terra optimc exponitur potestative ut sic 
 dicam, id est accipiat terra vim gcrminandi. Sicut in eodem 
 capite dicitur crcscite ct multiplicamini. Tertio potest confirmari, 
 quiaactualis productio vegetaLilium non tarn ad opus creationis, 
 quam ad oj)US propagationis pertinet, quod postea factum est. 
 Et banc sententiam sequitur Eucherius lib. 1, in Gen. cap. 11, et 
 illi faveat Glossa, interli. Hugo, et Lyran. dum verbum 
 gcrminet dicto mode exponunt. Nihilominus contraria 
 
 SENTENTIA TENENDA EST : SCILICET, PRODUXISSE DeUM HOC 
 DIE HERBAM, ARBORES, ET ALIA VEGEI'ABILIA ACTU IN PROPRIA 
 
 SPECIE ET NATTJEA. Htec est communis sententia Patnmi. — 
 Basil, homil. 5 ; Exoemer. Ambros. lib. 3 ; Exasmer. cap. 8, 
 11, et 16 ; Cbrysost. bomil. 5 in Gen. Damascene, lib. 2 de Fid. 
 cap. 10 ; Theodor. Cyrilli. BedtB, Glossfe ordinarire et aliorum in 
 Gen. Et idem sentit Divus Thomas, supra, solvers argumenta 
 Augustini, quamvis propter reverentiam ejus quasi problematice 
 semper procedat. Denique idem sentiunt omnes qui in his 
 operibus veram successionem et temporalem distinctionem 
 agnoscant." 
 
 Secondly, with respect to animals, Suare^ is no 
 less decided : — 
 
 " De animalium rationa carentium productionc qidnto et sexto 
 die facta?- 
 "32. Primo ergo nobis certum sit licec animantia' non in 
 virtute tantum aut in semine, sed actu, et in soipsi.s, facta fuisse 
 his diebus in quibus facta narrantur. Quanquam Augustinus 
 lib. 3, Gen. ad liter, cap. 5 in sua persistans sententia contrarium 
 sen tire videatur." 
 
 But Suarez proceeds to refute Augnstin's 
 
 1 Loc. cit. Lib. II. cap. vii. ct viii. 1, 32, 35. 
 
V MR, Darwin's critics 141 
 
 opinions at great length, and his final judgment 
 may be gathered from the following passage : — 
 
 "35. Tertio dicendum est, htec animalia omnia his diebus 
 producta esse, in perfecto statu, in singulis individuis, seu 
 
 SPECIEBUS SUIS, JUXTA UNIUSCUJUSQUE NATURAM .... 
 ItAQUE FUERUNT OMNIA CREATA INTEGRA ET OMNIBUS SUIS 
 MEMBRIS PERFECTA." 
 
 As regards the creation of animals and plants, 
 therefore, it is clear that Suarez, so far from 
 " distinctly asserting derivative creating," denies 
 it as distinctly and positively as he can ; that 
 he is at much pains to refute St. Augustin's 
 opinions ; that he does not hesitate to regard 
 the faint acquiescence of St. Thomas Aquinas in 
 the views of his brother saint as a kindly subter- 
 fuge on the part of Divus Thomas ; and that he 
 afiGjTns his own view to be that which is supported 
 by the authority of the Fathers of the Church. 
 So that, when Mr. Mivart tells us that Catholic 
 theology is in harmony with all that modern 
 science can possibly require ; that " to the general 
 theory of evolution, and to the special Darwinian 
 form of it, no exception . . . need be taken on 
 the ground of orthodoxy ; " and that " law and 
 regularity, not arbitrary intervention, was the 
 Patristic ideal of creation," we have to choose 
 between his dictum, as a theologian, and that 
 of a great light of his Church, whom he him^- 
 self declares to be " widely venerated as an 
 
14.2 MR. DARWIN'S CRITICS V 
 
 authority, and whose orthodoxy has never been 
 questioned." 
 
 But Mr. Mivart does not hesitate to push his 
 attempt to harmonise science with Catholic 
 orthodoxy to its utmost limit ; and, while 
 assuming that the soul of man "arises from 
 immediate and direct creation," he supposes that 
 his body was " formed at first (as now in each 
 separate individual) by derivative, or secondary 
 creation, through natural laws " (p. 331). 
 
 This means, I presume, that an animal, having 
 the corporeal form and bodily powers of man, may 
 have been developed out of some lower form of 
 life by a process of evolution ; and that, after this 
 anthropoid animal had existed for a longer or 
 shorter time, God made a soul by direct creation, 
 and put it into the manlike body, which, hereto- 
 fore, had been devoid of that anima rationalis, 
 which is supposed to be man's distinctive 
 character. 
 
 This hypothesis is incapable of either proof or 
 disproof, and therefore may be true ; but if 
 Suarez is any authority, it is not Catholic 
 doctrine. " Nulla est in liomine forma educta de 
 potcntia materiee," ^ is a dictum Avhich is absolutely 
 inconsistent with the doctrine of the natural 
 evolution of any vital manifestation of the human 
 body. 
 
 Moreover, if man existed as an animal before 
 1 Disput. XV. § X. No. 27. 
 
V ME. Darwin's critics 143 
 
 he was provided with a rational soul, he must, in 
 accordance with the elementary requirements of 
 the philosophy in Avhich Mr. Mivart delights, have 
 possessed a distinct sensitive and vegetative soul, 
 or souls. Hence, when the " breath of life " was 
 breathed into the manlike animal's nostrils, he 
 must have already been a living and feeling 
 creature. But Suarez particularly discusses this 
 point, and not only rejects Mr. Mivart's view, but 
 adopts language of very theological strength 
 regarding it. 
 
 "Possent praeterea his adjungi argumenta theologica, ut est 
 illud quod suniitux ex illis verbis Genes. 2. Formavit Deu.t 
 hominem ex lim-o terrce et inspiravit in faciem ejus spiraculum 
 vitcB et factus est homo in animam viventcm . ille enim spiritus, 
 quam Deus spiravit, anima rationalis fuit, et PER EADEM FACTUS 
 
 EST HOMO VIVENS, ET CONSQUENTER, ETIAM SENTIEN'S. 
 
 " Aliud est ex VIII. Synodo Generali quEB est Constantinopol- 
 itana IV. can. 11, qui sic habet. Apparet quosdam in tanlum 
 impictatis venisse ut homines duos animas habere dogmatiz' nt : 
 talis igitur impictatis invcntores et similes sapientes, cum Fetus 
 et Novum Testamentum omnesque Ecclcsice patrcs unain animam 
 raiionalem hominem habere asicvcrcnt, Sancta et universalis 
 Synodus anathematizat." ^ 
 
 Moreover, if the animal nature of man was the 
 result of evolution, so must that of woman have 
 been. But the Catholic doctrine, according to 
 Suarez, is that woman was, in the strictest and 
 most literal sense of the words, made out of the 
 rib of man. 
 
 ■■ Disput. XV. " De causa formali substantiali," § x. No. 21. 
 
144 MK. DAllWIN'S CrJTICS V 
 
 " Nihilominus sententia Catholica est, verlia ilia Srripturfe 
 esse ad literam intelligenJa. Ac proinde vere, ac eealiter, 
 
 TL'LISSE DeUM COSTAM ADAMiE, ET, EX ILLA, CORPUS EvjB 
 FORMASSE." ^ 
 
 Nor is tliere any escape in the supposition that 
 some woman existed before Eve, after the fashion 
 of the Lilitli of the rabbis ; since Suarez quahfies 
 that notion, along with some other Judaic 
 imaginations, as simply '"' damnabilis." ^ 
 
 After the perusal of the " Tractatus de Opere " 
 it is, in fact, impossible to admit that Suarez held 
 any opinion respecting the origin of species, except 
 such as is consistent Avith the strictest and most 
 literal interpretation of the words of Genesis. 
 For Suarez, it is Catholic doctrine, that the world 
 was made in six natural days. On the first of 
 these days the materia prima was made out of 
 nothing, to receive afterwards those " substantial 
 forms " which moulded it into the universe of 
 vC things i^on the third day, the ancestors of all 
 living plants suddenly came into being, full-grown, 
 perfect, and possessed of all the properties which 
 now distinguish them ; while, on the fifth and 
 sixth days, the ancestors of all existing animals 
 were similarly caused to exist in their complete 
 and perfect state, by the infusion of their appro- 
 priate material substantial forms into the matter 
 
 1 Tradahts do Opera, Lib. III. " Do hominis creatione," cap. 
 ii. No. 3. _ ^ 
 
 •■ Ihid. Ijib. III. cap. iv. Nos. 8 and 9 
 
V MB. DARWIN'S CRITICS 145 
 
 whicli liad already been created. Finally, on the 
 sixth day, the anima rationulis — that rational and 
 immortal substantial form which is peculiar to 
 man — was created out of nothins:, and " breathed 
 into " a mass of matter which, till then, was mere 
 dust of the earth, and so man arose. But the 
 species man was represented by a solitary male 
 individual, until the Creator took out one of his 
 ribs and fashioned it into a female. 
 
 This is the view of the " Genesis of Species " 
 held by Suarez to be the only one consistent with 
 Catholic faith : it is because ho holds this view to 
 be Catholic that he does not hesitate to declare 
 St. Augustin unsound, and St. Thomas Aquinas 
 guilty of weakness, when the one swerved from 
 this view and the other tolerated the deviation. 
 And, until responsible Catholic authority — say, 
 for example, the Archbishop of Westminster — - 
 formally declares that Suarez was wrong, and 
 that Catholic priests are free to teach their llocks 
 that the world was not made in six natural days, 
 and that plants and animals were not created in 
 their perfect and complete state, but have been 
 evolved by natural processes through long ages 
 from certain germs in which they were potentially 
 contained, I, for one, shall feel bound to believe 
 that the doctrines of Suarez are the only ones 
 which are sanctioned by Infallible Authority, as 
 represented by the Holy Father and the Catholic 
 Church, 
 
146 MK. Darwin's ceitics v 
 
 I need hardly add that they are as absolutely 
 denied and repudiated by Scientific Authority, as 
 represented by Reason and Fact. The question 
 whether the earth and the immediate progenitors 
 of its present living population were made in six 
 natural days or not is no longer one upon which 
 two opinions can be held. 
 
 The fact that it did not so come into beino- 
 stands upon as sound a basis as any fact of 
 history whatever. It is not true that existing 
 plants and animals came into being within three 
 days of the creation of the earth out of nothing, for 
 it is certain that innumerable generations of other 
 plants and animals lived upon the earth before 
 its present population. And when, Sunday after 
 Sunday, men who profess to be our instructors in 
 righteousness read out the statement, "In six 
 days the Lord made heaven and earth, the sea, 
 and all that in them is," in innumerable churches, 
 they are either propagating what they may easily 
 know, and, therefore, are bound to know, to be 
 falsities ; or, if they use the words in some non- 
 natural sense, they fall below the moral standard of 
 the much-abused Jesuit. 
 
 Thus far the contradiction between Catholic 
 verity and Scientific verity is complete and 
 absolute, quite independently of the truth or false- 
 hood of the doctrine of evolution. But, for those 
 who hold the doctrine of evolution, all the Catholic 
 verities about the creation of living beings must 
 
V ME. DARWIN'S CRITICS 147 
 
 be no less false. For them, the assertion that the 
 progenitors of all existing plants were made on the 
 third day, of animals on the fifth and sixth days, 
 in the forms they now present, is simply false. 
 Nor can they admit that man was made suddenly 
 out of the dust of the earth ; while it would be an 
 insult to ask an evolutionist whether he credits the 
 preposterous fable respecting the fabrication of 
 woman to which Suarez pins his faith. If Suarez 
 has rightly stated Catholic doctrine, then is 
 evolution utter heresy. And such I believe it to 
 be. In addition to the truth of the doctrine of 
 evolution, indeed, one of its greatest merits in' 
 my eyes, is the fact that it occupies a position of 
 complete and irreconcilable antagonism to that 
 vigorous and consistent enemy of the highest intel- 
 lectual, moral, and social life of mankind — the 
 Catholic Church. No doubt, Mr. Mivart, like 
 other putters of new wine into old bottles, is 
 actuated by motives which are worthy of respect, 
 and even of sympathy ; but his attempt has met 
 with the fate which the Scripture prophesies for 
 all such. 
 
 Catholic theology, like all theologies which are 
 based upon the assumption of the truth of the 
 account of the origin of things given in the Book 
 of Genesis, being utterly irreconcilable with the 
 doctrine of evolution, the student of science, who is 
 satisfied that the evidence upon which the doctrine 
 of evolution rests, is incomparably stronger and 
 
148 MR. DARWIN S CRITICS V 
 
 better than that upon which the supposed author- 
 ity of the Book of Genesis rests, will not trouble 
 himself further with these theologies, but will 
 confine his attention to such arguments against 
 the view he holds as are based upon purely 
 scientific data — and by scientific data I do not 
 merely mean the truths of physical, mathematical, 
 or logical science, but those of moral and meta- 
 physical science. For by science I understand 
 all knowledge which rests upon evidence and 
 reasoning of a like character to that which claims 
 our assent to ordinary scientific propositions. And 
 if any one is able to make good the assertion that 
 his theology rests upon valid evidence and sound 
 reasoning, then it appears to me that such theology 
 will take its place as a part of science. 
 
 The present antagonism between theology and 
 science does not arise from any assumption by the 
 men of science that all theology must necessarily 
 be excluded from science, but simply because 
 they are unable to allow that reason and morality 
 have two weights and two measures ; and that the 
 belief in a proposition, because authority tells you 
 it is true, or because you wish to believe it, which 
 is a high crime and misdemeanour Avhen the sub- 
 ject matter of reasoning is of one kind, becomes 
 under the alias of " faith " the greatest of all 
 virtues when the subject matter of reasoning is of 
 another kind. 
 
 The Bishop of Brechin said well the other 
 
V ME. daewin's critics 149 
 
 day : — " Liberality in religion — I do not mean 
 tender and generous allowances for the mis- 
 takes of others — is only unfaithfulness to truth." ^ 
 And, with the same qualification, I venture 
 to paraphrase the Bishop's dictum : " Eccle- 
 siasticism in science is only unfaithfulness to 
 truth." 
 
 Elijah's great question, " Will you serve God or 
 Baal ? Choose ye," is uttered audibly enough in 
 the ears of every one of us as we come to man- 
 hood. Let every man who tries to answer it 
 seriously ask himself whether he can be satisfied 
 with the Baal of authority, and with all the good 
 things his worshippers are promised in this world 
 and the next. If he can, let him, if he be so 
 inclined, amuse himself with such scientific imple- 
 ments as authority tells him are safe and will not 
 cut his fingers ; but let him not imagine he is, or 
 can be, both a true son of the Church and a loyal 
 soldier of science. 
 
 And, on the other hand, if the blind acceptance 
 of authority appears to him in its true colours, as 
 mere private judgment in cxcelsis, and if he have 
 the courage to stand alone, face to face with the 
 abyss of the eternal and unknowable, let him be 
 content, once for all, not only to renounce the good 
 things promised by " Infallibility," but even to 
 bear the bad things which it prophesies ; content 
 
 1 Charge at the Diocesan Synod of Brechin. Scotsman, Sept. 
 14, 1871. 
 
150 MK. DARWIN'S CRITICS V 
 
 to follow reason and fact in singleness and honesty 
 of purpose, wherever they may lead, in the sure 
 faith that a hell of honest men will, to him, be 
 more endurable than a paradise full of angelic 
 shams. 
 
 Mr. Mivart asserts that " without a belief in a 
 personal God there is no religion worthy of the 
 name." This is a matter of opinion. But it may 
 be asserted, with less reason to fear contradiction, 
 that the worship of a personal God, who, on Mr. 
 Mivart's hypothesis, must have used language 
 studiously calculated to deceive His creatures and 
 worshippers, is "no religion worthy of the name." 
 " Incredible est, Deum illis verbis ad populum 
 fuisse locutum quibus deciperetur," is a verdict in 
 which, for once, Jesuit casuistry concurs with the 
 healthy moral sense of all mankind. 
 
 Having happily got quit of the theological 
 aspect of evolution, the supporter of that great 
 truth who turns to the scientific objections which 
 are brought against it by recent criticism, finds, to 
 his relief, that the work before him is greatly 
 lightened by the spontaneous retreat of the enemy 
 from nine-tenths of the tenitory which he occu- 
 pied ten years ago. Even the Quarterly Reviewer 
 not only abstains from venturing to deny that 
 evolution has taken place, but he openly admits 
 that Mr. Darwin has forced on men's minds " a 
 recognition of the probability, if not more, of 
 
T MR. daewin's critics 151 
 
 evolution, and of the certainty of the action of 
 natural selection " (p. 49). 
 
 I do not quite see, myself, how, if the action of 
 natural selection is certain, the occurrence of evolu- 
 tion is only po'oiahle ; inasmuch as the development 
 of a new species by natural selection is, so far as 
 it goes, evolution. However, it is not worth while 
 to quarrel with the precise terms of a sentence 
 which shows that the high water mark of intelli- 
 gence among those most respectable of Britons, the 
 readers of the Quarterly Mevieiv, has now reached 
 such a level that the next tide may lift them 
 easily and pleasantly on the once-dreaded shore of 
 evolution. Nor, having got there, do they seem 
 likely to stop, until they have reached the inmost 
 heart of that great region, and accepted the ape 
 ancestry of, at any rate, the body of man. For 
 the Reviewer admits that Mr. Darwin can be said 
 to have estabhshed : 
 
 "That if tlie various kinds of lower animals have been 
 evolved one from the other by a process of natural generation 
 or evolution, then it becomes highly probable, d priori, that 
 man's body has been similarly evolved ; but this, in such a 
 case, becomes equally probable from the admitted fact that he is 
 an animal at all " (p. 65). 
 
 From the principles laid down in the last sen- 
 tence it would follow that if man were constructed 
 upon a plan as different from that of any other 
 animal as that of a sea-urchin is from that of a 
 whale, it would be " equally probable " that he 
 39 
 
152 MR. DARWIN'S CRITICS V 
 
 had been developed from some other animal as it 
 is now, when we know that for every bone, muscle, 
 tooth, and even pattern of tooth, in man, there is a 
 corresponding bone, muscle, tooth, and pattern of 
 tooth, in an ape. And this shows one of two things 
 — either that the Quarterly Reviewer's notions of 
 probability are peculiar to himself, or that he has 
 such an overpowering faith in the truth of evolution 
 that no extent of structural break between one 
 animal and another is sufficient to destroy his con- 
 viction that evolution has taken place. 
 
 But this by the way. The importance of the 
 admission that there is nothing in man's physical 
 structure to interfere with his having been evolved 
 from an ape is not lessened because it is grudg- 
 ingly made and inconsistently qualified. And in- 
 stead of jubilating over the extent of the enemy's 
 retreat, it will be more worth while to lay siege to 
 his last stronghold — the position that there is a 
 distinction in kind between the mental faculties 
 of man and those of brutes, and that in consequence 
 of this distinction in kind no gradual progress 
 from the mental faculties of the one to those of the 
 other can have taken place. 
 
 The Quarterly Eeviewer entrenches himself 
 within formidable-looking psychological outworks, 
 and there is no getting at him without attacking 
 them one by one. 
 
 He begins by laying down the following pro- 
 position. " ' Sensation ' is not ' thought,' and no 
 
V MR. DARWIN'S CRITICS 153 
 
 amount of the former would constitute the most 
 rudimentary condition of the latter, though sen- 
 sations supply the conditions for the existence of 
 ' thought ' or ' knowledge' " (p. 67). 
 
 This proposition is true, or not, according to the 
 sense in which the word " thought " is employed. 
 Thought is not uncommonly used in a sense co- 
 extensive with consciousness, and, especially, with 
 those states of consciousness we call memory. If I 
 recall the impression made by a colour or an odour, 
 and distinctly remember blueness or muskiness, I 
 may say with perfect propriety that I " think of " 
 blue or musk ; and, so long as the thought lasts, 
 it is simply a faint reproduction of the state of 
 consciousness to which I gave the name in question, 
 when it first became known to me as a sensation. 
 
 Now, if that faint reproduction of a sensation, 
 which we call the memory of it, is properly termed 
 a thought, it seems to me to be a somewhat forced 
 proceeding to draw a hard and fast line of demar- 
 cation between thoughts and sensations. If sen- 
 sations are not rudimentary thoughts, it may be 
 said that some thoughts are rudimentary sensations. 
 No amount of sound constitutes an echo, but for 
 all that no one would pretend that an echo is some- 
 thing of totally diflferent nature from a sound. 
 Again, nothing can be looser, or more inaccurate, 
 than the assertion that " sensations supply the 
 conditions for the existence of thought or know- 
 ledge." If this implies that sensations supply the 
 
;^54 MR. DARWIN'S CRITICS V 
 
 conditions for the existence of our memory of sen- 
 sations or of our thoughts about sensations, it is a 
 truism which it is hardly worth while to state so 
 solemnly. If it implies that sensations supply any- 
 thino- else, it is obviously erroneous. And if it 
 means, as the context would seem to show it does, 
 that sensations are the subject-matter of all thought 
 or knowledge, then it is no less contrary to fact, 
 inasmuch as our emotions, which constitute a large 
 part of the subject-matter of thought or of know- 
 ledge, are not sensations. 
 
 More eccentric still is the Quarterly Reviewer's 
 next piece of psychology. 
 
 " Altogether, we may clearly distinguish at least six kinds of 
 action to which the nervous system ministers : — 
 
 " I. That in which impressions received result in appropriate 
 movements without the intervention of sensation or thought, as 
 in the cases of injury above given. — This is the reflex action of 
 the nervous system. 
 
 " II. That in which stimuli from without result in sensations 
 through the agency of which their due effects are wrought out. 
 — Sensation. 
 
 " III. That in which impressions received result in sensations 
 which give rise to the observation of sensible objects. — Sensible 
 perception. 
 
 "IV. That in which sensations and perceptions continue to 
 coalesce, agglutinate, and combine in more or less comjjlex 
 aggregations, according to the laws of the association of sensible 
 perceptions. — A ssociation. 
 
 " The above four groups contain only indeliberate operations, 
 consisting, as they do at the best, but of mere prescntative 
 sensible ideas in no way implying any reflective or representative 
 faculty. Such actions minister to and form Institiet. Besides these, 
 we may distinguish two other kinds of mental action, namely :— 
 
V MR. DARWIN'S CRITICS 155 
 
 "V. That in which sensations and sensible -perceptions are 
 reflected on by thought, and recognised as our own, and wo 
 ourselves recognised by ourselves as aflccted and perceiving. — 
 Self-consciousness. 
 
 "VI. That in which we reflect upon our sensations or 
 perceptions, and ask what they arc, and why they are. — Reason. 
 
 "These two latter kinds of action are deliberate operations, 
 performed, as they are, by means of representative ideas imply- 
 ing the use of a reflective representative faculty. Such actions 
 distinguish the inttllect or rational facuUJ^ Now, we assert 
 that possession in perfection of all the first four { prescntative) 
 kinds of action by no means implies the possession of the last 
 two {representative) kinds. All persons, we think, must admit 
 the truth of the following proposition : — 
 
 " Two faculties are distinct, not in degree but in kind, if wo 
 may possess the one in perfection without that fact implying 
 that w^e possess the other also. Still more will this be the case 
 if the two faculties tend to increase in an inverse ratio. Yet 
 this is the distinction between the instinctive and the intellectual 
 parts of man's nature. 
 
 "As to animals, we fully admit that they may possess all the 
 first four groups of actions — that they may have, so to speak, 
 mental images of sensible objects combined in all degrees of 
 comple.xity, as governed by the laws of association. "We deny 
 to them, on the other hand, the possession of the last two kinds 
 of mental action. We deny them, that is, the power of reflecting 
 on their own existences, or of inquiring into the nature of objects 
 and their causes. We deny that they know that they know or 
 know themselves in knowing. In other words, we deny them 
 reason. The possession of the prescntative faculty, as above 
 explained, in no way implies that of the reflective faculty ; nor 
 does any amount of direct operation imply the power of asking 
 the reflective question before mentioned, as to ' what ' and 
 'why.'" {Loc.cit. pp. 67, 68.) 
 
 Sundry points are worthy of notice in this 
 remarkable account of the intellectual powers. In 
 the first place the Reviewer ignores emotion and 
 
156 MR. Darwin's critics v 
 
 volition., though they are no inconsiderable " kinds 
 of action to which the nervous system ministers," 
 and memory has a place in his classification only 
 by implication. Secondly, we are told that the 
 second " kind of action to which the nervous 
 system ministers " is " that in which stimuli from 
 Avithout result in sensations through the agency 
 of which their due effects are wrought out. — 
 Sensation." Does this really mean that, in the 
 writer's opinion, "sensation" is the "agent" by 
 which the "due effect" of the stimulus, which, 
 gives rise to sensation, is " wrought out " ? 
 Suppose somebody runs a pin into me. The 
 " due effect " of that particular stimulus will 
 probably be threefold ; namely, a sensation of 
 pain, a start, and an interjectional expletive. 
 Does the Quarterly Reviewer really think that 
 the " sensation " is the " agent " by which the 
 other two phenomena are wrought out ? 
 
 But these matters are of little moment to 
 anyone but the Reviewer and those persons who 
 may incautiously take their physiology, or psycho- 
 logy, from him. The really interesting point is 
 this, that when he fully admits that animals 
 " may possess all the first four groups of actions," 
 he grants all that is necessary for the purposes of 
 the evolutionist. For he hereby admits that in 
 animals " impressions received result in sensations 
 which give rise to the observation of sensible 
 objects," and that they have what he calls 
 
V MR. daewin's critics 157 
 
 " sensible perception." Nor was it possible to 
 help the admission ; for we have as much reason 
 to ascribe to animals, as we have to attribute to 
 our fellow-men, the power, not only of perceiving 
 external objects as external, and thus practically 
 recognizing the difference between the self and the 
 not-self; but that of distinguishing between like 
 and unlike, and between simultaneous and suc- 
 cessive things. When a gamekeeper goes out 
 coursing with a greyhound in leash, and a hare 
 crosses the field of vision, he becomes the subject 
 of those states of consciousness we call visual 
 sensation, and that is all he receives from without. 
 Sensation, as such, tells him nothing whatever 
 about the cause of these states of consciousness; 
 but the thinking faculty instantly goes to work 
 upon the raw material of sensation furnished to it 
 through the eye, and gives rise to a train of 
 thoughts. First comes the thought that there is 
 an object at a certain distance ; then arises 
 another thought — the perception of the likeness 
 between the states of consciousness awakened by 
 this object to those presented by memory, as, on 
 some former occasion, called up by a hare ; this is 
 succeeded by another thought of the nature of an 
 emotion — namely, the desire to possess the hare ; 
 then follows a longer or shorter train of other 
 thoughts, which end in a volition and an act — the 
 loosing of the greyhound from the leash. These 
 several thoughts are the concomitants of a process 
 
158 MR. Darwin's critics v 
 
 which goes on in the nervous system of the man. 
 Unless the nerve-elements of the retina, of the 
 optic nerve, of the brain, of the spinal cord, and 
 of the nerves of the arms, went through certain 
 physical changes in due order and correlation, the 
 various states of consciousness which have been 
 enumerated would not make their appearance. So 
 that in this, as in all other intellectual operations, 
 we have to distinguish two sets of successive 
 changes — one in the physical basis of conscious- 
 ness, and the other in consciousness itself ; one set 
 which may, and doubtless will, in course of time, 
 be followed through all their complexities by the 
 anatomist and the physicist, and one of which only 
 the man himself can have immediate knowledge. 
 
 As it is very necessary to keep up a clear 
 distinction between these two processes, let the one 
 be called neurosis, and the other psychosis. When 
 the gamekeeper was first trained to his work 
 every step in the process of neurosis Avas accom- 
 panied by a corresponding step in that of psychosis, 
 or nearly so. He was conscious of seeing some- 
 thing, conscious of making sure it was a hare, 
 conscious of desiring to catch it, and therefore to 
 loose the greyhound at the right time, conscious of 
 the acts by which he let the dog out of the leash. 
 But with practice, though the various steps of the 
 neurosis remain — for otherwise the impression on 
 the retina would not result in the loosinsr of the 
 dog — the great majority of the steps of the 
 
V ME. daewin's ceitics 159 
 
 psychosis vanish, and the loosing of the dog follows 
 unconsciously, or as we say, without thinking about 
 it, upon the sight of the hare. No one will deny 
 that the series of acts which originally intervened 
 between the sensation and the letting go of the 
 dog were, in the strictest sense, intellectual and 
 rational operations. Do they cease to be so when 
 the man ceases to be conscious of them? That 
 depends upon what is the essence and what the 
 accident of those operations, which, taken to- 
 gether, constitute ratiocination. 
 
 Now ratiocination is resolvable into predication, 
 and predication consists in marking, in some way, 
 the existence, the co-existence, the succession, the 
 likeness and unlikeness, of things or their ideas. 
 Whatever does this, reasons ; and if a machine pro- 
 duces the effects of reason, I see no more ground 
 for denying to it the reasoning power, because it 
 is unconscious, than I see for refusing to Mr. 
 Babbage's engine the title of a calculating machine 
 on the same grounds. 
 
 Thus it seems to me that a gamekeeper reasons, 
 whether he is conscious or unconscious, whether 
 his reasoning is carried on by neurosis alone, or 
 whether it involves more or less psychosis. And 
 if this is true of the gamekeeper, it is also true of 
 the greyhound. The essential resemblances in all 
 points of structure and function, so far as they can 
 be studied, between the nervous system of the man 
 and that of the dog, leave no reasonable doubt 
 
160 MR. daewin's critics V 
 
 that the processes which go on in the one are just 
 like those which take place in the other. In the 
 dog, there can be no doubt that the nervous 
 matter which lies between the retina and the 
 muscles undergoes a series of changes, precisely 
 analogous to those which, in the man, give rise to 
 sensation, a train of thought, and volition. 
 
 Whether this neurosis is accompanied by such 
 psychosis as ours it is impossible to say ; but 
 those who deny that the nervous changes, which, 
 in the dog, correspond with those which underlie 
 thought in a man, are accompanied by conscious- 
 ness, are equally bound to maintain that those 
 nervous changes in the dog, which correspond with 
 those which underlie sensation in a man, are also 
 unaccompanied by consciousness. In other words, 
 if there is no ground for believing that a dog thinks, 
 neither is there any for believing that he feels. 
 
 As is well known, Descartes boldly faced this 
 dilemma, and maintained that all animals were 
 mere machines and entirely devoid of consciousness. 
 But he did not deny, nor can anyone deny, that in 
 this case they are reasoning machines, capable of 
 performing all those operations which are per- 
 formed by the nervous system of man when he 
 reasons. For even supposing that in man, and in 
 man only, psychosis is superadded to neurosis — the 
 neurosis which is common to both man and animal 
 gives their reasoning processes a fundamental 
 unity. But Descartes' position is open to very 
 
V Ma. DARWIN'S CRITICS 161 
 
 serious objections if the evidence that animals feel 
 is insufficient to prove that they really do so. What 
 is the value of the evidence which leads one to 
 believe that one's fellow-man feels ? The only 
 evidence in this argument of analogy is the 
 similarity of his structure and of his actions to 
 one's own. And if that is good enough to prove 
 that one's fellow-man feels, surely it is good 
 enough to prove that an ape feels. For the differ- 
 ences of structure and function between men and 
 apes are utterly insufficient to warrant the 
 assumption that while men have those states of 
 consciousness we call sensations apes have nothing 
 of the kind. Moreover, we have as good evidence 
 that apes are capable of emotion and volition as 
 we have that men other than ourselves are. But 
 if apes possess three out of the four kinds of states 
 of consciousness which we discover in ourselves, 
 what possible reason is there for denying them the 
 fourth ? If they are capable of sensation, emotion, 
 and volition, Avhy are they to be denied thought 
 (in the sense of predication) ? 
 
 No answer has ever been given to these 
 questions. And as the law of continuity is as 
 much opposed, as is the common sense of man- 
 kind, to the notion that all animals are unconscious 
 machines, it may safely be assumed that no 
 sufficient answer ever will be given to them. 
 
 There is every reason to believe that con- 
 sciousness is a function of nervous matter, when 
 
1G2 MR. DARWIN'S CRITICS T 
 
 that nervous matter lias attained a certain degree 
 of organisation, just as we know the other 
 " actions to which the nervous system ministers," 
 such as reflex action and the like, to be. As I 
 have ventured to state my view of the matter 
 elsewhere, " our thoughts are the expression of 
 molecular changes in that matter of life which is 
 the source of our other vital phenomena." 
 
 Mr. Wallace objects to this statement in the 
 following terms : — ■ 
 
 " Not having been able to find any clue in Professor Huxley's 
 writings to the steps by which he passes from those vital pheno- 
 mena, which consist only, in their last analysis, of movements 
 by particles of matter, to those other phenomena which we term 
 thought, sensation, or consciousness ; but, knowing that so 
 positive an expression of opinion from him will have great weight 
 with many persons, I shall endeavour to show, with as much 
 lirevity as is compatible with clearness, that this theory is not 
 only incapable of proof, but is also, as it appears to me, 
 inconsistent with accurate conceptions of molecular physics. " 
 
 With all respect for Mr. Wallace, it appears to 
 me that his remarks are entirely beside the ques- 
 tion. I really know nothing whatever, and never 
 hope to know anything, of the steps by which the 
 passage from molecular movement to states of 
 consciousness is effected ; and I entirely agree 
 with the sense of the passage which he quotes 
 from Professor Tyndall, apparently imagining that 
 it is in opposition to the view I hold. 
 
 All that I have to say is, that, in my belief, 
 consciousness and molecular action axe capable of 
 
V MK. Darwin's critics 163 
 
 being expressed by one another, just as heat and 
 mechanical action are capable of being expressed 
 in terms of one another. Whether we shall ever 
 be able to express consciousness in foot-pounds, or 
 not, is more than I will venture to say ; but that 
 there is evidence of the existence of some corre- 
 lation between mechanical motion and conscious- 
 ness, is as plain as anything can be. Suppose the 
 poles of an electric battery to be connected by 
 a platinum Avire. A certain intensity of the 
 current gives rise in the mind of a bystander to 
 that state of consciousness we call a " dull red 
 light" — a little greater intensity to another which 
 we call a " bright red light ; " increase the inten- 
 sity, and the light becomes white ; and, finally, it 
 dazzles, and a new state of consciousness arises, 
 which we term pain. Given the same wire and 
 the same nervous apparatus, and the amount of 
 electric force required to give rise to these several 
 states of conciousness will be the same, however 
 often the experiment is repeated. And as the 
 electric force, the light waves, and the nerve- 
 vibrations caused by the impact of the light- waves 
 on the retina, are all expressions of the molecular 
 changes which are taking place in the elements of 
 the battery ; so consciousness is, in the same 
 sense, an expression of the molecular changes 
 which take place in that nervous matter, which is 
 the organ of consciousness. 
 
 And, since this, and any number of similar 
 
164 MR. Darwin's critics v 
 
 examples that may be required, prove that one 
 form of consciousness, at any rate, is, in the 
 strictest sense, the expression of molecular change, 
 it really is not worth while to pursue the inquiry, 
 whether a fact so easily established is consistent with 
 any particular system of molecular physics or not. 
 Mr. Wallace, in fact, appears to me to have 
 mixed up two very distinct propositions : the one, 
 the indisputable truth that consciousness is corre- 
 lated with molecular changes in the organ of 
 consciousness ; the other, that the nature of that 
 correlation is known, or can be conceived, which 
 is quite another matter. Mr. Wallace, presumably, 
 believes in that correlation of phenomena which 
 we call cause and effect as firmly as I do. But if 
 he has ever been able to form the faintest notion 
 how a cause gives rise to its effect, all I can say is 
 that I envy him. Take the simplest case imagin- 
 able — suppose a ball in motion to impinge upon 
 another ball at rest. I know very well, as a matter 
 of fact, that the ball in motion will communicate 
 some of its motion to the ball at rest, and that 
 the motion of the two balls, after collision, is 
 precisely correlated with the masses of both balls 
 and the amount of motion of the first. But how 
 does this come about ? In what manner can we 
 conceive that the vis viva of the first ball passes 
 into the second ? I confess I can no more form 
 any conception of what happens in this case, than 
 I can of what takes place when the motion of 
 
V MR. DARWIN'S CRITICS 1G5 
 
 particles of my nervous matter, caused by the 
 impact of a similar ball gives rise to the state of 
 consciousness I call pain. In ultimate analysis ; 
 everything is incomprehensible, and the whole 
 object of science is simply to reduce the funda- 
 mental incomprehensibilities to the smallest possi- 
 ble number. 
 
 But to return to the Quarterly Reviewer. He 
 admits that animals have " mental images of 
 sensible objects, combined in all degrees of com- 
 plexity, as governed by the laws of association." 
 Presumably, by this confused and imperfect state- 
 ment the Reviewer means to admit more than the 
 words imply. For mental images of sensible 
 objects, even though " combined in all degrees of 
 complexity,'' are, and can be, nothing more than 
 mental images of sensible objects. But judg- 
 ments, emotions, and volitions cannot by any 
 possibility be included under the head of " mental 
 images of sensible objects." If the greyhound 
 had no better mental endowment than the 
 Reviewer allows him, he might have the " mental 
 image " of the " sensible object '' — the hare — and 
 that might be combined with the mental imasfes 
 of other sensible objects, to any degree of com- 
 plexity, but he would have no power of judging 
 it to be at a certain distance from him ; no power 
 of perceiving its similarity to his menaory of a 
 hare ; and no desire to get at it. Consequently 
 he would stand stock still, and the noble art of 
 
16G MR. Darwin's critics t 
 
 couisinc: would have no existence. On the other 
 hand, as that art is largely practised, it follows 
 that greyhounds alone possess a number of mental 
 powers, the existence of which, in any animal, is 
 absolutely denied by the Quarterly Reviewer. 
 
 Finally, what are the mental powers which he 
 reserves as the especial prerogative of man ? 
 They are two. First, the recognition of "our- 
 selves by ourselves as affected and perceiving, — ■■ 
 Self-consciousness." 
 
 Secondly. " The reflection upon our sensations 
 and perceptions, and asking what they are and 
 why they are. — Reason." 
 
 To the faculty defined in the last sentence, the 
 Reviewer, without assio'ning the least ground for 
 thus departing from both common usage and 
 technical propriety, applies the name of reason. 
 But if man is not to be considered a reasoning 
 being, unless he asks what his sensations and per- 
 ceptions are, and why they are, what is a Hot- 
 tentot, or an Aixstralian " black-fellow " ; or what 
 the " swinked hedger " of an ordinary agricultural 
 district ? Nay, what becomes of an average 
 country squire or parson ? How many of these 
 worthy persons who, as their wont is, read the 
 Quarterly Review, would do other than stand 
 agape, if you asked them whether they had ever 
 reflected what their sensations and perceptions 
 are and why they are ? 
 
 S-"* that if the RevieAver's new definition of rea- 
 
V MK, Darwin's critics 167 
 
 son be correct, the majority of men, even among the 
 most civilised nations, are devoid of that supreme 
 characteristic of manhood. And if it be as absurd 
 as I believe it to be, then, as reason is certainly not 
 self-consciousness, and since it, as certainly, is one of 
 the " actions to which the nervous system minis- 
 ters," we must, if the Reviewer's classification is 
 to be adopted, seek it among those four faculties 
 which he allows animals to possess. And thus, for 
 the second time, he really surrenders, while seem- 
 ing to defend, his position. 
 
 The Quarterly ^Reviewer, as we have seen, 
 lectures the evolutionists upon their want of know- 
 ledge of philosophy altogether. Mr. Mivart is not 
 less pained at Mr. Darwin's ignorance of moral 
 science. It is grievous to him that Mr. Darwin 
 (and nous autres) should not have grasped the 
 elementary distinction between material and formal 
 morality ; and he lays down as an axiom, of which 
 no tyro ought to be ignorant, the position that 
 " acts, unaccompanied by mental acts of conscious 
 will directed towards the fulfilment of duty," are 
 " absolutely destitute of the most incipient degree 
 of real or formal goodness." 
 
 Now this may be Mr. Mivart's opinion, but it is 
 a proposition which really does not stand on the 
 footing of an undisputed axiom. Mr. Mill denies 
 it in his work on Utilitarianism. The most in- 
 fluential writer of a totally opposed school, Mr. 
 Carlyle, is never weary of denying it, and upholding 
 40 
 
168 MR. Darwin's critics v 
 
 the merit of that virtue which is unconscious ; 
 nay, it is, to my understanding, extremely hard to 
 reconcile Mr. Mivart's dictum with that noble sum- 
 mary of the whole duty of man — " Thou shalt love 
 the Lord thy God with all thy heart, and with all 
 thy soul, and with all thy strength : and thou shalt 
 love thy neighbour as thyself." According to Mr. 
 Mivart's definition, the man who loves God and his 
 neighbour, and, out of sheer love and affection for 
 both, does all he can to please them, is, neverthe- 
 less, destitute of a particle of real goodness. 
 
 And it further happens that Mr. Darwin, who is 
 charged by Mr. Mivart with being ignorant of the 
 distinction between material and formal goodness, 
 discusses the very question at issue in a passage 
 which is well worth reading (vol. i. p. 87), and also 
 comes to a conclusion opposed to Mr. Mivart's 
 axiom. A proposition which has been so much 
 disputed and repudiated, should, under no circum- 
 stances, have been thus confidently assumed to be 
 true. For myself, I utterly reject it, inasmuch as 
 the logical consequence of the adoption of any such 
 principle is the denial of all moral value to 
 sympathy and affection. According to Mr. Mivart's 
 axiom, the man who, seeing another struggling in 
 the water, leaps in at the risk of his own life to 
 save him, does that which is " destitute of the most 
 incipient degree of real goodness," unless, as he 
 strips off his coat, he says to himself, " Now, mind, 
 I am going to do this because it is my duty and 
 
V MR. Darwin's critics 169 
 
 for no other reason ; " and the most beautiful 
 character to which humanity can attain, that of the 
 man who does good without thinking about it, be- 
 cause he loves justice and mercy and is repelled 
 by evil, has no claim on our moral approbation. 
 The denial that a man acts morally because he does 
 not think whether he does so or not, may be put 
 upon the same footing as the denial of the title of 
 an arithmetician to the calculating boy, because he 
 did not know how he worked his sums. If man- 
 kind ever generally accept and act upon Mr. 
 Mivart's axiom, they will simply become a set of 
 most unendurable prigs ; but they never have ac- 
 cepted it, and I venture to hope that evolution has 
 nothing so terrible in store for the human race. 
 
 But if an action, the motive of which is nothing 
 but affection or sympathy, may be deserving of 
 moral approbation and really good, who that has 
 ever had a dog of his own will deny that animals 
 are capable of such actions ? Mr. Mivart indeed 
 says : — " It may be safely affirmed, however, that 
 there is no trace in brutes of any actions simulat- 
 ing morality which are not explicable by the fear 
 of punishment, by the hope of pleasure, or by per- 
 sonal affection " (p. 221). But it may be affirmed, 
 with equal truth, that there is no trace in men of 
 any actions which are not traceable to the same 
 motives. If a man does anything, he does it 
 either because he fears to be punished if he does 
 not do it, or because he hopes to obtain pleasure 
 
170 MR. DARWIN'S CRITICS V 
 
 by doing it, or because he gratifies his affections^ 
 by doing it. 
 
 Assuming the position of the absolute moralists, 
 let it be granted that there is a perception of right 
 and wrong innate in every man. This means, 
 simply, that when certain ideas are presented to 
 his mind, the feeling of approbation arises ; and 
 when certain others, the feeling of disapprobation. 
 To do your duty is to earn the approbation of your 
 conscience, or moral sense ; to fail in your duty is 
 to feel its disapprobation, as we all say. Now, is 
 approbation a pleasure or a pain ? Surely a 
 pleasure. And is disapprobation a pleasure or a 
 pain 1 Surely a pain. Consequently, all that is 
 really meant by the absolute moralists is that there 
 is, in the very nature of man, something which 
 enables him to be conscious of these particular 
 pleasures and pains. And when they talk of immut- 
 able and eternal principles of morality, the only in- 
 telligible sense which I can put upon the words, is 
 that the nature of man being what it is, he always 
 has been, and always will be, capable of feeling these 
 particular pleasures and pains. A priori, I have 
 nothing to say against this proposition. Admitting 
 its truth, I do not see how the moral faculty is on 
 a different footing from any of the other faculties 
 of man. If I choose to say that it is an immutable 
 
 ' In separating pleasure and the gratification of affection, I 
 simply follow Mr. Mivart without admitting the justice of the 
 separation. 
 
V ME. Darwin's critics 171 
 
 and eternal law of human nature that " ginger is 
 hot in the mouth," the assertion has as much 
 foundation of truth as the other, though I think 
 it would be expressed in needlessly pompous 
 language. I must confess that I have never been 
 able to understand why there should be such a 
 bitter quarrel between the intuitionists and the 
 utilitarians. The intuitionist is, after all, only a 
 utilitarian who believes that a particular class of 
 pleasures and pains has an especial importance, by 
 reason of its foundation in the nature of man, and 
 its inseparable connection with his very existence 
 as a thinking being. And as regards the motive 
 of personal affection : Love, as Spinoza profoundly 
 says, is the association of pleasure with that which 
 is loved.^ Or, to put it to the common sense of 
 mankind, is the gratification of affection a pleasure 
 or a pain ? Surely a pleasure. So that whether 
 the motive which leads us to perform an action 
 is the love of our neighbour, or the love of God, it 
 is undeniable that pleasure enters into that motive. 
 Thus much in reply to Mr. Mivart's arguments. 
 I cannot but think that it is to be regretted that 
 he ekes them out by ascribing to the doctrines of 
 the philosophers with whom he does not agree, 
 logical consequences which have been over and 
 over again proved not to flow from them : and when 
 reason fails him, tries the effect of an injurious 
 
 ^ " Nempe, Amor nihil aliud est, quam Lsetitia, concomitante 
 idea causK externfe. " — Ethiees, HI. xiii. 
 
172 MR. Darwin's critics v 
 
 nickname. According to the views of Mr. Spencer, 
 Mr. Mill, and Mr. Darwin, Mr. Mivart tells 
 us, " virhie is a mere kind of retrieving : " and, 
 that we may not miss the point of the joke, he 
 puts it in italics. But what if it is ? Does that 
 make it less virtue ? Suppose I say that sculp- 
 ture is a " mere way " of stone-cutting, and 
 painting a " mere way " of daubing canvas, and 
 music a " mere way '' of making a noise, the 
 statements are quite true ; but they only show 
 that I see no other method of depreciating some 
 of the noblest aspects of humanity than that of 
 using language in an inadequate and misleading 
 sense about them. And the peculiar inappro- 
 priateness of this particular nickname to the views 
 in question, arises from the circumstance which 
 Mr. Mivart would doubtless have recollected, if his 
 Avish to ridicule had not for the moment obscured 
 his judgment — that whether the law of evolution 
 applies to man or not, that of hereditary transmis- 
 sion certainly does. Mr. Mivart will hardly deny 
 that a man owes a large share of the moral 
 tendencies which he exhibits to his ancestors ; and 
 the man who inherits a desire to steal from a 
 kleptomaniac, or a tendency to benevolence from a 
 Howard, is, so far as he illustrates hereditary 
 transmission, comparable to the dog who inherits 
 the desire to fetch a duck out of the water from 
 his retrieving sire. So that, evolution, or no 
 evolution, moral qualities are comparable to a 
 
V MR. DARWIN'S CRITICS 173 
 
 "kind of retrieving;" though the comparison, if 
 meant for the purposes of casting obloquy on 
 evolution, does not say much for the fairness of 
 those who make it. 
 
 The Quarterly Reviewer and Mr. Mivart base 
 their objections to the evolution of the mental facul- 
 ties of man from those of some lower animal form 
 upon what they maintain to be a difference in kind 
 between the mental and moral faculties of men and 
 brutes ; and I have endeavoured to show, by exposing 
 the utter unsoundness of their philosophical basis, 
 that these objections are devoid of importance. 
 
 The objections which Mr. Wallace brings for- 
 ward to the doctrine of the evolution of the mental 
 faculties of man from those of brutes by natural 
 causes, are of a different order, and require 
 separate consideration. 
 
 If I understand him rightly, he by no means 
 doubts that both the bodily and the mental facul- 
 ties of man have been evolved from those of 
 some lower animal ; but he is of opinion that 
 some agency beyond that which has been con- 
 cerned in the evolution of ordinary animals has 
 been operative in the case of man. " A superior 
 intelligence has guided the development of man 
 in a definite direction and for a special purpose, 
 just as man guides the development of many 
 animal and vegetable forms." ^ I understand this 
 
 ^- "The Limits of Natural Selection as applied to Man " {loc. 
 cit. p. 359). 
 
174 MR. daewin's critics V 
 
 to mean that, just as the rock-iDigeon has been 
 produced by natural causes, while the evolution of 
 the tumbler from the blue rock has required the 
 special intervention of the intelligence of man, so 
 some anthropoid form may have been evolved by 
 variation and natural selection ; but it could never 
 liave given rise to man, unless some superior intel- 
 ligence had played the part of the pigeon-fancier. 
 According to Mr. Wallace, " whether we com- 
 pare the savage with the higher developments of 
 man, or with the brutes around him, we are alike 
 driven to the conclusion, that, in his large and 
 well-developed brain, he possesses an organ quite 
 disproportioned to his requirements " (p. 343) ; 
 and he asks, " What is there in the hfe of the 
 savage but the satisfying of the cravings of ap- 
 petite in the simplest and easiest way ? What 
 thoughts, idea, or actions are there that raise him 
 many grades above the elephant or the ape?" 
 (p. 342.) I answer Mr. Wallace by citing a re- 
 markable passage which occurs in his instructive 
 paper on " Instinct in Man and Animals." 
 
 "Savages make long journeys in many directions, and, their 
 vhole faculties being directed to the subject, they gain a wide 
 and accurate knowledge of the topography, not only of their 
 own district, but of all the regions round about. Every one 
 who has travelled in a new direction communicates his know- 
 ledge to those who have travelled less, and descriptions of routes 
 and localities, and minute incidents of travel, form one of the 
 main staples of conversation around the evening fire. Every 
 wanderer or captive from another tribe adds to the store of 
 
V MR. DARWIN'S CRITICS 175 
 
 information, and, as the very existence of individuals and of 
 whole families and tribes depends upon the completeness of this 
 knowledge, all the acute perceptive faculties of the adult savage 
 are directed to acquiring and perfecting it. The good hunter or 
 warrior thus comes to know the bearing of every hill and moun- 
 tain range, the directions and junctions of all the streams, the 
 situation of each tract characterised by peculiar vegetation, not 
 only within the area he has himself traversed, but perhaps for 
 a hundred miles around it. His acute observation enables him 
 to detect the slightest undulations of the surface, the various 
 changes of subsoil and alterations in the character of the vegeta- 
 tion that would be quite imperceptible to a stranger. His eye is 
 always open to the direction in which he is going ; the mossy 
 side of trees, the presence of certain plants under the shade of 
 rocks, the morning and evening flight of birds, are to him 
 indications of direction almost as sure as the sun in the heavens " 
 (pp. 207, 208). 
 
 I have seen enough of savages to be able to 
 declare that nothing can be more admirable than 
 this description of what a savage has to learn. 
 But it is incomplete. Add to all this the know- 
 ledge which a savage is obliged to gain of the 
 properties of plants, of the characters and habits 
 of animals, and of the minute indications by which 
 their course is discoverable : consider that even an 
 Australian can make excellent baskets and nets, 
 and neatly fitted and beautifully balanced spears ; 
 that he learns to use these so as to be able to 
 transfix a quartern loaf at sixty yards ; and that 
 very often, as in the case of the American Indians, 
 the language of a savage exhibits complexities 
 which a well-trained European finds it difficult to 
 master : consider that every time a savage tracks 
 
176 MR. Darwin's critics v 
 
 his game he employs a minuteness of observation^ 
 and an accuracy of inductive and deductive reason- 
 ing which, applied to other matters, would assure 
 some reputation to a man of science, and I think 
 we need ask no further why he possesses such a 
 fair supply of brains. In complexity and diflficulty, 
 I should say that the intellectual labour of a " good 
 hunter ur warrior " considerably exceeds that of 
 an ordinary Englishman. The Civil Service Ex- 
 aminers are held in great terror by young English- 
 men ; but even their ferocity never tempted them 
 to require a candidate to possess such a knowledge 
 of a parish as Mr. Wallace justly points out 
 savages may possess of an area a hundred miles 
 or more in diameter. 
 
 But suppose, for the sake of argument, that a 
 savage has more brains than seems proportioned 
 to his wants, all that can be said is that the objec- 
 tion to natural selection, if it be one, applies quite 
 as strongly to the lower animals. The brain of a 
 porpoise is quite wonderful for its mass, and for the 
 development of the cerebral convolutions. And 
 yet since we have ceased to credit the story of 
 Arion, it is hard to believe that porpoises are much 
 troubled with intellect : and still more difficult is 
 it to imagine that their big brains are only a pre- 
 paration for the advent of sonae accomplished 
 cetacean of the future. Surely, again, a wolf must 
 have too much brains, or else how is it that a dog 
 with only the same quantity and form of brain is 
 
V MR. DARWIN'S CRITICS 177 
 
 able to develop such singular intelligence ? The 
 wolf stands to the dog in the same relation as the 
 savage to the man ; and, therefore, if Mr. Wallace's 
 doctrine holds good, a higher power must have 
 superintended the breeding up of wolves from 
 some inferior stock, in order to . prepare them to 
 become dogs. 
 
 Mr. Wallace further maintains that the origin 
 of some of man's mental faculties by the preserva- 
 tion of useful variations is not possible. Such, 
 for example, are " the capacity to form ideal con- 
 ceptions of space and time, of eternity and infin- 
 ity; the capacity for intense artistic feelings of 
 pleasure in form, colour, and composition ; and for 
 those abstract notions of form and number which 
 render geometry and arithmetic possible." " How,'' 
 he asks, " were all or any of these faculties first 
 developed, when they could have been of no pos- 
 sible use to man in his early stages of barbarism ? " 
 
 Surely the answer is not far to seek. The 
 lowest savages are as devoid of any such concep- 
 tions as the brutes themselves. What sort of 
 conceptions of space and time, of form and num- 
 ber, can be possessed by a savage who has not got 
 so far as to be able to count beyond five or six, who 
 does not know how to draw a triangle or a circle, 
 and has not the remotest notion of separating the 
 particular quality we call form, from the other 
 qualities of bodies ? None of these capacities are 
 exhibited by men, unless they form part of a 
 
178 MR. Darwin's critics v 
 
 tolerably advanced society. And, in such a society, 
 there are abundant conditions by which a selective 
 influence is exerted in favour of those persons who 
 exhibit an approximation towards the possession 
 of these capacities. 
 
 The savage who can amuse his fellows by telling 
 a good story over the nightly fire, is held by them 
 in esteem and rewarded, in one way or another, 
 for so doing — in other words, it is an advantage to 
 him to possess this power. He who can carve a 
 paddle, or the figure-head of a canoe better, 
 similarly profits beyond his duller neighbour. He 
 who counts a little better than others, gets most 
 yams when barter is going on, and forms the 
 shrewdest estimate of the numbers of an opposing 
 tribe. ^ The experience of daily life shows that the 
 conditions of our present social existence exercise 
 the most extraordinarily powerful selective influence 
 in favour of novelists, artists, and strong intellects 
 of all kinds ; and it seems unquestionable that all 
 forms of social existence must have had the same 
 tendency, if we consider the indisputable facts that 
 even animals possess the power of distinguishing 
 form and number, and that they are capable of 
 deriving pleasure from particular forms and 
 sounds. If we admit, as Mr. Wallace does, that 
 the lowest savages are not raised " many grades 
 above the elephant and the ape ; " and if we 
 further admit, as I contend must be admitted, that 
 the conditions of social life tend, powerfully, to 
 
V MB. DARWIN'S CRITICS 179 
 
 give an advantage to those individuals who 
 vary in the direction of intellectual or aesthetic 
 excellence, what is there to interfere with the 
 belief that these higher faculties, like the rest, owe 
 their development to natural selection ? 
 
 Finally, with respect to the development of the 
 moral sense out of the simple feelings of pleasure 
 and pain, liking and disliking, with which the 
 lower animals are provided, I can find nothing in 
 Mr. Wallace's reasonings which has not already 
 been met by Mr. Mill, Mr. Spencer, or Mr. 
 Darwin, 
 
 I do not propose to follow the Quarterly 
 Reviewer and Mr. Mivart through the long string 
 of objections in matters of detail which they 
 bring against Mr. Darwin's views. Every one who 
 has considered the matter carefully will be able to 
 ferret out as many more " difficulties " ; but he 
 will also, I believe, fail as completely as they 
 appear to me to have done, in bringing forward 
 any fact which is really contradictory of Mr. 
 Darwin's views. Occasionally, too, their objections 
 and criticisms are based upon errors of their own. 
 As, for example, when Mr. Mivart and the 
 Quarterly Reviewer insist upon the resemblances 
 between the eyes of Cephalopoda and Verteirata, 
 quite forgetting that there are striking and alto- 
 gether fundamental differences between them ; or 
 when the Quarterly Reviewer corrects Mr. Darwin 
 
180 MR. Darwin's critics v 
 
 for saying that the gibbons, " without having been 
 taught, can walk or run upright with tolerable 
 quickness, though they move awkwardly, and much 
 less securely than man." The Quarterly Reviewer 
 says, " This is a little misleading, inasmuch as it is 
 not stated that this upright progression is effected 
 by placing the enormously long arms behind the 
 head, or holding them out backwards as a balance 
 in progression." 
 
 Now, before carping at a small statement like 
 this, the Quarterly Reviewer should have made 
 sure that he was quite right. But he happens to 
 be quite wrong. I suspect he got his notion of 
 the manner in which a gibbon walks from a citation 
 in " Man's Place in Nature." But at that time I 
 had not seen a gibbon walk. Since then I have, 
 and I can testify that nothing can be more precise 
 than Mr. Darwin's statement. The gibbon I saw 
 walked without either putting his arms behind 
 his head or holding them out backwards. All he 
 did was to touch the ground with the outstretched 
 ■fingers of his long arms now and then, just as one 
 sees a man who carries a stick, but does not need 
 one, touch the ground with it as he walks along. 
 
 Again, a large number of the objections brought 
 forward by Mr. Mivart and the Quarterly Reviewer 
 apply to evolution in general, quite as much as to 
 the particular form of that doctrine advocated by 
 Mr. Darwin ; or, to their notions of Mr. Darwin's 
 views and not to what they really are. An excel- 
 
V MR. DARWIN'S CRITICS 181 
 
 lent example of this class of difficulties is to be 
 found in Mr. Mivart's chapter on " Independent 
 Similarities of Structure.'' Mr. Mivart says that 
 these cannot be explained by an " absolute and 
 pure Darwinian," but " that an innate power and 
 evolutionary law, aided by the corrective action 
 of natural selection, should have furnished like 
 needs with like aids, is not at all improbable " 
 (p. 82). 
 
 I do not exactly know what Mr. Mivart means 
 by an " absolute and pure Darwinian ; " indeed 
 Mr. Mivart makes that creature hold so many 
 smgular opinions that I doubt if I can ever have 
 seen one alive. But I find nothing in his 
 statement of the view which he imagines to be 
 originated by himself, which is really inconsistent 
 with what I understand to be Mr. Darwin's views. 
 
 I apprehend that the foundation of the theory 
 of natural selection is the fact that living bodies 
 tend incessantly to vary. This variation is neither 
 indefinite, nor fortuitous, nor does it take place in 
 all directions, in the strict sense of these words. 
 
 Accurately speaking, it is not indefinite, nor 
 does it take place in all directions, because it is 
 limited by the general characters of the type to 
 which the organism exhibiting the variation 
 belongs. A whale does not tend to vary in the 
 direction of producing feathers, nor a bird in the 
 direction of developing whalebone. In popular 
 language there is no harm in saying that the 
 
182 MK. daewin's critics V 
 
 waves which break upon the sea-shore are inde- 
 finite, fortuitous, and break in all directions. In 
 scientific language, on the contrary, such a state- 
 ment would be a gross error, inasmuch as every 
 particle of foam is the result of perfectly definite 
 forces, operating according to no less definite laws. 
 In like manner, every variation of a living form, 
 however minute, however apparently accidental, is 
 inconceivable except as the expression of the 
 operation of molecular forces or " powers " resident 
 within the organism. And, as these forces certainly 
 operate according to definite laws, their general 
 result is, doubtless, in accordance with some general 
 law which subsumes them all. And there appears 
 to be no objection to call this an "evolutionary 
 law." But nobody is the wiser for doing so, or has 
 thereby contributed, in the least degree, to the 
 advance of the doctrine of evolution, the great 
 need of which is a theory of variation. 
 
 When Mr. Mivart tells us that his "aim has 
 been to support the doctrine that these specTes 
 have been evolved by ordinary natural laws (for 
 the most part unknown), aided by the subordinate 
 action of ' natural selection ' " (pp. 332-3), he seems 
 to be of opinion that his enterprise has the merit 
 of novelty. All I can say is that I have never had 
 the slightest notion that Mr. Darwin's aim is in 
 any way different from this. If I affirm that 
 " species have been evolved by variation ^ (a natural 
 ' Including under this head hereditary transmission. 
 
V MB. darwin's critics 183 
 
 process, the laws of which are for the most part 
 unknown), aided by the subordinate action of 
 natural selection," it seems to me that I enunciate 
 a proposition which constitutes the very pith and 
 marrow of the first edition of the " Origin of 
 Species." And what the evolutionist stands in 
 need of just now, is not an iteration of the funda- 
 mental principle of Darwinism, but some light 
 upon the questions, What are the limits of varia- 
 tion ? and, If a variety has arisen, can that variety 
 be perpetuated, or even intensified, when selective 
 conditions are indifferent, or perhaps unfavourable 
 to its existence ? I cannot find that Mr. Darwin 
 has ever been very dogmatic in answering these 
 questions. Formerly, he seems to have inclined 
 to reply to them in the negative, while now his 
 inclination is the other way. Leaving aside those 
 broad questions of theology, philosophy, and 
 ethics, by the discussion of which neither the 
 Quarterly Reviewer nor Mr. Mivart can be said to 
 have damaged Darwinism — whatever else they 
 have injured — this is what their criticisms come 
 to. They confound a struggle for some rifle-pits 
 with an assault on the fortress. 
 
 In some respects, finally, I can only characterise 
 the Quarterly Reviewer's treatment of Mr. Darwin 
 as alike unjust and unbecoming. Language of 
 this strength requires justification, and on that 
 ground I add the remarks which follow. 
 
 The Quarterly Reviewer opens his essay by a 
 
 41 
 
184 MR. DARWIN'S CRITICS V 
 
 careful enumeration of all those points upon which, 
 during the course of thirteen years of incessant 
 labour, Mr. Darwin has modified his opinions. It 
 has often and justly been remarked, that what 
 strikes a candid student of Mr. Darwin's works is 
 not so much his industry, his knowledge, or even 
 the surprising fertility of his inventive genius ; 
 but that unswerving truthfulness and honesty 
 which never permit him to hide a weak place, or 
 gloss over a difficulty, but lead him, on all occa- 
 sions, to point out the weak places in his own 
 armour, and even sometimes, it appears to me, to 
 make admissions against himself which are quite 
 unnecessary. A critic who desires to attack Mr, 
 Darwin has only to read his works with a desire to 
 observe, not their merits, but their defects, and he 
 will find, ready to hand, more adverse suggestions 
 than are likely ever to have suggested themselves 
 to his own sharpness, without Mr. Darwin's self- 
 denying aid. 
 
 Now this quality of scientific candour is not so 
 common that it needs to be discouraged ; and it 
 appears to me to deserve other treatment than 
 that adopted by the Quarterly Reviewer, who deals 
 with Mr. Darwin as an Old Bailey barrister deals 
 with a man against whom he wishes to obtain a 
 conviction, per fas aut nefas, and opens his case 
 by endeavouring to create a prejudice against the 
 prisoner in the minds of the jury. In his eager- 
 ness to carry out this laudable design, the Quarterly 
 
V MR. Darwin's critics 185 
 
 Reviewer cannot even state the history of the 
 doctrine of natural selection without an oblique 
 and entirely unjustifiable attempt to depreciate 
 Mr. Darwin. " To Mr. Darwin," says he, " and 
 (through Mr. Wallace's reticence) to Mr. Darwin 
 alone, is due the credit of having first brought it 
 prominently forward and demonstrated its truth.'' 
 No one can less desire than I do, to throw a doubt 
 upon Mr. Wallace's originality, or to qiiestiou his 
 claim to the honour of being one of the originators 
 of the doctrine of natural selection ; but the state- 
 ment that Mr. Darwin has the sole credit of 
 originating the doctrine because of Mr. Wallace's 
 reticence is simply ridiculous. The proof of this 
 is, in the first place, afforded by Mr. Wallace him- 
 self, whose noble freedom from petty jealousy in 
 this matter smaller folk would do well to imitate, 
 and who writes thus : — " I have felt all my life, 
 and I still feel, the most sincere satisfaction 
 that Mr. Darwin had been at work long before 
 me and that it was not left for me to attempt to 
 write the ' Origin of Species.' I have long since 
 measured my own strength, and know well that it 
 would be quite unequal to that task.'' So that if 
 there was any reticence at all in the matter, it was 
 Mr. Darwin's reticence during the long twenty 
 years of study which intervened between the con- 
 ception and the publication of his theory, which 
 gave Mr. Wallace the chance of being an indepen- 
 dent discoverer of the importance of natural 
 
186 MR. DARWIN'S CRITICS v 
 
 selection. And, finally, if it be recollected that 
 Mr. Darwin's and Mr. Wallace's essays were 
 published simultaneously in the " Journal of the 
 Linnsean Society " for 1858, it follows that the 
 Reviewer, while obliquely depreciating Mr. Dar- 
 win's deserts, has in reality awarded to him a 
 priority which, in legal strictness, does not exist. 
 Mr. Mivart, whose opinions so often concur with 
 those of the Quarterly Reviewer, puts the case in 
 a way, which I much regret to be obliged to say, 
 is, in my judgment, quite as incorrect ; though 
 the injustice may be less glaring. He says that 
 the theory of natural selection is, in general, ex- 
 clusively associated with the name of Mr. Darwin, 
 " on account of the noble self-abnegation of Mr. 
 Wallace." As I have said, no one can honour Mr. 
 Wallace more than I do, both for what he has 
 done and for what he has not done, in his relation 
 to Mr. Darwin. And perhaps nothing is more 
 creditable to him than his frank declaration that 
 he could not have written such a work as the 
 " Origin of Species." But, by this declaration, the 
 person most directly interested in the matter re- 
 pudiates, by anticipation, Mr. Mivart's suggestion 
 that Mr. Darwin's eminence is more or less due to 
 Mr. Wallace's modesty. 
 
VI 
 EVOLUTION IN BIOLOGY 
 
 [1878] 
 
 In the former lialf of the eighteenth century, the 
 term " evolution " was introduced into biological 
 writings, in order to denote the mode in which 
 some of the most eminent physiologists of that time 
 conceived that the generations of living things took 
 place ; in opposition to the hypothesis advocated, 
 in the preceding century, by Harvey in that re- 
 markable work ^ which would give him a claim to 
 rank among the founders of biological science, even 
 had he not been the discoverer of the circulation 
 of the blood. 
 
 One of Harvey's prime objects is to defend and 
 establish, on the basis of direct observation, the 
 opinion already held by Aristotle ; that, in the 
 higher animals at any rate, the formation of the 
 
 * The Exercitationes de Generatione Animalium, which Dr 
 George Ent extracted from him and published in 1651. 
 
188 EVOLUTION IN BIOLOGY VI 
 
 new organism by the process of generation takes 
 place, not suddenly, by simultaneous accretion of 
 rudiments of all, or of the most important, of the 
 organs of the adult ; nor by sudden metamorphosis 
 of a formative substance into a miniature of the 
 whole, which subsequently grows ; but by cpigencsis, 
 or successive differentiation of a relatively homo- 
 geneous rudiment into the parts and structures 
 which are characteristic of the adult. 
 
 " Et prim6, quidem, quoniam per epigenesin sive partium 
 superexorientimn additanientum pullum fabricari certum est : 
 queenam pars ante alias omnes exstruatur, et quid de ilia ejusque 
 generandi modo observandum veniat, dispiciemus. Ratum sane 
 est et in ovo manifeste apparet quod Aristoteles de perfectorum 
 aninialium generationc enuntiat : niminim, non omnes partes 
 simul fieri, sed ordine aliam post aliam ; primumque existere 
 particulam genitalem, cujus virtute postea (tanquam ex principio 
 quodam) reliquaj omnes partes prosiliant. Qualem in plantarum 
 seminibus (fabis, puta, aut glandibus) gemmam sive apicem pro- 
 tuberantem cernimus, totius futurse arboris principium. Estque 
 Juxc particiUa vclut films cinan-cipatus seorsumqiic collocatus, et 
 principmm per sc vivcns ; uncle postea membrorum ordo describ- 
 itur ; el qiiceatnqite ad absolvcndiom animal pertinent, dispon- 
 untur.^ Cluon\a.n\ cvixm. nulla pars se ipsain generat ; sed post- 
 qiiam gcneraia est, sc ipsain jam auget ; ideo cam primuvi oriri 
 neccsse est, qucB principium augendi contineat {sive enim planta, 
 sive animal est, ceque omnibus inest quod vim, habcat vegetandi, 
 sive mUricndi),' simulque reliquas omnes partes sue quamque 
 ordine distinguat et formet ; proindeque in eadem primogenita 
 particula anima primario inest, sensus, motusque, et totius vitae 
 auctor et principium." (Exercitatio 51.) 
 
 ^ De Generatione Animalium, lib. ii. cap. i. 
 ^ De Generationc, lib. ii, cap. iv. 
 
VT EVOLUTION IN BIOLOGY 189 
 
 Harvey proceeds to contrast this view with that 
 of the " Medici," or followers of Hippocrates and 
 Galen, who, " badly philosophising," imagined that 
 the brain, the heart, and the liver were simul- 
 taneously first generated in the form of vesicles ; 
 and, at the same time, while expressing his 
 agreement with Aristotle in the principle of epi- 
 genesis, he maintains that it is the blood which is 
 the primal generative part, and not, as Aristotle 
 thought, the heart. 
 
 In the latter part of the seventeenth century, 
 the doctrine of epigenesis, thus advocated by 
 Harvey, was controverted, on the ground of direct 
 observation, by Malpighi, who affirmed that the 
 body of the chick is to be seen in the ^g'g, before 
 the 'puiidum sanguineum makes it appearance. 
 But, from this perfectly correct observation a con- 
 clusion which is by no means warranted was drawn ; 
 namely, that the chick, as a whole, really exists in 
 the egg antecedently to incubation ; and that what 
 happens in the course of the latter process is no 
 addition of new parts, " alias post alias natas," as 
 Harvey puts it, but a simple expansion, or unfold- 
 ing, of the organs which already exist, though they 
 are too small and inconspicuous to be discovered. 
 The weight of Malpighi's observations therefore 
 fell into the scale of that doctrine which Harvey 
 terms metamooyhosis, in contradistinction to epi- 
 genesis. 
 
 The views of Malphigi were warmly welcomed, 
 
190 EVOLUTION IN BIOLOGY vi 
 
 on philosophical grounds, by Leibnitz/ who found 
 in them a support to his hypothesis of monads, 
 and by Malebranche ; ^ while, in the middle of the 
 eighteenth century, not only speculative consider- 
 ations, but a great number of new and interesting 
 observations on the phenomena of generation, led 
 the ingenious Bonnet, and Haller,^ the first physi- 
 ologist of the age, to adopt, advocate, and extend 
 them. 
 
 * "Cependant, pour revenir aux formes ordinaires ou aux 
 ames materielles, cettc duree qu'il leur faut attiibuer a la place 
 de celle qu'on avoit attribuee aux atonies pouiroit faire douter 
 si elles ne vont pas de corps en corps ; ce qui seroit la me- 
 tempsychose, a peu pres comme quelques philosophes out cru la 
 transmission du mouvemont et celle des especes. Mais cette 
 imagination est bien eloignee de la nature des choses. II n'y a 
 point de tel passage ; et c'est ici ou les transformations de 
 Messieurs Swammerdam, Malpighi, et Leewenhoek, qui sent 
 des x>lus excellens observateurs de notre tems, sont venues k mon 
 secours, et m'ont fait admettre plus aisement, que I'animal, et 
 toute autre substance organisee ne commence point lorsque nous 
 Ic croyons, et que sa generation apparente n'est qu'iine de- 
 veloppement et une espece d'augmentation. Aussi ai je remarque 
 que i'auteur de la Recherche de la Verit4, M. Regis, M. Hart- 
 soeker, et d'autres liabiles h.ommes n'ont pas ete fort eloignes 
 de ce sentiment." Leibnitz, Sysihnc Nouvcau de la Nature, 
 1695. The doctrine of " Emboitement " is contained in the 
 Considirations sur le Principe de Vie, 1705 ; the preface to the 
 Theodicee, 1710 ; and the Principcs de la Nature et dc la Grace 
 (§ 6), 1718. 
 
 - "11 est vrai que la pensee la plus raisonnable et la plus 
 conforme a Fexperience sur cette c^uestion tres difficile de la 
 formation du foetus ; c'est que les enfans sont deja presque tout 
 formes avant meme Taction par laquelle ils sont census ; et que 
 leurs meres ne font que leur donner I'accroissement ordinaire 
 dans le temps de la grossesse. " De la Recherche de la Verit6, 
 livre ii. chap. vii. p. 334, 7th ed., 1721. 
 
 ^ The writer is indebted to Dr. Allen Thomson for reference 
 to the evidence contained in a note to Haller's edition of Boer- 
 haave's Proilectioius Academiccs, vol. v. pt. ii. p. 497, published 
 in 1744, that Haller originally advocated epigenesis. 
 
VI EVOLUTION IN BIOLOGY 191 
 
 Bonnet affirms that, before fecundation, the hen's 
 egg contains an excessively minute but complete 
 chick ; and that fecundation and incubation simply 
 cause this germ to absorb nutritious matters, which 
 are deposited in the interstices of the elementary 
 structures of which the miniature chick, or germ, 
 is made up. The consequence of this intussuscep- 
 tive growth is the " development " or " evolution '' 
 of the germ into the visible bird. Thus an organ- 
 ised individual (toiit organist) " is a composite body 
 consisting of the original, or elementary, parts and 
 of the matters which have been associated with 
 them by the aid of nutrition ; " so that, if these 
 matters could be extracted from the individual 
 (tout), it would, so to speak, become concentrated 
 in a point, and would thus be restored to its 
 primitive condition of a germ ; "just as by extract- 
 ing from a bone the calcareous substance which is 
 the source of its hardness, it is reduced to its 
 primitive state of gristle or membrane." ^ 
 
 " Evolution " and " development " are, for 
 Bonnet, synonymous terms ; and since by " evolu- 
 tion " he means simply the expansion of that 
 which was invisible into visibility, he was natur- 
 ally led to the conclusion, at which Leibnitz had 
 arrived by a different line of reasoning, that no 
 such thing as generation, in the proper sense of 
 the word, exists in Nature. The growth of an 
 
 * Considerations sur les Corps organises, chap. Xi 
 
192 EVOLUTION IN BIOLOGY VI 
 
 organic being is simply a process of enlargement 
 as a particle of dry gelatine may be swelled 
 up by the intussusception of water; its death 
 is a shrinkage, such as the swelled jelly might 
 undergo on desiccation. Nothing really new is 
 produced in the living world, but the germs which 
 develop have existed since the beginning of things ; 
 and nothing really dies, but, when what we call 
 death takes place, the living thing shrinks back 
 into its germ state.'^ 
 
 The two parts of Bonnet's hypothesis, namely, 
 the doctrine that all living things proceed from 
 pre-existing germs, and that these contain, one 
 
 ^ Bonnet had the courage of his opinions, and in the 
 Palinginisic Fhilosophique, part vi. chap, iv., he develops a. 
 hypothesis which he terms "Evolution naturelle ; " and which, 
 making allowance for hfs peculiar views of the nature of 
 generation, bears no small resemblance to what is understood 
 by " evolution " at the present day : — 
 
 " Si la volonte divine a cree par un seul Acte 1' Universalite 
 des etres, d'ou venoient ces plantes et ces animaux dont Moyse 
 nous decrit la Production au troisieme et au cinquieme jour du 
 renouvcllement de notre monde ? 
 
 " Abuserois-je de la liberte de conjectures si je disois, que les 
 Plantes et les Animaux qui existent aujourd'hui sont parvenus 
 par une sorte d'evolution naturelle des Etres organises qui 
 peuplaient ce premier Monde, sorti immediatement des Mains 
 du Createur ? . . . 
 
 ' ' Ne supposons que trois revolutions. La Terre vient de sortir 
 des Mains du Createur. Des causes preparees par sa Sagesse 
 font developper de toutes parts les Gernies. Les Etres organises 
 commencent a jouir de I'existence. lis etoient probablement 
 alors bien differens de ce qu'ils sont aujourd'hui. lis I'etoient 
 autant que ce premier Monde differoit de cf lui que nous habitons. 
 Nous manquons de moyens pour juger de ces dissemblances, 
 et peut-etre que le plus habile Naturaliste qui auroit ete ]'lace 
 dans ce premier Monde y auroit entierement meconnu nos Plantes 
 et nos Animaux." 
 
VI EVOLUTION IN BIOLOGY 193 
 
 inclosed within the other, the gerntis of all future 
 living things, which is the hypothesis of " emhoite- 
 ment ; " and the doctrine that every germ contains 
 in miniature all the organs of the adult, which is 
 the hypothesis of evolution or development, in the 
 primary senses of these words, must be carefully 
 distinguished. In fact, while holding firmly by 
 the former. Bonnet more or less modified the 
 latter in his later writings, and, at length, he 
 admits that a " germ " need not be an actual 
 miniature of the organism ; but that it may be 
 merely an " original preformation " capable of 
 producing the latter.^ 
 
 But, thus defined, the germ is neither more nor 
 less than the " particula genitalis " of Aristotle, 
 or the " primordium vegetale " or " ovum " of 
 Harvey; and the "evolution" of such a germ 
 would not be distinguishable from " epigenesis." 
 
 Supported by the great axithority of Haller, the 
 doctrine of evolution, or development, prevailed 
 throughout the whole of the eighteenth century, 
 and Cuvier appears to have substantially adopted 
 Bonnet's later views, though probably he would 
 not have gone all lengths in the direction of 
 " emboitement." In a well-known note to 
 Laurillard's " filoge," prefixed to the last edition 
 
 ^ "Ce mot (germe) ne designera pas seulement un corps 
 organise riduit en ■petit ; il designera encore toute espece (^L^pri- 
 formation onginelle dont un Toitt organique peut resuUcr comme 
 de sonprincipe immediat." — PalingiTtAsio Philosophiqxoe, part x. 
 chap. ii. 
 
194 EVOLUTION IN BIOLOGY vi 
 
 of the " Ossemens fossiles," the " radical de I'etre " 
 is much the same thing as Aristotle's " particula 
 genitalis " and Harvey's " ovum." ^ 
 
 Bonnet's eminent contemporary, Buffon, held 
 nearly the same views with respect to the nature 
 of the germ, and expresses them even more con- 
 fidently. 
 
 " Ccux qui ontcru que le ccBur etoit le premier form^ se sont 
 trompes ; ceux qui disent que c'est le sang se trompent aussi : 
 tout est forme en meme temps. Si Ton ne consulte que I'obser- 
 vation, Ic poulet se voit dans I'ceuf avant qu'il ait ete couve." ^ 
 
 "J'ai ouvert une grande quantite d'ceufs k differens temps 
 avant et apres I'incubation, et je me suis convaincu par mes 
 yeux que le poulet existe en entier dans le milieu de la cicatricule 
 au moment qu'il sort du corps de la poule." ^ 
 
 The " moule interieur " of Buffon is the aggre- 
 gate of elementary parts which const,'.tute the 
 individual, and is thus the equivalent of Bonnet's 
 germ,* as defined in the passage cited above. 
 But Buffon further imagined that innumerable 
 " molecules organiques " are dispersed throughout 
 the world, and that alimentation consists in the 
 
 ^ "M. Cuvier considerant que tous les etres organises sont 
 derives de parens, et ne voj^ant dans la nature aucune force 
 capable de produire I'organisation, croyait a la pre-existence 
 des germes ; non pas a la pre-existence d'un etre tout forme, 
 puisqu'il est bien evident que ce n'estque par des developpemens 
 successifs que I'etre acquiert sa forme ; mais, si Ton peut 
 s'exprimer ainsi, a la pre-existence du radical de I'Ure, radical 
 qui existe avant que la serie des evolutions ne commence, et qui 
 remonte certainement, suivant la belle observation de Bonnet, a 
 plusieurs generations." — Laurillard, Eloqc de Cuvier, note 12. 
 
 ^ Histoire Nalurellc, tom. ii. ed. ii. 1750, p. 350. 
 
 8 Ibid., p. 351. * See particularly Buffon, I.e. p. 41. 
 
VI EVOLUTION IN BIOLOGY 195 
 
 appropriation by the parts of an organism of those 
 molecules which are analogous to them. Growth, 
 therefore, was, on this hypothesis, a process 
 partly of simple evolution, and partly of what has 
 been termed "syngenesis." Buffon's opinion is, 
 in fact, a sort of combination of views, essentially 
 similar to those of Bonnet, with others, somewhat 
 similar to those of the " Medici " whom Harvey 
 condemns. The " molecules organiques " are 
 physical equivalents of Leibnitz's " monads." 
 
 It is a striking example of the difficulty of 
 getting people to use their own powers of investiga- 
 tion accurately, that this form of the doctrine of 
 evolution should have held its ground so long ; 
 for it was thoroughly and completely exploded, 
 not long after its enunciation, by Casper Friederich 
 Wolff, who in his " Theoria Generationis," pub- 
 lished in 1759, placed the opposite theory of 
 epigenesis upon the secure foundation of fact, 
 from which it has never been displaced. But 
 Wolff had no immediate successors. The school 
 of Cuvier was lamentably deficient in embryo- 
 logists ; and it was only in the course of the first 
 thirty years of the present century, that Provost 
 and Dumas in France, and, later on, Dollinger, 
 Pander, "Von Bar, Rathke, and Remak in Germany, 
 founded modern embryology ; while, at the same 
 time, they proved the utter incompatibility of the 
 hypothesis of evolution, as formulated by Bonnet 
 and Haller, with easily demonstrable facts. 
 
196 EVOLUTION IN BIOLOGY VI 
 
 Nevertheless, though the conceptions originally 
 denoted by " evolution " and " development " were 
 shown to be untenable, the words retained their 
 application to the process by which the embryos of 
 living beings gradually make their appearance ; 
 and the terms " Development," " Entwickelung," 
 and " Evolutio," are now indiscriminately used for 
 the series of genetic changes exhibited by living 
 beings, by writers who would emphatically deny 
 that " Development " or " Entwickelung " or 
 "Evolutio," in the sense in which these words 
 were usually employed by Bonnet or by Haller, 
 ever occurs. 
 
 Evolution, or development, is, in fact, at present 
 employed in biology as a general name for the 
 history of the steps by which any living being has 
 acquired the morphological and the physiological 
 characters which distinguish it. As civil history 
 may be divided into biography, which is the history 
 of individuals, and universal history, which is the 
 history of the human race, so evolution falls 
 naturally into two categories — the evolution of the 
 individual, and the evolution of the sum of living 
 beings. It will be convenient to deal with the 
 modern doctrine of evolution under these two heads. 
 
 I. The Evolution of the Indimdital. 
 No exception is at this time, known to the 
 general law, established upon an immense multi- 
 tude of direct observations, that every living thing 
 
VI EVOLUTION IN BIOLOGY 197 
 
 is evolved from a particle of matter in which no 
 trace of the distinctive characters of the adult 
 form of that living thing is discernible. This 
 particle is termed a germ. Harvey^ says — ■ 
 
 "Omnibus viventibus primordium insit, ex quo et a quo pro- 
 veniant. \Ac&a.th.ocnohiii primordium vcgetalavi.Qjmna.vt ; nempe 
 substantiam quandam corpoream vitam habentem potentia ; vel 
 quoJdam per se existens, quod aptum sit, in vegetativani 
 formam, ab interno principio operante, mutari. Quale nempe 
 primordium, ovum est et plantarum semen ; tale etiam vivi- 
 parorum conceptus, et insectorum vermis ab Aristotele dictus : 
 diversa scilicet diversorum viventium primordia. " 
 
 The definition of a germ, as " matter potentially 
 alive, and having within itself the tendency to 
 assume a definite living form," appears to meet 
 all the requirements of modern science. For, 
 notwithstanding it might be justly questioned 
 whether a germ is not merely potentially, but 
 rather actually, alive, though its vital manifesta- 
 tions are reduced to a minimum, the term 
 " potential " may fairly be used in a sense broad 
 enough to escape the objection. And the quali- 
 fication of " potential " has the advantage of 
 reminding us that the great characteristic of 
 the germ is not so much what it is, but what it 
 may, under suitable conditions, become. Harvey 
 shared the belief of Aristotle — whose writings he 
 so often quotes and of whom he speaks as his 
 
 ^ Exereitationes de Generatiorie. Ex. 62, "Ovum esse 
 primordium commune omnibus animalibus." 
 
198 EVOLUTION IN BIOLOGY TI 
 
 precursor and model, with the generous respect with 
 which one genuine worker should regard another 
 — that such germs may arise by a process of 
 " equivocal generation " out of not-living matter ; 
 and the aphorism so commonly ascribed to him, 
 " omnc vivum ex ovo" and which is indeed a fair 
 summary of his reiterated assertions, though 
 incessantly employed against the modem advo- 
 cates of spontaneous generation, can be honestly 
 so used only by those who have never read a 
 score of pages of the " Exercitationes." Harvey, 
 in fact, believed as implicitly as Aristotle did in the 
 equivocal generation of the lower animals. But, 
 while the course of modern investigation has only 
 brought out into greater prominence the accuracy 
 of Harvey's conception of the nature and mode of 
 development of germs, it has as distinctly tended 
 to disprove the occurrence of equivocal generation, 
 or abiogenesis, in the present course of nature. 
 In the immense majority of both plants and 
 animals, it is certain that the germ is not merely 
 a body in which life is dormant or potential, but 
 that it is itself simply a detached portion of 
 the substance of a pre-existing living body ; and 
 the evidence has yet to be adduced which will 
 satisfy any cautious reasoner that " omne vivum 
 ex vivo " is not as well-established a law of 
 the existing course of nature as " omne vivum 
 ex ovo." 
 
 In all instances which have yet been investi- 
 
VI EVOLUTION IN BIOLOGY 199 
 
 gated, the substance of this germ has a peculiar 
 chemical composition, consisting of at fewest four 
 elementary bodies, viz., carbon, hydrogen, oxygen, 
 and nitrogen, united into the ill-defined compound 
 known as protein, and associated with much 
 water, and very generally, if not always, with 
 sulphur and phosphorus in minute proportions. 
 Moreover, up to the present time, protein is known 
 only as a product and constituent of living 
 matter. Again, a true germ is either devoid of 
 any structure discernible by optical means, or, at 
 most, it is a simple nucleated cell.^ 
 
 In all cases the process of evolution consists in 
 a succession of changes of the form, structure, 
 and functions of the germ, by which it passes, 
 step by step, from an extreme simplicity, or rela- 
 tive homogeneity, of visible structure, to a greater 
 or less degree of complexity or heterogeneity ; 
 and the course of progressive differentiation is 
 usually accompanied by growth, which is effected 
 by intussusception. This intussusception, how- 
 ever, is a very different process from that imagined 
 either by Buffon or by Bonnet. The substance 
 by the addition of which the germ is enlarged is 
 in no case simply absorbed, ready-made, from the 
 not-living world and packed between the elemen- 
 tary constituents of the germ, as Bonnet imagined; 
 
 ^ In some cases of sexless multiplication the germ is a cell- 
 nggretjate — if we call germ only that which is already detached 
 from the parent organism. 
 42 
 
200 EVOLUTION IN BIOLOGY VI 
 
 still less does it consist of the " molecules or- 
 ganiques " of Buffon. The new material is, in great 
 measure, not only absorbed but assimilated, so 
 that it becomes part and parcel of the molecular 
 structure of the living body into which it enters. 
 And, so far from the fully developed organism 
 being simply the germ plus the nutriment which 
 it has absorbed, it is probable that the adult con- 
 tains neither in form, nor in substance, more than 
 an inappreciable fraction of the constituents of 
 the germ, and that it is almost, if not wholly, 
 made up of assimilated and metamorphosed 
 nutriment. In the great majority of cases, at 
 any rate, the full-grown organism becomes what 
 it is by the absorption of not -living matter, and 
 its conversion into living matter of a specific type. 
 As Harvey says (Ex. 45), all parts of the body 
 are nourished " ab eodem succo alibili, aliter 
 aliterque cambiato," " ut planta; omnes ex eodem 
 communi nutrimento (sive rore seu terrse 
 humore)." 
 
 In all animals and plants above the lowest the 
 germ is a nucleated cell, using that term in its 
 broadest sense ; and the first step in the process 
 of the evolution of the individual is the division 
 of this cell into two or more portions. The pro- 
 cess of division is repeated, until the organism, 
 from being unicellular, bc^comes multicellular. 
 The single cell becomes a cell-aggregate ; and it 
 is to the growth and metamorphosis of the cells 
 
TI EVOLUTION IN BIOLOGY 201 
 
 of the cell-aggregate thus produced, that all the 
 organs and tissues of the adult owe their origin. 
 
 In certain animals belonging to every one of 
 the chief groups into which the Metazoa are 
 divisible, the cells of the cell-aggregate which 
 results from the process of yelk-division, and 
 which is termed a morula, diverge from one 
 another in such a manner as to give rise to a 
 central space, around which they dispose them- 
 selves as a coat or envelope ; and thus the morula 
 becomes a vesicle filled with fluid, the planula. 
 The wall of the planula is next pushed in on one 
 side, or invaginated, whereby it is converted into 
 a double-walled sac with an opening, the hlasto- 
 porc, which leads into the cavity lined by the 
 inner wall. This cavity is the primitive alimen- 
 tary cavity or archenteron ; the inner or inva- 
 ginated layer is the hypoUast ; the outer the 
 cpihlast ; and the embryo, in this stage, is termed 
 a gastrula. In all the higher animals a layer of 
 cells makes its appearance between the hypoblast 
 and the epiblast, and is termed the viesohlast. In 
 the further course of development the epiblast 
 becomes the ectoderm, or epidermic layer of the 
 body ; the hypoblast becomes the epithelium of 
 the middle portion of the alimentary canal ; and 
 the mesoblast gives rise to all the other tissues, 
 except the central nervous system, which origin- 
 ates from an ingrowth of the epiblast. 
 
 With more or less modification in detail, the 
 
202 EVOLUTION IN BIOLOGY VI 
 
 embryo lias been observed to pass through these 
 successive evolutional stages in sundry Sponges, 
 Coelenterates, Worms, Echinoderms, Tunicates, 
 Arthropods, Mollusks, and Vertebrates ; and there 
 are valid reasons for the belief that all animals of 
 higher organisation than the Protozoa agree in the 
 general character of the early stages of their indi- 
 vidual evolution. Each, starting from the condition 
 of a simple nucleated cell, becomes a cell-aggregate ; 
 and this passes through a condition which re- 
 presents the gastrula stage, before taking on the 
 features distinctive of the group to which it belongs. 
 Stated in this form, the " gastroea theory " of 
 Haeckel appears to the present writer to be one of 
 most important and best founded of recent general- 
 isations. So far as individual plants and animals 
 are concerned, therefore, evolution is not a specu- 
 lation but a fact ; and it takes place by epigenesis. 
 
 "Animal. . . per cyzfccwesm procreatiir, materiam simul attra- 
 hit, parat, concoquit, et eadem utitur ; formatur simul et augetur 
 . . . primum futuri corporis concrementum . . . prout augotur, 
 diviJitur sensirn et distinguitur in partes, non simul omnes, sed 
 alias post alias natas, et ordine quasque suo emergentes." ^ 
 
 In these words, by the divination of genius, 
 Harvey, in the seventeenth century, summed up 
 the outcome of the work of all those who, with 
 appliances he could not dream Df, are continuing 
 his labours in the nineteenth century. 
 
 ^ Harvey, Excrcitationes dc Gciicratione. Ex. 45, "Quoeuam 
 sit pulli materia et quomodo fiat in Ovo. " 
 
YI EVOLUTION IN BIOLOGY 203 
 
 Nevertheless, though the doctrine of epigenesis, 
 as understood by Harvey, has definitively triumphed 
 over the doctrine of evolution, as understood 
 by his opponents of the eighteenth century, 
 it is not impossible that, when the analysis of the 
 process of development is carried still further, and 
 the origin of the molecular components of the 
 physically gross, though sensibly minute, bodies 
 ■which we term germs is traced, the theory of de- 
 velopment will approach more nearly to meta- 
 morphosis than to epigenesis. Harvey thought 
 that impregnation influenced the female organism 
 as a contagion ; and that the blood, which he con- 
 ceived to be the first rudiment of the germ, arose 
 in the clear fluid of the " colliquamentum " of the 
 ovum by a process of concrescence, as a sort of 
 living precipitate. We now know, on the contrary, 
 that the female germ or ovum, in all the higher 
 animals and plants, is a body which possesses the 
 structure of a nucleated cell; that impregnation 
 consists in the fusion of the substance ^ of another 
 more or less modified nucleated cell, the male germ, 
 with the ovum ; and that the structural com- 
 ponents of the body of the embryo are all derived, 
 by a process of division, from the coalesced male 
 and female germs. Hence it is conceivable, and 
 indeed probable, that every part of the adult con- 
 tains molecules, derived both from the male and 
 
 1 [At any rate of the nuclei of the two germ-cells. 1893]. 
 
204 EVOLUTION IN BIOLOGY vi 
 
 from the female parent ; and that, regarded as a 
 mass of molecules, the entire organism may be com- 
 pared to a web of which the warp is derived from the 
 female and the woof from the male. And each of 
 these may constitute one individuality, in the same 
 sense as the whole organism is one individual, al- 
 thousfh the matter of the orcranism has been con- 
 stantly changing. The primitive male and female 
 molecules may play the part of Buffon's "monies 
 organiques," and mould the assimilated nutriment, 
 each according to its own type, into innumerable 
 new molecules. From this point of view the process, 
 which, in its superficial aspect, is epigenesis, appears 
 in essence, to be evolution, in the modified sense 
 adopted in Bonnet's later writings; and develop- 
 ment is merely the expansion of a potential organ- 
 ism or " original preformation " according to fixed 
 laws. 
 
 II. The Evolution of the Sum of Living Beings. 
 
 The notion that all the kinds of animals and 
 plants may have come into existence by the growth 
 and modification of primordial germs is as old as 
 speculative thought ; but the modern scientific 
 form of the doctrine can be traced historically to 
 the influence of several converging lines of philo- 
 sophical speculation and of physical observation, 
 none of which go farther back than the seven- 
 teenth century. These are : — 
 
VI EVOLUTION IN BIOLOGY 205 
 
 1. The enunciation by Descartes of the concep- 
 tion that the physical universe, whether living or 
 not living, is a mechanism, and that, as such, it is 
 explicable on physical principles. 
 
 2. The observation of the gradations of struc- 
 ture, from extreme simplicity to very great com- 
 plexity, presented by living things, and of the 
 relation of these graduated forms to one another. 
 
 3. The observation of the existence of an anal- 
 ogy between the series of gradations presented by 
 the species which compose any great group of 
 animals or plants, and the series of embryonic 
 conditions of the highest members of that group. 
 
 4. The observation that large groups of species 
 of widely different habits present the same funda- 
 mental plan of structure ; and that parts of the 
 same animal or plant, the functions of which are 
 very different, likewise exhibit modifications of a 
 common plan. 
 
 5. The observation of the existence of structures, 
 in a rudimentary and apparently useless condition, 
 in one species of a group, which are fully devel- 
 oped and have definite functions in other species 
 of the same group. 
 
 6. The observation of the effects of varying 
 conditions in modifying living organisms. 
 
 7. The observation of the facts of geographical 
 distribution. 
 
 8. The observation of the facts of the geological 
 succession of the forms of life. 
 
206 EVOLUTION IN BIOLOGY VI 
 
 1. Notwithstanding the elaborate disguise which 
 fear of the powers that were led Descartes to 
 throw over his real opinions, it is impossible to 
 read the " Principes de la Philosophie " without 
 acquiring the conviction that this great philosopher 
 held that the physical world and all things in it, 
 whether living or not living, have originated by a 
 process of evolution, due to the continuous opera- 
 tion of purely physical causes, out of a primitive 
 relatively formless matter.^ 
 
 The following passage is especially instructive : — 
 
 " Et tant s'eu faut que je veuille que Ton croie toutes les 
 choses que j'ecrirai, que meme je pretends en proposer ici quelques 
 unes que je crois absolument etre fausses ; h savoir, je ne doute 
 point quo le men Je n'ait ete cree au commencement avec autaut 
 de perfection qu'il en a ; en sorte que le soleil, la terre, la lune, 
 et les ctoiles out ete des lors ; et que la terre n'a pas eu seulement 
 en soi les semences dcs plautes, mais quo les plantes meme en 
 ont couvert une partie ; et qu' Adam et Eve n'ont pas ete crees 
 enfans mais en age d'liommes parfaits. La religion cliretienne 
 veut que nous le croyons ainsi, et la raison naturelle nous persuade 
 entierement cette verite ; car si nous considerons la toute puis- 
 sance de Dieu, nous Jevons juger que tout ce qu'il a fait a eu des 
 le commencement toute la perfection qu'il devoit avoir. Mais 
 neanmoins, comme on connOitroit beaucoup mieux quelle a ete la 
 nature d'Adam et celle des arbres de Paradis si on avoit examine 
 comment les enfants se forment peu kpeu dans le ventre de leurs 
 meres et comment les plantes sortent de leurs semences, que si 
 on avoit seulement considere quels ils ont ete quand Dieu les a 
 crees : tout de meme, nous ferons mieux entendre quelle est 
 
 •* As Bufllbn has well said : — " L'idee de ramener I'explication 
 de tons les phenomenes h des principes mecaniques est assure- 
 ment grande et belle, ce pas eat le plus liardi qu'on peut faixe eu 
 pkilosophie, etc'est Descartes qui I'a fait." — I.e. p. 50. 
 
VI EVOLUTION IN BIOLOGY 207 
 
 generalement la nature de toutes les choses qui sontau monde si 
 nous pouvons imaginer quelqnes principes qui soient fort intelli- 
 gibles et fort simples, desquels nous puissions voir clairement que 
 les astres et la terra et enfin tout ce monde visible auroit pu etre 
 produit ainsi que de quelques semences (bien que nous sachions 
 qu'il n'a pas ete produit en cette fa^on) que si nous la decrivions 
 seulement comme il est, ou bien comme nous croyons qu'il a ete 
 cree. Et parceque je pense avoir trouve des principes qui sont 
 tels, je tacherai ici de les expliquer. " ^ 
 
 If we read between the lines of this singular 
 exhibition of force of one kind and weakness of 
 another, it is clear that Descartes believed that he 
 had divined the mode in which the physical uni- 
 verse had been evolved ; and the " Traite de 
 I'Homrae," and the essay " Sur les Passions " afford 
 abundant additional evidence that he sought for, 
 and thought he had found, an explanation of the 
 phenomena of physical life by deduction from 
 purely physical laws. 
 
 Spinoza abounds in the same sense, and is as 
 usual perfectly candid — 
 
 " Naturae leges, et regulae, secundum quas omnia fiunt et ex 
 unis formis in alias mutantur, sunt ubique et semper eadem." ^ 
 
 Leibnitz's doctrine of continuity necessarily led 
 him in the same direction ; and, of the infinite 
 multitude of monads with which he peopled the 
 world, each is supposed to be the focus of an end- 
 less process of evolution and involution. In the 
 
 * Principes ch la PJdlosophi'; Troisieme partic, § 45. 
 ^ Khiccs, Pars tertia, Traifatio. 
 
208 EVOLUTION IN EIOLOGY VI 
 
 " ProtogJBa," xxvi., Leibnitz distinctly suggests tlie 
 mutability of species — 
 
 " Alii mirantur in saxis passim species videri quas vel in orbe 
 cognito, vel saltern in vicinis locis frustra quteras. ' Ita Cornua 
 Ammonis,' qiife ex nautilorum numero habeantur, passim et 
 forma et magnitudine (nam et pedali diametro aliquando reperiun- 
 tur) ab omnibus illis naturis discrepare dicunt, quas prtebct mare. 
 Sed quis absconditos ejus recessus aut subterraneas abyssos per- 
 vestigavit 1 quam multa nobis animalia antea ignota otfert nevus 
 orbis ? Et credibile est per magnas illas conversiones etiani 
 animalium species plurimum immutatas." 
 
 Thus, in the end of the seventeenth century, 
 the seed was sown which has, at intervals, brought 
 forth recurrent crops of evolutional hypotheses, 
 based, more or less completely, on general 
 reasonings. 
 
 Among the earliest of these speculations is 
 that put forward by Benoit de Maillet in his 
 " Telliamed," which, though printed in 1735, was 
 not published until twenty-three years later. 
 Considering that this book was written before the 
 time of Haller, or Bonnet, or Linnaeus, or Hutton, 
 it surely deserves more respectful consideration 
 than it usually receives. For De Maillet not only 
 has a definite conception of the plasticity of living 
 things, and of the production of existing species 
 by the modification of their predecessors ; but he 
 clearly apprehends the cardinal maxim of modern 
 geological science, that the explanation of the 
 structure of the globe is to be sought in the 
 
VI EVOLUTION IN BIOLOGY 20!) 
 
 deductive application to geological phenomena of 
 the principles established inductively by the study 
 of the present course of nature. Somewhat later, 
 Maupertuis^ suggested a curious hypothesis as to 
 the causes of variation, which he thinks may be 
 sufficient to account for the origin of all animals 
 from a single pair. Robinet ^ followed out much 
 the same line of thought as De Maillet, but less 
 soberly ; and Bonnet's speculations in the " Paling- 
 ^nesie," which appeared in 17G9, have already 
 been mentioned. Buffon (1753 1778), at first a 
 partisan of the absolute immutability of species, 
 subsequently appears to have believed that larger 
 or smaller groups of species have been produced 
 by the modification of a primitive stock ; but ho 
 contributed nothing to the general doctrine of 
 evolution. 
 
 Erasmus Darwin ("Zoonomia," 1794), though a 
 zealous evolutionist, can hardly be said to have 
 made any real advance on his predecessors ; and, 
 notwithstanding that Goethe (1791-4) had the 
 advantage of a wide knowledge of morphological 
 facts, and a true insight into their signification, 
 while he threw all the power of a great poet into 
 the expression of his conceptions, it may be ques- 
 tioned whether he supplied the doctrine of evolu- 
 
 ^ SijsUme de la Nature, " Essai sur la Fonnation des Cori)3 
 Organises," 1751, xiv. 
 
 - CoTisidiralions Philosophiqucs sur la gradation nnturdle dcs 
 formes de I'Ure j ou Ics cssais da la nature qui a-pprend a /aire 
 Vlunnme, 1768. 
 
210 EVOLUTION IN BIOLOGY VI 
 
 tion with a firmer scientific basis than it already- 
 possessed. Moreover, whatever the value of 
 Goethe's labours in that field, they were not 
 published before 1820, long after evolutionism had 
 taken a new departure from the works of Trevir- 
 anus and Lamarck — the first of its advocates who 
 were equipped for their task with the needful 
 large and accurate knowledge of the phenomena of 
 life, as a whole. It is remarkable that each of 
 these writers seems to have been led, independ- 
 ently and contemporaneously, to invent the same 
 name of " Biology '' for the science of the pheno- 
 mena of life ; and thus, following Buffon, to have 
 recognised the essential unity of these phenomena, 
 and their contradistinction from those of inanimate 
 nature. And it is hard to say whether Lamarck 
 or Treviranus has the priority in propounding the 
 main thesis of the doctrine of evolution ; for 
 though the first volume of Treviranus's " Biologie " 
 appeared only in 1802, he says, in the preface to 
 his later work, the "Erscheinungen und Gesetze 
 des organischen Lebens," dated 1831, that he 
 wrote the first volume of the " Biologie " " nearly 
 five-and-thirty years ago," or about 1796. 
 
 Now, in 1794, there is evidence that Lamarck 
 held doctrines which present a striking contrast to 
 those which are to be found in the " Philosophie 
 Zoologique," as the following passages show : — 
 
 " 685. Quoique mon unique objet dans cet article n'ait etSque 
 de traiter de la cause physique de I'entreticn de la vie des etres 
 
VI EVOLUTION IN BIOLOGY 211 
 
 organiques, malgre cola j'ai ose avancer en debutant, que I'exist- 
 ence de ces etres etonnants n'appartiennent nullement a la 
 nature ; que tout ce qu'on peut entendre par le mot nature, ne 
 pouvoit donner la vie, c'est-i-dire, que toutes les qualites de la 
 raatiere, jointes a toutes les circonstances possibles, et meme k 
 I'activite repandue dans I'univers, ne pouvaient point produire 
 un 6tre muni du mouvement organique, capable de reproduire 
 son semblable, et sujet h, la mort. 
 
 "686. Tous les individus de cette nature, qui existent, pro- 
 viennent d'individus semblables qui tous ensemble constituent 
 I'espece entiere. Or, je crois qu'il est aussi impossible a I'homme 
 de connoitre la cause physique du premier individu de chaque 
 espece, que d'assigner aussi physiquement la cause de I'existence 
 de la matiere ou de I'univeis en tier. C'est au nioins ce que le 
 resultat de mes connaissances et de mes reflexions me portent a 
 penser. S'il existe beaucoup de varietes produites par I'effet des 
 circonstances, ces varietes ne denaturent point les especes ; mais 
 on se trompe, sans doute souvent, en indiquant comme espece, ce 
 qui n'est que variete ; et alors je sens que cette erreur peut tirer 
 k consequence dans les raisonnements que Ton fait sur cette 
 matifere."^ 
 
 The first three volumes of Treviranus's " Bio- 
 logie," which contain his general views of 
 evolution, appeared between 1802 and 1805. The 
 " Recherches sur 1' organisation des corps vivants," 
 in which the outlines of Lamarck's doctrines are 
 given, was published in 1802 ; but the full develop- 
 
 ^ BechercJies sur les causes des principaux fails phijaiqucs, 
 par J. B. Lamarck. Paiis. Secondc aunee de la Republique. 
 In Ibe preface, Lamarck says that the work was written in 1776, 
 and presented to the Academy in 1780 ; but it was not published 
 before 1794, and, at that time, it presumably expressed Lamaick's 
 mature views. It would be interesting to know what brought 
 about the change of opinion manifested in the Uccharches sur 
 Torganisation des corps vivants, published only seven years 
 later. 
 
212 EVOLUTION IN BIOLOGY VI 
 
 ment of his views, in the " Philosophie 
 Zoologique," did not take place until 1809. 
 
 The "Biologie" and the " Philosophie Zoolo- 
 gique " are both very remarkable productions, and 
 are still worthy of attentive study, but they fell 
 upon evil times. The vast authority of Cuvier 
 was employed in support of the traditionally 
 respectable hypotheses of special creation and of 
 catastrophism ; and the wild speculations of the 
 " Discours sur les E.^volutions de la Surface du 
 Globe " were held to be models of sound scientific 
 thinking, while the really much more sober and 
 philosophical hypotheses of the " Hydrogeologie " 
 were scouted. For many years it was the fashion 
 to speak of Lamarck with ridicule, while Trevir- 
 anus was altosjether ignored. 
 
 Nevertheless, the work had been done. The 
 conception of evolution was henceforward irrepres- 
 sible, and it incessantly reappears, in one shape or 
 another,^ up to the year 1858, when Mr. Darwin 
 and Mr. Wallace published their " Theory of 
 Natural Selection." The " Origin of Species " 
 appeared in 1859 ; and it is within the knowledge 
 of all whose memories go back to that time, that, 
 henceforward, the doctrine of evolution has 
 assumed a position and acquired an importance 
 which it never before possessed. In the " Origin 
 of Species," and in his other numerous and 
 
 ' Sec the "Historical Sketch '' prefixed to the last edition of 
 
 the Orirjin of Species. 
 
VI EVOLUTION IN BIOLOGY 213 
 
 important contributions to the solution of the 
 problem of biological evolution, Mr. Darwin con- 
 fines himself to the discussion of the causes which 
 have brought about the present condition of living 
 matter, assuming such matter to have once come 
 into existence. On the other hand, llr. Spencer ^ 
 and Professor Haeckel ^ have dealt with the whole 
 problem of evolution. The profound and vigorous 
 writings of Mr. Spencer embody the spirit ofi 
 Descartes in the knowledge of our own day, and 
 may be regarded as the " Principes de la 
 Philosophie " of the nineteenth century ; while, 
 whatever hesitation may not unfrequently be felt 
 by less daring minds, in following Haeckel in many 
 of his speculations, his attempt to systematise the 
 doctrine of evolution and to exhibit its influence 
 as the central thought of modern biology, cannot 
 fail to have a far-reaching influence on the progress 
 of science. 
 
 If we seek for the reason of the diiference 
 between the scientific position of the doctrine of 
 evolution a century ago, and that which it occupies 
 now, we shall find it in the great accumulation 
 of facts, the several classes of which have been 
 enumerated above, under the second to the eighth 
 heads. For those which are grouped under the 
 second to the seventh of these classes, respectively, . 
 have a clear significance on the hypothesis of 
 
 ^ First Principles, and rrintiples of Biolwjy, 1860-1864. 
 ' Gr,ncrcHe Morpholoji \ 1866. 
 
214 EVOLUTION IN BIOLOGY VI 
 
 evolution, while they are unintelligible if that 
 hypothesis be denied. And those of the eighth 
 group are not only unintelligible without the 
 assumption of evohition, but can be proved never 
 to be discordant with that hypothesis, while, in 
 some cases, they are exactly such as the hypothesis 
 requires. The demonstration of these assertions 
 would require a volume, but the general nature of 
 the evidence on which they rest may be briefly 
 indicated. 
 
 2. The accurate investigation of the lowest 
 forms of animal life, commenced by Leeuwenhoek 
 and Swammerdam, and continued by the remark- 
 able labours of Reaumur, Trembley, Bonnet, and a 
 host of other observers, in the latter part of the 
 seventeenth and the first half of the eighteenth 
 centuries, drew the attention of biologists to the 
 gradation in the complexity of organisation which 
 is presented by living beings, and culminated in 
 the doctrine of the " echelle des etres," so power- 
 fully and clearly stated by Bonnet ; and, before 
 him, adumbrated by Locke and by Leibnitz. In 
 the then state of knowledge, it appeared that all 
 the species of animals and plants could be 
 arranged in one series ; in such a manner that, by 
 insensible gradations, the mineral passed into the 
 plant, the plant into the polype, the polype into 
 the worm, and so, through gradually higher forms 
 of life, to man, at the summit of the animated 
 world. 
 
VI EVOLUTION IN BIOLOGY 215 
 
 But, as knowledge advanced, this conception 
 ceased to be tenable in the crude form in which 
 it was lirst put forward. Taking into account 
 existing, animals and plants alone, it became 
 obvious that they fell into groups which were 
 more or less sharply separated from one another ; 
 and, moreover, that even the species of a genus 
 can hardly ever be arranged in linear series. 
 Their natural resemblances and differences are 
 only to be expressed by disposing them as if they 
 were branches springing from a common hypo- 
 thetical centre. 
 
 Lamarck, while affirming the verbal proposition 
 that animals form a single series, was forced by his 
 vast acquaintance with the details of zoology to 
 limit the assertion to such a series as may be 
 formed out of the abstractions constituted by the 
 common characters of each group.^ 
 
 Cuvier on anatomical, and Von Baer on embryo- 
 logical grounds, made the further step of proving 
 that, even in this limited sense, animals cannot be 
 arranged in a single series, but that there are 
 several distinct plans of organisation to be observed 
 among them, no one of which, in its highest and 
 most complicated modification, leads to any of the 
 others. 
 
 ^ " II s'agit done de prouver que la serie qui constitua 
 I'^chelle aniniale reside cssentiellement dans la distribution des 
 masses principales qui la composentet non dans celle des espfeces 
 ni meme toujours dans cello des genres. " — Philosophic Zoolucjique, 
 chap. V. 
 
 48 
 
216 EVOLUTION IN BIOLOGY TI 
 
 The conclusions enunciated by Cuvier and Yon 
 Baer have been confirmed, in principle, by all 
 subsequent research into the structure of animals 
 and plants. But the effect of the adoption of 
 these conchisions has been rather to substitute a 
 new metaphor for that of Bonnet than to abolish 
 the conception expressed by it. Instead of regard- 
 ing living things as capable of arrangement in one 
 series like the steps of a ladder, the results of 
 modern investigation compel us to dispose them 
 as if they were the twigs and branches of a tree. 
 The ends of the twigs rejDresent individuals, the 
 smallest groups of twigs species, larger groups 
 genera, and so on, until we arrive at the source of 
 all these ramifications of the main branch, which 
 is represented by a common plan of structure. At 
 the present moment, it is impossible to draw up 
 any definition, based on broad ana,tomical or 
 developmental characters, by which any one of 
 Cuvier's great groups shall be separated from all 
 the rest. On the contrary, the lower members of 
 each tend to converge towards the lower members 
 of all the others. The same may be said of the 
 vegetable world. The apparently clear distinction 
 between flowering and flowerless plants has been 
 broken down by the series of gradations between 
 the two exhibited by the Lycopodiacem, Rhizo- 
 carpccc, and Gymnospcrmcoi. The groups of Ftcngi, 
 Lichencs, and Algce have completely run into one 
 another, and, when the lowest forms of each are 
 
TI EVOLUTION IN BIOLOGY 217 
 
 alone considered, even the animal and vegetable 
 kingdoms cease to have a definite frontier. 
 
 If it is permissible to speak of the relations of 
 living forms to one another metaphorically, the 
 similitude chosen must undoubtedly be that of a 
 common root, whence two main trunks, one repre- 
 senting the vegetable and one the animal world, 
 spring; and, each dividing into a few main 
 branches, these subdivide into multitudes of 
 branchlets and these into smaller groups of 
 twigs. 
 
 As Lamarck has well said — ^ 
 
 "II n'y a <iue ceux qui. se sont longtempsetfortementoccupes 
 de la determination des especes, et qui ont consulte de riches 
 collections, qui peuvent savoir jusqu'a quel point les cspiccx, 
 parmi IfS corps vivants se fon dent les uues dans les autres, et qui 
 ont pu se convaincre que, dans les parties ou nous voyons des 
 esptccs isoles, cela n'est ainsi que pareequ'il nous en manque 
 d'autres qui en sont plus voisines et que nous n'avons pas encore 
 recueillies. 
 
 " Je ne veux pas dire pour cela que les animaux qui existent 
 forment une serie tres-simple et partout egalement nuancee ; 
 niais.je dis qu'ils forment une serie ramense, irregulierement 
 graduee et qui n'a point de discontinuite dans ses parties, ou qui, 
 du moins, n'en a toujours pas eu, s'il est vrai que, par suite de 
 quelques espfeces perdues, il s'eu tiouve quelque part. II en 
 resulte que les cspeccs qui terminent chaque rameau do la serie 
 generale tiennent, au moins d'un cute, a d'autres especes voisines 
 qui se nuancent avee elles. Voila ce que I'etat bicn connu des 
 clioses me met maintenant k portee de demontrer. Je n'ai 
 bosoin d'aucunc hypothese ni d'aucune supposition pour cela : 
 j'en attestc tons les naturalistes observateurs. " 
 
 ^ PJuloiupJiie Zoologique, premiere partie, chap. iii. 
 
218 EVOLUTION IN BIOLOGY VI 
 
 3. In a remarkable essay -^ Meckel remarks — 
 
 "There is no good physiologist who has not been strack hy 
 the observation that the origiual form of all organisms is one and 
 the same, and that out of this one form, all, the lowest as well as 
 the highest, are developed in such a manner that the latter pass 
 tlirough the permanent forms of the former as transitory stages. 
 Aristotle, Hallcr, Harvey, Kielmeyer, Autenrieth, and many 
 others, have either made this observation incidentally, or, 
 especially the latter, have drawn particular attention to it, 
 and deduced therefrom results of permanent importance for 
 physiology." 
 
 Meckel proceeds to exemplify the thesis, that 
 the lower forms of animals represent stages in 
 the course of the development of the higher, with 
 a larcfe series of illustrations. 
 
 After comparing the Salamanders and the 
 perennibranchiate Urodcla with the Tadpoles and 
 the Frogs, and enunciating the law that the more 
 highly any animal is organised the more quickly 
 does it pass through the lower stages, Meckel goes 
 on to say — 
 
 " From these lowest Vertebrata to the highest, and to the 
 highest forms among these, the comparison between the embry- 
 onic conditions of the higher animals and the adult states of the 
 lower can be more completely and thoroughly instituted than if 
 the survey is extended to the Invertebrata, inasmuch as the latter 
 are in many respects constructed upon an altogether too dissimilar 
 type ; indeed they often differ from one another far more than 
 the lowest vertebrate does from the highest mammal ; yet the 
 
 1 " Entwurf eiiier Parstellung der zwischen dem Embryozus- 
 tande der hoheren Tliiere und dem pernianenten der niederca 
 stattfindenden Parallele, " Beytrdgc zitr VergleicJicndcn Anatomic, 
 Bd. ii. 1811. 
 
VI EVOLUTION" IN BIOLOGY 219 
 
 following pages will show that the comparison may also be 
 extended to them with interest. In fact, there is a period when, 
 as Aristotle long ago said, the embryo of the highest animal 
 has the form of a mere worm ; and, devoid of internal and 
 external organisation, is merely an almost structureless lump of 
 polype substance. Nothwithstanding the origin of organs, it 
 still for a certain time, by reason of its want of an internal bony 
 skeleton, remains worm and moUusk, and only later enters into 
 the series of the Vertebrata, although traces of the vertebral 
 column even in the earliest periods testify its claim to a placo 
 in that series." — Op. cit. pp. 4, 5. 
 
 If Meckel's proposition is so far qualified, that 
 the comparison of adult with embryonic forms is 
 restricted within the limits of one type of organi- 
 sation ; and, if it is further recollected that the 
 resemblance between the permanent lower form 
 and the embryonic stage of a higher form is not 
 special but general, it is in entire accordance with 
 modem embryology ; although there is no branch 
 of biology which has grown so largely, and im- 
 proved its methods so much, since Meckel's time, 
 as this. In its original form, the doctrine of 
 " arrest of development," as advocated by Geofifroy 
 Saint-Hilaire and Serres, was do doubt an over- 
 statement of the case. It is not true, for example, 
 that a fish is a reptile arrested in its development, 
 or that a reptile was ever a fish : but it is true 
 that the reptile embryo, at one stage of its 
 development, is an organism which, if it had an 
 independent existence, must be classified among 
 fishes; and all the organs of the reptile pass, in 
 the course of their development, through conditions 
 
220 EVOLUTION IN BIOLOGY VI 
 
 which are closely analogovis to those which are 
 permanent in some fishes. 
 
 4. That branch of biology which is termed Mor- 
 phology is a commentary upon, and expansion of, 
 the proposition that widely different animals or 
 plants, and widely different parts of animals or 
 plants, are constructed upon the same plan. 
 From the rough comparison of the skeleton of a 
 bird with that of a man by Belon, in the sixteenth 
 century (to go no farther back), down to the 
 theory of the limbs and the theory of the skull at 
 the present day ; or, from the first demonstration c-f 
 the homologies of the parts of a flower by C. F. 
 Wolff, to the present elaborate analysis of the 
 floral organs, morphology exhibits a continual 
 advance towards the demonstration of a funda- 
 mental unity among the seeming diversities of 
 living: structures. And this demonstration has 
 been completed by the final establishment of the 
 cell theory, which involves the admission of a 
 primitive conformity, not only of all the elemen- 
 tary structures in animals and plants respectively, 
 but of those in the one of these great divisions 
 of living things with those in the other. No d 
 priori difficulty can be said to stand in the way of 
 evolution, when it can be shown that all animals 
 and all plants proceed by modes of development, 
 which are similar in principle, from a fundamental 
 protoplasmic material. 
 
 5. The innumerable cases of structures, which are 
 
Ti EVOLUTION IN BIOLOGY 221 
 
 rudimentary and apparently useless, in species, 
 the close allies of which possess well- developed 
 and functionally important homologous structures, 
 are readily intelligible on the theory of evolution, 
 while it is hard to conceive their raison d'etre on 
 any other hypothesis. However, a cautious rea- 
 soner will probably rather explain such cases 
 deductively from the doctrine of evolution than 
 endeavour to support the doctrine of evolution by 
 them. For it is almost impossible to prove that 
 any structure, however rudimentary, is useless — 
 that is to say, that it plays no part whatever in 
 the economy; and, if it is in the slightest degree 
 useful, there is no reason why, on the hypothesis 
 of direct creation, it should not have been created. 
 Nevertheless, double-edged as is the argument 
 from rudimentary organs, there is probably none 
 which has produced a greater effect in promoting 
 the general acceptance of the theory of evo- 
 lution. 
 
 6. The older advocates of evolution sought for the 
 causes of the process exclusively in the influence of 
 varying conditions, such as climate and station, or 
 hybridisation, upon living forms. Even Treviranus 
 has got no farther than this point. Lamarck in- 
 troduced the conception of the action of an animal 
 on itself as a factor in producing modification. 
 Starting from the well-known fact that the 
 habitual use of a limb tends to develop the muscles 
 of the limb, and to produce a greater and greater 
 
222 EVOLUTION IN BIOLOGY VI 
 
 facility In using it, he made the general assumption 
 that the effort of an animal to exert an organ in a 
 given direction tends to develop the organ in that 
 direction. But a little consideration showed that, 
 though Lamarck had seized what, as far it goes, is 
 a true cause of modification, it is a cause the actual 
 effects of which are wholly inadequate to account 
 for any considerable modification in animals, and 
 which can have no influence at all in the vegetable 
 world ; and probably nothing contributed so much 
 to discredit evolution, in the early part of this 
 century, as the floods of easy ridicule which were 
 poured upon this part of Lamarck's speculation. 
 The theory of natural selection, or survival of the 
 fittest, was suggested by Wells in 1813, and 
 further elaborated by Matthew in 1831. But the 
 pregnant suggestions of these writers remained 
 practically unnoticed and forgotten, until the theory 
 was independently devised and promulgated by 
 Darwin and Wallace in 1858, and the effect of its 
 publication was immediate and profound. 
 
 Those who were unwilling to accept evolution, 
 without better grounds than such as are offered by 
 Lamarck, or the author of that particularly un- 
 satisfactory book, the ' Vestiges of the Natural 
 History of the Creation," and who therefore 
 preferred to suspend their judgment on the 
 question, found, in the principle of selective 
 breeding, pursiied in all its applications with 
 marvellous knowledge and skill by Mr. Darwin, a 
 
VI EVOLUTION IN BIOLOGY 223 
 
 valid explanation of the occiuTence of varieties and 
 races ; and they saw clearly that, if the explanation 
 would apply to species, it would not only solve the 
 problem of their evolution, but that it would ac- 
 count for the facts of teleology, as well as for those 
 of morphology ; and for the persistence of some 
 forms of life unchanged through long epochs of 
 time, while others undergo comparatively rapid 
 metamorphosis. 
 
 How far " natural selection " suffices for the pro- 
 duction of species remains to be seen. Few can 
 doubt that, if not the whole cause, it is a very im- 
 portant factor in that operation ; and that it must 
 play a great part in the sorting out of varieties 
 into those which are transitory and those which 
 are permanent. 
 
 But the causes and coiMiitions of variation have 
 yet to be thoroughly explored ; and the importance 
 of natural selection will not be impaired, even if 
 further inquiries should prove that variability 
 is definite, and is determined in certain directions 
 rather than in others, by conditions inherent in 
 that which varies. It is quite conceivable that 
 every species tends to produce varieties of a 
 limited number and kind, and that the effect of, 
 natural selection is to favour the development of 
 some of these, while it opposes the development 
 of others along their predetermined lines of modi- 
 fication. 
 
 7. No truths brought to light by biological 
 
224) EVOLUTION IN BIOLOGY vi 
 
 investigation were better calculated to inspire 
 distrust of the dogmas intruded upon science in 
 the name of theology, than those which relate to 
 the distribution of animals and plants on the 
 surface of the earth. Very skilful accommodation 
 was needful, if the limitation of sloths to South 
 America, and of the ornithorhynchus to Australia, 
 was to be reconciled with the literal interpretation 
 of the history of the deluge ; and with the estab- 
 lishment of the existence of distinct provinces of 
 distribution, any serious belief in the peopling of 
 the world by migration from Mount Ararat came 
 to an end. 
 
 Under these circumstances, only one alternative 
 was left for those who denied the occurrence of 
 evolution — namely, tlie supposition that the 
 characteristic animals and plants of each great 
 province were created as such, within the limits in 
 which we find them. And as the hypothesis of 
 " specific centres," thus formulated, was heterodox 
 from the theological point of view, and unintelli- 
 gible under its scientific aspect, it may be passed 
 over without further notice, as a phase of transi- 
 tion from the creational to the evolutional hypo- 
 thesis. 
 
 8. In fact, the strongest and most conclusive 
 arguments in favour of evolution are those which 
 are based upon the facts of geographical, taken 
 in conjunction with those of geological, distri- 
 bution. 
 
VI EVOLUTION IN BIOLOGY 225 
 
 Both Mr. Darwin, and Mr. Wallace lay great 
 stress on the close relation which obtains between 
 the existing fauna of any region and that of the 
 immediately antecedent geological epoch in the 
 same region ; and rightly, for it is in truth in- 
 conceivable that there should be no genetic 
 connection between the two. It is possible to put 
 into words the proposition that all the animals and 
 plants of each geological epoch were annihilated 
 and that a new set of very similar forms was 
 created for the next epoch ; but it may be doubted 
 if any one who ever tried to form a distinct mental 
 image of this process of spontaneous geiieration on 
 the grandest scale, ever really succeeded in real- 
 ising it. 
 
 Within the last twenty years, the attention of 
 the best palseontologists has been withdrawn from 
 the hodman's work of making " new species " of 
 fossils, to the scientific task of completing our 
 knowledge of individual species, and tracing out 
 the succession of the forms presented by any 
 given type in time. 
 
 Those who desire to inform themselves of the 
 nature and extent of the evidence bearing on these 
 questions may consult the works of Riitimeyer, 
 Gaudry, Kowalewsky, Marsh, and the writer of the 
 present article. It must suffice, in this place, to 
 say that the successive forms of the Equine type 
 have been fully Avorked out ; wliile those of nearly 
 all the other existing types of Ungulate mammals 
 
226 EVOLUTION IN BIOLOGY vi 
 
 and of the Carnivora have been almost as closely 
 followed through the Tertiary deposits ; the gra- 
 dations between birds and reptiles have been 
 traced ; and the modifications undergone by the 
 Crocodilia, from the Triassic epoch to the present 
 day, have been demonstrated. On the evidence of 
 palaeontology, the evolution of many existing forms 
 of animal life from their predecessors is no longer 
 an hypothesis, but an historical fact ; it is only the 
 nature of the physiological factors to which 
 that evolution is due which is still open to dis- 
 cussion. 
 
 [At page 209, tho reference to Erasmus D-rwin does not do 
 justice to that ingenious writer, who, in the 39th section of thfr 
 Znonoviia, clearly and repeatedly enunciates the theory of the 
 inheritance of acquired modifications. For example: "From 
 their first rudiment, or primordium, to the termination of their 
 lives, all animals undergo perpetual transformations ; which are 
 in part produced by their own exertions in consequence of their 
 desires and aversions, of their pleasures and their pains, or of 
 irritation, or of associations ; and many of these acquired forms 
 or propensities are transmitted to their posterity." Zoonomia I., 
 p. 506. 1893.] 
 
VII 
 
 THE COMING OF AGE OF " THE ORIGIN 
 OF SPECIES" 
 
 [1880] 
 
 Many of you will be familiar with the aspect of 
 this small green-covered book. It is a copy of the 
 first edition of the " Origin of Species," and bears 
 the date of its production — the 1st of October 
 1859. Only a few months, therefore, are needed 
 to complete the full tale of twenty-one years since 
 its birthday. 
 
 Those whose memories carry them back to this 
 time will remember that the infant was remarkably 
 lively, and that a great number of excellent per- 
 sons mistook its manifestations of a vigorous 
 individuality for mere naughtiness ; in fact there 
 was a very pretty turmoil about its cradle. My 
 recollections of the period are particularly vivid ; 
 for, having conceived a tender aifection for a child 
 of what appeared to me to be such remarkable 
 promise, I acted for some time in the capacity of a 
 
228 THE COMING OF AGE OF VII 
 
 sort of under-nurse, and thus came in for my share 
 of the storms which threatened the very life of 
 the young creature. For some years it was 
 undoubtedly warm work ; but considering how 
 exceedingly unpleasant the apparition of the new- 
 comer must have been to those who did not fall in 
 love with him at first sight, I think it is to the 
 credit of our age that the war was not fiercer, and 
 that the more bitter and unscrupulous forms of 
 opposition died away as soon as they did. 
 
 I speak of this period as of something past and 
 gone, possessing merely an historical, I had almost 
 said an antiquarian interest. For, during the 
 second decade of the existence of the " Origin of 
 Species," opposition, though by no means dead, 
 assumed a different aspect. On the part of all 
 those who had any reason to respect themselves, 
 it assumed a thoroughly respectful character. By 
 this time, the dullest began to perceive that the 
 child was not likely to perish of any congenital 
 weakness or infantile disorder, but was growing 
 into a stalwart personage, upon whom mere goody 
 scoldings and threatenings with the birch-rod 
 were quite thrown away. 
 
 In fact, those who have watched the progress of 
 science within the last ten years Avill bear me out 
 to the full, when I assert that there is no field of 
 biological inquiry in Avhich the influence of the 
 " Origin of Species " is not traceable ; the foremost 
 men of science in every country are either avowed 
 
VII " THE ORIGIN OF SPECIES " 229 
 
 champions of its leading doctrines, or at any rate 
 abstain from opposing them ; a host of young and 
 ardent investigators seek for and find inspiration 
 and guidance in Mr. Darwin's great work ; and the 
 general doctrine of evolution, to one side of which 
 it gives expression, obtains, in the phenomena of 
 biology, a firm base of operations whence it may 
 conduct its conquest of the whole realm of Nature. 
 
 History warns us, however, that it is the cus- 
 tomary fate of new truths to begin as heresies and 
 to end as superstitions ; and, as matters now stand, 
 it is hardly rash to anticipate that, in another 
 twenty years, the new generation, educated under 
 the influences of tlie present day, will be in danger 
 of accepting the main doctrines of the " Origin of 
 Species,'' with as little reflection, and it may be 
 with as little justification, as so many of our con- 
 temporaries, twenty years ago, rejected them. 
 
 Against any such a consummation let us all 
 devoutly pray; for the scientific spirit is of more 
 value than its products, and irrationally held 
 truths may be more harmful than reasoned errors. 
 Now the essence of the scientific spirit is criticism. 
 It tells us that whenever a doctrine claims our 
 assent we should reply, Take it if you can compel 
 it. The struo^crle for existence holds as much in 
 
 DO 
 
 the intellectual as in the physical world. A theory 
 is a species of thinking, and its right to exist is 
 coextensive with its power of resisting extinction 
 by*its rivals. 
 
230 THE COMING OF AGE OF vii 
 
 From tliis point of view, it appears to me that 
 it would be but a poor way of celebrating the 
 Coming of Age of the " Origin of Species/' were I 
 merely to dwell upon the facts, undoubted and re- 
 markable as they are, of its far-reaching influence 
 and of the great following of ardent disciples who 
 are occupied in spreading and developing its 
 doctrines. Mere insanities and inanities have 
 before now swollen to portentous size in the course 
 of twenty years. Let us rather ask this prodigious 
 change in opinion to justify itself : let us inquire 
 whether anything has happened since 1859, which 
 will explain, on rational grounds, why so many 
 are worshipping that which they burned, and burn- 
 ing that which they worshipped. It is only in 
 this way that we shall acquire the means of 
 judging whether the movement we have witnessed 
 is a mere eddy of fashion, or truly one with the 
 irreversible current of intellectual progress, and, 
 like it, safe from retrogressive reaction. 
 
 Every belief is the product of two factors : the 
 first is the state of the mind to which the evidence 
 in favour of that belief is presented ; and the 
 second is the logical cogency of the evidence itself. 
 In both these respects, the history of biological 
 science during the last twenty years appears to me 
 to afford an ample explanation of the change 
 which has taken place ; and a brief consideration 
 of the salient events of that history will enable us 
 to understand why, if the " Origin of Species " ftp- 
 
Vir "THE ORIGIN OF SPECIES" 231 
 
 peared now, it would meet with a very different 
 reception from that which greeted it in 1859. 
 
 One-and-twenty years ago, in spite of the work 
 commenced by Hutton and continued with rare 
 skill and patience by Lyell, the dominant view of 
 the past history of the earth was catastrophic. 
 Great and sudden physical revolutions, wholesale 
 creations and extinctions of living beings, were the 
 ordinary machinery of the geological epic brought 
 into fashion by the misapplied genius of Cuvier. 
 It was gravely maintained and taught that the 
 end of every geological epoch was signalised by a 
 cataclysm, by which every living being on the 
 globe was swept away, to be replaced by a brand- 
 new creation when the world returned to quies- 
 cence. A scheme of nature which appeared to be 
 modelled on the likeness of a succession of rubbers 
 of whist, at the end of each of which the players 
 upset the table and called for a new pack, did not 
 seem to shock anybody. 
 
 I may be wrong, but I doubt if, at the present 
 time, there is a single responsible representative 
 of these opinions left. The progress of scientific 
 geology has elevated the fundamental principle of 
 unifomiitarianism, that the explanation of the past 
 is to be sought in the study of the present, into 
 the position of an axiom ; and the wild specula- 
 tions of the catastrophists, to which wc all listened 
 with respect a quarter of a century ago, would 
 hardly find a single patient hearer at the present 
 44 
 
232 THE COMING OF AGE OF VII 
 
 day. No physical geologist now dreams of seeking, 
 outside the range of known natural causes, for the 
 explanation of anything that happened millions of 
 years ago, any more than he would be guilty 
 of the like absurdity in regard to current events. 
 
 The effect of this change of opinion upon biolo- 
 gical speculation is obvious. For, if there have 
 been no periodical general physical catastrophes, 
 what brought about the assumed general ex- 
 tinctions and re-creations of life which are the 
 corresponding biological catastrophes ? And, if no 
 such interruptions of the ordinary course of nature 
 have taken place in the organic, any more than in 
 the inorganic, world, what alternative is there to 
 the admission of evolution ? 
 
 The doctrine of evolution in biology is the 
 necessary result of the logical application of the 
 principles of uniformitarianism to the phenomena 
 of life. Darwin is the natural successor of Hutton 
 and Lyell, and the " Origin of Species " the logical 
 sequence of the " Principles of Geology." 
 
 The fundamental doctrine of the "Origin of 
 Species," as of all forms of the theory of evolution 
 applied to biology, is " that the innumerable 
 species, genera, and families of organic beings with 
 which the world is peopled have all descended, 
 each within its own class or group, from common 
 parents, and have all been modified in the course of 
 descent." ^ 
 
 ' Origin of Species, ed. 1, p, 457, 
 
vn "THE ORIGIN OF SPECIES " 233 
 
 And, in view of the facts of geology, it follows 
 that all living animals and plants " are the lineal 
 descendants of those which lived long hefore the 
 Silurian epoch." ^ 
 
 It is an obvious consequence of this theory of 
 descent with modification, as it is sometimes called, 
 that all plants and animals, however different they 
 may now be, must, at one time or other, have been 
 connected by direct or indirect intermediate grada- 
 tions, and that the appearance of isolation presented 
 by various groups of organic beings must be unreal. 
 
 No part of Mr. Darwin's work ran more directly 
 counter to the prepossessions of naturalists twenty 
 years ago than this. And such prepossessions were 
 very excusable, for there was undoubtedly a great 
 deal to be said, at that time, in favour of the fixity 
 of species and of the existence of great breaks, 
 which there was no obvious or probable means of 
 filling up, between various groups of organic beings. 
 
 For various reasons, scientific and unscientific, 
 much had been made of the hiatus between man 
 and the rest of the higher mammalia, and it is no 
 wonder that issue was first joined on this part of 
 the controversy. I have no wish to revive past 
 and happily forgotten controversies ; but I must 
 state the simple fact that the distinctions in the 
 cerebral and other characters, which were so hotly 
 affirmed to separate man from all other animals in 
 1860, have all been demonstrated to be non- 
 ^ Origin of Species, p. 458. 
 
234 THE COMING OF AGE OF VII 
 
 existent, and that the contrary doctrine is now 
 universally accepted and taught. 
 
 But there were other cases in which the wide 
 structural gaps asserted to exist between one group 
 of animals and another were by no means fictitious ; 
 and, when such structural breaks were real, Mr. 
 Darwin could account for them only by supposing 
 that the intermediate forms which once existed 
 had become extinct. In a remarkable passage he 
 
 says — 
 
 " We may thus account even for the distinctness 
 of whole classes from each other — for instance, of 
 birds from all other vertebrate animals — by the 
 belief that many animal forms of life have been 
 utterly lost, through which the early progenitors 
 of birds were formerly connected with the early 
 progenitors of the other vertebrate classes." '■ 
 
 Adverse criticism made merry over such sugges- 
 tions as these. Of course it was easy to get out of 
 the difficulty by supposing extinction ; but where 
 was the slightest evidence that such intermediate 
 forms between birds and reptiles as the hypothesis 
 required ever existed ? And then probably followed 
 a tirade upon this terrible forsaking of the paths 
 of " Baconian induction." 
 
 But the progress of knowledge has justified Mr. 
 Darwin to an extent which could hardly have 
 been anticipated. In 1862, the specimen of 
 Arcliccoidcryx, which, until the last two or three 
 
 1 Origin of Species^ p. 431. 
 
VII "THE ORIGIN OF SPECIES " 235 
 
 years, has remained unique, was discovered ; and 
 it is an animal wliich, in its feathers and the 
 greater part of its organisation, is a veritable 
 bird, while, in other parts, it is as distinctly- 
 reptilian. 
 
 In 1868, I had the honour of bringing under 
 your notice, in this theatre, the results of investi- 
 gations made, up to that time, into the anatomical 
 characters of certain ancient reptiles, which 
 showed the nature of the modifications in virtue 
 of which the type of the quadrupedal reptile 
 passed into that of a bipedal bird ; and abundant 
 confirmatory evidence of the justice of the con- 
 clusions which I then laid before you has since 
 come to light. 
 
 In 1875, the discovery of the toothed birds of 
 the cretaceous formation in North America by 
 Professor Marsh completed the series of transitional 
 forms between' birds and reptiles, and removed 
 Mr. Darwin's proposition that " many animal 
 forms of life have been utterly lost, through 
 which the early progenitors of birds were 
 formerly connected with the early progenitors of 
 the other vertebrate classes," from the region 
 of hypothesis to that of demonstrable fact. 
 
 In 1859, there appeared to be a very sharp 
 and clear hiatus between vertebrated and inverte- 
 brated animals, not only in their structure, but, 
 what was more important, in their development. 
 I do not think that we even yet know the precise 
 
236 THE COMING OF AGE OF VII 
 
 links of connection between the two ; but the 
 investigations of Kowalewsky and others upon 
 the development of A^nphioxus and of the Tunicata 
 prove, beyond a doubt, that the differences which 
 were supposed to constitute a barrier between 
 the two are non-existent. There is no longer any 
 difficulty in understanding how the vertebrate 
 type may have arisen from the invertebrate, 
 though the full proof of the manner in which 
 the transition was actually effected may still be 
 lacking. 
 
 Again, in 1859, there appeared to be a no less 
 sharp separation between the two great groups of 
 flowering and flowerless plants. It is only subse- 
 quently that the series of remarkable investiga- 
 tions inaugurated by Hofmeister has brought to 
 light the extraordinary and altogether unexpected 
 modifications of the reproductive apparatus in the 
 Zycopodiacece, the BMzocarpece, and the Gymno- 
 spermece, by which the ferns and the mosses are 
 gradually connected with the Phanerogamic 
 division of the vegetable world. 
 
 So, again, it is only since 1859 that we have 
 acquired that wealth of knowledge of the lowest 
 forms of life which demonstrates the futility of 
 any attempt to separate the lowest plants from 
 tlie lowest animals, and shows that the two king- 
 doms of living nature have a common borderland 
 which belongs to both, or to neither. 
 
 Thus it will be observed that the whole ten- 
 
VII "THE ORIGIN OF SPECIES " 237 
 
 dency of biological investigation, since 1859, has 
 been in the direction of removing the difficulties 
 which the apparent breaks in the series created 
 at that time ; and the recognition of gradation 
 is the first step towards the acceptance of evolu- 
 tion. 
 
 As another great factor in bringing about the 
 change of opinion which has taken place among 
 naturalists, I count the astonishing progress which 
 has been made in the study of embryology. 
 Twenty years ago, not only were we devoid of any 
 accurate knowledge of the mode of development 
 of many groups of animals and plants, but the 
 methods of investigation were rude and imperfect. 
 At the present time, there is no important group 
 of organic beings the development of which has 
 not been carefully studied ; and the modem 
 methods of hardening and section-making enable 
 the embryologist to determine the nature of the 
 process, in each case, with a degree of minuteness 
 and accuracy which is truly astonishing to those 
 whose memories carry them back to the 
 beginnings of modern histology. And the results 
 of these embryological investigations are in com- 
 plete harmony with the requirements of the 
 doctrine of evolution. The first beginnings of all 
 the higher forms of animal life are similar, and 
 however diverse their adult conditions, they start 
 from a common foundation. Moreover, the pro- 
 cess of development of the animal or the plant 
 
238 THE COMING OF AGE OF Til 
 
 from its primary egg, or germ, is a true process of 
 evolution — a progress from almost formless to 
 more or less highly organised matter, in virtue of 
 the properties inherent in that matter. 
 
 To those who are familiar with the process of 
 development, all cu priori objections to the doctrine 
 of biological evolution appear childish. Any one 
 who has watched the gradual formation of a com- 
 plicated animal from the protoplasmic mass, which 
 constitutes the essential element of a frog's or a 
 hen's egg, has had under his eyes sufficient 
 evidence that a similar evolution of the whole 
 animal world from the like foundation is, at any 
 rate, possible. 
 
 Yet another product of investigation has 
 largely contributed to the removal of the objec- 
 tions to the doctrine of evolution current in 1859, 
 It is the proof afforded by successive discoveries 
 that Mr. Darwin did not over-estimate the 
 imperfection of the geological record. No more 
 striking illustration of this is needed than a com- 
 parison of our knowledge of the mammalian fauna 
 of the Tertiary epoch in 1859 with its present 
 condition. M. Gaudry's researches on the fossils 
 of Pikermi were published in 1868, those of 
 Messrs. Leidy, Marsh, and Cope, on the fossils of 
 the Western Territories of America, have appeared 
 almost wholly since 1870, those of M. Filhol on 
 the phosphorites of Quercy in 1878. The general 
 effect of these investigations has been to intro- 
 
VII " THE ORIGIN OF SPECIES " 239 
 
 duce to us a multitude of extinct animals, the 
 existence of wliich was previously hardly sus- 
 pected; just as if zoologists were to become 
 acquainted with a country, hitherto unknown, as 
 rich in novel forms of life as Brazil or South 
 Africa once were to Europeans. Indeed, the fossil 
 fauna of the Western Territories of America bid 
 fair to exceed in interest and importance all other 
 known Tertiary deposits put together ; and yet, 
 with the exception of the case of the American 
 tertiaries, these investigations have extended over 
 very limited areas ; and, at Pikermi, were con- 
 fined to an extremely small space. 
 
 Such appear to me to be the chief events in the 
 history of the progress of knowledge during the 
 last twenty years, which account for the changed 
 feehng with which the doctrine of evolution is at 
 present regarded by those who have followed the 
 advance of biological science, in respect of those 
 problems which bear indirectly upon that doc- 
 trine. 
 
 But all this remains mere secondary evidence. 
 It may remove dissent, but it does not compel 
 assent. Primary and direct evidence in favour of 
 evolution can be furnished only by palaeontology. 
 The geological record, so soon as it approaches 
 completeness, must, when properly questioned, 
 yield either an affirmative or a negative answer : 
 if evolution has taken place, there will its mark 
 
240 THE COMING OF AGE OP vn 
 
 be left ; if it has not taken place, there will lie 
 its refutation. 
 
 What was the state of matters in 1859 ? Let 
 us hear Mr. Darwin, who may be trusted always 
 to state the case against himself as strongly as 
 possible. 
 
 " On this doctrine of the extermination of an 
 infinitude of connecting links between the living 
 and extinct inhabitants of the world, and at each 
 successive period between the extinct and still 
 older species, why is not every geological forma- 
 tion charged with such links ? Why does not 
 every collection of fossil remains afford plain 
 evidence of the gradation and mutation of the 
 forms of life ? We meet with no such evidence, 
 and this is the most obvious and plausible of the 
 many objections which may be urged against my 
 tlieory." ^ 
 
 Nothing could have been more useful to the 
 opposition than this characteristically candid 
 avowal, twisted as it immediately was into an 
 admission that the writer's views were contra- 
 dicted by the facts of palaeontology. But, in fact, 
 Mr. Darwin made no such admission. What he 
 says in effect is, not that palaeontological evidence 
 is against him, but that it is not distinctly in his 
 favour ; and, without attempting to attenuate the 
 fact, he accounts for it by the scantiness and the 
 imperfection of that evidence. 
 
 1 Origin of Species, ed. 1, p. 463. 
 
Til " THE ORIGIN OF SPECIES " 241 
 
 What is the state of the case now, when, as we 
 have seen, the amount of our knowledge respect- 
 ing the mammaha of the Tertiary epoch is 
 increased fifty-fold, and in some directions even 
 approaches completeness ? 
 
 Simply this, that, if the doctrine of evolution 
 had not existed, palaeontologists must have in- 
 vented it, so irresistibly is it forced upon the 
 mind by the study of the remains of the Tertiary 
 mammalia which have been brought to light since 
 1859. 
 
 Among the fossils of Pikermi, Gaudry found 
 the successive stages by which the ancient civets 
 passed into the more modern hyenas ; through 
 the Tertiary deposits of Western America, Marsh 
 tracked the successive forms by which the ancient 
 stock of the horse has passed into its present 
 form ; and innumerable less complete indications of 
 the mode of evolution of other groups of the 
 higher mammaha have been obtained. In the 
 remarkable memoir on the phosphorites of 
 Quercy, to which I have referred, M. Filhol de- 
 scribes no fewer than seventeen varieties of the 
 genus Cynodictis, which fill up all the interval 
 between the viverine animals and the , bear-like 
 dog Amphicyon ; nor do I know any solid ground 
 of objection to the supposition that, in this 
 Cynodictis-Aviphicyon group, we have the stock 
 whence all the Viveridse, Felidse, Hyaenidae, 
 Canidai, and perhaps the Procyonidte and Ursidae, 
 
242 THE COMING OF AGE OF vn 
 
 of the present fauna have been evolved. On 
 the contrary, there is a great deal to be said in 
 favour. 
 
 In the course of summing up his results, M. 
 Filhol observes : — 
 
 " During the epoch of the phosphorites, great 
 changes took place in animal forms, and almost 
 the same types as those which now exist became 
 defined from one another. 
 
 " Under the influence of natural conditions of 
 which we have no exact knowledge, though traces 
 of them are discoverable, species have been modi- 
 fied in a thousand ways : races have arisen which, 
 becoming fixed, have thus produced a corresponding 
 number of secondary species." 
 
 In 1859, language of which this is an uninten- 
 tional paraphrase, occurring in the " Origin of 
 Species," was scouted as wild speculation ; at pres- 
 ent, it is a sober statement of the conclusions to 
 which an acute and critically-minded investigator 
 is led by large and patient study of the facts of 
 palaeontology. I venture to repeat what I have 
 said before, that so far as the animal world is 
 concerned, evolution is no longer a speculation, but 
 a statement of historical fact. It takes its place 
 alongside of those accepted truths which must be 
 reckoned with by philosophers of all schools. 
 
 Thus when, on the first day of October next, 
 " The Origin of Species " comes of age, the pro- 
 mise of its youth will be amply fulfilled ; and we 
 
VII " THE ORIGIN OF SPECIES " 243 
 
 shall be prepared to congratulate the venerated 
 author of the book, not only that the greatness of 
 his achievement and its enduring influence upon 
 the progress of knowledge have won him a place 
 beside our Harvey ; but, still more, that, like 
 Harvey, he has lived long enough to outlast 
 detraction and opposition, and to see the stone 
 that the builders rejected become the head-stone 
 of the corner. 
 
YIII 
 CHAELES DARWIN 
 
 [Nature, April 27th, 1882] 
 
 Very few, even among those who have taken the 
 keenest interest in the progress of the revolution 
 in natural knowledge set afoot by the publication 
 of " The Origin of Species," and who have watched, 
 not without astonishment, the rapid and complete 
 change which has been effected both inside and 
 outside the boundaries of the scientific world in 
 the attitude of men's minds towards the doctrines 
 which are expounded in that great work, can have 
 been prepared for the extraordinary manifestation 
 of affectionate regard for the man, and of profound 
 reverence for the philosopher, which followed the 
 announcement, on Thursday last, of the death of 
 Mr. Darwin. 
 
 Not only in these islands, where so many have 
 felt the fascination of personal contact with an 
 
VIII CHARLES DARWIN 245 
 
 intellect which had no superior, and with a charac- 
 ter which was even nobler than the intellect ; but, 
 in all parts of the civilised world, it would seem 
 that those whose business it is to feel the pulse of 
 nations and to know what interests the masses of 
 mankind, were well aware that thousands of their 
 readers would think the world the poorer for 
 Darwin's death, and would dwell with eager 
 interest upon every incident of his history. In 
 France, in Germany, in Austro-Hungary, in Italy, 
 in the United States, writers of all shades of 
 opinion, for once unanimous, have paid a willing 
 tribute to the worth of our great countryman, 
 ignored in life by the official representatives of the 
 kingdom, but laid in death among his peers in 
 Westminster Abbey by the will of the intelligence 
 of the nation. 
 
 It is not for us to allude to the sacred sorrows 
 of the bereaved home at Down ; but it is no secret 
 that, outside that domestic group, there are many 
 to whom Mr. Darwin's death is a wholly irreparable 
 loss. And this not merely because of his wonder- 
 fully genial, simple, and generous nature ; his 
 cheerful and animated conversation, and the in- 
 finite variety and accuracy of his information ; but 
 because the more one knew of him, the more he 
 seemed the incorporated ideal of a man of science. 
 Acute as were his reasoning powers, vast as was 
 his knowledge, marvellous as was his tenacious 
 industry, under physical difficulties which would 
 
246 CHARLES DARWIN VIII 
 
 have converted nine men out of ten into aimless 
 invalids ; it was not these qualities, great as they 
 were, which impressed those who were admitted 
 to his intimacy with involuntary veneration, but a 
 certain intense and almost passionate honesty by 
 which all his thoughts and actions were irradiated, 
 as by a central fire. 
 
 It was this rarest and greatest of endowments 
 which kept his vivid imagination and great specu- 
 lative powers within due bounds ; which compelled 
 him to undertake the prodigious labours of original 
 investigation and of reading, upon which his 
 published works are based ; which made him 
 accept criticisms and suggestions from anybody 
 and everybody, not only without impatience, but 
 with expressions of gratitude sometimes almost 
 comically in excess of their value ; which led him 
 to allow neither himself nor others to be deceived 
 by phrases, and to spare neither time nor pains 
 in order to obtain clear and distinct ideas upon 
 every topic with which he occupied himself 
 
 One could not converse with Darwin without 
 being reminded of Socrates. There was the same 
 desire to find some one wiser than himself; the 
 same belief in the sovereignty of reason ; the same 
 ready humour ; the same sympathetic interest in 
 all the Avays and works of men. But instead of 
 turning away from the problems of Nature as 
 hopelessly insoluble, our modern philosopher 
 devoted his whole life to attacking them in the 
 
Till CilAKLJKS UAKWXJN 247 
 
 spirit of Heraclitus and of Democritus, with results 
 whicli are the substance of which their specula- 
 tions were anticipatory shadows. 
 
 The due appreciation, or even enumeration, of 
 these results is neither practicable nor desirable at 
 this moment. There is a time for all things — a 
 time for glorying in our ever-extending conquests 
 over the realm of Nature, and a time for mourning 
 over the heroes who have led us to victory. 
 
 None have foiaght better, and none have been 
 more fortunate, than Charles Darwin. He found 
 a great truth trodden underfoot, reviled by bigots, 
 and ridiculed by all the world ; he lived long 
 enough to see it, chiefly by his own efforts, 
 irrefragably established in science, inseparably 
 incorporated with the common thoughts of men, 
 and only hated and feared by those who would 
 revile, but dare not. What shall a man desire 
 more than this ? Once more the image of Socrates 
 rises unbidden, and the noble peroration of the 
 " Apology " rings in our ears as if it were Charles 
 Darwin's farewell : — 
 
 " The hour of departure has arrived, and we go 
 our ways — I to die and you to live. Which is the 
 better, God only knows." 
 
 46 
 
IX 
 
 THE DARWIN MEMORIAL 
 
 [June 9th, 1885] 
 
 Address by the President of the Royal Society, in the 
 
 name of the Memorial Committee, on handing over 
 
 the statue of Dartoin to H.R.H. the Prince of 
 
 Wales, as representative of the Tnostees of the 
 
 British Muscicm. 
 
 Your Royal Highness, — It is now three years 
 since the announcement of the death of our famous 
 countryman, Charles Darwin, gave rise to a 
 manifestation of public feeling, not only in these 
 realms, but throughout the civilised world, which, 
 if I mistake not, is without precedent in the 
 modest annals of scientific biography. 
 
 The causes of this deep and wide outburst of 
 emotion are not far to seek. We had lost one of 
 these rare ministers and interpreters of Nature 
 whose names mark epochs in the advance of 
 
IX THE DARWIN MEMORIAL 249 
 
 natural knowledge. For, whatever be the ultimate 
 verdict of posterity upon this or that opinion 
 which Mr. Darwin has propounded ; whatever 
 adumbrations or anticipations of his doctrines may- 
 be found in the writings of his predecessors ; the 
 broad fact remains that, since the publication and 
 by reason of the publication, of " The Origin of 
 Species " the fundamental conceptions and the 
 aims of the students of living Nature have been 
 completely changed. From that work has sprung 
 a great renewal, a true " instauratio magna " of the 
 zoological and botanical sciences. 
 
 But the impulse thus given to scientific thought 
 rapidly spread beyond the ordinarily recognised 
 limits of biology. Psychology, Ethics, Cosmology 
 were stirred to their foundations, and the " Origin 
 of Species" proved itself to be the fixed point 
 which the general doctrine of evolution needed in 
 order to move the world. " Darwinism," in one 
 form or another, sometimes strangely distorted 
 and mutilated, became an everyday topic of men's 
 speech, the object of an abundance both of 
 vituperation and of praise, more often than of 
 serious study. 
 
 It is curious now to remember how largely, at 
 first, the objectors predominated ; but considering 
 the usual fate of new views, it is still more 
 curious to consider for how short a time the phase 
 of vehement opposition lasted. Before twenty 
 years had passed, not only had the importance of 
 
250 THE DARWIN MEMORIAL IX 
 
 Mr. Darwin's work been fully recognised, but the 
 world had discerned the simple, earnest, generous 
 character of the man, that shone through every 
 page of his writings. 
 
 I imagine that reflections such as these swept 
 through the minds alike of loving friends and of 
 honourable antagonists when Mr. Darwin died ; 
 and that they were at one in the desire to honour 
 the memory of the man who, without fear and 
 without reproach, had successfully fought the 
 hardest intellectual battle of these days. 
 
 It was in satisfaction of these just and generous 
 impulses that our great naturalist's remains were 
 deposited in Westminster Abbey ; and that, im- 
 mediately afterwards, a public meeting, presided 
 over by my lamented predecessor,Mr. Spottiswoode, 
 was held in the rooms of the Royal Society, 
 for the purpose of considering what further step 
 should be taken towards the same end. 
 
 It was resolved to invite subscriptions, with the 
 view of erecting a statue of Mr. Darwin in some 
 suitable locality ; and to devote any surplus to the 
 advancement of the biolos^ical sciences. 
 
 Contributions at once flowed in from Austria, 
 Belgium, Brazil, Denmark, France, Germany, 
 Holland, Italy, Norway, Portugal, Russia, Spain, 
 Sweden, Switzerland, the United States, and the 
 British Colonies, no less than from all parts of the 
 three kingdoms ; and they came from all classes of 
 the community. To mention one interesting case, 
 
IX THE DARWIN MEMORIAL 251 
 
 Sweden sent in 2296 subscriptions "from all sorts 
 of people," as the distinguished man of science 
 who transmitted them wrote, " from the bishop to 
 the seamstress, and in sums from five pounds to 
 two pence." 
 
 The Executive Committee has thus been enabled 
 to carry out the objects proposed. A " Darwin 
 Fund" has been created, which is to be held in 
 trust by the Royal Society, and is to be employed 
 in the promotion of biological research. 
 
 The execution of the statue was entrusted to 
 Mr. Boehm ; and I think that those who had the 
 good fortune to know Mr. Darwin personally will 
 admire the power of artistic divination which has 
 enabled the sculptor to place before us so very 
 characteristic a likeness of one whom he had not 
 seen. 
 
 It appeared to the Committee that, whether they 
 regarded Mr. Darwin's career or the requirements 
 of a work of art, no site could be so appropriate as 
 this great hall, and they applied to the Trustees of 
 the British Museum for permission to erect it in 
 its present position. 
 
 That permission was most cordially granted, and 
 I am desired to tender the best thanks of the 
 Committee to the Trustees for their willingness to 
 accede to our wishes. 
 
 I also beg leave to offer the expression of our 
 gratitude to your Royal Highness for kindly con- 
 senting to represent the Trustees to-day. 
 
252 THE DARWIN MEMORIAL IX 
 
 It only remains for me, your Royal Highness, 
 my Lords and Gentlemen, Trustees of the British 
 Museum, in the name of the Darwin Memorial 
 Committee, to request you to accept this statue of 
 Charles Darwin. 
 
 We do not make this request for the mere sake 
 of perpetuating a memory ; for so long as men 
 occupy themselves with the pursuit of truth, the 
 name of Darwin runs no more risk of oblivion 
 than does that of Copernicus, or that of Harvey. 
 
 Nor, most assuredly, do we ask you to preserve 
 the statue in its cynosural position in this 
 entrance-hall of our National Museum of Natural 
 History as evidence that Mr. Darwin's views have 
 received your official sanction ; for science does not 
 recognise such sanctions, and commits suicide 
 when it adopts a creed. 
 
 No ; we beg you to cherish this Memorial as a 
 symbol by which, as generation after generation of 
 students of Nature enter yonder door, they shall 
 be reminded of the ideal according to which they 
 must shape their lives, if they would turn to the 
 best account the opportunities offered by the 
 great institution under your charge. 
 
OBITUARY 1 
 
 [1888] 
 
 Chaeles Robert Darwin Avas the fifth child 
 and second son of Robert Warinsr Darwin and 
 Susannah Wedgwood, and was born on the 12th 
 February, 1809, at Shrewsbury, where his father 
 was a physician in large practice. 
 
 Mrs. Robert Darwin died when her son Charles 
 was only eight years old, and he hardly remem- 
 bered her. A daughter of the famous Josiah 
 Wedgwood, who created a new branch of the 
 potter's art, and established the great works of 
 Etruria, could hardly fail to transmit important 
 mental and moral qualities to her children ; and 
 there is a solitary record of her direct influence 
 in the story told by a schoolfellow, who remembers 
 Charles Danvin " bringing a flower to school, and 
 
 1 From the Obituary Notices of the Proceedings of the Royal 
 Society, vol. 44. 
 
254) OBITUAEY X 
 
 saying that his mother had taught him how, by 
 looking at the inside of the blossom, the name of 
 the plant could be discovered." (I., p. 28.^) 
 
 The theory that men of genius derive their 
 qualities from their mothers, however, can hardly 
 derive support from Charles Darwin's case, in the 
 face of the patent influence of his paternal fore- 
 fathers. Dr. Darwin, i'^ideed, though a man of 
 marked individuality of character, a quick and 
 acute observer, with much practical sagacity, is 
 said not to have had a scientific mind. But when 
 his son adds that his father " formed a theory for 
 almost everything that occurred " (I., p. 20), he 
 indicates a highly probable source for that in- 
 ability to refrain from forming an hypothesis on 
 every subject which he confesses to be one of the 
 leading characteristics of his own mind, some 
 pages further on (I., p. 103). Dr. R. W. Darwin, 
 again, was the third son of Erasmus Darwin, also 
 a physician of great repute, who shared the 
 intimacy of Watt and Priestley, and was 
 widely known as the author of " Zoonomia," and 
 other voluminous jDoetical and prose works which 
 had a great vojrue in the latter half of the 
 eighteenth century. The celebrity which they 
 enjoyed was in part due to the attractive style (at 
 least according to the taste of that day) in which 
 the author's extensive, though not very profound, 
 
 1 The references throughout tliis notice are to the Life and, 
 Letters, unless the contrary is expressly stated. 
 
X OBITUARY 255 
 
 acquaintance with natural phenomena was set 
 forth ; but in a still greater degree, probably, to 
 the boldness of the speculative views, always 
 ingenious and sometimes fantastic, in which he 
 indulged. The conception of evolution set afoot 
 by De Maillet and others, in the early part of the 
 century, not only found a vigorous champion in 
 Erasmus Darwin, but he propounded an hypo- 
 thesis as to the manner in which the species of 
 animals and plants have acquired their characters, 
 which is identical in principle with that subse- 
 quently rendered famous by Lamarck. 
 
 That Charles Darwin's chief intellectual in- 
 heritance came to him from the paternal side, 
 then, is hardly doubtful. But there is nothing to 
 show that he was, to any sensible extent, directly 
 influenced by his grandfather's biological work. 
 He tells us that a perusal of the " Zoonomia " in 
 early life produced no effect upon him, although 
 he greatly admired it ; and that, on reading it again, 
 ten or fifteen years afterwards, he was much disap- 
 pointed, "the proportion of speculation being so 
 large to the facts given." But with his usual 
 anxious candour he adds, " Nevertheless, it is proba- 
 ble that the hearing, rather early in life, such views 
 maintained and praised, may have favoured my 
 upholding them, in a different form, in my ' Origin 
 of Species.' " (I., p. 38.) Erasmus Darwin was in 
 fact an anticipator of Lamarck, and not of Charles 
 Darwin; there is no trace in his works of the 
 
266 OBITUARY X 
 
 conceptions by the addition of which his grandson 
 metamorphosed the theory of evolution as applied 
 to living things and gave it a new foundation. 
 
 Charles Darwin's childhood and youth afforded 
 no intimation that he would be, or do, anything 
 out of the common run. In fact, the prognosti- 
 cations of the educational authorities into whose 
 hands he first fell were most distinctly unfavour- 
 able ; and they counted the only boy of original 
 genius who is known to have come under their 
 hands as no better than a dunce. The history of 
 the educational experiments to which Darwin was 
 svibjected is curious, and not without a moral for 
 the present generation. There were four of them, 
 and three were failures. Yet it cannot be said 
 that the materials on which the pedagogic powers 
 operated were other than good. In his boyhood 
 Darwin Avas strong, well-gi'own, and active, taking 
 the keen delight in field sports and in every 
 description of hard physical exercise which is 
 natural to an English country-bred lad ; and, in 
 respect of things of the mind, he was neither 
 apathetic, nor idle, nor one-sided. The " Auto- 
 biography " tells us that he " had much 
 zeal for whatever interested " him, and he was 
 interested in many and very diverse topics. 
 He could work hard, and liked a complex 
 subject better than an easy one. The " clear 
 geometrical proofs " of Euclid delighted him. 
 His interest in jDractical chemistry, carried out in 
 
X OBITUAEY 257 
 
 an extemporised laboratory, in which he was per- 
 mitted to assist by his elder brother, kept him 
 late at work, and earned him the nickname of 
 " gas " among hi^ schoolfellows. And there could 
 have been no insensibility to literature in one 
 who, as a boy, could sit for hours reading Shake- 
 speare, Milton, Scott, and Byron ; who greatly 
 admired some of the Odes of Horace ; and who, 
 in later years, on board the " Beagle," when only 
 one book could be carried on an expedition, 
 chose a volume of Milton for his companion. 
 
 Industry, intellectual interests, the capacity for 
 taking pleasure in deductive reasoning, in obser- 
 vation, in experiment, no less than in the highest 
 works of imagination : where these qualities are 
 present any rational system of education should 
 surely be able to make something of them. Un- 
 fortunately for Darwin, the Shrewsbury Grammar 
 School, though good of its kind, was an institution 
 of a type universally prevalent in this country half 
 a century ago, and by no means extinct at the 
 present day. The education given was " strictly 
 classical," "especial attention" being "paid to 
 verse-making," while all other subjects, except a 
 little ancient geography and history, were ignored. 
 Whether, as in some famous English schools at that 
 date and much later, elementary arithmetic was 
 also left out of sight does not appear ; but the 
 instruction in Euclid which gave Charles Darwin 
 so much satisfaction was certainly supplied by a 
 
258 OBITUAKY X 
 
 private tutor. That a boy, even in his leisure 
 hours, should permit himself to be interested in 
 any but book-learning seems to have been regarded 
 as little better than an outrage by the head master, 
 who thought it his duty to administer a public 
 rebuke to young Darwin for wasting his time 
 on such a contemptible subject as chemistry. 
 English composition and literature, modern lan- 
 guages, modern history, modern geography, appear 
 to have been considered to be as despicable as 
 chemistry. 
 
 For seven long years Darwin got through his 
 appointed tasks ; construed without cribs, learned 
 by rote whatever was demanded, and concocted 
 his verses in approved schoolboy fashion. And 
 the result, as it appeared to his mature judgment, 
 was simply negative. " The school as a means of 
 education to me was simply a blank." (I. p. 32.) 
 On the other hand, the extraneous chemical 
 exercises, which the head master treated so 
 contumeliously, are gratefully spoken of as the 
 " best part " of his education while at school. 
 Such is the judgment of the scholar on the school ; 
 as might be expected, it has its counterpart in the 
 judgment of the school on the scholar. The 
 collective intelligence of the staff of Shrewsbury 
 School could find nothing but dull mediocrity in 
 Charles Darwin. The mind that found satisfac- 
 tion in knowledge, but very little in mere learning ; 
 that could appreciate literature, but had no par- 
 
X OBITUARY 259 
 
 ticular aptitude for grammatical exercises ; appeared 
 to the " strictly classical" pedagogue to be no mind 
 at all. As a matter of fact, Darwin's school 
 education left him ignorant of almost all the 
 things which it would have been well for him to 
 know, and untrained in all the things it would 
 have been useful for him to be able to do, in 
 after life. Drawing, practice in English compo- 
 sition, and instruction in the elements of the 
 physical sciences, would not only have been infi- 
 nitely valuable to him in reference to his future 
 career, but would have furnished the discipline 
 suited to his faculties, whatever that career might 
 be. And a knowledge of French and German, 
 especially the latter, would have removed from his 
 path obstacles which he never fully overcame. 
 
 Thus, starved and stunted on the intellectual 
 side, it is not surprising that Charles Darwin's 
 energies were directed towards athletic amuse- 
 ments and sport, to such an extent, that even his 
 kind and sagacious father could be exasperated 
 into telling him that " he cared for nothing but 
 shooting, dogs, and rat-catching." (I. p. 32.) It 
 would be unfair to expect even the wisest of fathers 
 to have foreseen that the shooting and the rat- 
 catching, as training in the ways of quick observa- 
 tion and in physical endurance, would prove more 
 valuable than the construing and verse-making to 
 his son, whose attempt, at a later period of his life, 
 to persuade himself '" that shooting was almost an 
 
260 OBITUARY X 
 
 intellectual employment : it required so much skill 
 to judge where to find most game, and to hunt the 
 dogs well " (I. p. 43), was by no means so sophis- 
 tical as he seems to have been ready to admit. 
 
 In 1825, Dr. Darwin came to the very just con- 
 clusion that his son Charles would do no good by 
 remaining at Shrewsbury School, and sent him to 
 join his elder brother Erasmus, who was studying 
 medicine at Edinburgh, with the intention that 
 the younger son should also become a medical 
 practitioner. Both sons, however, were well aware 
 that their inheritance would relieve them from the 
 urgency of the struggle for existence which most 
 professional men have to face ; and they seemed to 
 have allowed their tastes, rather than the medical 
 curriculum, to have guided their studies. Erasmus 
 Darwin was debarred by constant ill-health from 
 seeking the public distinction which his high in- 
 telligence and extensive knowledge would, under 
 ordinary circumstances, have insured. He took 
 no great interest in biological subjects, but his 
 companionship must have had its influence on 
 his brother. Still more was exerted by friends 
 like Coldstream and Grant, <both subsequently 
 well-known zoologists (and the latter an enthu- 
 siastic Lamarckian), by whom Darwin was induced 
 to interest himself in marine zoology. A notice 
 of the ciliated germs of Flustra, communicated to 
 the Plinian Society in 1826, was the first fruits of 
 Darwin's half century of scientific work. Occa- 
 
X OBITUARY 261 
 
 sional attendance at the Wernerian Society brought 
 him into relation with that excellent ornithologist 
 the elder Macgillivray, and enabled him to see and 
 hear Audubon. Moreover, he got lessons in bird- 
 stuffing from a negro, who had accompanied the 
 eccentric traveller Waterton in his wanderings, 
 before settling in Edinburgh. 
 
 No doubt Darwin picked up a great deal of 
 valuable knowledge during his two years' residence 
 in Scotland ; but it is equally clear that next to 
 none of it came through the regular channels of 
 academic education. Indeed, the influence of the 
 Edinburgh professoriate appears to have been 
 mainly negative, and in some cases deterrent ; 
 creating in his mind, not only a very low estimate 
 of the value of lectures, but an antipathy to the 
 subjects which had been the occasion of the 
 boredom inflicted upon him by their instrument- 
 ality. With the exception of Hope, the Professor 
 of Chemistry, Darwin found them all " intolerably 
 dull." Forty years afterwards he writes of the 
 lectures of the Professor of Materia Medica that 
 they were " fearful to remember." The Professor 
 of Anatomy made his lectures " as dull as he was 
 himself," and he must have been very dull to have 
 wrung from his victim the sharpest personal remark 
 recorded as his. But the climax seems to have 
 been attained by the Professor of Geology and 
 Zoology, whose praelections were so " incredibly 
 dull " that they produced in their hearer the some- 
 
262 OBITUARY X 
 
 what rash determination never " to read a book on 
 geology or in any way to study the science " so 
 long as he lived. (I. p. 41.) 
 
 There is much reason to believe that the 
 lectures in question were eminently qualified to 
 produce the impression which they made ; and 
 there can be little doubt, that Darwin's conclusion 
 that his time was better employed in reading 
 than in listening to such lectures was a sound 
 one. But it was particularly unfortunate that 
 the personal and professorial dulness of the 
 Professor of Anatomy, combined with Darwin's 
 sensitiveness to the disagreeable concomitants of 
 anatomical work, drove him away from the 
 dissecting room. In after life, he justly recognised 
 that this was an " irremediable evil " in reference 
 to the pursuits he eventually adopted ; indeed, it 
 is marvellous that he succeeded in making up for 
 his lack of anatomical discipline, so far as his 
 work on the Cirripedes shows he did. And the 
 neglect of anatomy had the further unfortunate 
 result that it excluded him from the best 
 opportunity of bringing himself into direct contact 
 with the facts of nature which the University had 
 to offer. In those days, almost the only practical 
 scientific work accessible to students was anatomi- 
 cal, and the only laboratory at their disposal the 
 dissecting room. 
 
 We may now console ourselves with the 
 reflection that the partial evil was the general 
 
X OBITUARY 263 
 
 good. Darwin had already shown an aptitude for 
 practical medicine (I. p. 37) ; and his subsequent 
 career proved that he had the making of an 
 excellent anatomist. Thus, though his horror of 
 operations would probably have shut him off from 
 surgery, there was nothing to prevent him (any 
 more than the same peculiarity prevented his 
 father) from passing successfully through the 
 medical curriculum and becoming, like his father 
 and grandfather, a successful physician, in which 
 case " The Origin of Species " would not have been 
 written. Darwin has jestingly alluded to the 
 fact that the shape of his nose (to which Captain 
 Fitzroy objected), nearly prevented his embarka- 
 tion in the " Beagle " ; it may be that the 
 sensitiveness of that organ secured him for 
 science. 
 
 At the end of two years' residence in Edin- 
 burgh it hardly needed Dr. Darwin's sagacity to 
 conclude that a young man, who found nothing 
 but dulness in professorial lucubrations, could not 
 bring himself to endure a dissecting room, fled 
 from operations, and did not need a profession as 
 a means of livelihood, was hardly likely to 
 distinguish himself as a student of medicine. He 
 therefore made a new suggestion, proposing that 
 his son should enter an English University and 
 quahfy for the ministry of the Church. Charles 
 Darwin found the proposal agreeable, none the 
 less, probably, that a good deal of natural history 
 
 46 
 
264 OBITUAEY X 
 
 and a little shooting were by no means held, 
 at that time, to be incompatible with the 
 conscientious performance of the duties of a 
 country clergyman. But it is characteristic of the 
 man, that he asked time for consideration, in 
 order that he might satisfy himself that he could 
 sign the Thirty-nine Articles with a clear con- 
 science. However, the study of " Pearson on the 
 Creeds " and a few other books of divinity soon 
 assured him that his religious opinions left 
 nothing to be desired on the score of orthodoxy, 
 and he acceded to his father's proposition. 
 
 The English University selected was Cambridge; 
 but an unexpected obstacle arose from the fact 
 that, within the two years which had elapsed, 
 since the young man who had enjoyed seven 
 years of the benefit of a strictly classical education 
 had left school, he had forgotten almost every- 
 thing he had learned there, " even to some few of 
 the Greek letters." (I. p. 46.) Three months 
 with a tutor, however, brought him back to the 
 point of translating Homer and the Greek Testa- 
 ment " with moderate facility," and Charles 
 Darwin commenced the third educational experi- 
 ment of which he was the subject, and was en- 
 tered on the books of Christ's College in October 
 1827. So far as the direct results of the academic 
 training thus received are concerned, the English 
 University was not more successful than the 
 Scottish. " During the three years which I spent 
 
X OBITUARY 265 
 
 at Cambridge my time was wasted, as far as the 
 academical studies were concerned, as completely 
 as at Edinburgh and as at school." (I. p. 46.) 
 And yet, as before, there is ample evidence that 
 this negative result cannot be put down to any 
 native defect on the part of the scholar. Idle and 
 dull young men, or even young men who being 
 neither idle nor dull, are incapable of caring for 
 anything but some hobby, do not devote them- 
 selves to the thorough study of Paley's " Moral 
 Philosophy," and " Evidences of Christianity " ; 
 nor are their reminiscences of this particular 
 portion of their studies expressed in terms such 
 as the following : " The logic of this book [the 
 ' Evidences '] and, as I may add, of his ' Natural 
 Theology' gave me as much delight as did 
 Euclid." (I. p. 47.) 
 
 The collector's instinct, strong in Darwin from 
 his childhood, as is usually the case in great 
 naturalists, turned itself in the direction of Insects 
 during his residence at Cambridge. In childhood 
 it had been damped by the moral scruples of a 
 sister, as to the propriety of catching and killing 
 insects for the mere sake of possessing them, but 
 now it broke out afresh, and Darwin became an 
 enthusiastic beetle collector. Oddly enough he 
 took no scientific interest in beetles, not even 
 troubling himself to make out their names ; his 
 delight lay in the capture of a species which 
 turned out to be rare or new, and still more in 
 
266 OBITTJAET X 
 
 finding his name, as captor, recorded in print. 
 Evidently, this beetle-hunting hobby had little to 
 do with science, but was mainly a new phase of 
 the old and undiminished love of sport. In the 
 intervals of beetle-catching, when shooting and 
 hunting were not to be had, riding across country 
 answered the purpose. These tastes naturallj'' 
 threw the young undergraduate among a set of 
 men who preferred hard riding' to hard reading, 
 and wasted the midnight oil upon other pursuits 
 than that of academic distinction. A superficial 
 observer might have had some grounds to fear 
 that Dr. Darwin's wrathful prognosis might yet be 
 verified. But if the eminently social tendencies 
 of a vigorous and genial nature sought an outlet 
 among a set of jovial sporting friends, there were 
 other and no less strong proclivities which 
 brought him into relation with associates of a very 
 different stamj). 
 
 Though almost without ear and with a very 
 defective memory for music, Darwin was so 
 strongly and pleasurably affected by it that he 
 became a member of a musical society ; and an 
 equal lack of natural capacity for drawing did not 
 prevent him from studying good works of art with 
 much care. 
 
 An acquaintance with even the rudiments of 
 physical science was no part of the requirements 
 for the ordinary Cambridge degree. But there 
 were professors both of Geology and of Botany 
 
X OBITUARY 267 
 
 whose lectures were accessible to those who chose 
 to attend them. The occupants of these chairs, in 
 Darwin's time, were eminent men and also admir- 
 able lecturers in their widely different styles. The 
 horror of geological lectures which Darwin had 
 acquired at Edinburgh, unfortunately prevented 
 him from going within reach of the fervid elo- 
 quence of Sedgwick ; but he attended the botanical 
 course, and though he paid no serious attention to 
 the subject, he took great delight in the country 
 excursions, which Henslow so well knew how to 
 make both pleasant and instructive. The 
 Botanical Professor was, in fact, a man of rare 
 character and singularly extensive acquirements 
 in all branches of natural history. It was his 
 greatest pleasure to place his stores of knowledge 
 at the disposal of the young men who gathered 
 about him, and who found in him, not merely an 
 encyclopedic teacher but a wise counsellor, and, 
 in case of worthiness, a warm friend. Darwin's 
 acquaintance with him soon ripened into a friend- 
 ship which was terminated only by Henslow's 
 death in 1861, when his quondam pupil gave 
 touching expression to his sense of what he owed 
 to one whom he calls (in one of his letters) his 
 " dear old master in Natural History." (II. p. 217.) 
 It was by Henslow's advice that Darwin was led 
 to break the vow he had registered against making 
 an acquaintance with geology ; and it was through 
 Henslow's good offices with Sedgwick that he 
 
268 OBITUARY X 
 
 obtained the opportunity of accompanying the 
 Geolog^ical Professor on one of his excursions in 
 Wales. He then received a certain amount of 
 practical instruction in Geology, the value of which 
 he subsequently warmly acknowledged. (I. p. 
 237.) In another direction, Henslow did him an 
 immense, though not altogether intentional 
 service, by recommending him to buy and study 
 the recently published first volume of Ly ell's 
 " Principles." As an orthodox geologist of the 
 then dominant catastrophic school, Henslow 
 accompanied his recommendation with the 
 admonition on no account to adopt Ly ell's 
 general views. But the warning fell on deaf 
 ears, and it is hardly too much to say that 
 Darwin's greatest work is the outcome of the 
 unflinching application to Biology of the leading 
 idea and the method applied in the "Principles" 
 to geology.^ Finally, it was through Henslow, 
 and at his suggestion, that Darwin was offered the 
 appointment to the " Beagle " as naturalist. 
 
 During the latter part of Darwin's residence at 
 Cambridge the prospect of entering the Church, 
 though the plan was never formally renounced, 
 
 * "After my return to England it appeared to mo that ty 
 following the example of Lyell in Geology, and by collecting all 
 facts which bore in anyway on the variation of animals and 
 plants under domestication and nature, some light might per- 
 haps be thrown on the whole subject [of the origin of species]." 
 (I. p. 83.) See also the dedication of the second edition of the 
 Journal of a Naturalist. 
 
\J±J± X \J -fVXV J. 
 
 269 
 
 seems to have gi'own very shadowy. Humboldt's 
 " Personal Narrative," and Herschel's " Introduc- 
 tion to the Study of Natural Philosophy," fell in 
 his way and revealed to him his real vocation. 
 The impression made by the former work was 
 very strong. " My whole course of life," says 
 Darwin in seudincj a message to Humboldt, " is 
 due to having read and re-read, as a youth, his 
 personal narrative." (I. p. 336.) The description 
 of Teneriffe inspired Darwin with such a strong 
 desire to visit the island, that he took some steps 
 towards going there — inquiring about ships, and 
 
 so on. 
 
 But, while this project was fermenting, Henslow, 
 who had been asked to recommend a naturalist for 
 Captain Fitzroy's projected expedition, at once 
 thought of his pupil. In his letter of the 24th 
 August, 1831, he says : " I have stated that I 
 consider you to be the best qualified person I know 
 of who is likely to undertake such a situation. I 
 state this — not on the supposition of your being a 
 finished naturalist, but as amply qualified for 
 collecting, observing, and noting anything worthy 
 to be noted in Natural History .... The voyage 
 is to last two years, and if you take plenty of 
 books with you, anything you please may be done." 
 (I. p. 193.) The state of the case could not have 
 been better put. Assuredly the young naturalist's 
 theoretical and practical scientific training had 
 gone no further than- might suffice for the outfit 
 
270 OBITUARY X 
 
 of an intelligent collector and note-taker. He was 
 fully conscious of the fact, and his ambition hardly 
 rose above the hope that he should bring back 
 materials for the scientific " lions " at home of 
 sufficient excellence to prevent them from turning 
 and rending him. (I. p. 248.) 
 
 But a fourth educational experiment was to be 
 tried. This time Nature took him in hand herself 
 and showed him the way by which, to borrow 
 Henslow's prophetic phrase, " anything he pleased 
 might be done." 
 
 The conditions of life presented by a ship-of-war 
 of only 242 tons burthen, would not, primd facie, 
 appear to be so favourable to intellectual develop- 
 ment as those offered by the cloistered retirement 
 of Christ's College. Darwin had not even a cabin 
 to himself; while, in addition to the hindrances 
 and interruptions incidental to sea-life, which can 
 be appreciated only by those who have had 
 experience of them, sea-sickness came on whenever 
 the little ship was " lively " ; and, considering the 
 circumstances of the cruise, that must have been 
 her normal state. Nevertheless, Darwin found on 
 board the " Beagle " that which neither the 
 pedagogues of Shrewsbury, nor the professoriate 
 of Edinburgh, nor the tutors of Cambridge had 
 managed to give him. " I have always felt that I 
 owe to the voyage the first real training or 
 education of my mind (I. p. 61) ; " and in a letter 
 written as he was leaving England, he calls the 
 
X OBITUARY 271 
 
 voyage on which he was starting, with just insight, 
 his " second life." (I. p. 214.) Happily for Darwin's 
 education, the school time of the "Beagle" lasted 
 five years instead of two; and the countries 
 which the ship visited were singularly well fitted 
 to provide him with object-lessons, on the nature 
 of things, of the greatest value. 
 
 While at sea, he diligently collected, studied, 
 and made copious notes upon the surface Fauna. 
 But with no previous training in dissection, hardly 
 any power of drawing, and next to no knowledge 
 of comparative anatomy, his occupation with work 
 of this kind— notwithstanding all his zeal and 
 industry — resulted, for the most part, in a 
 vast accumulation of useless manuscript. Some 
 acquaintance with the marine Crustacea, observa- 
 tions on Flanarioi and on the ubiquitous Sagitta, 
 seem to have been the chief results of a great 
 amount of labour in this direction. 
 
 It was otherwise with the terrestrial phenomena 
 which came under the voyager's notice : and 
 Geology very soon took her revenge for the scorn 
 which the much-bored Edinburgh student had 
 poured upon her. Three weeks after leaving 
 England the ship touched land for the first time 
 at St. Jago, in the Cape de Verd Islands, and 
 Darwin found his attention vividly engaged by the 
 volcanic phenomena and the signs of upheaval 
 which the island presented. His geological 
 studies had already indicated the direction in 
 
272 OBITUAEY X 
 
 which a great deal might be done, beyond collect- 
 ing ; and it was while sitting beneath a low lava 
 cliff on the shore of this island, that a sense of his 
 real capability first dawned upon Darwin, and 
 prompted the ambition to write a book on the 
 geology of the various countries visited. (I. p. 66.) 
 Even at this early date, Darwin must have thought 
 much on geological topics, for he was already 
 convinced of the superiority of Lyell's views to 
 those entertained by the catastrophists ^ ; and his 
 subsequent study of the tertiary deposits and of the 
 terraced gravel beds of South America was 
 eminently fitted to strengthen that conviction. 
 The letters from South America contain little 
 reference to any scientific topic except geology ; 
 and even the theory of the formation of coral 
 reefs was prompted by the evidence of extensive 
 and gradual changes of level afforded by the 
 geology of South America ; " No other work of 
 mine," he says, " was begun in so deductive a spirit 
 as this ; for the whole theory was thought out on 
 the West Coast of South America, before I had 
 seen a true coral reef. I had, therefore, only to 
 verify and extend my views by a careful exam- 
 
 ^ " I had brought with me the first volume of Lyell's Principles 
 of Geology, which I studied attentively ; and tlie book was of 
 the highest service to mo in many ways. The very first place 
 which I examined, namely, St. Jago, in the Cape de Verd 
 Islands, showed me clearly the wonderful superiority of Lyell's 
 manner of treating Geology, compared with that of any other 
 -luthor \^hose works I had with, me or ever afterwards 
 read"— (I. p. 62.) 
 
X OBITUARY "273 
 
 ination of living reefs.' (I. p. 70.) In 1835, when 
 starting from Lima for the Galapagos, he recom- 
 mends his friend, W. D. Fox, to take np geology : 
 — " There is so much larger a field for thought 
 than in the other bi-anches of Natural History. 
 I am become a zealous disciple of ilr. Lyell's views, 
 as made known in his admirable book. Geologising 
 in South America, I am tempted to carry parts to 
 a greater extent even than he does. Geology is a 
 capital science to begin with, as it requires nothing 
 but a little reading, thinking, and hammering." 
 (I. p. 263.) The truth of the last statement, when 
 it was written, is a curious mark of the subsequent 
 progress of geology. Even so late as 1836, Darwin 
 speaks of being " much more inclined for geology 
 than the other branches of Natural History." 
 (I. p. 275.) 
 
 At the end of tlie letter to Mr. Fox, however, a 
 little doubt is expressed whether zoological studies 
 might not, after all, have been more profitable ; 
 and an interesting passage in the " Autobiography " 
 enables us to understand the origin of this 
 hesitation. 
 
 " During the voyage of the ' Beagle ' I had been 
 deeply impressed by discovering in the Pampean 
 formation great fossil animals covered with armour 
 like that on the existing armadillos ; secondly, by 
 the manner in which closely-allied animals replace 
 one another in proceeding southwards over the 
 continent ; and, thirdly, by the South American 
 
27^ OBITUARY X 
 
 character of most of the productions of the 
 Galapagos Archipelago, and, more especially, by 
 the manner in which they differ slightly on each 
 island of the group ; some of the islands appearing 
 to be very ancient in a geological sense. 
 
 " It was evident that such facts as these, as well 
 as many others, could only be explained on the 
 supposition that species gradually become modi- 
 fied ; and the subject haunted me. But it was 
 equally evident that neither the action of the 
 surrounding conditions, nor the will of the organ- 
 isms (especially in the case of plants) could account 
 for the innumerable cases in which organisms of 
 every kind are beautifully adapted to their habits 
 of life ; for instance, a woodpecker or a tree-frog to 
 climb trees, or a seed for dispersal by hooks or 
 plumes. I had always been much struck by such 
 adaptations, and until these could be explained it 
 seemed to me almost useless to endeavour to prove 
 by indirect evidence that species have been modi- 
 fied." (I. p. 82.) 
 
 The facts to which reference is here made were, 
 without doubt, eminently fitted to attract the at- 
 tention of a philosophical thinker ; but, until the 
 relations of the existing with the extinct species and 
 of the species of the different geographical areas 
 with one another, were determined with some 
 exactness, they afforded but an unsafe foundation 
 for speculation. It was not possible that this 
 determination should have been effected before 
 
X 
 
 OBITUARY 275 
 
 the return of the " Beagle " to England ; and thus 
 the date which Darwin (writing in 1837) assigns to 
 the dawn of the new light which was rising in his 
 mind becomes intelligible.^ 
 
 " In July opened first note-book on Transmuta- 
 tion of Species. Had been greatly struck from 
 about the month of previous March on character 
 of South American fossils and species on Gala- 
 pagos Archipelago. These facts (especially latter) 
 origin of all my views." (I. p. 276.) 
 
 From March, 1837, then, Darwin, not without 
 many misgivings and fluctuations of opinion, 
 inclined towards transmutation as a provisional 
 hypothesis. Three months afterwards he is hard 
 at work collecting facta for the purpose of test- 
 ing the hypothesis ; and an almost apologetic 
 passage in a letter to Lyell shows that, already, 
 the attractions of biology are beginning to pre- 
 dominate over those of geology. 
 
 " I have lately been sadly tempted to be idle^ — 
 
 ' I am indebted to Mr. F. Darwin for the knowledge of a 
 letter addressed by his father to Dr. Otto Zacharias in 1877 
 ■which contains the following paragraph, confirmatory of the 
 view expressed above : "Wlien I was on board the Beagle, I 
 believed in the permanence of species, but, as far as I can 
 remember, vague doubts occasionally flitted across my mind. 
 On my return home in the autumn of 1836, I immediately began 
 to prepare my journal for publication, and then saw how many 
 facts indicated tlie common descent of species, so that in July, 
 1837, I opened a note-book to record any facts which might bear 
 on the question. But I did not become convinced that species 
 were mutable until. I think, two or three years had elapsed." 
 
 - Darwin generally uses the word "idle " in a peculiar sense. 
 He means by it working hard at something he likes when he 
 
276 OBITUARY X 
 
 that is, as far as pure Geology is concerned — by 
 the delightful number of new views which have 
 been coming in thickly and steadily — on the 
 classification and affinities and instincts of animals 
 — bearing on the question of species. Note-book 
 after note-book has been filled with facts which 
 begin to group themselves clearly under sub-laws." 
 (I. p. 298.) 
 
 The problem which was to be Darwin's chief 
 subject of occupation for the rest of his life thus 
 presented itself, at first, mainly under its distribu- 
 tional aspect. Why do species present certain re- 
 lations in space and in time ? Why are the 
 animals and plants of the Galapagos Archipelago 
 so like those of South America and yet difi'erent 
 from them ? Why are those of the several islets 
 more or less different from one another ? Why 
 are the animals of the latest geological epoch in 
 South America similar in fades to those which 
 exist in the same region at the present day, and 
 yet specifically or generically different ? 
 
 The reply to these questions, which was almost 
 universally received fifty years ago, was that ani- 
 mals and plants were created such as they arc ; 
 and that their present distribution, at any rate so 
 far as terrestrial organisms are concerned, has been 
 effected by the migration of their ancestors from 
 
 ought to be occupied with a less attractive subject. Though it 
 sounds paradoxical, there is a good deal to be said in favour of 
 this view of pleasant woik. 
 
y OBITUARY 277 
 
 the region in which the ark stranded after the 
 subsidence of the deluge. It is true that the 
 geologists had drawn attention to a good many 
 tolerably serious difficulties in the way of the 
 diluvial part of this hypothesis, no less than to the 
 supposition that the work of creation had occupied 
 only a brief space of time. But even those, such 
 as Lyell, who most strenuously argued in favour 
 of the sufficiency of natural causes for the pro- 
 duction of the phenomena of the inorganic world, 
 held stoutly by the hypothesis of creation in the 
 case of those of the world of life. 
 
 For persons who were unable to feel satisfied 
 with the fashionable doctrine, there remained only 
 two alternatives — the hypothesis of spontaneous 
 generation, and that of descent with modiiication. 
 The former was simply the creative hypothesis 
 with the creator left out ; the latter had already 
 been propounded by De Maillet and Erasmus 
 Darwin, among others ; and, later, systematically 
 expounded by Lamarck. But in the eyes of the 
 naturalist of the " Beagle " (and, probably, in those 
 of most sober thinkers), the advocates of transmu- 
 tation had done the doctrine they expounded more 
 harm than good. 
 
 Darwin's opinion of the scientific value of the 
 " Zoonomia " has already been mentioned. His 
 verdict on Lamarck is given in the following pas- 
 sage of a letter to Lyell (March, 1863) : — 
 
 " Lastly, you refer repeatedly to my view as a 
 
278 OBITUARY 
 
 X 
 
 modification of Lamarck's doctrine of development 
 and progression. If this is your deliberate opinion 
 there is nothing to be said, but it does not seem 
 so to me. Plato, Buffon, my grandfather, before 
 Lamarck and others, propounded the obvious view 
 that if species were not created separately they 
 must have descended from other species, and I 
 can see nothing else in common between the 
 " Origin " and Lamarck. I believe this way of 
 putting the case is very injurious to its acceptance, 
 as it implies necessary progression, and closely 
 connects Wallace's and my views with what I con- 
 sider, after two deliberate readings, as a wretched 
 book, and one from which (I well remember to my 
 surprise) I gained nothing." 
 
 " But," adds Darwin with a little touch of 
 banter, " I know you rank it higher, Avhich is curi- 
 ous, as it did not in the least shake your belief." 
 (III. p. 14 ; see also p. 16, "to me it was an ab- 
 solutely useless book.") 
 
 Unable to find any satisfactory theory of the 
 process of descent with modification in the works 
 of his predecessors, Darwin proceeded to lay the 
 foundations of his own views independently ; and 
 he naturally turned, in the first place, to the only 
 certainly known examples of descent with modifi- 
 cation, namely, those which are presented by 
 domestic animals and cultivated plants. He 
 devoted himself to the study of these cases with 
 a thoroughness to which none of his predecessors 
 
X OBITUARY 279 
 
 even remotely approximated ; and he very soon 
 had his reward in the discovery "that selec- 
 tion was the keystone of man's success in mak- 
 ing useful races of animals and plants." (I. p. 
 83.) 
 
 This was the first step in Darwin's progress, 
 though its immediate result was to bring him face 
 to face with a great difficulty. " But how selection 
 could be applied to organisms living in a state of 
 nature remained for some time a mystery to me." 
 (I. p. 83.) 
 
 The key to this mystery was furnished by the 
 accidental perusal of the famous essay of Mai thus 
 " On Population " in the autumn of 1838. The 
 necessary result of unrestricted multiplication is 
 competition for the means of existence. The suc- 
 cess of one competitor involves the failure of the 
 rest, that is, their extinction ; and this " selection " 
 is dependent on the better adaptation of the suc- 
 cessful competitor to the conditions of the com- 
 petition. Variation occurs under natural, no less 
 than under artificial, conditions. Unrestricted 
 multipKcation implies the competition of varieties 
 and the selection of those which are relatively best 
 adapted to the conditions. 
 
 Neither Erasmus Darwin, nor Lamarck, had any 
 inkling of the possibility of this process of " natural 
 selection " ; and though it had been foreshadowed 
 by Wells in 1813, and more fully stated by 
 Matthew in 1831, the speculations of the latter 
 
 47 
 
280 OBITUAEY X 
 
 writer remained unknown to naturalists until after 
 tlie publication of the " Origin of Species." 
 
 Darwin found in the doctrine of the selection of 
 favourable variations by natural causes, which thus 
 presented itself to his mind, not merely a probable 
 theory of the origin of the diverse species of living 
 forms, but that explanation of the phenomena of 
 adaptation, which previous speculations had utterly 
 failed to give. The process of natural selection is, 
 in fact, dependent on adaptation — it is all one, 
 whether one says that the competitor which sur- 
 vives is the " fittest '' or the " best adapted." And 
 it was a perfectly fair deduction that even the 
 most complicated adaptations might result from 
 the summation of a long series of simple favour- 
 able variations. 
 
 Darwin notes as a serious defect in the first 
 sketch of his theory that he had omitted to con- 
 sider one very important problem, the solution of 
 which did. not occur to him till some time after- 
 wards. " This problem is the tendency in organic 
 beings descended from the same stock to diverge 
 in character as they become modified. . . . The 
 solution, as I believe, is that the modified offspring 
 of all dominant and increasing forms tend to 
 become adapted to many and highly diversified 
 places in the economy of nature." (1. p. 84.) 
 
 It is curious that so mujsh importance should be 
 attached to this supplementary idea. It seems 
 obvious that the theory of the origin of species 
 
X OBITUARY 281 
 
 by natural selection necessarily involves the diverg- 
 ence of the forms selected. An individual which 
 varies, ipso /ado diverges from the type of its 
 species ; and its progeny, in which the variation 
 becomes intensified by selection, must diverge still 
 more, not only from the parent stock, but from 
 any other race of that stock starting from, a varia- 
 tion of a different character. The selective process 
 could not take place unless the selected variety 
 was either better adapted to the conditions than 
 the original stock, or adapted to other conditions 
 than the original stock. In the first case, the 
 original stock would be sooner or later extirpated ; 
 in the second, the type, as represented by the 
 original stock and the variety, would occupy more 
 diversified stations than it did before. 
 
 The theory, essentially such as it was published 
 fourteen years later, was written out in 1844, and 
 Darwin was so fully convinced of the importance 
 of his work, as it then stood, that he made special 
 arrangements for its publication in case of his 
 death. Btit it is a singular example of reticent 
 fortitude, that, although fpr the next fourteen years 
 the subject never left his mind, and during the 
 latter half of that period he was constantly en- 
 gaged in amassing facts bearing upon it from wide 
 reading, a colossal correspondence, and a long series 
 of experiments, only two or three friends were 
 cognisant of his views. To the outside world he 
 seemed to have his hands quite sufficiently full of 
 
282 OBITUARY X 
 
 other matters. la 1844, he pubHshed his observa- 
 tions on the volcanic islands visited during the 
 voyage of the " Beagle." In 1845, a largely re- 
 modelled edition of his " Journal " made its appear- 
 ance, and immediately won, as it has ever since 
 held, the favour of both the scientific and the un- 
 scientific public. In 1843, the " Geological Ob- 
 servations in South America " cams out, and this 
 book was no sooner finished than Darwin set to 
 work upon the Cirripedes. He was led to under- 
 take this long and heavy task, partly by his desire 
 to make out the relations of a very anomalous 
 form which he had discovered on the coast of 
 Chili ; and partly by a sense of " presumption in 
 accumulating facts and speculating on the subject 
 of variation without having worked out my due 
 share of species." (11. p. 81.) The eight or nine 
 years of labour, which resulted in a monograph of 
 first-rate importance in systematic zoology (to say 
 nothing of such novel points as the discovery of 
 complemental males), left Darwin no room to re- 
 proach himself on this SMie, and few will share 
 his " doubt whether the work was worth the con- 
 sumption of so much time." (I. "p. 82.) 
 
 In science no man can safely speculate about 
 the nature and relation of things with which he is 
 unacquainted at first hand, and the acquirement 
 of an intimate and practical knowledge of the 
 process of species-making and of all the uncertain- 
 ties which underlie the boundaries between species 
 
2 OBITUARY 283 
 
 and varieties, drawn by even the most careful and 
 conscientious systematists ^ were of no less im- 
 portance to the author of the " Origin of Species " 
 than was the bearing of the Cirripede work upon 
 " the principles of a natural classification." (I. p. 
 81.) No one, as Darwin justly observes, has a 
 " right to examine the question of species who 
 has not minutely described many.'' (II. p. 39.) 
 
 In September, 1854, the Cirripede work was 
 finished, " ten thousand barnacles " had been sent 
 " out of the house, all over the world," and Darwin 
 had the satisfaction of being free to turn again to 
 his " old notes on species." In 1855, he began to 
 breed pigeons, and to make observations on the 
 effects of use and disuse, experiments on seeds, 
 and so on, while resuming his industrious collec- 
 tion of facts, with a? view " to see how far they 
 favour or are opposed to the notion that wild species 
 are mutable or immutable. I mean with my 
 utmost power to give all arguments and facts on 
 both sides. I have a number of people helping 
 me every way, and giving me most valuable 
 
 * "After describing a set of forms as distinct species, tearing 
 up my MS., and making them one species, tearing that up and 
 making them separate, and then making them one again (which 
 has happened to me), I have gnashed my teeth, cursed species, 
 and asked what sin I had committed to be so punished." (II. 
 p. 40. ) Is there any naturalist provided with a logical sense and 
 a large suite of specimens, who has not undergone pangs of the 
 sort described in this vigorous paragraph, which might, with 
 advantage, be printed on the title-page of every systematic 
 monogiaph as a warning to the uninitiated ? 
 
284 OBITUARY X 
 
 assistance ; but I often doubt whether the subject 
 will not quite overpower me." (II. p. 49.) 
 
 Early in 18.56, on Lyell's advice, Darwin began 
 to write out his views on the origin of species on a 
 scale three or four times as extensive as that of the 
 work published in 1859. In July of the same 
 year he gave a brief sketch of his theory in a 
 letter to Asa Gray ; and, in the year 1857, his 
 letters to his correspondents show him to be busily 
 engaged on what he calls his " big book." (II, 
 pp. 85, 94.) In May, 1857, Darwin writes to 
 Wallace : " I am now preparing my work [on the 
 question how and in what way do species and 
 varieties differ from each other] for publication, 
 but I fiad the subject so very large, that, though 
 I have written many chapters, I do not suppose I 
 shall go to press for two years." (II. p. 95.) In 
 December, 1857, he Avrites, in the course of a long 
 letter to the same correspondent, " I am extremely 
 glad to hear that you are attending to distribution 
 in accordance with theoretical ideas. I am a firm 
 believer that without speculation there is no good 
 and original observation." (II. p. 1 08.) ^ In 
 June, 1858, he received from Mr. Wallace, then 
 in the Malay Archipelago, an " Essay on the 
 tendency of varieties to depart indefinitely from 
 
 1 The last remark contains a pregnant truth, but it must be 
 confcssrd it hardly squares with the declaration in the Auto- 
 hiogropJiy, (I. p. 83), that he worked on "true Baconian 
 principles." 
 
X OBITUARY 285 
 
 the original type," of which Darwin says, " If 
 Wallace had my MS. sketch written out in 1842 
 he could not have made a better short abstract ! 
 Even his terms stand now as heads of my chapters. 
 Please return me the MS., which he does not say 
 he wishes me to publish, but I shall, of course, at 
 once write and offer to send it to any journal. 
 So all my originality, whatever it may amount to, 
 will be smashed, though my book, if ever it will 
 have any value, will' not be deteriorated ; as all 
 the labour consists in the application of the 
 theory." (II. p. 116.) 
 
 Thus, Darwin's first impulse was to publish 
 Wallace's essay without note or comment of his 
 own. But, on consultation with Lyell and Hooker, 
 the latter of whom had read the sketch of 1844, 
 they suggested, as an undoubtedly more equitable 
 course, that extracts from the MS. of 1844 and 
 from the letter to Dr. Asa Gray should be com- 
 municated to the Linnean Society along with 
 Wallace's essay. The joint communication was 
 read on July 1, 1858, and published under the 
 title " On the Tendency of Species to form 
 Varieties ; and on the Perpetuation of Varieties 
 and Species by Natural Means of Selection." 
 This was followed, on Darwin's part, by the com- 
 position of a summary account of the conclusions 
 to which his twenty years' work on the species 
 question had led him. It occupied him for 
 thirteen months, and appeared in November, 
 
286 OBITUAKY t 
 
 1859, under the title " On the Origin of Species 
 by means of Natural Selection or the Preservation 
 of Favoured Races in the Struggle of Life." 
 
 It is doubtful if any single book, except the 
 " Principia," ever worked so great and so rapid a 
 revolution in science, or made so deep an 
 impression on the general mind. It aroused a 
 tempest of opposition and met with equally 
 vehement support, and it must be added that 
 no book has been more widely and persistently 
 misunderstood by both friends and foes. In 1861, 
 Darwin remarks to a correspondent, " You under- 
 stand my book perfectly, and that I find a very 
 rare event with my critics." (I. p. 313.) The 
 immense popularity which the " Origin " at once 
 acquired was no doubt largely due to its many 
 points of contact with philosophical and theo- 
 logical questions in which every intelligent man 
 feels a profound interest; but a good deal must 
 be assigned to a somewhat delusive simplicity of 
 style, which tends to disguise the complexity and 
 difficulty of the subject, and much to the wealth 
 of information on all sorts of curious problems of 
 natural history, which is made accessible to the 
 most unlearned reader. But long occupation with 
 the work has led the present writer to believe 
 that the " Origin of Species " is one of the hardest 
 of books to master ; ^ and he is justified in this 
 
 ^ He is comforted to find that probably the best qualified 
 judge among all the readers of the Oriyin in 1859 was of the 
 
X ' OBITUAKY 287 
 
 convictioa by observing that although the 
 " Origin " has been close on thirty- years before the 
 world, the strangest misconceptions of the 
 essential nature of the theory therein advocated 
 are still put forth by serious writers. 
 
 Although, then, the present occasion is not 
 suitable for any detailed criticism of the theory, or 
 of the objections which have been brought against 
 it, it may not be out of place to endeavour to 
 separate the substance of the theory from its 
 accidents ; and to show that a variety not only of 
 hostile comments, but of friendly would-be im- 
 provements lose their raison d'Stre to the careful 
 student. Observation proves the existence among 
 all living beings of phenomena of three kinds, de- 
 noted by the terms heredity, variation, and multi- 
 plication. Progeny tend to resemble their parents ; 
 nevertheless all their organs and functions are sus- 
 ceptible of departing more or less from the average 
 parental character ; and their number is in excess 
 of that of their parents. Severe competition for 
 the means of living, or the struggle for existence, 
 is a necessary consequence of unlimited multipli- 
 cation ; while selection, or the preservation of 
 favourable variations and the extinction of others, 
 is a necessary consequence of severe competition. 
 " Favourable variations " are those which are 
 better adapted to surrounding conditions. It 
 
 same opinion. Sir J. Hooker writes, "It is the very hardest 
 book to read, to full profit, that I ever tried." (II. p. 242.) 
 
288 OBITUAET X 
 
 follows, therefore, that every variety which is 
 selected into a species is so favoured and pre- 
 served in consequence of being, in some one or 
 more respects, better adapted to its surroundings 
 than its rivals. In other words, every species 
 which exists, exists in virtue of adaptation, and 
 whatever accounts for that adaptation accounts for 
 the existence of the species. 
 
 To say that Darwin has put forward a theory of 
 the adaptation of species, but not of their origin, 
 is therefore to misunderstand the first principles 
 of the theory. For, as has been pointed out, it is 
 a necessary consequence of the theory of selection 
 that every species must have some one or more 
 structural or functional peculiarities, in virtue of 
 the advantage conferred by which, it has fought 
 through the crowd of its competitors and achieved 
 a certain duration. In this sense, it is true 
 that every species has been " originated " by 
 selection. 
 
 There is another sense, however, in which it is 
 equally true that selection originates nothing, 
 " Unless profitable variations .... occur natural 
 selection can do nothing" (" Origin,", Ed. I. p. 82). 
 " Nothing can be effected unless favourable 
 variations occur" (ibid., p. 108). " What applies 
 to one animal will apply throughout time to all 
 animals — that is, if they vary — for otherwise 
 natural selection can do nothing. So it will be 
 with plants" (ibid., p. 113). Strictly speaking, 
 
X OBITUARY 289 
 
 therefore, the origin of species in general lies in 
 variation ; while the origin of any particular 
 species lies, firstly, in the occurrence, and secondly, 
 in the selection and preservation of a particular 
 variation. Clearness on this head will relieve one 
 from the necessity of attending to the fallacious 
 assertion that natural selection iS a deus ex macliind, 
 or occult agency. 
 
 Those, again, who confuse the operation of the 
 natural causes which bring about variation and 
 selection with what they are pleased to call 
 •' chance " can hardly have read the opening 
 paragraph of the fifth chapter of the " Origin " 
 (Ed. I, p. 131) : " I have sometimes spoken as if 
 the variations .... had been due to chance. 
 This is of course a wholly incorrect expression, 
 but it seems to acknowledge plainly our igno- 
 rance of the cause of each particular variation." 
 
 Another point of great importance to the right 
 ' comprehension of the theory, is, that while every 
 species must needs have some adaptive advanta- 
 geous characters to which it owes its preservation 
 by selection, it may possess any number of others 
 which are neither advantageous nor disadvanta- 
 geous, but indifferent, or even slightly disadvan - 
 tageous. (/Sid, p. 81.) For variations take place, 
 not merely in one organ or function at a time, but 
 in many ; and thus an advantageous variation, 
 which gives rise to the selection of a new race or 
 species, may be accompanied by others which are 
 
290 OBITUARY X 
 
 indifferent, but which are just as strongly heredi- 
 tary as the advantageous variations. The advan- 
 tageous structure is but one product of a modified 
 general constitution which may manifest itself by 
 several other products ; and the selective process 
 carries the general constitution along with the 
 advantageous special peculiarity. A given species 
 of plant may owe its existence to the selective 
 adaptation of its flowers to insect fertilisers ; but the 
 character of its leaves may be the result of varia- 
 tions of an indifferent character. It is the origin 
 of variations of this kind to which Darwin refers in 
 his frequent reference to what he calls " laws of 
 correlation of growth " or " correlated variation." 
 
 These considerations lead us further to see the 
 inappropr lateness of the objections raised to 
 Darwin's theory on the ground that natural 
 selection does not account for the first commence- 
 ments of useful organs. But it does not pretend 
 to do so. The source of such commencements is 
 necessarily to be sought in different variations, 
 which remain, unaffected by selection until they 
 have taken such a form as to become utilisable in 
 the struggle for existence. 
 
 It is not essential to Darwin's theory that 
 anything more should be assumed than the facts 
 of heredity, variation, and unlimited multiplication ; 
 and the validity of the deductive reasoning as to 
 the effect of the last (that is, of the struggle for 
 existence which it involves) upon the varieties 
 
X OBITUARY 291 
 
 resulting from the operation of the former. Nor 
 is it essential that one should take up any 
 particular position in regard to the mode of 
 variation, whether, for example, it takes place per 
 salhbm or gradually ; whether it is definite in 
 character or indefinite. Still less are those who 
 accept the theory hound to any particular views as 
 to the causes of heredity or of variation. 
 
 That Dai-win held strong opinions on some or all 
 of these points may be quite true ; but, so far as 
 the theory is concerned, they must be regarded as 
 ohiter dicta. With respect to the causes of vari- 
 ation, Darwin's opinions are, from first to last, 
 put forward altogether tentatively. In the first 
 edition of the " Origin," he attributes the strongest 
 influence to changes in the conditions of life of 
 parental organisms, which he appears to think act 
 on the germ through the intermediation of the 
 sexual organs. He points out, over and over again, 
 that habit, use, disuse, and the direct influence of 
 conditions have some effect, but he does not think 
 it great, and he draws attention to the difficulty 
 of distinguishing between effects of these agencies 
 and those of selection. There is, however, one 
 class of variations which he withdraws from the 
 direct influence of selection, namely, the variations 
 in the fertility of the sexual union of more or less 
 closely allied forms. He regards less fertility, or 
 more or less complete sterility, as "incidental to 
 other acquired differences." (-ZZjzcZ., p. 245.) 
 
292 OBITUARY X 
 
 Considering the difficulties which surround the 
 question of the causes of variation, it is not to be 
 wondered at, that Darwin should have inclined, 
 sometimes, rather more to one and, sometimes, 
 rather more to another of the possible alternatives. 
 There is little difference between the last edition 
 of the " Origin " (1872) and the first on this head. 
 In 1876, however, he writes to Moritz Wagner, 
 " In my opinion, the greatest error which I have 
 committed has been not allowing sufficient weight 
 to the direct action of the environments, i.e., food, 
 climate, &c., independently of natural selection. 
 . . . . When I wrote the ' Origin,' and for some 
 years afterwards, I could find little good evidence 
 of the direct action of the environment ; now there 
 is a large body of evidence, and your case of the 
 Saturnia is one of the most remarkable of which 
 I have heard." (Ill, p. 159.) But there is really 
 nothing to prevent the most tenacious adherent to 
 the theory of natural selection from taking any 
 view he pleases as to the importance of the direct 
 influence of conditions and the hereditary trans- 
 missibility of the modifications which they produce. 
 In fact, there is a good deal to be said for the view 
 that the so-called direct influence of conditions is 
 itself a case of selection. Whether the hypothesis 
 of Pangenesis be accepted or rejected, it can hardly 
 be doubted that the struggle for existence goes on 
 not merely between distinct organisms, but between 
 the physiological units of which each organism is 
 
X OBITUARY 293 
 
 composed, and that changes in external conditions 
 favour some and hinder others. 
 
 After a short stay in Cambridge, Darwin resided 
 in London for the first five years which followed 
 his return to England ; and for three years, he held 
 the post of Secretary to the Geological Society, 
 though he shared to the full his friend Lyell's 
 objection to entanglement in such engagements. 
 In fact, he ixsed to say in later life, more than half 
 in earnest, that he gave up hoping for work from 
 men who accepted ofiicial duties and, especially. 
 Government appointments. Happily for him, he 
 was exempted from the necessity of making any 
 sacrifice of this kind, but an even heavier burden 
 was laid upon him. During the earlier half of his 
 voyage Darwin retained the vigorous health of his 
 boyhood, and indeed proved himself to be excep- 
 tionally capable of enduring fatigue and privation. 
 An anomalous but severe disorder, which laid him 
 up for several weeks at Valparaiso in 1834, how- 
 ever, seems to have left its mark on his constitution ; 
 and, in the later years of his London life, attacks 
 of illness, usually accompanied by severe vomiting 
 and great prostration of strength, became frequent. 
 As he grew older, a considerable part of every day, 
 even at his best times, was spent in misery ; while, 
 not unfrequently, months of suffering rendered work 
 of any kind impossible. Even Darwin's remarkable 
 tenacity of purpose and methodical utilisation of 
 
294) OBITUAKY X 
 
 every particle of available energy could not have 
 enabled him to achieve a fraction of the vast 
 amount of labour he got through, in the course of 
 the following forty years, had not the wisest and the 
 most loving care unceasingly surrounded him from 
 the time of his marriage in 1839. As early as 
 1842, the failure of health was so marked 
 that removal from London became imperatively 
 necessary; and Darwin purchased a house and 
 grounds at Down, a solitary hamlet in Kent, which 
 was his home for the rest of his life. Under the 
 strictly regulated conditions of a valetudinarian 
 existence, the intellectual activity of the invalid 
 might have put to shame most healthy men ; and, 
 so long as he could hold his head up, there was no 
 limit to the genial kindness of thought and action 
 for all about him. Those friends who were 
 privileged to share the intimate life of the house- 
 hold at Down have an abiding memory of the 
 cheerful restfulness which jDervaded and character- 
 ised it. 
 
 After mentioning his settlement at Down, 
 Darwin writes in his Autobiography : — 
 
 " My chief enjoyment and sole employment 
 throughout life has been scientific work ; and the 
 excitement from such work makes me, for the time, 
 forget, or drives quite away, my daily discomfort. 
 I have, therefore, nothing to record during the rest 
 of my life, except the publication of my several 
 books." (I, p. 79.) 
 
X OBITUARY 295 
 
 Of such works published subsequently to 1859, 
 several are monographic discussions of topics 
 briefly dealt with in the " Origin," which, it must 
 always be recollected, was considered by the 
 author to be merely an abstract of an optbs majus. 
 
 The earliest of the books which may be placed 
 in this category, " On the Various Contrivances 
 by which Orchids are Fertilised by Insects," was 
 published in 1862, and whether we regard its 
 theoretical significance, the excellence of the ob- 
 servations and the ingenuity of the reasonings 
 which it records, or the prodigious mass of sub- 
 sequent investigation of which it has been the 
 parent, it has no superior in point of importance. 
 The conviction that no theory of the origin of 
 species could be satisfactory which failed to offer 
 an explanation of the way in which mechanisms 
 involving adaptations of structure and function to 
 the performance of certain operations are brought 
 about, was, from the first, dominant in Darwin's 
 mind. As has been seen, he rejected Lamarck's 
 views because of their obvious incapacity to furnish 
 such an explanation in the case of the great 
 majority of animal mechanisms, and in that 
 of all those presented by the vegetable world. 
 
 So far back as 1793, the wonderful work of 
 Sprengel had established, beyond any reasonable 
 doubt, the fact that, in a large number of cases, a 
 flower is a piece of mechanism the object of which 
 is to convert insect visitors into agents of fertilisa- 
 48 
 
296 OBITUARY X 
 
 tion. Sprengel's observations had been most 
 undeservedly neglected and well-nigh forgotten ; 
 but Robert Brown having directed Darwin's 
 attention to them in 1841, he was attracted 
 towards the subject, and verified many of Sprengel's 
 statements. (Ill, p. 258.) It may be doubted 
 whether there was a living botanical specialist, 
 except perhaps Brown, who had done as much. 
 If, however, adaptations of this kind were to be 
 explained by natural selection, it was necessary to 
 show that the plants which were provided with 
 mechanisms for ensuring the aid of insects as 
 fertilisers, were by so much the better fitted 
 to compete with their rivals. This Sprengel 
 had not done. Darwin had been attending to 
 cross fertilisation in plants so far back as 1839, 
 from having arrived, in the course of his specu- 
 lations on the origin of species, at the convic- 
 tion " that crossing played an important part 
 in keeping specific forms constant" (I, p. 90). 
 The further development of his views on the 
 importance of cross fertilisation appears to have 
 taken place between this time and 1857, when he 
 published his first papers on the fertilisation of 
 flowers in the " Gardener's Chronicle." If the 
 conclusion at which he ultimately arrived, that 
 cross fertilisation is favourable to the fertility of 
 the parent and to the vigour of the offspring, is 
 correct, then it follows that all those mechanisms 
 which hinder self-fertilisation and favour crossing 
 
X OBITUARY 297 
 
 must be advantageous in the struggle for exist- 
 ence ; and, the more perfect the action of the 
 mechanism, the greater the advantage. Thus the 
 way lay open for the operation of natural selection 
 in gradually perfecting the flower as a fertilisation - 
 trap. Analogous reasoning applies to the fertil- 
 ising insect. The better its structure is adapted 
 to that of the trap, the more will it be able to 
 profit by the bait, whether of honey or of pollen, 
 to the exclusion of its competitors. Thus, by a 
 sort of action and reaction, a two-fold series of 
 adaptive modifications will be brought about. 
 
 In 1865, the important bearing of this subject 
 on his theory led Darwin to commence a great 
 series of laborious and difficult experiments on the 
 fertilisation of plants, which occupied him for 
 eleven years, and furnished him with the unex- 
 pectedly strong evidence in favour of the influence 
 of crossing which he published in 1876, under the 
 title of " The Effects of Cross and Self Fertilisation 
 in the Vegetable Kingdom." Incidentally, as it 
 were, to this heavy piece of work, he made the 
 remarkable series of observations on the different 
 arrangements by which crossing is favoured and, 
 in many cases, necessitated, which appeared in the 
 work on "The Different Forms of Flowers in 
 Plants of the same Species " in 1877. 
 
 In the course of the twenty years during which 
 Darwin was thus occupied in opening up new 
 regions of investigation to the botanist and 
 
298 OBITUARY X 
 
 showing the profound physiological significance of 
 the apparently meaningless diversities of floral 
 structure, his attention was keenly alive to any 
 other interesting phenomena of plant life which 
 came in his way. In his correspondence, he not 
 unfrequently laughs at himself for his ignorance 
 of systematic botany ; and his acquaintance with 
 vegetable anatomy and physiology was of the 
 slenderest. Nevertheless, if any of the less 
 common features of plant life came under his 
 notice, that imperious necessity of seeking for 
 causes which nature had laid upon him, impelled, 
 and indeed compelled, him to inquire the how 
 and the why of the fact, and its bearing on his 
 general views. And as, happily, the atavic ten- 
 dency to frame hypotheses was accompanied 
 by an equally strong need to test them by well- 
 devised experiments, and to acquire all possible 
 information, before publishing his results, the 
 effect was that he touched no topic without 
 elucidating it. 
 
 Thus the investigation of the operations of 
 insectivorous plants, embodied in the work on that 
 topic published in 1875, was started fifteen years 
 before, by a passing observation made during one 
 of Dai'win's rare holidays. 
 
 '' In the summer of 1860, I was idling and 
 resting near Hartfield, where two species of 
 Drosera abound ; and I noticed that numerous 
 insects had been entrapped by the leaves. I 
 
X OBITUARY 299 
 
 carried home some plants, and on giving them 
 some insects saw the movements of the tentacles, 
 and this made me think it possible that the insects 
 were caught for some special purpose. Fortu- 
 nately, a crucial test occurred to me, that of placing 
 a large number of leaves in various nitrogenous 
 and non-nitrogenous fluids of equal density ; and 
 as soon as I found that the former alone excited 
 energetic movements, it was obvious that here was 
 a fine new field for investigation." (I, p. 95.) 
 
 The researches thus initiated led to the proof 
 that plants are capable of secreting a digestive 
 fluid hke that of animals, and of profiting by the 
 result of digestion ; whereby the peculiar appara- 
 tuses of the insectivorous plants were brought 
 within the scope of natural selection. Moreover, 
 these inquiries widely enlarged our knowledge of 
 the manner in which stimuli are transmitted in 
 plants, and opened up a prospect of drawing closer 
 the analogies between the motor processes of plants 
 and those of animals. 
 
 So with respect to the books on " Climbing 
 Plants" (1875), and on the " Power of Movement 
 in Plants " (1880), Darwin says ;— 
 
 " I was led to take up this subjed; by reading a 
 short paper by Asa Gray, published in 1858. He 
 sent me some seeds, and on raising some plants I 
 was so much fascinated and perplexed by the 
 revolving movements of the tendrils and stems, 
 which movements are really very simple, though 
 
800 OBITUARY X 
 
 appearing at first sight very complex, that I pro- 
 cured various other kinds of climbing plants 
 and studied the whole subject. . . . Some of the 
 adaptations displayed by climbing plants are as 
 beautiful as those of orchids for ensuring cross- 
 fertilisation." (I, p. 93.) 
 
 In the midst of all this amount of work, 
 remarkable alike for its variety and its importance, 
 among plants, the animal kingdom was by no 
 means neglected. A large moiety of " The 
 Variation of Animals and Plants under Domesti- 
 cation " (1868), which contains the j^i^ces justifica- 
 tives of the first chapter of the " Origin," is devoted 
 to domestic animals, aud the hypothesis of 
 " pangenesis " propounded in the second volume 
 applies to the whole living world. In the " Ori- 
 gin " Darwin throws out some suggestions as to 
 the causes of variation, but he takes heredity, as it 
 is manifested by individual organisms, for granted, 
 as an ultimate fact ; pangenesis is an attempt to 
 account for the phenomena of heredity in the 
 organism, on the assumption that the physiological 
 units of which the organism is composed give off 
 gemmules, which, in virtue of heredity, tend to 
 reproduce the unit from which they are derived. 
 
 That Darwin had the application of his theory 
 to the origin of the human species clearly in his 
 mind in 1859, is obvious from a passage in the 
 first edition of " The Origin of Species." (Ed. I, 
 p. 488.) " In the distant future I see open fields 
 
X OBITUARY 301 
 
 for far more important researches. Psychology 
 will he hased on a new foundation, that of the 
 necessary acquirement of each mental power and 
 capacity by gradation. Light will be thrown on 
 the origin of man and his history." It is one of 
 the curiosities of scientific literature, that, in the 
 face of this plain declaration, its author should have 
 been charged with concealing his opinions on the 
 subject of the origin of man. But he reserved the 
 full statement of his views until 1871, when the 
 " Descent of Man " was published. The " Expres- 
 sion of the Emotions " (originally intended to form 
 only a chapter in the " Descent of Man ") grew into 
 a separate volume, which appeared in 1872. 
 Although always taking a keen interest in geology, 
 Darwin naturally found no time disposable for 
 geological work, even had his health permitted it, 
 after he became seriously engaged with the great 
 problem of species. But the last of his labours is, 
 in some sense, a return to his earliest, inasmuch as 
 it is an expansion of a short paper read before the 
 Geological Society more than forty years before, 
 and, as he says, " revived old geological thoughts " 
 (I, p. 98). In fact, " The Formation of Vegetable 
 Mould through the Action of Worms," affords as 
 striking an example of the great results produced 
 by the long-continued operation of small causes as 
 even the author of the " Principles of Geology " 
 could have desired. 
 
 In the early months of 1882 Darwin's health 
 
302 OBITUARY X 
 
 underwent a change for the "worse ; attacks of 
 giddiness and fainting supervened, and on the 19th 
 of April he died. On the 24th, his remains were 
 interred in Westminster Abbey, in accordance with 
 the general feeling that such a man as he should 
 not go to the grave without some public recogni- 
 tion of the greatness of his work. 
 
 &* 
 
 Mr. Darwin became a Fellow of the Royal 
 Society in 1839 ; one of the Royal Medals was 
 awarded to him in 1853, and he received the 
 Copley Medal in 1864. The " Life and Letters," 
 edited with admirable skill and judgment by Mr. 
 Francis Darwin, gives a full and singularly vivid 
 presentment of his father's personal character, of 
 his mode of work, and of the events of his life. In 
 the present brief obituary notice, the writer has 
 attempted nothing more than to select and put 
 together those facts which enable us to trace the 
 intellectual evolution of one of the greatest of the 
 many great men of science whose names adorn the 
 long roll of the Fellows of the Royal Society. 
 
XI 
 
 ON OUR KNOWLEDGE OF THE CAUSES 
 OF THE PHENOMENA OF ORGANIC 
 NATURE 
 
 [Six Lectures to Working Men. — 1863.] 
 I. 
 
 THE PRESENT CONDITION OF ORGANIC NATURE. 
 
 When it was my duty to consider what subject I 
 would select for the six lectures which I shall now 
 have the pleasure of delivering to you, it occurred 
 to me that I could not do better than endeavour 
 to put before you in a true light, or in what I 
 might perhaps with more modesty call, that which 
 I conceive myself to be the true light, the position 
 of a book which has been more praised and more 
 abused, perhaps, than any book which has appeared 
 for some years ; — I mean Mr. Darwin's work on the 
 "Origin of Species." That work, I doubt not, 
 many of you have read ; for I know the inquiring 
 spirit which is rife among you. At any rate, all 
 of you will have heard of it, — some by one kind of 
 report and some by another kind of report ; the 
 
304 THE CAUSES OF THE XI 
 
 attention of all and the curiosity of all have been 
 probably more or less excited on the subject of 
 that Avork. All I can do, and all I shall attempt 
 to do, is to put before you that kind of judgment 
 which has been formed by a man, who, of course, 
 is liable to judge erroneously ; but, at any rate, of 
 one whose business and profession it is to form 
 judgments upon questions of this nature. 
 
 And here, as it will always happen when dealing 
 with an extensive subject, the greater part of my 
 course — if, indeed, so small a number of lectures 
 can be properly called a course — must be devoted 
 to preliminary matters, or rather to a statement of 
 those facts and of those principles which the work 
 itself dwells upon, and brings more or less directly 
 before us. I have no right to suppose that all or 
 any of you are naturalists ; and, even if you were, 
 the misconceptions and misunderstandings prev- 
 alent even among naturalists, on these matters, 
 would make it desirable that I should take the 
 course I now propose to take, — that I should 
 start from the beginning, — that I should endeavour 
 to point out what is the existing state of the 
 organic world — that I should point out its past 
 condition, — that I should state what is the precise 
 nature of the undertaking which Mr. Darwin has 
 taken in hand ; that I should endeavour to show 
 you what are the only methods by which that 
 imdertaking can be brought to an issue, and to 
 point out to you how far the author of the work 
 
XI PHENOMENA OF OEGiNIC~NATURE 305 
 
 in question has satisfied those conditions, how far 
 he has not satisfied them, how far they are satis- 
 fiable by man, and how far they are not satisfiable 
 by man. 
 
 To-night, in taking up the first part of the 
 question, I shall endeavour, to put before you a 
 sort of broad notion of our knowledge of the con- 
 dition of the living world. There are many ways 
 of doing this. I might deal with it pictorially and 
 graphically. Following the example of Humboldt 
 in his " Aspects of Nature," I might endeavour to 
 point out tlie infinite variety of organic life in 
 every mode of its existence, with reference to the 
 variations of climate and the like ; and such an 
 attempt would be fraught with interest to us all ; 
 but considering the subject before us, such a course 
 would not be that best calculated to assist us. In 
 an argument of this kind we must go further and 
 dig deeper into the matter ; we must endeavour to 
 look into the foundations of living Nature, if I 
 may so say, and discover the principles involved in 
 some of her most secret operations. I propose, 
 therefore, in the first place, to take some ordinary 
 animal with which you are all familiar, and, by 
 easily comprehensible and obvious examples drawn 
 from it, to .show what are the kind of problems 
 which living beings in general lay before us ; and 
 1 shall then show you that the same problems are 
 laid open to us by all kinds ot living beings. 
 But. first, let mc say in what sense I have used the 
 
306 THE CAUSES OF THE XI 
 
 words " organic nature." In speaking of the 
 causes which lead to our present knowledge of 
 orofanic nature, I have used it almost as an 
 equivalent of the word " living," and for this 
 reason, — that in almost all living beings you can 
 distinguish several distinct portions set apart to 
 do particular things and work in a particular way. 
 These are termed " organs," and the whole 
 together is called " orcranic." And as it is 
 universally characteristic of them, the term 
 " organic " has been very conveniently employed 
 to denote the whole of living nature, — the Avhole 
 of the plant world, and the whole of the animal 
 world. 
 
 Few animals can be more familiar to you than 
 that whose skeleton is shown on our diagi-am. 
 You need not bother yourselves with this " Equus 
 caballus " written under it ; that is only the Latin 
 name of it, and does not make it any better. It 
 simply means the common horse. Suppose we 
 wish to understand all about the horse. Our 
 first object must be to study the structure of the 
 animal. The whole of his body is inclosed within 
 a hide, a skin covered with hair ; and if that hide 
 or skin be taken off, we find a great mass of flesh, 
 or what is technically called muscle, being the 
 substance which by its power of contraction enables 
 the animal to move. These muscles move the hard 
 parts one upon the other, and so give that strength 
 and power of motion which renders the horse so 
 
XI PHENOMENA OF ORGANIC NATURE 307 
 
 useful to us in the performance of those services 
 in which we employ him. 
 
 And then, on separating and removing the whole 
 of this skin and flesh, you have a great series 
 of bones, hard structures, bound together with 
 ligaments, and forming the skeleton which is 
 represented here. 
 
 In that skeleton there are a number of parts to 
 be recognised. The long series of bones, beginning 
 from the skull and ending in the tail, is called the 
 spine, and those in front are the ribs ; and then 
 there are two pairs of limbs, one before and one 
 behind ; and there are what we all know as the 
 fore-legs and the hind -legs. If we pursue our 
 researches into the interior of this animal, we find 
 within the framework of the skeleton a great 
 cavity, or rather, I should say, two great cavities, 
 — one cavity beginning in the skull and running 
 through the neck-bones, along the spine, and 
 ending in the tail, containing the brain and the 
 spinal marrow, which are extremely important 
 organs. The second great cavity, commencing 
 with the mouth, contains the gullet, the stomach, 
 the long intestine, and all the rest of those internal 
 apparatus which are essential for digestion ; and 
 then in the same great cavity, there are lodged the 
 heart and all the great vessels going from it ; and, 
 besides that the organs of respiration — the lungs : 
 and then the kidneys, and the organs of repro- 
 duction, and so on. Let us now endeavour to 
 
308 
 
 THE CAUSES OF THE 
 
 SI 
 
 reduce this notion of a horse that we now have, to 
 some such kind of simple expressions as can be at 
 once, and without difficulty, retained in the mind, 
 apart from all minor details. If I make a trans- 
 verse section, that is, if I were to saw a dead 
 horse across, I should find that, if I left out the 
 details, and supposing 1 took my section through 
 the anterior region, and through the fore-limbs, I 
 should have here this kind of section of the body 
 (Fig. 1). Here would be the upper part of the 
 
 animal — that great 
 mass of bones that 
 we spoke of as the 
 spine (a, Fig. 1). 
 Here I should have 
 the alimentary 
 
 canal (b, Fig. 1). 
 Here I should have 
 the heart (c, Fig. 
 1) ; and then you 
 see, there would be 
 a kind of double 
 tube, the whole 
 being inclosed with- 
 in the hide ; the spinal marrow would be placed 
 in the upper tube (a, Fig. 1), and in the lower 
 tube (d d. Fig. 1), there would be the ahmentary 
 canal {h), and the heart (c) ; and here I shall 
 have the legs pi:oceeding from each side. For 
 simplicity's sake. I represent them merely as 
 
XI PHENOMENA OF ORGANIC NATURE 309 
 
 stumps (e e, Fig. 1). Now that is a horse — as 
 mathematicians would say — reduced to its most 
 simple expression. Carry that in your minds, if 
 you please, as a simplified idea of the structure of 
 the horse. The considerations which I have now 
 put before you belong to what we technically call 
 the " Anatomy " of the horse. Now, suppose we 
 go to work upon these several parts, — flesh and 
 hair, and skin and bone, and lay open these various 
 organs with our scalpels, and examine them by 
 means of our magnifying-glasses, and see what we 
 can make of them. We shall find that the flesh 
 is made up of bundles of strong fibres. The brain 
 and nerves, too, we shall find, are made up of 
 fibres, and these queer-looking things that are 
 called ganglionic corpuscles. If we take a slice of 
 the bone and examine it, we shall find that it is 
 very like this diagram of a section of the bone of 
 on ostrich, though differing, of course, in some 
 details ; and if we take any part whatsoever of the 
 tissue, and examine it, we shall find it all has a 
 minute structure, visible only under the microscope. 
 All these parts constitute microscopic anatomy or 
 "Histology." These parts are constantly being 
 changed ; every part is constantly growing, decay- 
 ing, and being replaced lUiring the life of the animal. 
 The tissue is constantly replaced by new material ; 
 and if you go back to the young state of the tissue 
 in the case of muscle, or in the case of skin, or any 
 of the organs I have mentioned, you will find that 
 
310 THE CAUSES OF THE SI 
 
 they all come under the same condition. Every 
 one of these microscopic filaments and fibres (I 
 now speak merely of the general character of the 
 whole process) — every one of these parts — could 
 be traced down to some modification of a tissue 
 which can be readily divided into little particles of 
 fleshy matter, of that substance which is composed 
 of the chemical elements, carbon, hydrogen, oxygen, 
 and nitrogen, having such a shape as this (Fig. 2). 
 These particles, into which all primitive tissues 
 break up, are called cells. If I were to make a 
 section of a piece of the skin of my 
 hand, I should find that it was 
 made up of these cells. If I 
 examine the fibres which form the 
 various organs of all living animals, 
 ^. I should find that all of them, at 
 
 onetime or other, had been formed 
 out of a substance consisting of similar elements ; 
 so that you see, just as we reduced the whole body 
 in the gross to that sort of simple expression given 
 in Fig. 1, so we may reduce the whole of the 
 microscopic structural elements to a form of even 
 greater simplicity ; just as the plan of the whole 
 body may be so represented in a sense (Fig. 1), so 
 the primary structure of every tissue may be 
 represented by a mass of cells (Fig. 2). 
 
 Having thus, in this sort of general way, 
 sketched to you what I may call, perhaps, the 
 architecture of the body of the horse (what we 
 
XI PHENOMENA OF ORGANIC NATURE 311 
 
 term technically its Morphology), T must now turn 
 to another aspect. A horse is not a mere dead 
 structure : it is an active, living, working machine. 
 Hitherto we have, as it were, been looking at a 
 steam-engine with the fires out, and nothing in the 
 boiler ; but the body of the living animal is a 
 beautifully-formed active machine, and every part 
 has its different work to do in the working of that 
 machine, which is what we call its life. The 
 horse, if you see him after his day's work is done, 
 is cropping the grass in the fields, as it may be, or 
 munching the oats in his stable. What is he 
 doing ? His jaws are working as a mill — and a 
 very complex mill too — grinding the corn, or 
 crushing the grass to a pulp. As soon as that 
 operation has taken place, the food is passed down 
 to the stomach, and there it is mixed with the 
 chemical fluid called the gastric juice, a substance 
 which has the peculiar property of making soluble 
 and dissolving out the nutritious matter in the 
 grass, and leaving behind those parts which are 
 not nutritious ; so that you have, first, the mill, 
 then a sort of chemical digester ; and then the 
 food, thus partially dissolved, is carried back 
 by the muscular contractions of the intestines into 
 the hinder parts of the body, while the soluble 
 portions are taken up into the blood. The blood 
 is contained in a vast system of pipes, spreading 
 through the whole body, connected with a force- 
 pump, — the heart, — which, by its position and by 
 
 49 
 
312 THE CAUSES OF THE XI 
 
 the contractions of its valves, keeps tlie blood 
 constantly circulating in one direction, never 
 allowing it to rest ; and then, by means of this 
 circulation of the blood, laden as it is with the 
 products of digestion, the skin, the flesh, the hair, 
 and every other part of the body, draws from it 
 that which it wants, and every one of these organs 
 derives those materials which are necessary to 
 enable it to do its work. 
 
 The action of each of these organs, the per- 
 formance of each of these various duties, involve 
 in their operation a continual absorption of the 
 matters necessary for their support, from the 
 blood, and a constant formation of waste products, 
 which are returned to the blood, and conveyed by 
 it to the lungs and the kidneys, which are organs 
 that have allotted to them the office of extractinsr, 
 separating, and getting rid of these waste products ; 
 and thus the general nourishment, labour, and 
 repair of the whole machine are kept up with order 
 and regularity. But not only is it a machine 
 which feeds and appropriates to its own support 
 the nourishment necessary to its existence- — it is 
 an engine for locomotive purposes. The horse 
 desires to go from one place to another ; and to 
 enable it to do this, it has those strong contractile 
 bundles of muscles attached to the bones of its 
 limbs, which are put in motion by means of a sort 
 of telegraphic apparatus formed by the brain and 
 the great spinal cord running through the spine or 
 
XI PHENOMENA OF ORGANIC NATURE 313 
 
 backbone ; and to this spinal cord are attached a 
 number of fibres termed nerves, which proceed to 
 all parts of the structure. By means of these the 
 eyes, nose, tongue, and skin — all the organs of per- 
 ception — transmit impressions or sensations to the 
 brain, which acts as a sort of great central tele- 
 graph-office, receiving impressions and sending 
 messages to all parts of the body, and putting in 
 motion the muscles necessary to accomplish any 
 movement that maybe desired. So that you have 
 here an extremely complex and beautifully-pro- 
 portioned machine, with all its parts working 
 harmoniously together towards one common 
 object — the preservation of the life of the 
 animal. 
 
 Now, note this : the horse makes up its waste 
 by feeding, and its food is grass or oats, or perhaps 
 other vegetable products ; therefore, in the long 
 run, the source of all this complex machinery lies in 
 the vegetable kingdom. But where does the grass, 
 or the oat, or any other plant, obtain this nourish- 
 ing food-producing material ? At first it is a little 
 seed., which soon begins to draw into itself from 
 the earth and the surrounding air matters which 
 in themselves contain no vital properties what- 
 ever; it absorbs into its own substance water, 
 an inorganic body ; it draws into its substance 
 carbonic acid, an inorganic matter ; and ammonia, 
 another inorganic matter, found in the air ; and 
 then, by some wonderful chemical process, the 
 
314 THE CAUSES OF THE XI 
 
 details of which chemists do not yet understand, 
 though they are near foreshadowing them, it 
 combines them into one substance, which is known 
 to us as " Protein," a complex compouild of carbon, 
 hydrogen, oxygen, and nitrogen, which alone pos- 
 sesses the property of manifesting vitality and of 
 permanently supporting animal life. So that, you 
 see," the waste products of the animal economy, 
 the effete materials which are continually being 
 thrown off by all living beings, in the form of 
 organic matters, are constantly replaced by sup- 
 plies of the necessary repairing and rebuilding 
 materials drawn from the plants, which in their 
 turn manufacture them, so to speak, by a 
 mystei-ious combination of those same inorganic 
 materials. 
 
 Let us trace out the history of the horse in 
 another direction. After a certain time, as the 
 result of sickness or disease, the effect of accident, 
 or the consequence of old age, sooner or later, the 
 animal dies. The multitudinous operations of 
 this beautiful mechanism flag in their perform- 
 ance, the horse loses its vigour, and after passing 
 through the curious series of changes comprised 
 in its formation and preservation, it finally decays, 
 and ends its life by going back into that inorganic 
 world from which all but an inappreciable fraction 
 of its substance was derived. Its bones become 
 mere carbonate and phosphate of lime ; the matter 
 of its flesh, and of its other parts, becomes, in the 
 
XI 
 
 PHENOMENA OF ORGANIC NATURE 
 
 315 
 
 long run, con-verted into carbonic acid, into water, 
 and into ammonia. You will now, perhaps, under- 
 stand the curious relation of the animal with the 
 plant, of the organic with the inorganic world, 
 which is shown in this diagram. 
 
 laorgaidc World 
 
 CARBONIC ACID, 
 
 WATER. AMMONIA. 
 
 SALINES. 
 
 Vegetable World 
 
 Fig:.3. 
 
 Animal World 
 
 The plant gathers these inorganic materials 
 together and makes them up into its own 
 substance. The animal eats the plant and appro- 
 priates the nutritious portions to its own susten- 
 ance, rejects and gets rid of the useless matters ; 
 and, finally, the animal itself dies, and its whole 
 body is decomposed and returned into the inorganic 
 world. T here is thus a constant circulation from 
 one to the other, a continual formation of organic 
 life from inorganic matters, and as constant 
 a return of the matter of living bodies to the 
 inorganic world ; so that the materials of which 
 
316 THE CAUSES OF THE XI 
 
 our bodies are composed are largely, in all 
 probability, the substances which constituted the 
 matter of long extinct creations, but which have 
 in the interval constituted a part of the inorganic 
 world. 
 
 Thus we come to the conclusion, strange at first 
 sight, that the Matter constituting the living 
 world is identical with that which forijis the 
 inorganic world. And not less true is it that, 
 remarkable as are the powers or, in other words, 
 as are the FORCES which are exerted by living 
 beings, yet all these forces are either identical 
 with those which exist in the inorganic world, or 
 they are convertible into them ; I mean in just the 
 same sense as the researches of physical philo- 
 sophers have shown that heat is convertible into 
 electricity, that electricity is convertible into 
 magnetism, magnetism into mechanical force or 
 chemical force, and any one of them with the 
 other, each being measurable in terms of the other, 
 — even so, I say, that great law is applicable to 
 the living world. Consider why is the skeleton of 
 this horse capable of supporting the masses of 
 flesh and the various organs forming the living 
 body, unless it is because of the action of the same 
 forces of cohesion which combines together the 
 particles of matter composing this piece of chalk ? 
 What is there in the muscular contractile power 
 of the animal but the force which is expressible, 
 and which is in a certain sense convertible, into 
 
XI PHENOMENA OF ORGANIC NATURE 317 
 
 the force of gravity which it overcomes ? Or, if 
 you go to more hidden processes, in what does the 
 process of digestion differ from those processes 
 which are carried on in the laboratory of the 
 chemist ? Even if we take the most recondite 
 and most complex operations of animal life — those 
 of the nervous system, these of late years have 
 been shown to be — I do not say identical in any 
 sense with the electrical processes — but this has 
 been shown, that they are in some way or other 
 associated \vith them ; that is to say, that every 
 amount of nervous action is accompanied by a 
 certam amount of electrical disturbance in the 
 particles of the nerves in which that nervous 
 action is carried on. In this way the nervous 
 action is related to electricity in the same way 
 that heat is related to electricity ; and the same 
 sort of argument which demonstrates the two latter 
 to be related to one another shows that the nervous 
 forces are correlated to electricity ; for the experi- 
 ments of M. Dubois Reymond and others have 
 shown that whenever a nerve is in a state of 
 excitement, sending a message to the muscles or 
 conveying an impression to the brain, there is a 
 disturbance of the electrical condition of that 
 nerve which does not exist at other times ; and 
 there are a number of other facts and phenomena 
 of that sort ; so that we come to the broad con- 
 clusion that not only as to living matter itself, but 
 as to the forces that matter exerts, there is a close 
 
318 THE CAUSES OF THE SI 
 
 relationship between the organic and the inorganic 
 ^orld — the difference between them arising from 
 the diverse combination and disposition of identical 
 forces, and not from any primary diversity, so far 
 as we can see. 
 
 I said just now that the horse eventually died 
 and became converted into the same inorganic 
 substances from whence all but an inappreciable 
 fraction of its substance demonstrably originated, 
 so that the actual wanderings of matter are as 
 remarkable as the transmigrations of the soul 
 fabled by Indian tradition. But before death has 
 occurred, in the one sex or the other, and in fact 
 in both, certain products or parts of the organism 
 have been set free, certain parts of the organisms 
 of the two sexes have come into contact with one 
 another, and from that conjunction, from that 
 union which then takes place, there results the 
 formation of a new being. At stated times the 
 mare, from a particular part of the interior of her 
 body, called the ovary, gets rid of a minute 
 particle of matter comparable in all essential 
 respects with that which we called a cell a little 
 while since, which cell contains a kind of nucleus 
 in its centre, surrounded by a clear space and by a 
 viscid mass of protein substance (Fig. 2) ; and 
 though it is different in appearance from the eggs 
 which we are mostly acquainted with, it is really 
 an egg. After a time this minute particle of 
 inatter, which may o*^'" be a small fraction of a 
 
XI PHENOMENA OF ORGANIC NATURE 319 
 
 grain in weight, undergoes a series of changes, — 
 •wonderful, complex changes. Finally, upon its 
 surface there is fashioned a little elevation, which 
 afterwards becomes divided and marked by a 
 groove. The lateral boundaries of the groove 
 extend upwards and downwards, and at length 
 give rise to a double tube. In the upper and 
 smaller tube the spinal marrow and brain are 
 fashioned ; in the lower, the alimentary canal and 
 heart ; and^at length two pairs of buds shoot out at 
 the sides of the body, and they are the rudiments 
 of the limbs. In fact a true drawing of a section 
 of the embryo in this state would in all essential 
 respects resemble that diagram of a horse reduced 
 to its simplest expression, which I first placed 
 before you (Fig. 1). 
 
 Slowly and gradually these changes take place. 
 The whole of the body, at first, can be broken up 
 into "cells," which become in one place meta- 
 morphosed into muscle, — in another place into 
 gristle and bone, — in another place into fibrous 
 tissue, — and in another into hair ; every part 
 becoming gradually and slowly fashioned, as if 
 there were an artificer at work in each of these 
 complex structures that I have mentioned. This 
 embryo, as it is called, then passes into other con- 
 ditions. I should tell you that there is a time when 
 the embryos of neither dog, nor horse, nor porpoise, 
 nor monkey, nor man, can be distinguished by any 
 essential feature one from the other ; there is a 
 
320 THE CAUSES OF THE XI 
 
 time when they each and all of them resemble 
 this one of the dog. But as development 
 advances, all the parts acquire their speciality, 
 till at length you have the embryo converted into 
 the form of the parem from which it started. So 
 that you see, this living animal, this horse, begins 
 its existence as a minute particle of nitrogenous 
 matter, which, being supplied with nutriment 
 (derived, as I have shown, from the inorganic 
 world), grows up according to the special type and 
 construction of its parents, works and undergoes a 
 constant waste, and that waste is made good by 
 nutriment derived from the inorganic world ; the 
 waste given off in this way being directly added 
 to the inorganic world. Eventually the animal 
 itself dies, and, by the process of decomposition, 
 its whole body is returned to those conditions 
 of inorganic matter in which its substance 
 originated. 
 
 This, then, is that which is true of every living 
 form, from the lowest plant to the highest animal 
 — to man himself. You might define the life of 
 every one in exactly the same terms as those 
 which I have now used ; the difference between 
 the highest and the lowest being simply in the 
 complexity of the developmental changes, the 
 variety of the structural forms, and the diversity 
 of the physiological functions which are exerted 
 by each. 
 
 If I were to take an oak tree, as a specimen of 
 
XI PHENOMENA OF ORGANIC NATURE 321 
 
 the plant world, I should find that it originated in 
 an acorn, which, too, commenced in a cell ; the 
 acorn is placed in the ground, and it very speedily 
 oeglns to absorb the inorganic matters I have 
 named, adds enormously to its bulk, and we can 
 see it, year after year, extending itself upward 
 and downward, attracting and appropriating to 
 itself inorganic materials, which it vivifies, and 
 eventually, as it ripens, gives off its own proper 
 acorns, which again run the same course. But I 
 need not multiply examples, — from the highest to 
 the lowest the essential features of life are the 
 same as I have described in each of these cases. 
 
 So much, then, for these particular features of 
 the organic world, which you can understand and 
 comprehend, so long as you confine yourself to one 
 sort of living being, and study that only. 
 
 But, as you know, horses are not the only living 
 creatures in the world ; and again, horses, like all 
 other animals, have certain limits — are confined 
 to a certain area on the surface of the earth on 
 which we live, — and, as that is the simpler matter, 
 I may take that first. In its wild state, and before 
 the discovery of America, when the natural state 
 of things was interfered with by the Spaniards, the 
 horse was only to be found in parts of the earth 
 which are known to geographers as the Old 
 World ; that is to say, you might meet with 
 horses in Europe, Asia, or Africa ; but there were 
 non^ in Australia, and there were none whatsoever 
 
322 THE CAUSES OF THE xi 
 
 in the whole continent of America, from Labrador 
 down to CajDe Horn. This is an empirical fact, and 
 it is what is called, stated in the way I have 
 given it you, the " Geographical Distribution " of 
 the horse. 
 
 Why horses should be found in Europe, Asia, 
 and Africa, and not in America, is not obvious ; 
 the explanation that the conditions of life in 
 America are unfavourable to their existence, and 
 that, therefore, they had not been created there, 
 evidently does not apply ; for when the invading 
 Spaniards, or our own yeomen farmers, conveyed 
 horses to these countries for their own use, they 
 were found to thrive well and multiply very 
 rapidly ; and many are even now running wild in 
 those countries, and in a perfectly natural condition. 
 Now, suppose we were to do for every animal 
 what we have here done for the horse, — that is, 
 to mark off and distinguish the particular district 
 or region to which each belonged ; and supposing 
 we tabulated all these results, that would be 
 called the Geographical Distribution of animals, 
 while a corresponding study of plants would yield 
 as a result the Geographical Distribution of 
 plants. 
 
 I pass on from that now, as I merely wished to 
 explain to you what I meant by the use of the 
 term " Geographical Distribution." As I said, 
 there is another aspect, and a much more im- 
 portant one, and that is, the relations of the various 
 
XI PHENOMENA OF ORGANIC NATURE 323 
 
 animals to one another. The horse is a very well- 
 defined matter-of-fact sort of animal, and we are 
 all joretty familiar with its structure. I dare say 
 it may have struck you, that it resembles very 
 much no other member of the animal kingdom, 
 except perhaps the zebra or the ass. But let me 
 ask you to look along these diagrams. Here is 
 the skeleton of the horse, and here the skeleton 
 of the dog. You will notice that we have in the 
 horse a skull, a backbone and ribs, shoulder-blades 
 and haunch-bones. In the fore-limb, one upj er 
 arm-bone, two fore arm-bones, wrist-bones (wrongly 
 called knee), And middle hand-bones, ending in 
 the three bones of a finsrer, the last of which is 
 sheathed in the homy hoof of the fore-foot : in the 
 hind-limb, one thigh-bone, two leg-bones, ankle- 
 bones, and middle foot-bones, ending in the three 
 bones of a toe, the last of which is encased in the 
 hoof of the hind-foot. Now turn to the dog's 
 skeleton. We find identically the same bones, but 
 more of them, there being more toes in each foot, 
 and hence more toe-bones. 
 
 Well, that is a very curious thing ! The fact is 
 that the dog and the horse — when one gets a 
 look at them without the outward impediments of 
 the skin — are found to be made in very much the 
 same sort of fashion. And if I were to make a 
 transverse section of the dog, I should find the 
 same organs that I have already shown you as 
 forming parts of the horse. Well, here is another 
 
324 THE CAUSES OF THE XI 
 
 skeleton— that of a kind of lemur — you see he 
 has just the same bones ; and if I were to make a 
 transverse section of it, it would be just the same 
 again. In your mind's eye turn him round, so as 
 to put his backbone in a position inclined obliquely 
 upwards and forwards, just as in the next three 
 diagrams, which represent the skeletons of an 
 orang, a chimpanzee, and a gorilla, and you find 
 you have no trouble in identifying the bones 
 throughout ; and lastly turn to the end of the 
 series, the diagram representing a man's skeleton, 
 and still you find no great structural feature 
 essentially altered. There are the same bones in 
 the same relations. From the horse we pass on 
 and on, with gradual steps until we arrive at last 
 at the highest known forms. On the other hand, 
 take the other line of diagrams, and pass from the 
 horse downwards in the scale to this fish ; and 
 still, though the modifications are vastly greater, 
 the essential framework of the organisation 
 remains unchanged. Here, for instance, is a' 
 porpoise : here is its strong backbone, with the 
 cavity running through it, which contains the 
 spinal cord ; here are the ribs, here the shoulder- 
 blade ; here is the little short upper-arm bone, 
 here are the two forearm bones, the wrist-bone, 
 and the finger-bones. 
 
 Strange, is it not, that the porpoise should have 
 in this queer-looking affair — its flapper (as it is 
 called), the same fundamental elements as the 
 
XI PHENOMENA OF OEGANIC NATURE 325 
 
 fore-leg of the horse or the dog, or the ape or 
 man; and here you will notice a very curious 
 thing, — the hinder limbs are absent. Now, let 
 us make another jump. Let us go to the codfish : 
 here you see is the forearm, in this large pectoral fin 
 — carrying your mind's eye onward from the flapper 
 of the porpoise. And here you have the hinder 
 limbs restored in the shape of these ventral fins. 
 If I were to make a transverse section of this, I 
 should find just the same organs that we have 
 before noticed. So that, you see, there comeS" out 
 this strange conclusion as the result of our 
 investigations, that the horse, when examined 
 and compared with other animals, is found by no 
 means to stand alone in Nature ; but that there 
 are an enormous number of other creatures which 
 have backbones, ribs, and legs, and other parts 
 arranged in the same general manner, and iu 
 all their formation exhibiting the same broad 
 peculiarities. 
 
 I am sure that you cannot have followed me 
 even in this extremely elementary exposition of 
 the structural relations of animals, without seeing 
 what I have been driving at all through, which is, 
 
 to show you tWf^tpp ^y "^pp, naturalists haj^ft 
 
 coi:^e jiothe idea of a unity of plan, or conform ity 
 of c gnstruction. among animals which ap peared at 
 
 first sight tr^ b e ^YfT-Amply rl La aijaa i 1 a r 
 
 And here you have evidence of such a unity of 
 plan among all the animals which have backbones, 
 
326 THE CAUSES OF THE XI 
 
 and which we technically call Vcrtehrata. But 
 there are multitudes of other animals, such as 
 crabs, lobsters, spiders, and so on, which we term 
 Anmblosa. In these I could not point out to you the 
 parts that correspond with those of the horse, — 
 the backbone, for instance, — as they are constructed 
 upon a very different principle, which is also 
 common to all of them ; that is to say, the lobster, 
 the spider, and the centipede, have a common 
 plan running through their whole arrangement, 
 in just the same way that the horse, the dog, 
 and the porpoise assimilate to each other. 
 
 Yet other creatures — whelks, cuttlefishes, 
 oysters, snails, and all their tribe {Mollusca) — 
 resemble one another in the same way, but differ 
 from both Vertebrata and Annulosa ; and the like 
 is true of the animals called Ccelenterata (Polypes) 
 and Protozoa (animalcules and sponges). 
 
 Now, by pursuing this sort of comparison, 
 naturalists have arrived at the conviction that 
 there are, — some think five, and some seven, — but 
 certainly not more than the latter number — and 
 perhaps it is simpler to assume five — distinct plans 
 or constructions in the whole of the animal world ; 
 and that the hundreds of thousands of species 
 of creatures on the surface of the earth, are all 
 reducible to those five, or, at most, seven, plans of 
 organisation. 
 
 But can we go no further than that ? Wlien 
 one has got so far, one is tempted to go on a step 
 
XX PHENOMENA OF ORGANIC NATURE 327 
 
 and inquire whether we cannot go back yet 
 further and bring down the whole to modifications 
 of one primordial unit. The anatomist cannot do 
 this ; but if he call to his aid the study of develop- 
 ment, he can do it. For we shall find that, dis- 
 tinct as those plans are, whether it be a porpoise 
 or man, or lobster, or any of those other kinds I 
 have mentioned, every one begins its existence 
 with one and the sa me primitive form, — that of 
 the egg, consisting, as y^^e have seen, of a nitro- 
 genous substance, having a small particle or nucleus 
 in the centre of it. Furthermore, the earlier 
 changes of each are substantially the same. And 
 it is in this that lies that true " unity of organi- 
 sation " of the animal kingdom which has been 
 guessed at and fancied for many years ; but which 
 it has been left to the present time to be demon- 
 strated by the careful study of development. But 
 is it possible to go another step further still, and 
 to show that in the same way the whole of the 
 organic world is reducible to one primitive con- 
 dition of form ? Is there among the plants the 
 same primitive form of organisation, and is that 
 identical with that of the animal kingdom ? The 
 reply to that question, too, is not uncertain or 
 doubtful. It is now proved that every plant 
 begins its existence under the same form ; that is 
 to say, in that of a cell — a particle of nitrogenous 
 matter having substantially the same conditions. 
 
 So that if you trace back the oak to its first 
 50 
 
328 THE CAUSES OF THE xi 
 
 germ, or a man, or a horse, or lobster, or oyster, or 
 any other animal you choose to name, you shall find 
 each and all of these commencing their existence 
 in forms essentially similar to each other ; and, 
 furthermore, that the first processes of growth, 
 and many of the subsequent modifications, are 
 essentially the same in principle in almost all. 
 
 In conclusion, let me, in a few words, recapitu- 
 late the positions which I have laid down. And 
 you must understand that I have not been 
 talking mere theory ; I have been speaking of 
 matters which are as plainly demonstrable as the 
 commonest propositions of Euclid — of facts that 
 must form the basis of all speculations and beliefs 
 in Biological science. We have gradually traced 
 down all organic forms, or, in other words, we have 
 analysed the present condition of animated nature, 
 until we found that each species took its origin in 
 a form similar to that under which all the others 
 commenced their existence. We have found the' 
 whole of the vast array of living forms with which 
 Ave are surrounded, constantly growing, increasing, 
 decaying and disappearing ; the animal constantly 
 attracting, modifying, and applying to its susten- 
 ance the matter of the vegetable kingdom, which 
 derived its support from the absorption and con- 
 version of inorganic matter. And so constant and 
 universal is this absorption, waste, and repro- 
 duction, that it may be said with perfect certainty 
 that there is left in no one of our bodies at the 
 
XI PHENOMENA OF ORGANIC NATURE 329 
 
 present moment a millionth part of the matter of 
 which they were originally formed ! We have 
 seen, again, that not only is the living matter 
 derived from the inorganic world, but that the 
 forces of that matter are all of them correlative 
 with and convertible into those of inorganic 
 nature. 
 
 This, for our present purposes, is the best view 
 of the present condition of organic nature which I 
 can lay before you : it gives you the great outlines 
 of a vast picture, which you must fill up by your 
 own study. 
 
 In the next lecture I shall endeavour in the 
 same way to go back into the past, and to sketch 
 in the same broad manner the history of life in 
 epochs preceding our own. 
 
n 
 
 THE PAST CONDITION OF ORGANIC NATURE, 
 
 In the lecture which I delivered last Monday 
 evening, I endeavoured to sketch in a very brief 
 manner, but as well as the time at my disposal 
 would permit, the present condition of organic 
 nature, meaning by that large title simply an 
 indication of the great, broad, and general 
 principles which are to be discovered by those 
 who look attentively at the phenomena of organic 
 nature as at present displayed. The general 
 result of our investigations might be summed up 
 thus : we found that the multiplicity of t he forms 
 of animal life, great as that ma y be, may^o e 
 reduced to a comparatively few prim iti ve plans or 
 types of construction ; that a further study of the 
 development of those diflferent forms revealed to 
 us that they were again reducible, until we at 
 last brought the infinite diversity of animal, and 
 even vegetable life, down to the primordial form 
 of a single cell. 
 
xr PHENOMENA OF ORGANIC NATURE 331 
 
 We found that our analysis of the organic 
 world, whether animals or plants, showed, in the 
 long run, that they might both be reduced into, 
 and were, in fact, composed of, the same con- 
 stituents. And we saw that the plant obtained 
 the materials constituting its substance by a 
 peculiar combination of matters belonging entirely 
 to the inorganic world ; that, then, the animal was 
 constantly appropriating the nitrogenous matters 
 of the plant to its own nourishment, and returning 
 them back to the inorganic world, in what we 
 spoke of as its waste ; and that finally, when the 
 animal ceased to exist, the constituents of its body 
 were dissolved and transmitted to that inorganic 
 world whence they had been at first abstracted. 
 Thus we saw in both the blade of grass and the 
 horse but the same elements differently combined 
 and arranged. We discovered a continual circula- 
 tion going on, — the plant drawing in the elements 
 of inorganic nature and combining them into food 
 for the animal creation ; the animal borrowing 
 from the plant the matter for its own support, 
 giving off during its life products which returned 
 immediately to the inorganic world; and that, 
 eventually, the constituent materials of the whole 
 structure of both animals and plants were thus 
 returned to their original source : there was a 
 constant passage from one state of existence to 
 another, and a returning back again. 
 
 Lastly, when we endeavoured to form some 
 
332 THE CAUSES OF THE XI 
 
 notion of the nature of the forces exercised hy 
 living beings, we discovered that they — if not 
 capable of being subjected to the same minute 
 analysis as the constituents of those beings them- 
 selves — that they were correlative with — that they 
 were the equivalents of the forces of inorganic 
 nature — that they were, in the sense in which the 
 term is now used, convertible with them. That was 
 our general result. 
 
 And now, leaviug the Present, I must endeavour 
 in the same manner to put before you the facts 
 that are to be discovered in the Past history of 
 the living world, in the past conditions of organic 
 nature. We have, to-night, to deal with the facts 
 of that history — a history involving periods of 
 time before which our mere human records sink 
 into utter insignificance — a history the variety and 
 physical magnitude of whose events cannot even 
 be foreshadowed by the history of human life and 
 human phenomena— a history of the most varied 
 and complex character. 
 
 We must deal with the history, then, in the 
 first place, as we should deal with all other 
 histories. The historical student knows that his' 
 first business should be to inquire into the validity 
 of his evidence, and the nature of the record in 
 which the evidence is contained, that he may be 
 able to form a proper estimate of the correctness 
 of the conclusions which have been drawn from 
 that evidence. So, here, we must pass, in the first 
 
xr PHENOMENA OF ORGANIC NATURE 333 
 
 place, to the consideration of a matter which may 
 seem foreign to the question under discussion. 
 We must dwell upon the nature of the records,, 
 and the credibility of the evidence they contain ; 
 we must look to the completeness or incomplete- 
 ness of those records themselves, before we turn to 
 that which they contain and reveal. The question 
 of the credibility of the history, happily for us, 
 will not require much consideration, for, in this 
 history, unlike those of human origin, there can 
 be no cavilling, no differences as to the reality and 
 truth of the facts of which it is made up ; the 
 facts state themselves, and are laid out clearly 
 before us. 
 
 But, although one of the greatest difficulties of 
 the historical student is cleared out of our path, 
 there are other difficulties — difficulties in rightly 
 interpreting the facts as they are presented to us 
 — which may be compared with the greatest 
 difficulties of any other kinds of historical study. 
 
 What is this record of the past history of the 
 globe, and what are the questions which are 
 involved in an inquiry into its completeness or 
 incompleteness ? That record is composed of 
 mud ; and the question which we have to investi- 
 gate this evening resolves itself into a question of 
 the formation of mud. You may think, perhaps, 
 that this is a vast step — of almost from the 
 sublime to the ridiculous — from the contemplation 
 of the history of the past ages of the world's 
 
334 THE CAUSES OF THE xi 
 
 existence to the consideration of the history of the 
 formation of mud ! But, in Nature, there is 
 nothing mean and unworthy of attention ; there is 
 nothing ridiculous or contemptible in any of her 
 works ; and this inquiry, you will soon see, I hope, 
 takes us to the very root and foundations of our 
 subject. 
 
 How, then, is mud formed ? Always, with 
 some trifling exceptions, which I need not consider 
 now — always, as the result of the action of water, 
 wearing down and disintegrating the surface of 
 the earth and rocks with which it comes in 
 contact — pounding and grinding it down, and 
 carrying the particles away to places where they 
 cease to be disturbed by this mechanical action, 
 and where they can subside and rest. For the 
 ocean, urged by winds, washes, as we know, a long 
 extent of coast, and every wave, loaded as it is 
 with particles of sand and gravel as it breaks 
 upon the shore, does something towards the dis- 
 integrating process. And thus, slowly but surely, 
 the hardest rocks are gradually ground down to a 
 powdery substance ; and the mud thus formed, 
 coarser or finer, as the case may be, is carried by 
 the rush of the tides, or currents, till it reaches 
 the comparatively deeper parts of the ocean, in 
 which it can sink to the bottom, that is, to parts 
 where there is a depth of about fourteen or fifteen 
 fathoms, a depth at which the water is, usually, 
 nearly motionless, and in which, of course, the 
 
XI PHENOMENA OF ORGANIC NATURE 335 
 
 finer particles of this detritus, or mud as we call 
 it, sinks to the bottom. 
 
 Or, again, if you take a river, rushing down 
 from its mountain sources, brawling over the 
 stones and rocks that intersect its path, loosening, 
 removing, and carrying with it in its downward 
 course the pebbles and lighter matters from its 
 banks, it crushes and pounds down the rocks and 
 earths in precisely the same way as the wearing 
 action of the sea waves. The matters forming the 
 deposit are torn from the mountain-side and 
 whirled impetuously into the valley, more slowly 
 over the plain, thence into the estuary, and from 
 the estuary they are swept into the sea. The 
 coarser and heavier fragments are obviously 
 deposited first, that is, as soon as the current 
 begins to lose its force by becoming amalgamated 
 with the stiller depths of the ocean, but the finer 
 and lighter particles are carried further on, and 
 eventually deposited in a deeper and stiller portion 
 of the ocean. 
 
 It clearly follows from this that mud gives us a 
 chronology ; for it is evident that supposing this, 
 which I now sketch, to be the sea bottom, and 
 supposing this to be a coast-line ; from the wash- 
 ing action of the sea upon the rock, wearing and 
 grinding it down into a sediment of mud, the mud 
 will be carried down, and, at length, deposited in 
 the deeper parts of this sea bottom, where it will 
 form a layer ; and then, while that first layer is 
 
336 THE CAUSES OF THE xi 
 
 hardening, other mud which is coming from the 
 same source will, of course, be carried to the same 
 place ; and, as it is quite impossible for it to get 
 beneath the layer already there, it deposits itself 
 above it, and forms another layer, and in that 
 way you gradually have layers of mud constantly 
 forming and hardening one above the other, and 
 conveying a record of time. 
 
 It is a necessary result of the operation of the 
 law of gravitation that the uppermost layer shall 
 be the youngest and the lowest the oldest, and 
 that the different beds shall be older at any 
 particular point or spot in exactly the ratio of their 
 depth from the surface. So that if they were 
 upheaved afterwards, and you had a series of 
 these different layers of mud, converted into sand- 
 stone, or limestone, as the case might be, you 
 might be sure that the bottom layer was deposited 
 / first, and that the upper layers were formed after- 
 1 wards. Here, you see, is the first step in the history 
 — these layers of mud give us an idea of time. 
 
 The whole surface of the earth, — I speak 
 broadly, and leave out minor qualifications, — is 
 made up of such layers of mud; so hard, the 
 majority of them, that we call them rock whether 
 limestone or sandstone, or other varieties of rock. 
 And, seeing that every part of the crust of the 
 earth is made up in this way, you might think 
 that the determination of the chronology, the 
 fixing of the time which it has taken to form this 
 
XI PHENOMENA OF OKGANIC NATURE 337 
 
 cnist is a comparatively simple matter. Take a 
 broad average, ascertain how fast the mud is 
 deposited upon the bottom of the sea, or in the 
 estuary of rivers ; take it to be an inch, or two, or 
 three inches a year, or whatever you may roughly 
 estimate it at ; then take the total thickness of 
 the whole series of stratified rocks, which ffeolo- 
 gists estimate at twelve or thirteen miles, or about 
 seventy thousand feet, make a sum in short 
 division, divide the total thickness by that of the 
 quantity deposited in one year, and the result will, 
 of course, give you the number of years which the 
 crust has taken to form. 
 
 Truly, that looks a very simple process ! It 
 would be so except for certain difficulties, the very 
 first of which is that of finding how rapidly 
 sediments are deposited ; but the main difficulty 
 ■ — a difficulty which renders any certain calcula- 
 tions of such a matter out of the question — is 
 this, the sea-bottom on which the deposit takes 
 place is continually shifting. 
 
 Instead of the surface of the earth being that 
 stable, fixed thing that it is popularly believed to 
 be, being, in common parlance, the very emblem 
 of fixity itself, it is incessantly moving, and is, 
 in fact, as unstable as the surface of the sea, 
 except that its undulations are infinitely slower 
 and enormously higher and deeper. 
 
 Now, what is the efifect of this oscillation? 
 Take the case to which I have previously 
 
338 
 
 THE CAUSES OF THE 
 
 xr 
 
 referred. The finer or coarser sediments that 
 are carried down by the current of the river, 
 will only be carried out a certain distance, and 
 eventually, as we have already seen, on reaching 
 the stiller part of the ocean, will be deposited at 
 the bottom. 
 
 Let C y (Fig. 4) be the sea-bottom, y D the 
 shore, x y the sea-level, then the coarser deposit 
 Avill subside over the region B, the finer over A, 
 while beyond A there will be no deposit at all • 
 
 yi^^ 
 
 Fig.4. 
 
 and, consequently, no record will be kept, simply 
 because no deposit is going on. Now, suppose 
 that the whole land, C, D, which we have regarded 
 as stationary, goes down, as it does so, both A and 
 B go further out from the shore, which will be at 
 y^; x^, 2/^ being the new sea-level. The con- 
 sequence will be that the layer of mud (A), being 
 now, for the most part, further than the force of 
 the current is strong enough to convey even the 
 finest debris, will, of course, receive no more 
 
SI PHENOMENA OF ORGANIC NATURE 339 
 
 deposits, and having attained a certain thickness 
 will now grow no thicker. 
 
 We should be misled in taking the thickness of 
 that layer, whenever it may be exposed to our 
 view, as a record of time in the manner in which 
 we are now regarding this subject, as it would 
 give us only an imperfect and partial record : 
 it would seem to represent too short a period of 
 time. 
 
 Suppose, on the other hand, that the land (C D) 
 had gone on rising slowly and gradually — say an 
 inch or two inches in the course of a century, — 
 what would be the practical effect of that move- 
 ment ? Why, that the sediment A and B which 
 has been already deposited, would eventually be 
 brought nearer to the shore-level and again sub- 
 jected to the wear and tear of the sea ; and directly 
 the sea begins to act upon it, it would of course 
 soon cut up and carry it way, to a greater or less 
 extent, to be re-deposited further out. 
 
 Well, as there is, in all probability, not one single 
 spot on the whole surface of the earth, which has 
 not been up and down in this way a great many 
 times, it follows that the thickness of the deposits 
 formed at any particular spot cannot be taken 
 (even supposing we had at first obtained correct 
 data as to the rate at which they took place), as 
 affording reliable information as to the period of 
 time occupied in its deposit. So that you see it is 
 absolutely necessary from these facts, seeing that 
 
340 THE CAUSES OF THE XI 
 
 our record entirely consists of accumulations of 
 mud, superimposed one on the other ; seeing in 
 the next place that any particular spots on which 
 accumulations have occurred, have been constantly 
 moving up and down, and sometimes out of the 
 reach of a deposit, and at other times its own 
 deposit broken up and carried away, it follows that 
 our record must be in the highest degree imper- 
 fect, and we have hardly a trace left of thick 
 deposits, or any definite knowledge of the area 
 that they occupied, in a great many cases. And 
 mark this ! That supposing even that the whole 
 surface of the earth had been accessible to the 
 geologist, — that man had had access to every part 
 of the earth, and had made sections of the whole, 
 and put them all together, — even then his record 
 must of necessity be imperfect. 
 
 But to how much has man really access ? If 
 you will look at this map you will see that it 
 represents the proportion of the sea to the earth : 
 this coloured part indicates all the dry land, and 
 this other portion is the water. You will notice 
 at once that the water covers threo-fifths of the 
 whole surface of the globe, and has covered it in 
 the same manner ever since man has kept any 
 record of his own observations, to say nothing of 
 the minute period during which he has cultivated 
 geological inquiry. So that three-fifths of the 
 surface of the earth is shut out from us because 
 it is under the sea. Let us look at the other 
 
XI PHENOMENA OF OKGANIC NATURE 341 
 
 two-fifths, and see what are the countries in 
 which anything that may be termed searching 
 geological inquiry has been carried out : a good 
 deal of France, Germany, and Great Britain and 
 Ireland, bits of Spain, of Italy, and of Russia, have 
 been examined, but of the whole great mass of 
 Africa, except parts of the southern extremity, 
 we know next to nothing ; little bits of India, but 
 of the greater part of the Asiatic continent 
 nothing; bits of the Northern American States 
 and of Canada^ but of the greater part of the 
 "continent of North America, and in still larger 
 proportion, of South America, nothing ! 
 
 Under these circumstances, it follows that even 
 with reference to that kind of imperfect informa- 
 tion which we can possess, it is only of about the 
 ten-thousandth part of the accessible parts of the 
 earth that has been examined properly. There- 
 fore, it is with justice that the most thoughtful of 
 those who are concerned in these inquiries insist 
 continually upon the imperfection of the geological 
 record ; for, I repeat, it is absolutely necessary, 
 from the nature of things, that that record should 
 be of the most fragmentary and imperfect 
 character. Unfortunately this circumstance has 
 been constantly forgotten. Men of science, like 
 young colts in a fresh pasture, are apt to be 
 exhilarated on being turned into a new field of 
 inquiry, to go off at a hand-gallop, in total 
 disregard of hedges and ditches, to lose sight of 
 
342 THE CAUSES OF 'THE 
 
 XI 
 
 the real limitation of their inquiries, and to 
 forget the extreme imperfection of what is really 
 known. Geologists have imagined that they could 
 tell us what was going on at all parts of the 
 earth's surface during a given epoch ; they have 
 talked of this deposit being contemporaneous with 
 that deposit, until, from our little local histories of 
 the changes at limited spots of the earth's surface, 
 they have constructed a universal history of the 
 globe as full of wonders and portents as any other 
 story of antiquity. 
 
 But what does this attempt to construct a 
 universal history of the globe imply ? It implies 
 that we shall not only have a precise knowledge of 
 the events which have occurred at any particular 
 point, but that we shall be able to say what events, 
 at any one spot, took place at the same time with 
 those at other spots. 
 
 Let us see how far that is in the nature of 
 things practicable. Suppose that here I make 
 a section of the Lake of Killarney, and here the 
 section of another lake — that of Loch Lomond 
 in Scotland for instance. The rivers that flow 
 into them are constantly carrying down deposits " 
 of mud, and beds, or strata, are being as constantly 
 formed, one above the other, at the bottom of 
 those lakes. Now, there is not a shadow of doubt 
 that in these two lakes the lower beds are all 
 older than the upper — there is no doubt about 
 that ; but what does this tell us about the age of 
 
xr 
 
 PHENOMENA OF OEGANIC NATURE 
 
 343 
 
 any given bed in Loch Lomond, as compared with 
 that of any given bed in the Lake of Killarney ? 
 It is, indeed, obvious that if any two sets of 
 deposits are separated and discontinuous, there is 
 absolutely bo means whatever given you by the 
 nature of the deposit of saying whether one is 
 much younger or older than the other ; but you 
 may say, as many have said and think, that the 
 case is very much altered if the beds which we 
 are comparing are continuous. Suppose two beds 
 
 Fig.s- 
 
 of mud hardened into rock, — A and B — are seen 
 in section. (Fig. 5.) 
 
 Well, you say, it is admitted that the lower- 
 most bed is always the older. Very well ; B, 
 therefore, is older than A. No doubt, as a whole, 
 it is so ; or if any parts of the two beds which are 
 in the same vertical line are compared, it is so. 
 But suppose you take what seems a very natural 
 step further, and say that the part a of the bed A 
 is younger than the part b of the bed B. Is this 
 sound reasoning ? If you find any record of 
 changes taking place at h, did they occur before 
 
 51 
 
344 THE CAUSES OF THE XI 
 
 any events which took place while a was being 
 deposited ? It looks all very plain sailing, indeed, 
 to say that they did ; and yet there is no proof of 
 anything of the kind. As the former Director of 
 this Institution, Sir H. De la Beche, long ago 
 showed, this reasoning may involve an entire 
 fallacy. It is extremely possible that a may have 
 been deposited ages before h. It is very easy to 
 understand how that can be. To return to Fig. 
 4 ; when A and B were deposited, they were 
 substantially contemporaneous ; A being simply 
 the finer deposit, and B the coarser of the same 
 detritus or waste of land. Now suppose that 
 that sea-bottom goes down (as shown in Fig. 4), 
 so that the first deposit is carried no farther than 
 a, forming the bed A^, and the coarse no farther 
 than h, forming the bed B^, the result will be the 
 formation of two continuous beds, one of fine 
 sediment (A A^) over-lapping another of coarse 
 sediment (B B^). Now suppose the whole sea- 
 bottom is raised up, and a section exposed about 
 the point A^ ; no doubt, at this spot, the upper 
 bed is younger than the lower. But we should 
 obviously greatly err if we concluded that the 
 mass of the upper bed at A was younger than the 
 lower bed at B ; for we have just seen that they 
 are contemporaneous deposits. Still more should 
 we be in error if we supposed the upper bed at A 
 to be younger than the continuation of the lower 
 bed at B ^ ; for A was deposited long before B \ 
 
XI PHENOMENA OF ORGANIC NATURE 845 
 
 la fine, if, instead of comparing immediately 
 adjacent parts of two beds, one of which lies upon 
 another, we compare distant parts, it is quite 
 possible that the upper may be any number of 
 years older than the under, and the under any 
 number of years younger than the upper. 
 
 Now you must not suppose that I put this 
 before you for the purpose of raising a paradoxical 
 difficulty; the fact is, that the great mass of 
 deposits have taken place in sea-bottoms which 
 are gradually sinking, and have been formed 
 under the very conditions I am here supposing. 
 
 Do not run away with the notion that this 
 subverts the principle I laid down at first. The 
 error lies in extending a principle which is per- 
 fectly applicable to deposits in the same vertical 
 line to deposits which are not in that relation to 
 one another. 
 
 It is in consequence of circumstances of this 
 kind, and of others that I might mention to you, 
 that our conclusions on and interpretations of the 
 record are really and strictly only valid so long as 
 we confine ourselves to one vertical section. I do 
 not mean to tell you that there are no qualifying 
 circumstances, so that, even in very considerable 
 areas, we may safely speak of conformably super- 
 imposed beds being older or younger than others 
 at many dififerent points. But we can never be 
 quite sure in coming to that conclusion, and 
 especially we cannot be sure if there is any break 
 
346 THE CAUSES OF THE xi 
 
 in. their continuity, or any very great distance 
 between the points to be compared. 
 
 Well now, so much for the record itself, — so 
 much for its imperfections, — so much for the con- 
 ditions to be observed in interpreting it, and its 
 chronological indications, the moment we pass 
 beyond the limits of a vertical linear section. »• 
 
 Now let us pass from the record to that which it 
 contains, — from the book itself to the writing and 
 the figures on its pages. This writing and these 
 figures consist of remains of animals and plants 
 which, in the great majority of cases, have lived 
 and died in the very spot in which we now find 
 them, or at least in the immediate vicinity. You 
 must all of you be aware — and I referred to the 
 fact in my last lecture — that there are vast 
 numbers of creatures living at the bottom of the 
 sea. These creatures, like all others, sooner or 
 later die, and their shells and hard parts lie at 
 the bottom ; and then the fine mud which is 
 being constantly brought down by rivers and the 
 action of the wear and tear of the sea, covers 
 them over and protects them from any further 
 change or alteration ; and, of course, as in process 
 of time the mud becomes hardened and solidified, 
 the shells of these animals are preserved and 
 firmly imbedded in the limestone or sandstone 
 which is being thus formed. You may see in the 
 galleries of the Museum up stairs specimens of 
 limestones in which such fossil remains of existing 
 
XI PHENOMENA OF ORGANIC NATURE 347 
 
 animals are imbedded. There are some specimens 
 in which turtles' eggs have been imbedded in 
 calcareous sand, and before the sun had hatched 
 the young turtles, they became covered over with 
 calcareous mud, and thus have been preserved 
 and fossilised. 
 
 Not only does this process of imbedding and 
 fossilisation occur with marine and other aquatic 
 animals and plants, but it affects those land 
 animals and plants which are drifted away to sea, 
 or become buried in bogs or morasses ; and the 
 animals which have been trodden down by their 
 fellows and crushed in the mud at the river's 
 bank, as the herd have come to drink. In any of 
 these cases, the organisms may be crashed or be 
 mutilated, before or after putrefaction, in such a 
 manner that perhaps only a part will be left in 
 the form in which it reaches us. It is, indeed, a 
 most remarkable fact", that it is quite an exceptional 
 case to find a skeleton of any one of all the 
 thousands of wild land animals that we know are 
 constantly being killed, or dying in the course of 
 nature : they are preyed on and devoured by 
 other animals, or die in places where their bodies 
 are not afterwards protected by mud. There are 
 other animals existing on the sea, the shells of 
 which form exceedingly large deposits. You are 
 probably aware that before the attempt was made 
 to lay the Atlantic telegraphic cable, the Govern- 
 ment employed vessels in making a series of very 
 
348 THE CAUSES OF THE xr 
 
 careful observations and soundings of the bottom 
 of the Atlantic; and although, as we must all 
 regret, that up to the present time that project has 
 not succeeded, "we have the satisfaction of knowing 
 that it yielded some most remarkable results to 
 science. The Atlantic Ocean had to be sounded 
 right across, to depths of several miles in some 
 places, and the nature of its bottom was carefully- 
 ascertained. Well, now, a space of about 1,000 
 miles wide from east to Avest, and I do not exactly 
 know how many from north to south, but at any 
 rate 600 or 700 miles, was carefully examined, and 
 it was found that over the whole of that immense 
 area an excessively fine chalky mud is being 
 deposited ; and this deposit is entirely made up of 
 animals whose hard parts are deposited in this 
 part of the ocean, and are doubtless gradually 
 acquiring solidity and becoming metamorphosed 
 into a chalky limestone. Thus, you see, it is quite 
 possible in this way to preserve unmistakable 
 records of animal and vegetable life. Whenever 
 the sea-bottom, by some of those undiilations of 
 the earth's crust that I have referred to, becomes 
 up-heaved, and sections or borings are made, or 
 pits are dug, then we become able to examine 
 the contents and constituents of these ancient sea- 
 bottoms, and find out what manner of animals 
 lived at that period. 
 
 Now it is a very important consideration in its 
 bearing on the completeness of the record, to 
 
XI PHENOMENA OF ORGANIC NATURE 349 
 
 inquire how far the remains contained in these 
 fossiliferous limestones are able to convey any- 
 thing like an accurate or complete account of the 
 animals which were in existence at the time of its 
 formation. Upon that point we can form a very 
 clear judgment, and one in which there is no 
 possible room for any mistake. There are of 
 course a great number of animals — such as jelly- 
 fishes, and other animals — without any hard parts, 
 of which we cannot reasonably expect to find any 
 traces whatever : there is nothing of them to pre- 
 serve. Within a very short time, you will have 
 noticed, after they are removed from the water, 
 they dry up to a mere nothing ; certainly they 
 are not of a nature to leave any very visible traces 
 of their existence on such bodies as chalk or mud. 
 Then again, look at land animals ; it is, as I have 
 said, a very uncommon thing to find a land animal 
 entire after death. Insects and other carnivorous 
 animals very speedily pull them to pieces, putre- 
 faction takes place, and so, out of the hundreds of 
 thousands that are known to die every year, it is 
 the rarest thing in the world to see one imbedded 
 in such a way that its remains would be preserved 
 for a lengthened period. Not only is this the 
 case, but even when animal remains have been 
 safely imbedded, certain natural agents may wholly 
 destroy and remove them. 
 
 Almost all the hard parts of animals — the 
 bones and so on — are composed chiefly of phosphate 
 
350 THE CAUSES OF THE xi 
 
 of lime and carbonate of lime. Some years ago, 
 I had to make an inquiry into the nature of some 
 very curious fossils sent to me from the North of 
 Scotland. Fossils are usually hard bony structures 
 that have become imbedded in the way I have de- 
 scribed, and have gradually acquired the nature and 
 solidity of the body with which they are associated ; 
 but in this case I had a series of holes in some 
 pieces of rock, and nothing else. Those holes, 
 however, had a certain definite shape about them, 
 and when I got a skilful workman to make castings 
 of the interior of these holes, I found that they 
 were the impressions of the joints of a backbone 
 and of the armour of a great reptile, twelve or more 
 feet long. This great beast had died and got 
 buried in the sand ; the sand had gradually 
 hardened over the bones, but remained porous. 
 Water had trickled through it, and that water 
 being probably charged with a superfluity of 
 carbonic acid, had dissolved all the phosphate and 
 carbonate of lime, and the bones themselves had 
 thus decayed and entirely disappeared ; but as 
 the sandstone happened to have consolidated by 
 that time, the precise shape of the bones was 
 retained. If that sandstone had remained soft a 
 little longer, we should have known nothing what- 
 soever of the existence of the reptile whose bones 
 it had encased. 
 
 How certain it is that a vast number of animals 
 which have existed at one period on this earth 
 
XI PHENOMENA OF ORGAMIO MATURE 351 
 
 have entirely perislied, and left no trace whatever 
 of their forms, may be proved to you by other 
 considerations. There are large tracts of sand- 
 stone in various parts of the world, in which 
 nobody has yet found anything but footsteps. 
 Not a bone of any description, but an enormous 
 number of traces of footsteps. There is no 
 question about them. There is a whole valley in 
 Connecticut covered with these footsteps, and not 
 a single fragment of the animals which made 
 them have yet been found. Let me mention 
 another case while upon that matter, which is 
 even more surprising than those to which I have 
 yet referred. There is a limestone formation near 
 Oxford, at a place called Stonesfield, which has 
 yielded the remains of certain very interesting 
 mammalian animals, and up to this time, if I 
 recollect rightly, there have been found seven 
 specimens of its lower jaws, and not a bit of any- 
 thing else, neither limb-bones nor skull, nor any 
 part whatever; not a fragment of the whole 
 system ! Of course, it would be preposterous to 
 imagine that the beasts had nothing else but a 
 lower jaw ! The probability is, as Dr. Buckland 
 showed, as the result of his observations on dead 
 dogs in the river Thames, that the lower jaw, not 
 being secured by very firm ligaments to the bones 
 of the head, and being a weighty aflfair, would 
 easily be knocked off, or might drop away from 
 the body as it floated in water in a state of de- 
 
352 THE CAUSES OF THE si 
 
 composition. The jaw would thus be deposited 
 immediately, while the rest of the body would 
 float and drift away altogether, ultimately reaching 
 the sea, and perhaps becoming destroyed. The 
 jaw becomes covered up and preserved in the river 
 silt, and thus it comes that we have such a 
 curious circumstance as that of the lower jaws in 
 the Stonesfield slates. So that, you see, faulty as 
 these layers of stone in the earth's crust are, 
 defective as they necessarily are as a record, the 
 account of contemporaneous vital phenomena 
 presented by them is, by the necessity of the case, 
 infinitely more defective and fragmentary. 
 
 It was necessary that I should put all this very 
 strongly before you, because, otherwise, you might 
 have been led to think differently of the com- 
 pleteness of our knowledge by the next facts I 
 shall state to you. 
 
 The researches of the last three-quarters of a 
 century have, in truth, revealed a wonderful 
 richness of organic life in those rocks. Certainly 
 not fewer than thirty or forty thousand different 
 species of fossils have been discovered. You have 
 no more ground for doubting that these creatures 
 really lived and died at or near the places in 
 which we find them than you have for like 
 scepticism about a shell on the sea-shore. The 
 evidence is as good in the one case as in the other. 
 
 Our next business is to look at the general 
 character of these fossil remains, and it is a subject 
 
XI FHJKJSOMEJSI A UJ? ' ORtJAJSiiU JSIAT URE 353 
 
 ■which will be requisite to consider carefully ; and 
 the first point for us is to examine how much the 
 extinct Flora and Fauna as a whole — disregarding 
 altogether the succession of their constituents, of 
 which I shall speak afterwards — differ from the 
 Flora and Fauna of the present day ; — how far they 
 differ in what we do know about them, leavinsr 
 altogether out of consideration speculations based 
 upon what we do not know. 
 
 I strongly imagine that if it were not for the 
 peculiar appearance that fossilised animals have, 
 any of you might readily walk through a 
 museum which contains fossil remains mixed up 
 with those of the present forms of life, and I doubt 
 very much whether your uninstructed eyes would 
 lead you to see any vast or wonderful diffierence 
 between the two. If you looked closely, you would 
 notice, in the first place, a great many things very 
 like animals with which you are acquainted now : 
 you would see differences of shape and proportion, 
 but on the whole a close similarity. 
 
 I explained what I meant by Orders the other 
 day, when I described the animal kingdom as 
 being divided into sub-kingdoms, classes and 
 orders. If you divide the animal kingdom into 
 orders you will find that there are above one 
 hundred and twenty. The number may vary on 
 one side or the other, but this is a fair estimate. 
 That is the sum total of the orders of all the 
 animals which we know now, and which have 
 
354 THE CAUSES OF THE xi 
 
 been known in past times, and left remains 
 behind. 
 
 Now, bow many of those are absolutely extinct ? 
 That is to say, how many of these orders of animals 
 have lived at a former period of the world's history 
 but have at present no representatives ? That is 
 the sense in which I meant to use the word 
 " extinct." I mean that those animals did live 
 on this earth at one time, but 'have left no one 
 of their kind with us at the present moment. 
 So that estimating the number of extinct animals 
 is a sort of way of comparing the past creation as 
 a whole with the present as a whole. Among the 
 mammalia and birds there are none extinct ; but 
 when we come to the reptiles there is a most 
 wonderful thing : out of the eight orders, or 
 thereabouts, which you can make among reptiles, 
 one-half are extinct. These diagrams of the 
 plesiosaurus, the ichthyosaurus, the pterodactyle, 
 give you a notion of some of these extinct reptiles. 
 And here is a cast of the pterodactyle and bones 
 of the ichthyosaurus and the plesiosaurus, just as 
 fresh-looking as if it had been recently dug up in a 
 churchyard. Thus, in the reptile class, there are 
 no less than half of the orders which are absolutely 
 extinct. If we turn to the Amphibia, there was 
 one extinct order, the Labyrinthodonts, typified 
 by the large salamander-like beast shown in this 
 diagram. 
 
 No order of fishes is known to be extinct. 
 
XI I'HJtiJSIUMEJNA Uj)' UKUAMIU JNA'i'URE 355 
 
 Every fish that we find in the strata — to which I 
 have heen referring — can he identified and placed 
 in one of the orders which exist at the present day. 
 There is not known to be a single ordinal form 
 of insect extinct. There are only two orders 
 extinct among the Crustacea. There is not known 
 to be an extinct order of these creatures, the 
 parasitic and other worms ; but there are two, not 
 to say three, absolutely extinct orders of this 
 class, the Echinodermata ; out of all the orders of 
 the Ccelenterata and Protozoa only one, the Rugose 
 Corals. 
 
 So that, you see, out of somewhere about 120 
 orders of animals, taking them altogether, you 
 will not, at the outside estimate, find above ten 
 or a dozen extinct. Summing up all the order of 
 animals which have left remains behind them, 
 you will not find above ten or a dozen which 
 cannot be arranged with those of the present day ; 
 that is to say, that the difierence does not amount 
 to much more than ten per cent. : and the 
 proportion of extinct orders of plants is still 
 smaller. I think that that is a very astounding 
 a most astonishing fact : seemg the enormous 
 epochs of time which have elapsed during the 
 constitution of the surface of the earth as it at 
 present exists, it is, indeed, a most astounding 
 thing that the proportion of extinct ordinal types 
 should be so exceedingly small. 
 
 But now, there is another point of view in which 
 
356 THE CAUSES OF THE XI 
 
 we must look at this past creation. Suppose that 
 ■we were to sink a vertical pit through the floor 
 beneath us, and that I could succeed in making 
 a section right through in the direction of New 
 Zealand, I should find in each of the different 
 beds through which I passed the remains of 
 animals which I should find in that stratum and 
 not in the others. First, I should come upon 
 beds of gravel or drift containing the bones of 
 large animals, such as the elephant, rhinoceros, 
 and cave tiger. Rather curious things to fall 
 across in Piccadilly ! If I should dig lower still, 
 I should come upon a bed of what we call the 
 London clay, and in this, as you will see in 
 our galleries up stairs, are found remains of 
 strange cattle, remains of turtles, palms, and large 
 tropical fruits ; with shell-fish such as you see the 
 like of now only in tropical regions. If I went 
 below that, I should come upon the chalk, and 
 there I should find something altogether different, 
 the remains of ichthyosauria and pterodactyleS; 
 and ammonites, and so forth. 
 
 I do not know what Mr. Godwin Austin would 
 say comes next, but probably rocks containing 
 more ammonites, and more ichthyosauria and 
 plesiosauria, with a vast number of other things ; 
 and under that I should meet with yet older 
 rocks containing numbers of strange shells and 
 fishes ; and in thus passing from the surface to the 
 lowest depths of the earth's crust, the forms of 
 
XI PHKJSOMKNA OF OKtJAJJIL ' MAT URE 357 
 
 animal life and vegetable life which I should meet 
 with in the successive beds would, looking at them 
 broadly, be the more different the further that I 
 went down. Or, in other words, inasmuch as we 
 started with the clear principle, that in a series of 
 naturally-disposed mud beds the lowest are the 
 oldest, we should come to this result, that the 
 further we go back in time the more difference 
 exists between the animal and vegetable life of 
 an epoch and that which now exists. That was 
 the conclusion to which I wished to bring you at 
 the end of this lecture. 
 
in 
 
 THE METHOD BY WHICH THE CAUSES OF THE 
 PRESENT AND PAST CONDITIONS OF ORGANIC 
 NATURE ARE TO BE DISCOVERED, — THE 
 ORIGINATION OF LIVING BEINGS. 
 
 In the two preceding lectures I have endeavoured 
 to indicate to you the extent of the subject-matter 
 of the inquiry upon which we are engaged ; and 
 having thus acquired some conception of the past 
 and present phenomena of organic nature, I must 
 now turn to that which constitutes the great prob- 
 lem which we have set before ourselves ; — I mean, 
 the question of what knowledge we have of the 
 causes of these phenomena of organic nature, and 
 how such knowledge is obtainable. 
 
 Here, on the threshold of the inquiry, an 
 objection meets us. There are in the world a 
 number of extremely worthy, well-meaning 
 persons, whose judgments and opinions are 
 entitled to the utmost respect on account of 
 their sincerity, who are of opinion that vital 
 
XI PHENOMENA OF ORGANIC NATURE 359 
 
 plienomena, and especially all questions relating 
 to the origin of vital phenomena, are questions 
 quite apart from the ordinary run of inquiry, and 
 are, by their very nature, placed out of our reach. 
 They say that all these phenomena originated 
 miraculously, or in some way totally different from 
 the ordinary course of nature, and that therefore 
 thej' conceive it to ba futile, not to say pre- 
 sumptuous, to attempt to inquire into them. 
 
 To such sincere and earnest persons, I would 
 only say, that a question of this kind is not to be 
 shelved upon theoretical or speculative grounds. 
 You may remember the story of the Sophist who 
 demonstrated to Diogenes in the most complete 
 and satisfactory manner that he could not walk ; 
 that, in fact, all motion was an impossibility ; and 
 that Diogenes refuted him by simply getting up 
 and walking round his tub. So, in the same way, 
 the man of science replies to objections of this 
 kind, by simply getting up and walking onward, 
 and showing what science has done and is doing 
 — by pointing to that immense mass of facts 
 which have been ascertained as systematised 
 under the forms of the great doctrines of morpho- 
 logy* of development, of distribution, and the 
 like. He sees an enormous mass of facts and laws 
 relating to organic beings, which stand on the 
 same good sound foundation as every other natural 
 law. With this mass of facts and laws before us, 
 therefore, seeing that, as far as organic matters 
 
 62 
 
360 THE CAUSES OF THE XI 
 
 have hitherto been accessible and studied, they 
 have shown themselves capable of yielding to 
 scientific investigation, we may accept this as 
 proof that order and law reign there as well as 
 in the rest of Nature. The man of science says 
 nothing to objectors of this sort, but supposes 
 that Ave can and shall walk to a knowledge of the 
 origin of organic nature, in the same way that we 
 have walked to a knowledge of the laws and 
 principles of the inorganic world. 
 
 But there are objectors who say the same from 
 ignorance and ill-will. To such I would reply 
 til at the objection comes ill from them, and that 
 the real presumption, I may almost say the real 
 blasphemy, in this matter, is in the attempt to 
 limit that inquiry into the causes of phenomena, 
 which is the source of all human blessings, and 
 from which has sprung all human prosperity and 
 progress ; for, after all, we can accomplish com- 
 paratively little ; the limited range of our own 
 faculties bounds us on every side, — the field of 
 our powers of observation is small enough, and 
 he who endeavours to narrow the sphere of our 
 inquiries is only pursuing a course that is likely 
 to produce the greatest harm to his fellow- 
 men. 
 
 But now, assuming, as we all do, I hope, that 
 these phenomena are properly accessible to inquiry^ 
 and setting out upon our search into the causes 
 of the phenomena of organic nature, or at any 
 
XI PHENOMENA OF ORGANIC NATURE 361 
 
 rate, setting out to discover how much we at 
 present know upon these abstruse matters, the 
 question arises as to what is to be our course of 
 proceeding, and what method we must lay down 
 for our guidance. I reply to that question, that 
 our method must be exactly the same as that which 
 is pursued in any oilier scientific inquiry, the 
 method of scientific investigation being the same 
 for all orders of facts and phenomena whatsoever. 
 
 I must dwell a little on this point, for I wish you 
 to leave this room with a very clear conviction that 
 scientific investigation is not, as many people seem 
 to suppose, some kind of modern black art. I say 
 that you might easily gather this impression from 
 the manner in which many persons speak of 
 scientific inquiry, or talk about inductive and 
 deductive philosophy, or the principles of the 
 " Baconian philosophy." I do protest that, of the 
 vast number of cants in this world, there are 
 none, to my mind, so contemptible as the pseudo- 
 scientific cant which is talked about the " Baconian 
 philosophy." 
 
 To hear people talk about the great Chancellor 
 — and a very great man he certainly was, — you 
 would think that it was he who had invented 
 science, and that there was no such thing as 
 sound reasoning before the time of Queen 
 Elizabeth ! Of course you say, that cannot 
 possibly be true ; you perceive, on a moment's 
 reflection, that such an idea is absurdly wrong, 
 
362 THE CAUSES OF THE xi 
 
 and yet, so firmly rooted is this sort of impression, 
 — I cannot call it an idea, or conception, — the 
 thing is too absurd to be entertained, — but so 
 completely does it exist at the bottom of most 
 men's minds, that this has been a matter of ob- 
 servation with me for many years past. There 
 are many men who, though knowing absolutely 
 nothing of the subject Avith which they may be 
 dealing, wish, nevertheless, to damage the author 
 of some view with which they think fit to disagree. 
 What they do, then, is not to go and learn some- 
 thing about the subject, which one would naturally 
 think the best way of fairly dealing with it ; but 
 they abuse the originator of the view they ques- 
 tion, in a general manner, and wind up by saying 
 that, " After all, you know, the principles and 
 method of this author are totally opposed to the 
 canons of the Baconian philosophy." Then every- 
 body applauds, as a matter of course, and agrees 
 that it must be so. But if you were to stop them 
 all in the middle of their applause, you would 
 probably find that neither the sj^eaker nor his 
 applauders could tell you how or in what way it 
 was so ; neither the one nor the other having the 
 slightest idea of what they mean when they speak 
 of the " Baconian philosophy." 
 
 You will understand, I hope, that I have not 
 the slightest desire to join in the outcry against 
 either the morals, the intellect, or the great genius 
 of Lord Chancellor Bacon. He was undoubtedly 
 
XI PHENOMENA OF ORGANIC NATURE 363 
 
 a very great man, let people say what they will of 
 him; but notwithstanding all that he did for 
 philosophy, it would be entirely wrong to suppose 
 that the methods of modern scientific inquiry 
 originated with him, or with his age ; tliey origin- 
 ated with the first man, whoever he was ; and 
 indeed existed long before him, for many of the 
 essential processes of reasoning are exerted by the 
 higher order of brutes as completely and effectively 
 as by ourselves. We see in many of the brute 
 creation the exercise of one, at least, of the same 
 powers of reasoning as that which we ourselves 
 employ. 
 
 The method of scientific investigation is nothing 
 but the expression of the necessary mode of work- 
 ing of the human mind. It is simply the mode 
 at which all phenomena are reasoned about, ren- 
 dered precise and exact. There is no more differ- 
 ence, but there is just the same kind of difference, 
 between the mental operations of a man of science 
 and those of an ordinary person, as there is between 
 the operations and methods of a baker or of a 
 butcher weighing out his goods in common scales, 
 and the operations of a chemist in performing a 
 difficult and complex analysis by means of his 
 balance and finely-graduated weights. It is not 
 that the action of the scales in the one case, and 
 the balance in the other, differ in the principles of 
 their construction or manner of working ; but the 
 beam of one is set on an infinitely finer axis than. 
 
364 THE CAUSES OF THE SI 
 
 the other, and of course turns by the addition of 
 a much smaller weight. 
 
 You will understand this better, perhaps, if I 
 give you some familiar example. You have all 
 heard it repeated, I dare say, that men of science 
 work by means of induction and deduction, and 
 that by the help of these operations, they, in a sort 
 of sense, wring from Nature certain other things, 
 which are called natural laws, and causes, and 
 that out of these, by some cunning skill of their 
 own, they build up hypotheses and theories. 
 And it is imagined by many, that the operations 
 of the common mind can be by no means com- 
 pared with these processes, and that they have to 
 be acquired by a sort of special apprenticeship to 
 the craft. To hear all these large words, you 
 would thmk that the mind of a man of science 
 must be constituted differently from that of his 
 fellow men ; but if you will not be frightened by 
 terms, you will discover that you are quite wrong, 
 and that all these terrible apparatus are being 
 used by yourselves every day and every hour of 
 your lives. 
 
 There is a well-known incident in one of 
 Moliere's plays, where the author makes the hero 
 express unbounded delight on being told that he 
 had been talking prose during the whole of his 
 life. In the same way, I trust, that you will take 
 comfort, and be delighted with yourselves, on the 
 discovery that you have been acting on the prin- 
 
XI rii li, JN oatESlS^O f-^OlKGAJS IC JX AT URE 365 
 
 ciples of inductive and deductive philosophy dur- 
 ing the same period. Probably there is not one 
 here who has not in the course of the day had 
 occasion to set in motion a complex train of reason- 
 ing, of the very same kind, though differing of 
 course in degree, as that which a scientific man 
 goes through in tracing the causes of natural 
 phenomena. 
 
 A very trivial circumstance will serve to ex- 
 emplify this. Suppose you go into a fruiterer's 
 shop, wanting an apple, — you take up one, and, 
 on biting it, you find it is sour; you look at it, 
 and see that it is hard and green. You take 
 up another one, and that too is hard, green, 
 and sour. The shopman offers you a third ; 
 but, before biting it, you examine it, and find 
 that it is hard and green, and you immediately 
 say that you will not have it, as it must 
 be sour, Uke those that you have already 
 tried. 
 
 Nothing can be more simple than that, you 
 think ; but if you will take the trouble to analyse 
 and trace out into its logical elements what has 
 been done by the mind, you will be greatly sur- 
 prised. In the first place, you have performed 
 the operation of induction. You found that, in 
 two experiences, hardness and greenness in apples 
 went toofether with sourness. It was so in the 
 first case, and it was confirmed by the second. 
 True, it is a very small basis, but still it is enough 
 
366 THE CAUSES OF THE XI 
 
 to make an induction from ; you generalise the 
 facts, and you expect to find sourness in apples 
 where you get hardness and greenness. You found 
 iipon that a general law, that all hard and green 
 apples are sour ; and that, so far as it goes, is a 
 perfect induction. Well, having got your natural 
 law in this way, when you are offered another 
 apple which you find is hard and green, you say, 
 " All hard and green apples are sour ; this apple 
 is hard and green, therefore this apple is sour." 
 That tram of reasoning is what logicians call a 
 syllogism, and has all its various parts and terms, 
 — its major premiss, its minor pre.niss, and its 
 conclusion. And, by the help of further reason- 
 ing, which, if drawn out, would have to be exhibited 
 in two or three other syllogisms, you arrive at your 
 final determination, '' I will not have that apple." 
 So that, you see, you have, in the first place, 
 established a law by induction, and upon that you 
 have founded a deduction, and reasoned out the 
 special conclusion of the particular case. Well 
 now, suppose, having got your law, that at some 
 time afterwards, you are discussing the qualities 
 of apples with a friend : you will say to him, " It is 
 a very curious thing, — but I find that all hard and 
 green apples are sour ! " Your friend says to you, 
 " But how do you know that ? " You at once 
 reply, " Oh, because I have tried them over and 
 over again, and have always found them to be so." 
 Well, if we were talking soience instead of common 
 
XI PHENOMENA OF ORGANIC NATURE 367 
 
 sense, we should call that an experimental verifica- 
 tion. And, if still opposed, you go further, and 
 say, " I have heard from the people in Somerset- 
 shire and Devonshire, where a large number of 
 applfes are grown, that they have observed the 
 same thing. It is also found to be the case in 
 Normandy, and in North America. In short, I 
 find it to be the universal experience of mankind 
 wherever attention has been directed to the sub- 
 ject." Whereupon, your friend, unless he is a 
 very unreasonable man, agrees with you, and is 
 .xoftvinced that you are quite right in the conclu- 
 sion you have drawn. He believes, althoi:gh per- 
 haps he does not know he believes it, that the 
 more extensive verifications are, — that the more 
 frequently experiments have been made, and re- 
 sults of the same kind arrived at, — that the more 
 varied the conditions under which the same results 
 are attained, the more certain is the ultimate con- 
 clusion, and he disputes the question no further. 
 He sees that the experiment has been tried under 
 all sorts of conditions, as to time, place, and people, 
 with the same result ; and he says with you, 
 therefore, that the law you have laid down must 
 be a good one, and he must believe it. 
 
 In science we do the same thing ; — the philo- 
 sopher exercises precisely the same faculties, 
 though iu a much more delicate manner. In 
 scientific inquiry it becomes a matter of duty to 
 expose a supposed law to every possible kind of 
 
368 THE CAUSES OF THE xi 
 
 verification, and to take care, moreover, that this 
 is done intentionally, and not left to a mere acci- 
 dent, as in the case of the apples. And in science, 
 as in common life, our confidence in a law is in 
 exact proportion to the absence of variation in 
 the result of our experimental verifications. For 
 instance, if you let go your grasp of an article 
 you may have in your hand, it will immediately 
 fall to the ground. That is a very common veri- 
 fication of one of the best established laws of 
 nature — that of gravitation. The method by 
 which men of science establisli the existence of 
 that law is .exactly the same as that by which we 
 have established the trivial proposition about the 
 sourness of hard and green apples. But we believe 
 it in such an extensive, thorough, and unhesitat- 
 ing manner because the universal experience of 
 mankind verifies it, and we can verify it ourselves 
 at any time ; and that is the strongest possible 
 foundation on which any natural law can rest. 
 
 So much, then, by way of proof that the method 
 of establishing laws in science is exactly the same 
 as that pursued in common life. Let us now turn 
 to another matter (though really it is but another 
 phase of the same question), and- that is, the 
 method by which, from the relations of certain 
 phenomena, we jjrove that some stand in the posi- 
 tion of causes towards the others. 
 
 I want to put the case clearly before you, and I 
 will therefore show you what I mean by another 
 
^4 x^^iivyjiAjQi^ATCjj; aKUfa:NitrTisr37ruRE 369 
 
 familiar example. I will suppose that one of you, 
 on coming down in the morning to the parlour of 
 your house, finds that a tea-pot and some spoons 
 which had been left in the room on the previous 
 evening are gone, — the window is open, and you 
 observe the mark of a dirty hand on the window- 
 frame, and perhaps, in addition to that, you notice 
 the impress of a hob-nailed shoe on the gravel 
 outside. All these phenomena have struck your 
 attention instantly, and before two seconds have 
 passed you say, " Oh, somebody has broken open 
 the window, entered the room, and run off with 
 the spoons and the tea-pot ! " That speech is out 
 of your mouth in a moment. And you will prob- 
 ably add, " I know there has ; I am quite sure of 
 it ! " You mean to say exactly what you know ; 
 but in reality you are giving expression to what 
 is, in all essential particulars, an hypothesis. 
 You do not know it at all ; it is nothing but au 
 hypothesis rapidly framed in your own mind. And 
 it is an hypothesis founded on a long train of in- 
 ductions and deductions. 
 
 What are those inductions and deductions, and 
 how have you got at this hypothesis ? You have 
 observed, in the first place, that the window is 
 open ; but by a train of reasoning involving many 
 iaductions and deductions, you have probably 
 arrived long before at the general law — and a 
 very good one it is — that windows do not open of 
 themselves; and you therefore conclude that 
 
370 THE CAUSES OF THE XI 
 
 something has opened the -window. A second 
 general law that you have arrived at in the same 
 way is, that tea-pots and spoons do not go out of 
 a window spontaneously, and you are satisfied that, 
 as they are not now where you left them, they 
 have been removed. In the third place, you look 
 at the marks on the window-sill, and the shoe- 
 marks outside, and you say that in all previous 
 experience the former kind of mark has never 
 been produced by anything else but the hand of a 
 human being ; and the same experience shows that 
 no other animal but man at present wears shoes 
 with hob-nails in them such as would produce the 
 marks in the gravel. I do not know, even if we 
 could discover any of those " missing links " that 
 are talked about, that they would help us to any 
 other conclusion ! At any rate the law which 
 states our present experience is strong enough for 
 my present purpose. You next reach the con- 
 clusion, that as these kinds of marks have not been 
 left by any other animals than men, or are liable 
 to be formed in any other way than by a man's 
 hand and shoe, the marks in question have been 
 formed by a man in that way. You have, further, 
 a general law, founded on observation and experi- 
 ence, and that, too, is, I am sorry to say, a very 
 universal and unimpeachable one, — that some men 
 are thieves ; and you assume at once from all these 
 premisses — and that is what constitutes your 
 hypothesis — that the man who made the marks 
 
XI PHENOMENA OF ORGANIC NATURE 371 
 
 outside and on the window-sill, opened the window, 
 got into the room, and stole your tea-pot and 
 spoons. You have now arrived at a vera causa ; 
 — you have assumed a cause which, it is plain, is 
 competent to produce all the phenomena you have 
 observed. You can explain all these phenomena 
 only by the hypothesis of a thief. But that is a 
 hypothetical conclusion, of the justice of which 
 you have no absolute proof at all ; it is only 
 rendered highly probable by a series of inductive 
 and deductive reasonings. 
 
 I suppose your first action, assuming that you 
 are a man of ordinary common sense, and that 
 you have established this hypothesis to your own 
 satisfaction, will very likely be to go off for the 
 police, and set them on the track of the burglar, 
 with the view to the recovery of your property. 
 But just as you are starting with this object, some 
 person comes in, and on learning what you are 
 about, says, " My good friend, you are going on a 
 great deal too fast. How do you know that the 
 man who really made the marks took the spoons ? 
 It might have been a monkey that took them, and 
 the man may have merely looked in afterwards." 
 You would probably reply, " Well, that is all very 
 well, but you see it is contrary to all experience 
 of the way tea-pots and spoons are abstracted ; so 
 that, at any rate, your hypothesis is less probable 
 than mine." While you are talking the thing 
 over in this way, another friend arrives, one of 
 
372 THE CAUSES OF THE xi 
 
 that good kind of people that I was talking of a 
 little while ago. And he might say, " Oh, my dear 
 sir, you are certainly going on a great deal too 
 fast. You are most presumptuous. You admit 
 that all these occurrences took place when you 
 were fast asleep, at a time when you could not 
 possibly have known anything about what was 
 taking place. How do you know that the laws of 
 Nature are not suspended during the night ? It 
 may be that there has been some kind of super- 
 natural interference in this case." In point of 
 fact, he declares that your hypothesis is one of 
 which you cannot at all demonstrate the truth, 
 and that you are by no means sure that the laws 
 of Nature are the same when you are asleep as 
 when you are awake. 
 
 Well, now, you cannot at the moment answer 
 that kind of reasoning. You feel that your worthy 
 friend has you somewhat at a disadvantage. You 
 will feel perfectly convinced in your own mind, 
 however, that you are quite right, and you say to 
 him, " My good friend, I can only be guided by 
 the natural probabilities of the case, and if you 
 will be kmd enough to stand aside and permit me 
 to pass, I will go and fetch the police." Well, we 
 will suppose that your journey is successful, and 
 that by good luck you meet with a policeman ; 
 that eventually the burglar is found with your 
 property on his person, and the marks correspond 
 to his hand and to his boots. Probably any jury 
 
XI PHENOMENA OF ORGANIC NATURE 373 
 
 would consider those facts a very good experimental 
 verification of your hypothesis, touching the cause 
 of the abnormal phenomena observed in your 
 parlour, and would act accordingly. 
 
 Now, in tliis suppositious case, I have taken 
 phenomena of a very common kind, in order that 
 you might see what are the different steps in an 
 ordinary process of reasoning, if you will only take 
 the trouble to analyse it carefully. All the opera- 
 tions I have described, you will see, are involved 
 in the mind of any man of sense in leading him 
 to a conclusion as to the course he should take in 
 order to make good a robbery and punish the 
 offender. I say that you are led, in that case, to 
 your conclusion by exactly the same train of 
 reasoning as that which a man of science pursues 
 when he is endeavouring to discover the origin and 
 laws of the most occult phenomena. The process 
 is, and always must be, the same ; and precisely^ 
 the same mode of reasoning was employed by 
 Newton and Laplace in their endeavours to dis- 
 cover and define the causes of the movements of 
 the heavenly bodies, as you, with your own common 
 sense, would employ to detect a burglar. The 
 only difference is, that the nature of the inquiry 
 being more abstruse, every step has to be most 
 carefully watched, so that there may not be a 
 single crack or flaw in your hypothesis. A 
 flaw or crack in many of the hypotheses of 
 
374 THE CAUSES OF THE XI 
 
 daily life may be of little or no moment as 
 affecting the general correctness of the conclusions 
 at which we may arrive ; but,, in a scientific in- 
 quiry, a fallacy, great or small, is always of im- 
 portance, and is sure to be in the long run 
 constantly productive of mischievous, if not fatal 
 results. 
 
 Do not allow yourselves to be misled by the 
 common notion that an hypothesis is untrustworthy 
 simply because it is an hypothesis. It is often 
 urged, in respect to some scientific conclusion, 
 that, after all, it is only an hypothesis. But what 
 more have we to guide us in nine-tenths of the 
 most important affairs of daily life than hypotheses, 
 and often very ill-based ones ? So that in science, 
 where the evidence of an hypothesis is subjected 
 to the most rigid examination, we may rightly 
 pursue the same course. You may have hypo- 
 theses and hypotheses. A man may say, if he 
 likes, that the moon is made of greea cheese : 
 that is an hypothesis. But another man, who has 
 devoted a great deal of time and attention to the 
 subject, and availed himself of the most powerful 
 telescopes and the results of the observations of 
 others, declares that in his opinion it is probably 
 composed of materials very similar to those of 
 which our own earth is made up : and that is also 
 only an hypothesis. But I need not tell you that 
 there is an enormous difference in the value of the 
 
XI PHENOMENA OF ORGANIC NATURE 375 
 
 two bypotheses. That one which is based on 
 sound scientific knowledge is sure to have a corre- 
 sponding value ; and that which is a mere hasty 
 random guess is likely to have but little value. 
 Every great step in our progress in discovering 
 causes has been made in exactly the same way as 
 that which I have detailed to you. A person 
 observing the occurrence of certain facts and 
 phenomena asks, naturally enough, what process, 
 what kind of operation known to occur in Nature 
 applied to the particular case, will unravel and 
 explain the mystery ? Hence you have the 
 scientific hypothesis ; and its value will be pro- 
 portionate to the care and completeness with which 
 its basis had been tested and verified. It is in 
 these matters as in the commonest affairs of prac- 
 tical life : the guess of the fool will be folly, while 
 the guess of the wise man will contain wisdom. 
 In all cases, you see that the value of the result 
 depends on the patience and faithfulness with 
 which the investigator applies to his hypothesis 
 every possible kind of verification. 
 
 I dare say I may have to return to this point 
 by and by ; but having dealt thus far with our 
 logical methods, I must now turn to something 
 which, perhaps, you may consider more interesting, 
 or, at any rate, more tangible. But in reality 
 there are but few things that can be more import- 
 ant for you to understand than the mental pro- 
 cesses and the means by which we obtain scientific 
 
 53 
 
376 THE CAUSES OF THE si 
 
 conclusions and theories.^ Having granted that 
 the inquiry is a proper one, and having determined 
 on the nature of the methods we are to pursue 
 and which only can lead to success, I must now 
 turn to the consideration of our knowledge of the 
 nature of the processes which have resulted in the 
 present condition of organic nature. 
 
 Here, let me say at once, lest some of you mis- 
 understand me, that I have extremely little to 
 report. The question of how the present condition 
 of organic nature came about, resolves itself into 
 two questions. The first is : How has organic or 
 living matter commenced its existence ? And the 
 second is : How has it been perpetuated ? On the 
 second question I shall have more to say hereafter. 
 But on the first one, what I now have to say will 
 be for the most part of a negative character. 
 
 If you consider what kind of evidence we can 
 have upon this matter, it will resolve itself into 
 two kinds. We may have historical evidence and we 
 may have experimental evidence. It is, for example, 
 'conceivable, that inasmuch as the hardened mud 
 which forms a considerable portion of the thick- 
 ness of the earth's crust contains faithful records 
 of the past forms of life, and inasmuch as these 
 differ more and more as we go further down, — it 
 is possible and conceivable that we might come to 
 
 1 Those who wish to study fully the doctrines of which I 
 have endeavoured to give some rougli-andready illustrations, 
 must read Mr. John Stuart Mill's System of Logic. 
 
XI PHENOMENA OF OEGANIC NATURE 377 
 
 some particular bed or stratum Avhich should con- 
 tain the remains of those creatures with which 
 organic life began upon the earth. And if we did 
 so, and if such forms of organic life were pre- 
 servable, we should have what I would call his- 
 torical evidence of the mode in which organic life 
 began upon this planet. Many persons will tell 
 you, and indeed you will find it stated in many 
 works on geology, that this has been done, and 
 that we really possess such a record ; there are 
 some who imagine that the earliest forms of life 
 of which we have as yet discovered any record, are 
 .in truth the forms in which animal life began upon 
 the globe. The grounds on which they base that 
 supposition are these : — That if you go through 
 the enormous thickness of the earth's crust and 
 get down to the older rocks, the higher vertebrate 
 animals — the quadrupeds, birds, and fishes — cease 
 to be found ; beneath them you find only the in- 
 vertebrate animals ; and in the deepest and lowest 
 rocks those remains become scantier and scantier, 
 not in any very gradual progression, however, 
 until, at length, in what are supposed to be the 
 oldest rocks, the animal remains which are found 
 are almost always confined to four forms — Oldhamia, 
 whose precise nature is not known, whether plant 
 or animal ; Lingula, a kind of mollusc ; H^ilobiks^ 
 a crustacean animal, having the same essential 
 plan of construction, though differing in many 
 details from a lobster or crab ; and Hymenocaris, 
 
378 THE CAUSES OF THE XI 
 
 which is also a crustacean. So that you have all 
 the Fauna reduced, at this period, to four forms : 
 one a kind of animal or plant that we know no- 
 thing about, and three undoubted animals — two 
 crustaceans and one mollusc. 
 
 I think, considering the organisation of these 
 mollusca and Crustacea, and looking at their very 
 complex nature, that it does indeed require a very 
 strong imagination to conceive that these were the 
 first created of all living things. And you must 
 take into consideration the fact that we have not 
 the slightest proof that these which we call the 
 oldest beds are really so : I repeat, we have not 
 the slightest proof of it. When you find in some 
 places that in an enormous thickness of rocks 
 there are but very scanty traces of life, or abso- 
 lutely none at all ; and that in other parts of the 
 world rocks of the very same formation are 
 crowded with the records of living forms, I think 
 it is impossible to place any reliance on the sup- 
 position, or to feel one's self justified in supposing 
 that these are the forms in which life first com- 
 menced. I have not time here to enter upon the 
 technical grounds upon which I am led to this 
 conclusion, — that could hardly be done properly 
 in half a dozen lectures on that part alone : — I 
 must content myself with saying that I do not 
 at all believe that these are the oldest forms 
 of life. 
 
 I turn to the experimental side to see what 
 
XI PHENOMENA OF ORGANIC NATURE 379 
 
 evidence we have there. To enable us to say that 
 we know anything about the experimental origin- 
 ation of organisation and life, the?' investigator 
 ought to be able to take inorganic matters, such 
 as carbonic acid, ammonia, water, and salines, in 
 any sort of inorganic combination, and be able to 
 build them up into protein matter, and then that 
 protein matter ought to begin to live in an 
 organic form. That, nobody has done as yet, and 
 I suspect ifc will be a long while before anybody 
 does do it. But the thing is by no means so 
 impossible as it looks ; for the researches of modern 
 chemistry have shown us — I won't say the road 
 towards it, but, if I may so say, they have shown 
 the finger-post pointing to the road that may lead 
 to it. 
 
 It is not many years ago — and you must recol- 
 lect that Organic Chemistry is a young science, 
 not above a couple of generations old, you must 
 not expect too much of it, — it is not many years 
 ago since it was said to be perfectly impossible to 
 fabricate any organic compound ; that is to say, 
 any non-mineral compound which is to be found 
 in an organised being. It remained so for a very 
 long period ; but it is now a considerable number 
 of years since a distinguished foreign chemist con- 
 trived to fabricate urea, a substance of a very 
 complex character, which forms one of the waste 
 products of animal structures. And of late years 
 a number of other compounds, such as butyric 
 
380 THE CAUSES OF THE SI 
 
 acid, and others, have been added to the list. I 
 need not tell you that chemistry is an enormous 
 distance from the goal I indicate ; all I wish to 
 point out to you is, that it is by no means safe 
 to say that that goal may not be reached one 
 day. It may be that it is impossible for us 
 to produce the conditions requisite to the origina- 
 tion of life ; but we must speak modestly about 
 the matter, and recollect that Science has put her 
 foot upon the bottom round of the ladder. Truly 
 he would be a bold man who would venture to 
 predict where she will be fifty years hence. 
 
 There is another inquiry which bears indirectly 
 upon this question, and upon which I must say a 
 few words. You are all of you aware of the 
 phenomena of what is called spontaneous genera- 
 tion. Our forefathers, down to the seventeenth 
 century, or thereabouts, all imagined, in perfectly 
 good faith, that certain vegetable and animal 
 forms gave birth, in the -process of their decom- 
 position, to insect life. Thus, if you put a piece 
 of meat in the sun, and allowed it to putrefy, they 
 conceived that the grubs which soon began to 
 appear were the result of the action of a; power of 
 spontaneous generation which the meat contained. 
 And they could give you receipts for making 
 various animal and vegetable preparations which 
 would produce particular kinds of animals. A 
 very distinguished Italian naturalist, named Redi, 
 took up the question, at a time when everybody 
 
XI PHENOMENA OF ORGANIC NATURE 381 
 
 believed in it ; among others our own great Harvey, 
 the discoverer of the circulation of the blood. 
 You will constantly find his name quoted, how- 
 ever, as an opponent of the doctrine of spontaneous 
 generation ; but the fact is, and you will see it if 
 you will take the trouble to look into his works, 
 Harvey believed it as profoundly as any man of 
 his time ; but he happened to enunciate a very 
 curious proposition— that every living thing came 
 from an egg ; he did not mean to use the word in 
 the sense in Avhich we now employ it, he only 
 meant to say that every living thing originated in 
 a little rounded particle of organised substance ; 
 and it is from this circumstance, probably, that 
 the notion of Harvey having opposed the doctrine 
 originated. Then came E.edi, and he proceeded 
 to upset the doctrine in a very simple manner. 
 He merely covered the piece of meat with some 
 very fine gauze, and then he exposed it to the 
 same conditions. The result of this was that no 
 grubs or insects were produced ; he proved, that 
 the grubs originated from the insects who came 
 and deposited their eggs in the meat, and that 
 they were hatched by the heat of the sun. By 
 this kind of inquiry he thoroughly upset the 
 doctrine of spontaneous generation, for his time 
 at least. 
 
 Then came the discovery and application of the 
 microscope to scientific inquiries, which showed to 
 naturalists that besides the organisms which they 
 
882 THE CAUSES OF THE XI 
 
 already knew as living beings and plants, there 
 were an immense number of minute things which 
 could be obtained apparently almost at will from 
 decaying vegetable and animal forms. Thus, if 
 you took some ordinary black pepper or some hay^ 
 and steeped it in water, you would find in the course 
 of a few days that the water had become impreg- 
 nated with an immense number of animalcules 
 swimming about in all directions. From facts of 
 this kind naturalists were led to revive the theory 
 of spontaneous generation. They were headed 
 here by an English naturalist, — Needham, — and 
 afterwards in France by the learned Buffon. They 
 said that these things were absolutely begotten 
 in the water of the decaying substances out of 
 which the infusion was made. It did not matter 
 whether you took animal or vegetable matter, you 
 had only to steep it in water and expose it, and 
 you would soon have plenty of animalcules. They 
 made an hypothesis about this which was a very 
 fair one. They said, this matter of the animal 
 world, or of the higher plants, appears to be dead, 
 but in reality it has a sort of dim life about it, 
 which, if it is placed under fair conditions, will 
 cause it to break up into the forms of these little 
 animalcules, and they will go through their lives 
 in the same way as the animal or plant of which 
 they once formed a part. 
 
 The question now became very hotly debated. 
 Spallanzani, an Italian naturalist, took up opposite 
 
XI PHENOMENA OF ORGANIC NATURE 383 
 
 views to those of Needham and Buffon, and by 
 means of certain experiments he showed that it 
 was quite possible to stop the process by boihng 
 the water, and closing the vessel in which it was 
 contamed. " Oh ! " said his opponents ; " but what 
 do you know you may be doing when you heat the 
 air over the water in this way ? You may be de- 
 stroying some property of the air requisite for the 
 spontaneous generation of the animalcules." 
 
 However, Spallanzani's views were supposed to 
 be upon the right side, and those of the others fell 
 into discredit ; although the fact was that Spallan- 
 zani had not made good his views. Well, then, 
 the subject continued to be revived from time to 
 time, and experiments were made by several per- 
 sons ; but these experiments were not altogether 
 satisfactory. It was found that if you put an in- 
 fusion in which animalcules would appear if it were 
 exposed to the air into a vessel and boiled it, and 
 then sealed up the mouth of the vessel, so that no 
 air, save such as had been heated to 212°, could 
 reach its contents, that then no animalcules would 
 be found ; but if you took the same vessel and ex- 
 posed the infusion to the air, then you would get 
 animalcules. Furthermore, it was found that if 
 you connected the mouth of the vessel with a red- 
 hot tube in such a way that the air would have to 
 pass through the tube before reaching the infusion, 
 that then you would get no animalcules. Yet 
 another thing was noticed : if you took two flasks 
 
384 THE CAUSES OF THE xi 
 
 containing the same kind of infusion, and left one 
 entirely exposed to the air, and in the mouth of 
 the other placed a ball of cotton wool, so that the 
 air would have to filter itself through it before 
 reaching the infusion, that then, although you 
 might have plenty of animalcules in the first flask, 
 you would certainly obtain none from the second. 
 
 These experiments, you see, all tended towards 
 one conclusion — that the infusoria were developed 
 from little minute spores or eggs which were con- 
 stantly floating in the atmosphere, and which lose 
 their power of germination if subjected to heat. 
 But one observer now made another experiment, 
 which seemed to go entirely the other way, and 
 puzzled him altogether. He took' some of this 
 boiled infusion that I have been speaking of, and 
 by the use of a mercurial bath — a kind of trough 
 used in laboratories — he deftly inverted a vessel 
 containing the infusion into the mercury, so that 
 the latter reached a little beyond the level of the 
 mouth of the inverted vessel. You see that he 
 thus had a quantity of the infusion shut off from 
 any possible communication with the outer air by 
 being inverted upon a bed of mercury. 
 
 He then prepared some pure oxygen and nitro- 
 gen gases, and passed them by means of a tube 
 going from the outside of the vessel, up through 
 the mercury into the infusion ; so that he thus 
 had it exposed to a perfectly pure atmosphere of 
 the same constituents as the external air. Of 
 
XI ruJiNOMiiNA OF OKGANIC NATURE 385 
 
 course, he expected he would get no infusorial 
 animalcules at all in that infusion ; but, to his 
 great dismay and discomfiture, he found he almost 
 always did get them. 
 
 Furthermore, it has been found that experi- 
 ments made in the manner described above answer 
 well with most infusions ; but that if you fill the 
 vessel with boiled milk, and then stop the neck 
 with cotton-wool, you will have infusoria. So that 
 you see there were two experiments that brought 
 you to one kind of conclusion, and three to an- 
 other ; which was a most unsatisfactory state of 
 things to arrive at in a scientific inquiry. 
 
 Some few years after this, the question began 
 to be very hotly discussed in France. There was 
 M. Pouchet, a professor at Rouen, a very learned 
 man, but certainly not a very rigid experimental- 
 ist. He published a number of experiments of his 
 own, some of which were very ingenious, to show 
 that if you went to work in a proper way, there 
 was a truth in the doctrine of spontaneous genera- 
 tion. Well, it was one of the most fortunate things 
 in the world that M. Pouchet took up this question, 
 because it induced a distinguished French chemist, 
 M. Pasteur, to take up the question on the other 
 side ; and he has certainly worked it out in the 
 most perfect manner. I am glad to say, too, that 
 he has published his researches in time to enable 
 me to give you an account of them. He verified 
 all the experiments which I have just mentioned 
 
386 THE CAUSES OF THE xi 
 
 to you— and then finding those extraordinary- 
 anomalies, as in the case of the mercury bath and 
 the milk, he set himself to work to discover their 
 nature. In the case of milk he found it to be a 
 question of temperature. Milk in a fresh state is 
 slightly alkaline ; and it is a very curious circum- 
 stance, but this very slight degree of alkalinity 
 seems to have the effect of preserving the organ- 
 isms which fall into it from the air from beingf 
 destroyed at a temperature of 212°, which is the 
 boiling point. But if you raise the temperature 
 10° when yoii boil it, the milk behaves like every- 
 thing else ; and if the air with which it comes in 
 contact, after being boiled at this temperature, is 
 passed through a red-hot tube, you will not get a 
 trace of organisms. 
 
 He then turned his attention to the mercury 
 bath, and found on examination that the surface of 
 the mercury was almost always covered with a 
 very fine dust. He found that even the mercury 
 itself was positively full of organic matters ; that 
 from being constantly exposed to the air, it had 
 collected an immense number of these infusorial 
 organisms from the air. Well, under these circum- 
 stances he felt that the case was quite clear, and 
 that the mercury was not what it had appeared to 
 M. Schwann to be, — a bar to the admission of these 
 organisms ; but that, in reality, it acted as a reservoir 
 from which the infusion was immediately supplied 
 with the large quantity that had so puzzled him. 
 
XI PHENOMENA OF ORGANIC NATURE 387 
 
 But not content with explaining the experiments 
 of others, M. Pasteur went to work to satisfy himself 
 completely. He said to himself : " If my view is 
 right, and if, in point of fact, all these appearances 
 of spontaneous generation are altogether due to the 
 falling of minute germs suspended in the atmo- 
 sphere, — why, I ought not only to be able to show 
 the germs, but I ought to be able to catch 
 and sow them, and produce the resulting organ- 
 isms." He, accordingly, constructed a very in- 
 genious apparatus to enable him to accomplish the 
 trapping of the " germ dust " in the air. He fixed 
 in the window of his room a glass tube, in the 
 centre of which he had placed a ball of gun-cotton, 
 which, as you all know, is ordinary cotton-wool, 
 which, from having been steeped in strong acid, is 
 converted into a substance of great explosive power. 
 It is also soluble in alcohol and ether. One end 
 of the glass tube was, of course, open to the ex- 
 ternal air; and at the other end of it he placed an 
 aspirator, a contrivance for causing a current of 
 the external air to pass through the tube. He 
 kept this apparatus going for four-and-twenty 
 hours, and then removed the dusted gun-cotton, 
 and dissolved it in alcohol and ether. He then 
 allowed this to stand for a few hours, and the re- 
 sult was, that a very fine dust was gradually de- 
 posited at the bottom of it. That dust, on being 
 transferred to the stage of a microscope, was found 
 to contain an enormous number of starch grains. 
 
388 THE CAUSES OF THE XI 
 
 You know that the materials of our food and the 
 greater portion of plants are composed of starch, 
 and we are constantly making use of it in a variety 
 of ways, so that there is always a quantity of it 
 suspended in the air. It is these starch grains 
 which form many of those bright specks that we 
 see dancing in a ray of light sometimes. But be- 
 sides these, M. Pasteur found also an immense 
 number of other organic substances such as spores 
 of fungi, which had been floating about in the air 
 and had got caged in this way. 
 
 He went farther, and said to himself, " If these 
 really are the things that give rise to the appear- 
 ance of spontaneous generation, I ought to be able 
 to take a ball of this dusted gun-cotton and put it 
 into one of my vessels, containing that boiled in- 
 fusion which has been kept away from the air, and 
 in which no infusoria are at present developed, and 
 then, if I am right, the introduction of this gun- 
 cotton will give rise to organisms." 
 
 Accordingly, he took one of these vessels of in- 
 fusion, which had been kept eighteen months, 
 without the least appearance of life in it, and by a 
 most ingenious contrivance, he managed to break 
 it open and introduce such a ball of gun-cotton, 
 without allowing the infusion or the cotton ball to 
 come into contact with an)'' air but that which had 
 been subjected to a red heat, and in twenty-four 
 hours he had the satisfaction of finding all the in- 
 dications of what had been hitherto called spon- 
 
XI PHENOMENA OF ORGANIC NATURE 889 
 
 taneous generation. He had succeeded in catching 
 the germs and developing organisras in the way 
 he had anticipated. 
 
 It now struck hinn that the truth of his conclu- 
 sions might be demonstrated without all the appa- 
 ratus he had employed. To do this, he took some 
 decaying animal or vegetable substance, such as 
 urine, which is an extremely decomposable sub- 
 stance, or the juice of yeast, or perhaps some other 
 artificial preparation, and filled a vessel having a 
 long tubular neck with it. He then boiled the 
 liquid and bent that long neck into an S shape or 
 zig-zag, leaving it open at the end. The infusion 
 then gave no trace of any appearance of spontaneous 
 generation, however long it might be left, as all 
 the germs in the air were deposited in the begin- 
 ning of the bent neck. He then cut the tube close 
 to the vessel, and allowed the ordinary air to have 
 free and direct access ; and the result of that was 
 the appearance of organisms in it, as soon as the 
 infusion had been allowed to stand long enough to 
 allow of the growth of those it received from the 
 air, which was about forty-eight hours. The re- 
 sult of M. Pasteur's experiments proved, therefore, 
 in the most conclusive manner, that all the appear- 
 ances of spontaneous generation arose from nothing 
 more than the deposition of the germs of organisms 
 which were constantly floating in the air. 
 
 To this conclusion, however, the objection was 
 made, that if that were the cause, then the air 
 
390 PHENOMENA OF ORGANIC NATURE xi 
 
 would contain such an enormous number of these 
 germs, that it would be a continual fog. But M. 
 Pasteur replied that they are not there in any- 
 thing like the number we might suppose, and that 
 an exaggerated view has been held on that subject; 
 he showed that the chances of animal or vegetable 
 life appearing in infusions, depend entirely on the 
 conditions under which they are exposed. If they 
 are exposed to the ordinary atmosphere around 
 us, why, of course, you may have organisms ap- 
 pearing early. But, on the other hand, if they are 
 exposed to air at a great height, or in some very 
 quiet cellar, you will often not find a single trace 
 of life. 
 
 So that M. Pasteur arrived at last at the clear 
 and definite result, that all these appearances are 
 like the case of the worms in the piece of meat, 
 which was refuted by Redi, simply germs carried 
 by the air and deposited in the liquids in which 
 they afterwards appear. For my own part, I con- 
 ceive that, with the particulars of M. Pasteur's ex- 
 periments before us, we cannot fail to arrive at his 
 conclusions ; and that the doctrine of spontaneous 
 generation has received a final coup de grdce. 
 
 You, of course, understand that all this in no 
 way interferes with the possibility of the fabrica- 
 tion of organic matters by the direct method to 
 which I have referred, remote as that possibility 
 may be. 
 
IV 
 
 THE PERPETUATION OF LIVING BEINGS, HEREDI- 
 TARY TRANSMISSION AND VARIATION. 
 
 The inquiry which we undertook, at our last 
 meeting, into the state of our knowledge of the 
 causes of the phenomena of organic nature, — of 
 the past and of the present, — resolved itself into 
 two subsidiary inquiries : the first was, whether we 
 know anything, either historically or experimen- 
 tally, of the mode of origin of living beings ; the 
 second subsidiary inquiry was, whether, granting 
 the origin, we know anything about the perpetua- 
 tion and modificationsof the forms of organic beings. 
 The reply which I had to give to the first question 
 was altogether negative, and the chief result of my 
 last lecture was, that, neither historically nor ex- 
 perimentally, do we at present know anything 
 whatsoever about the origin of living forms. We 
 saw that, historically, we are not likely to know 
 anything about it, although we may perhaps learn 
 something experimentally ; but tha* at present we 
 are an enormous distance from the goal I indicated. 
 64 
 
392 THE CAUSES OF THE XI 
 
 I now, then, take up the next question, What 
 do we know of the reproduction, the perpetuation, 
 and the modifications of the forms of living beings, 
 supposing that we have put the question as to their 
 origination on one side, and have assumed that at 
 present the causes of their origination are beyond 
 us, and that we know nothing about them ? Upon 
 this question the state of our knowledge is ex- 
 tremely different ; it is exceedingly large : and, if 
 not complete, our experience is certainly most ex- 
 tensive. It would be impossible to lay it all before 
 you, and the most I can do, or need do to-night, is 
 to take up the principal points and put them be- 
 fore you with such prominence as may subserve 
 the purposes of our present argument. 
 
 The method of the perpetuation of organic beings 
 is of two kinds, — the non-sexual and the sexual. In 
 the first the perpetuation takes place from and by 
 a particular act of an individual organism, which 
 sometimes may not be classed as belonging to any 
 sex at all. In the second case, it is in con- 
 sequence of the miitual action and interaction of 
 certain portions of the organisms of usually two 
 distinct individuals, — the male and the female. The 
 cases of non-sexual perpetuation are by no means 
 so common as the cases of sexual perpetuation ; 
 and they are by no means so common in the animal 
 as in the vegetable world. You are all probably 
 familiar with the fact, as a matter of experience, 
 that you can propagate plants by means of what 
 
XI PHENOMENA OF ORGANIC NATUEE 393 
 
 are called " cuttings " ; for example, that by tak- 
 ing a cutting from a geranium plant, and rearing 
 it properly, by supplying it with light and warmth 
 and nourishment from the earth, it grows up and 
 takes the form of its parent, having all the pro- 
 perties and peculiarities of the original plant. 
 
 Sometimes this process, which the gardener per- 
 forms artificially, takes place naturally ; that is to 
 say, a little bulb, or portion of the plant, detaches 
 itself, drops off, and becomes capable of growing 
 as a separate thing. That is the case with many 
 bulbous plants, which throw off in this way second- 
 ary bulbs, which are lodged in the ground and 
 become developed into plants. This is a non-sexual 
 process, and from it results the repetition or re- 
 production of the form of the original being from 
 which the bulb proceeds. 
 
 Among animals the same thing takes place. 
 Among the lower forms of animal life, the infusorial 
 animalculae we have already spoken of throw off 
 certain portions, or break themselves up in various 
 directions, sometimes transversely or sometimes 
 longitudinally ; or they may give off buds, which 
 detach themselves and develop into their proper 
 forms. There is the common fresh-water polype, 
 for instance, which multiplies itself in this way. 
 Just in the same way as the gardener is able to 
 multiply and reproduce the peculiarities and char- 
 acters of particular plants by means of cuttings, 
 so can the physiological experimentalist — as was 
 
394 THE CAUSES OF THE XI 
 
 shown by the Abh^ Trembley many years ago — so 
 can he do the same thing with many of the lower 
 forms of animal life. M. de Trembley showed 
 that you could take a polype and cut it into two, 
 or four, or many pieces, mutilating it in all direc- 
 tions, and the pieces would still grow up and re- 
 produce completely the original form of the animal. 
 These are all cases of non-sexual multiplication, 
 and there are other instances, and still more extra- 
 ordinary ones, in which this process takes place 
 naturally, in a more hidden, a more recondite kind 
 of way. You are all of you familiar with that 
 little green insect, the Aphis or blight, as it is 
 called. These little animals, during a very con- 
 siderable part of their existence, multiply them- 
 selves by means of a kind of internal budding, the 
 buds being developed into essentially non-sexual 
 animals, which are neither male nor female ; they 
 become converted into young Aphides, which re- 
 peat the process, and their offspring after them, 
 and so on again ; you may go on for nine or ten, 
 or even twenty or more successions ; and there is no 
 very good reason to say how soon it might terminate, 
 or how long it might not go on if the proper con- 
 ditions of warmth and nourishment were kept up. 
 • Sexual reproduction is quite a distinct matter. 
 Here, in all these cases, what is required is the 
 detachment of two portions of the parental 
 organisms, which portions we know as the egg 
 or the spermatozoon. In plants it is the ovule 
 
XI PHENOMENA OF ORGANIC NATURE 395 
 
 and the pollen-grain, as in the flowering plants, or 
 the ovule and the antherozooid, as in the flower- 
 less. Among all forms of animal life, the sperma- 
 tozoa proceed from the male sex, and the egg is 
 the product of the female. Now, what is remark- 
 able about this mode of reproduction is this, that 
 the egg by itself, or the spermatozoa by themselves, 
 are unable to assume the parental form ; but if 
 they be brought into contact with one another, 
 the efiect of the mixture of organic substances 
 proceeding from two sources appears to confer an 
 altogether new vigour to the mixed product. This 
 process is brought about, as we all know, by the 
 sexual intercourse of the two sexes, and is called 
 the act of impregnation. The result of this act 
 on the part of the male and female is, that the 
 formation of a new being is set up in the ovule or 
 egg; this ovule or egg soon begins to be divided 
 and subdivided, and to be fashioned into various 
 complex organs, and eventually to develop into 
 the form of one of its parents, as I explained in 
 the first lecture. These are the processes by 
 which the perpetuation of organic beings is secured. 
 Why there should be the two modes — why this 
 re-invigoration should be required on the part of 
 the female element we do not know ; but it is most 
 assuredly the fact, and it is presumable, that, how- 
 ever long the process of non-sexual multiplication 
 could be continued — I say there is good reason to 
 believe that it would come to an end if a new 
 
396 THE CAUSES OF THE xi 
 
 commencement were not obtained by a conjunc- 
 tion of the two sexual elements. 
 
 That character which is common to these two 
 distinct processes is this, that, whether we con- 
 sider the reproduction, or perpetuation, or modifica- 
 tion of organic beings as they take place non-sexu- 
 ally, or as they may take place sexually — in either 
 case, I say, the offspring has a constant tendency 
 to assume, speaking generally, the character of 
 the parent. As I said just now, if you take a slip 
 of a plant, and tend it with care, it will eventually 
 grow up and develop into a plant like that from 
 which it had sprung; and this tendency is so 
 strong that, as gardeners know, this mode of 
 multiplying by means of cuttings is the only secure 
 mode of propagating very many varieties of plants ; 
 the peculiarity of the primitive stock seems to be 
 better preserved if you propagate it by means of a 
 slip than if you resort to the sexual mode. 
 
 Again, in experiments upon the lower animals, 
 such as the polype, to which I have referred, it is 
 most extraordinary that, although cut up into 
 various pieces, each particular piece will grow up 
 into the form of the primitive stock ; the head, if 
 separated, will reproduce the body and the tail; 
 and if you cut off the tail, you will find that that 
 will reproduce the body and all the rest of the 
 members, without in any way deviating from the 
 plan of the organism from which these portions 
 have been detached. And so far does this go, that 
 
SI PHENOMENA OF ORGANIC NATURE 397 
 
 some experimentalists have carefully examined the 
 lower orders of animals, — among them the Abbe 
 Spallanzani, who made a number of experiments 
 upon snails and salamanders, — and have found 
 that they might mutilate them to an incredible 
 extent ; that you might cut off the jaw or the 
 greater part of the head, or the leg or the tail, and 
 repeat the experiment several times, perhaps cut- 
 ting off the same member again and again ; and 
 yet each of those types would be reproduced 
 according to the primitive type : Nature making 
 no mistake, never putting on a fresh kind of leg, 
 or head, or tail, but always tending to repeat and 
 to return to the primitive type. 
 
 It is the same in sexual reproduction : it is a 
 matter of perfectly common experience, that the 
 tendency on the part of the offspring always is, 
 speaking broadly, to reproduce the form of the 
 parents. The proverb has it that the thistle does 
 not bring forth grapes ; so, among ourselves, there 
 is always a likeness, more or less marked and dis- 
 tinct, between children and their parents. That is 
 a matter of familiar and ordinary observation. We 
 notice the same thing occurring in the cases of the 
 domestic animals — dogs, for instance, and their 
 offspring. In all these cases of propagation and 
 perpetuation, there seems to be a tendency in the 
 offspring to take the characters of the parental 
 organisms. To that tendency a special name is given 
 — and as I may very often use it, I will write it 
 
398 THE CAUSES OF THE SI 
 
 up here on this black-board that you may remem- 
 ber it — it is called Atavism ; it expresses this 
 tendency to revert to the ancestral type, and comes 
 from the Latin word atavus, ancestor. 
 
 Well, this Atavism which I shall speak of, is, as 
 I said before, one of the most marked and striking 
 tendencies of organic beings ; but, side by side 
 with this hereditary tendency there is an equally 
 distinct and remarkable tendency to variation. 
 The tendency to reproduce the original stock has, 
 as it were, its limits, and side by side with it there 
 is a tendency to vary in certain directions, as if 
 there were two opposing powers working upon the 
 organic being, one tending to take it in a straight 
 line, and the other tending to make it diverge 
 from that straight line, first to one side and then 
 to the other. 
 
 So that you see these two tendencies need not 
 precisely contradict one another, as the ultimate 
 result may not always be very remote from what 
 would have been the case if the line had been quite 
 straight. 
 
 This tendency to variation is less marked in that 
 mode of propagation which takes place non-sexu- 
 ally ; it is in that mode that the minor characters of 
 animal and vegetable structures are most com- 
 pletely preserved. Still, it will happen sometimes, 
 that the gardener, when he has planted a cutting 
 of some favourite plant, will find, contrary to his 
 expectation, that the slip grows up a little different 
 
XI PHENOMENA OF ORGANIC NATURE 399 
 
 from the primitive stock — that it produces flowers 
 of a different colour or make, or some deviation 
 in one way or another. This is what is called the 
 " sporting " of plants. 
 
 In animals the phenomena of non-sexual pro- 
 pagation are so obscure, that at present we cannot 
 be said to know much about them ; but if we turn to 
 that mode of perpetuation which results from the 
 sexual process, then we find variation a perfectly 
 constant occurrence, to a certain extent ; and, in- 
 deed, I think that a certain amount of variation 
 from the primitive stock is the necessary result of 
 the method of sexual prcrpagation itself; for, inas- 
 much as the thing propagated proceeds from two 
 organisms of different sexes and different makes 
 and temperaments, and as the offspring is to be 
 either of one sex or the other, it is quite clear that 
 it cannot be an exact diagonal of the two., or it 
 would be of no sex at all ; it cannot be an exact 
 intermediate form between that of each of its 
 parents — it must deviate to one side or the other. 
 You do not find that the male follows the precise 
 type of the male parent, nor does the female al- 
 ways inherit the precise characteristics of the 
 mother, — there is always a proportion of the female 
 character in the male offspring, and of the male 
 character in the female offspring. That mustbe quite 
 plain to all of you who have looked atall attentively 
 on your own children or those of your neighbours ; 
 you will have noticed how very often it may hap- 
 
400 THE CAUSES OF THE XI 
 
 pen that the son shall exhibit the maternal type 
 of character, or the daughter possess the character- 
 istics of the father's family. There are all sorts of 
 intermixtures and intermediate conditions between 
 the two, where complexion, or beauty, or fifty other 
 different peculiarities belonging to either side of 
 the house, are reproduced in other members of the 
 same family. Indeed, it is sometimes to be re- 
 marked in this kind of variation, that the variety 
 belongs, strictly speaking, to neither of the im- 
 mediate parents ; you will see a child in a family 
 who is not like either its father or its mother ; but 
 some old person who knew its grandfather or 
 grandmother, or, it may be, an uncle, or, perhaps, 
 even a more distant relative will see a great 
 similarity between the child and one of these. In 
 this way it constantly happens that the character- 
 istic of some previous member of the family comes 
 out and is reproduced and recognised in the most 
 unexpected manner. 
 
 But apart from that matter of general experience, 
 there are some cases which put that curious mix- 
 ture in a very clear light. You are aware that the 
 offspring of the ass and the horse, or rather of the" 
 he-ass and the mare, is what is called a mule ; and, 
 on the other hand, the offspring of the stallion 
 and the she-ass is what is called a hinny. It is 
 a very rare thing in this country to see a hinny. 
 I never saw one myself ; but they have been very 
 carefully studied. Now, the curious thing is this, 
 
ii jrjaii,iN(jivij<,jNA UJb- ORGANIC NATURE 401 
 
 that although you have the same elements in the 
 experiment in each case, the ofifspring is entirely 
 diflferent in character, according as the male influ- 
 ence comes from the ass or the horse. Where the 
 ass is the male, as in the case of the mule, you 
 find that the head is like that of the ass, that the 
 ears are long, the tail is tufted at the end, the feet 
 are small, and the voice is an unmistakable bray; 
 these are all points of similarity to the ass ; but, 
 on the other hand, the barrel of the body and tlie 
 cut of the neck are much more like those of the 
 mare. Then, if you look at the hinny, — the result 
 of the union of the stallion and the she-ass, then 
 you find it is the horse that has the predominance ; 
 that the head is more like that of the horse, the 
 ears are shorter, the legs coarser, and the type is 
 altogether altered ; while the voice, instead of being 
 a bray, is the ordinary neigh of the horse. Here, 
 you see, is a most curious thing : you take exactly 
 the same elements, ass and horse, but you combine 
 the sexes in a different manner, and the result is 
 modified accordingly. You have in this case, how- 
 ever, a result which is not general and universal — 
 there is usually an important preponderance, but 
 not always on the same side. 
 
 Here, then, is one intelligible, and, perhaps, 
 necessary cause of variation : the fact, that there 
 are two sexes sharing in the production of the off- 
 spring, and that the share taken by each is differ- 
 ent and variable, not only for each combination, 
 
402 THE CAUSES OF THE XI 
 
 but also for di£ferent members of the same 
 family. 
 
 Secondly, there is a variation, to a certain ex- 
 tent — though, in all probability, the influence of 
 this cause has been very much exaggerated — but 
 there is no doubt that variation is produced, to a 
 certain extent, by what are commonly known as 
 external conditions, — such as temperature, food, 
 warmth, and moisture. In the long run, every 
 variation depends, in some sense, upon external 
 conditions, seeing that everything has a cause of 
 its own. I use the term " external conditions " 
 now in the sense in which it is ordinarily em- 
 ployed : certain it is, that external conditions have 
 a definite effect. You may take a plant which has 
 single flowers, and by dealing with the soil, and 
 nourishment, and so on, you may by and by con- 
 vert single flowers into double flowers, and make 
 thorns shoot out into branches. You may thicken 
 or make various modifications in the shape of the 
 fruit. In animals, too, you may produce analogous 
 changes in this way, as in the case of that deep 
 bronze colour which peisons rarely lose after 
 having passed any length of time in tropical coun- 
 tries. You may also alter the development of the 
 muscles very much, by dint of training ; all the 
 world knows that exercise has a great effect in this 
 way ; we always expect to find the arm of a black- 
 smith hard and wiry, and possessing a large 
 development of the brachial muscles. No doubt 
 
XI PHENOMENA OF ORGANIC NATURE 403 
 
 training, which is one of the forms of external 
 conditions, converts what are originally only in- 
 structions, teachings, into habits, or, in other 
 words, into organisations, to a great extent ; but 
 this second cause of variation cannot be considered 
 to be by any means a large one. The third cause 
 that I have to mention, however, is a very exten- 
 sive one. It is one that, for want of a better 
 name, has been called " spontaneous variation " ; 
 which means that when we do not know anything 
 about the cause of phenomena, we call it spon- 
 taneous. In the orderly chain of causes and 
 effects in this world, there are very few things of 
 which it can be said with truth that they are 
 spontaneous. Certainly not in these physical 
 matters — in these there is nothing of the kind — ■ 
 everything depends on previous conditions. But 
 when we cannot trace the cause of phenomena, 
 we call them spontaneous. 
 
 Of these variations, multitudinous as they are, 
 but little is known with perfect accuracy. I will 
 mention to you some two or three cases, because 
 they are very remarkable in themselves, and also 
 because I shall want to use them afterwards. 
 Reaumur, a famous French naturalist, a great 
 many years ago, in an essay which he wrote upon 
 the art of hatching chickens — which was indeed a 
 very curious essay — had occasion to speak of 
 variations and monstrosities. One very remark- 
 able case had come under his notice of a variation 
 
404 THE CAUSES OF THE XI 
 
 in the form of a human member, m the person 
 of a Maltese, of the name of Gratio Kelleia, who 
 was born with six fingers upon each hand, and the 
 like number of toes to each of his feet. That 
 was a case of spontaneous variation. Nobody- 
 knows why he was born with that number of 
 fingers and toes, and as we don't know, we call it 
 a case of "spontaneous" variation. There is 
 another remarkable case also. I select these, 
 because they happen to have been observed and 
 noted very carefully at the time. It frequently 
 happens that a variation occurs, biit the persons 
 who notice it do not take any care in noting down 
 the particulars, until at length, when inquiries 
 come to be made, the exact circumstances are 
 forgotten ; and hence, multitudinous as may be 
 such " spontaneous " variations, it is exceedingly 
 difficult to get at the origin of them. 
 
 The second case is one of which you may find 
 the whole details in the '' Philosophical Transac- 
 tions " for the year 1813, in a paper communicated 
 by Colonel Humphrey to the President of the 
 Royal Society — " On a new Variety in the Breed 
 of Sheep," giving an account of a very remarkable 
 breed of sheep, which at one time was well known 
 in the northern states of America, and which 
 went by the name of the Ancon or the Otter 
 breed of sheep. In the year 1791, there was a 
 farmer of the name of Seth Wright in Massa- 
 chusetts, who had a flock of sheep, consisting of a 
 
XI PHENOMENA OF ORGANIC NATURE 405 
 
 ram and, I think, of some twelve or thirteen ewes. 
 Of this flock of ewes, one at the breeding-time 
 bore a lamb which was very singularly formed ; it 
 had a very long body, very short legs, and those 
 legs were bowed. I will tell you by and by how 
 this singidar variation in the 'breed of sheep came 
 to be noted, and to have the prominence that it 
 now has. For the present, I mention only these 
 two cases ; but the extent of variation in the breed 
 of animals is perfectly obvious to any one who has 
 studied natural history with ordinary attention, or 
 to any person who compares animals with others 
 of the same kind. It is strictly true that there 
 are never any two specimens which are exactly 
 alike ; however similar, they will always differ in 
 some certain particular. 
 
 Now let us go back to Atavism — to the here- 
 ditary tendency I spoke of. What will come of a 
 variation when you breed from it, when Atavism 
 comes, if I may say so, to intersect variation ? 
 The two cases of which I have mentioned the 
 history give a most excellent illustration of what 
 occurs. Gratio Kelleia, the Maltese, married when 
 he was twenty-two years of age, and, as I suppose 
 there were no six-fingered ladies in Malta, he 
 married an ordinary five-fingered person. The 
 result of that marriage was four children; the 
 first, who was christened Salvator, had six fingres 
 and six toes, like his father; the second was 
 George, who had five fingers and toes, but one of 
 
406 THE CAUSES OF THE xi 
 
 them was deformed, showing a tendency to varia- 
 tion ; the third was Andrfe ; he had five fingers 
 and five toes, quite perfect ; the fourth was a girl, 
 Marie ; she had five fingers and five toes, but her 
 thumbs were deformed, showing a tendency toward 
 the sixth. 
 
 These children grew up, and when they came to 
 adult years, they all married, and of course it 
 happened that they all married five-fingered and 
 five-toed persons. Now let us see what were the 
 results. Salvator had four children ; they were 
 two boys, a girl, and another boy ; the first two 
 boys and the girl were six-fingered and six-toed 
 like their grandfather ; the fourth boy had only 
 five fingers and five toes. George had only four 
 children ; there were two girls with six fingers 
 and six toes ; there was one girl with six fingers 
 and five toes on the right side, and five fingers 
 and five toes on the left side, so that she was half 
 and half. The last, a boy, had five fingers and 
 five toes. The third, Andr^, you will recollect, 
 was perfectly well-formed, and he had many 
 children whose hands and feet were all regularly 
 developed. Marie, the last, who, of course, mar- 
 ried a man who had only five fingsrs, had four 
 children ; the first, a boy, was born with six toes, 
 but the other three were normal. 
 
 Now observe what very extraordinary phenomena 
 are presented here. You have an accidental varia- 
 tion giving rise to what you may call a monstrosity ; 
 
XI PHENOMENA OF ORGANIC NATURE 407 
 
 you have that monstrosity or variation diluted 
 in the first instance by an admixture with 
 a female of normal construction, and you would 
 naturally expect that, in the results of such an 
 union, the monstrosity, if repeated, would be in 
 equal proportion with the normal type ; that is to 
 say, that the children would be half and half, some 
 taking the peculiarity of the father, and the others 
 being of the purely normal type of the mother ; 
 but you see we have a great preponderance of the 
 abnormal type. Well, this comes to be mixed once 
 more with the pure, the normal type, and the ab- 
 normal is again produced in large proportion, not- 
 withstanding the second dilution. Now what 
 would have happened if these abnormal types had 
 intermarried with each other ; that is to say, sup- 
 pose the two boys of Salvator had taken it into 
 their heads to marry their first cousins, the two 
 first girls of George, their uncle ? You Avill remem- 
 ber that these are all of the abnormal type of their 
 grandfather. The result would probably have been, 
 that their ofifspring would have been in every case 
 a further development of that abnormal type. You 
 see it is only in the fourth, in the person of Marie, 
 that the tendency, when it appears but slightly in 
 the second generation, is washed oxit in the third, 
 while the progeny of Andrfe, who escaped in the 
 first instance, escape altogether. 
 
 We have in this case a good example of nature's 
 tendency to the perpetuation of a variation. Here 
 
 66 
 
408 THE CAUSES OF THE XI 
 
 it is certainly a variation which carried with it no 
 use or benefit ; and yet you see the tendency to 
 perpetuation may be so strong, that, notwithstand- 
 ing a great admixture of pure blood, the variety 
 continues itself up to the third generation, which 
 is largely marked with it. In this case, as I have 
 said, there was no means of the second generation 
 intermarrying with any but five-fingered persons, 
 and the question naturally suggests itself, What 
 would have been the result of such marriage ? 
 Reaumur narrates this case only as far as the third 
 generation. Certainly it would have been an ex- 
 ceedingly curious thing if we could have traced this 
 matter any further ; had the cousins intermarried, 
 a six-fingered variety of the human race might 
 have been set up. 
 
 To show you that this supposition is by no means 
 an unreasonable one, let me now point out what 
 took place in the case of Seth Wright's sheep, 
 where it happened to be a matter of moment to 
 him to obtain a breed or raise a flock of sheep like 
 that accidental variety that I have described — and 
 I will tell you why. In that part of Massachusetts 
 where Seth Wright was living, the fields were 
 separated by fences, and the sheep, which were 
 very active and robust, would roam abroad, and 
 without much difficulty jump over these fences in- 
 to other people's farms. As a matter of course, 
 this exuberant activity on the part of the sheep 
 constantly gave rise to all sorts of quarrels, bicker- 
 
XI PHENOMENA OF OEGANIC NATURE 409 
 
 ings, and contentions among the farmers of the 
 neighbourhood ; so it occurred to Seth Wright, 
 •who was, like his successors, more or less 'cute, that 
 if he could get a stock of sheep like those with the 
 bandy legs, they would not be able to jump over 
 the fences so readily ; and he acted upon that idea. 
 He killed his old ram, and as soon as the young 
 one an'ived at maturity, he bred altogether from 
 it. The result was even more striking than in the 
 human experiment which I mentioned just now. 
 Colonel Humphreys testifies that it always hap- 
 pened that the offspring were either pure Ancons 
 or pure ordinary sheep ; that in no case was there 
 any mixing of the Ancons with the others. In 
 consequence of this, in the course of a very few 
 years, the farmer was able to get a very consider- 
 able flock of this variety, and a large number of 
 them were spread throughout Massachusetts. Most 
 unfortunately, however — I suppose it was because 
 they were so common — nobody took enough notice 
 of them to preserve their skeletons ; and although 
 Colonel Humphreys states that he sent a skeleton 
 to the President of the Royal Society at the same 
 time that he forwarded his paper, I am afraid 
 that the variety has entirely disappeared ; for a 
 short time after these sheep had become prevalent 
 in that district, the Merino sheep were introduced ; 
 and as their wool was much more valuable, and as 
 they were a quiet race of sheep, and showed no 
 tendency to trespass or jump over fences, the Otter 
 
410 THE CAUSES OF THE xi 
 
 breed of sheep, the wool of which was inferior to 
 that of the Merino, was gradually allowed to 
 die out. 
 
 You see that these facts illustrate perfectly well 
 what may be done if you take care to breed from 
 stocks that are similar to each other. After having 
 got a variation, if, by crossing a variation with the 
 original stock, you multiply that variation, and then 
 take care to keep that variation distinct from the 
 original stock, and make them breed together, — 
 then you may almost certainly produce a race whose 
 tendency to continue the variation is exceedingly 
 strong. 
 
 This is what is called " selection " ; and it is by 
 exactly the same process as that by which Seth 
 Wright bred his Ancon sheep, that our breeds of 
 cattle, dogs, and fowls are obtained. There are 
 some possibilities of exception, but still, speaking 
 broadly, I may say that this is the way in which 
 all our varied races of domestic animals have arisen ; 
 and you must understand that it is not one 
 peculiarity or one characteristic alone in which 
 animals may vary. There is not a single peculiarity 
 or characteristic of any kind, bodily or mental, in 
 which offspring may not vary to a certain extent 
 from the parent and other animals. 
 
 Among ourselves this is well known The sim- 
 plest physical peculiarity is mostly reproduced. I 
 know a case of a woman who has the lobe of one 
 of her ears a little flattened. An ordinary obser- 
 
SI PHENOMENA OF ORGANIC NATURE 411 
 
 ver might scarcely notice it, and yet every one of 
 her children has an approximation to the same 
 peculiarity to some extent. If you look at the 
 other extreme, too, the gravest diseases, such as 
 gout, scrofula, and consumption, may be handed 
 down with just the same certainty and persistence 
 as we noticed in the perpetuation of the bandy 
 legs of the Ancon sheep. 
 
 However, these facts are best illustrated in 
 animals, and the extent of the variation, as is well 
 known, is very remarkable in dogs. For example, 
 there are some dogs very much smaller than others ; 
 indeed, the variation is so enormous that probably 
 the smallest dog would be about the size of the 
 head of the largest ; there are very great variations 
 in the structural forms not only of the skeleton 
 but also in the shape of the skull, and in the pro- 
 portions of the face and the disposition of the teeth. 
 
 The Pointer, the Retriever, Bulldog, and the 
 Terrier differ very greatly, and yet there is every 
 reason to believe that every one of these races 
 has arisen from the same source, — that all the 
 most important races have arisen by this selective 
 breeding from accidental variation. 
 
 A still more striking case of what may be done 
 by selective breeding, and it is a better case, be- 
 cause there is no chance of that partial infusion of 
 error to which I alluded, has been studied very 
 carefully by Mr. Darwin, — the case of the domestic 
 pigeons. I dare say there may be some among you 
 
412 THE CAUSES OF THE XI 
 
 who may be pigeon fanciers, and I wish you to 
 understand that in approaching the subject, I would 
 speak with all humility and hesitation, as I regret 
 to say that I am not a pigeon fancier. I know it 
 is a great art and mystery, and a thing upon which 
 a man must not speak lightly ; but I shall en- 
 deavour, as far as my understanding goes, to give 
 you a summary of the published and unpublished 
 information which I have gained from Mr. Darwin. 
 Among the enormous variety, — I believe there 
 are somewhere about a hundred and fifty kinds of 
 pigeons, — there are four kinds which may be se- 
 lected as representing the extremest divergences 
 of one kind from another. Their names are the 
 Carrier, the Pouter, the Fantail, and the Tumbler. 
 In these large diagrams that I have here they are 
 each represented in their relative sizes to each 
 other. This first one is the Carrier; you will 
 notice this large excrescence on its beak ; it has a 
 comparatively small head ; there is a bare space 
 round the eyes ; it has a long neck, a very long 
 beak, very strong legs, large feet, long wings, and 
 so on. The second one is the Pouter, a very large 
 bird, with very long legs and beak. It is called 
 the Pouter because it is in the habit of causing- its 
 gullet to swell up by inflating it with air. I should 
 tell you that all pigeons have a tendency to do this 
 at times, but in the Pouter it is carried to an 
 enormous extent. The birds appear to be quite 
 proud of their power of swelling and puffing them- 
 
XI PHENOMENA OF ORGANIC NATURE 413 
 
 selves out in this way ; and I think it is about as 
 droll a sight as you can well see to look at a cage 
 full of these pigeons puffing and blowing them- 
 selves out in this ridiculous manner. 
 
 This diagram is a representation of the third 
 kind I mentioned — the Fantail. It is, you see, a 
 small bird, with exceedingly small legs and a very 
 small beak. It is most curiously distinguished by 
 the size and extent of its tail, which, instead of 
 containing twelve feathers, may have many more, 
 — say thirty, or even more — I believe there are 
 some with as many as forty-two. This bird has a 
 curious habit of spreading out the feathers of its 
 tail in such a way that they reach forward and 
 touch its head ; and if this can be accomplished, I 
 believe it is looked upon as a point of great beauty. 
 
 But here is the last great variety, — the Tumbler; 
 and of that great variety, one of the principal 
 kinds, and one most prized, is the specimen repre- 
 sented here— the short-faced Tumbler. Its beak, 
 you see, is reduced to a mere nothing. Just com- 
 pare the beak of this one and that of the first one, 
 the Carrier — I believe the orthodox comparison of 
 the head and beak of a thoroughly well-bred Tum- 
 bler is to stick an oat into a cherry, and that will 
 give you the proper relative proportions of the 
 beak and head. The feet and legs are exceedingly 
 small, and the bird appears to be quite a dwarf 
 when placed side by side with this great Carrier. 
 
 These are differences enough in regard to their 
 
414 THE CAUSES OF THE xi 
 
 external appearance ; but these differences are by 
 no means the whole or even the most important of 
 the differences which obtain between these birds. 
 There is hardly a single point of their structure 
 which has not become more or less altered ; and to 
 give you an idea of how extensive these alterations 
 are, I have here some very good skeletons, for which 
 I am indebted to my friend, Mr. Tegetmeier, a 
 great authority in these matters ; by means of 
 which, if you examine them by and by, you will 
 be able to see the enormous difference in their 
 bony structures. 
 
 I had the privilege, some time ago, of access to 
 some important MSS, of Mr. Darwin, who, I may 
 tell you, has taken very great pains and spent 
 much valuable time and attention on the investi- 
 gation of these variations, and getting together all 
 the facts that bear upon them. I obtained from 
 these MSS. the following summary of the differ- 
 ences between the domestic breeds of pigeons ; 
 that is to say, a notification of the various points 
 in which their organisation differs. In the first 
 place, the back of the skull may differ a good deal, 
 and the development of the bones of the face may 
 vary a great deal ; the back varies a good deal ; 
 the shape of the lower jaw varies ; the tongue 
 varies very greatly, not only in correlation to the 
 length and size of the beak, but it seems also to 
 have a kind of independent variation of its own. 
 Then the amount of naked skin round the eyes, 
 
XI PHENOMENA OF OEGANIC NATURE 415 
 
 and at the base of the beak, may vary enormously ; 
 so may the length of the eyelids, the shape of the 
 nostrils, and the length of the neck. I have al- 
 ready noticed the habit of blowing out the gullet, 
 so remarkable in the Pouter, and comparatively so 
 in the others. There are great diflferences, too, in 
 the size of the female and the male, the shape of 
 the body, the number and width of the processes 
 of the ribs, the development of the ribs, and the 
 size, shape, and development of the breastbone. 
 We may notice, too — and I mention the fact be- 
 cause it has been disputed by what is assumed to 
 be high authority, — the variation in the number 
 of the sacral vertebrae. The number of these 
 varies from eleven to fourteen, and that without 
 any diminution in the number of the vertebrae of 
 the back or of the tail. Then the number and 
 position of the tail-feathers may vary enormously, 
 and so may the number of the primary and second- 
 ary feathers of the wings. Again, the length of 
 the feet and of the beak, — although they have no 
 relation to each other, yet appear to go together, — 
 that is, you have a long beak wherever you have 
 long feet. There are differences also in the 
 periods of the acquirement of the perfect plum- 
 age — the size and shape of the eggs — the nature 
 of flight, and the powers of flight — so-called 
 '■ homing " birds having enormous flying powers ; ^ 
 
 ^ The "Carrier" I learn from Mr. Tegetmeier, does not 
 carry ; a high-bred bird of this breed being but a poor flier. 
 
416 PHENOMENA OF ORGANIC NATURE xi 
 
 while, on the other hand, the little Tumbler is so 
 called because of its extraordinary faculty of turn^ 
 ing head over heels in the air, instead of pursuing 
 a direct course. And, lastly, the dispositions and 
 voices of the birds may vary. Thus the case of 
 the pigeons shows you that there is hardly a 
 single particular — whether of instinct, or habit, 
 or bony structure, or of plumage — of either the 
 internal economy or the external shape, in which 
 some variation or change may not take place, 
 which, by selective breeding, may become perpetu- 
 ated, and form the foundation of, and give rise to, 
 a new race. 
 
 If you carry in your mind's eye these four 
 varieties of pigeons, you will bear with you as 
 good a notion as you can have, perhaps, of the 
 enormous extent to which a deviation from a 
 primitive type may be carried by means of this 
 process of selective breeding. 
 
 The birds which fly long distances, and come home — ' ' homing " 
 birds — and are conseq^uently used as carriers, are not "carriers" 
 in the fancy sense. 
 
THE CONDITIONS OF EXISTENCE AS AFFECTING 
 THE PERPETUATION OF LIVING BEINGS. 
 
 In the last Lecture I endeavoured to prove to 
 you that, while, as a general rule, organic beings 
 tend to reproduce their kind, there is in them, 
 also, a constantly recurring tendency to vary — to 
 vary to a greater or to a less extent. Such a 
 variety, I pointed out to you, might arise from 
 causes which we do not understand ; we there- 
 fore called it spontaneous ; and it might come 
 into existence as a definite and marked thing, 
 without any gradations between itself and the 
 form which preceded it. I further pointed out, 
 that such a variety having once arisen, might be 
 perpetuated to some extent, and indeed to a very 
 marked extent, without any direct interference, or 
 without any exercise of that process which we 
 called selection. And then I stated further, that 
 by such selection, when exercised artificially — if 
 you took care to breed only from those forms 
 which presented the same peculiarities of any 
 
418 THE CAUSES OF THE xi 
 
 variety whicli had arisen in this manner — the 
 variation might be perpetuated, as far as we can 
 see, indefinitely. 
 
 The next question, and it is an important one 
 for us, is this : Is there any Hmit to the amount 
 of variation from the primitive stock which can 
 be produced by this process of selective breeding ? 
 In considering this question, it will be useful to 
 class the characteristics, in respect of which 
 organic beings vary, under two heads : we may 
 consider structural characteristics, and we may 
 consider physiological characteristics. 
 
 In the first place, as regards structural charac- 
 teristics, I endeavoured to show you, by the 
 skeletons which I had upon the table, and by 
 reference to a great many well-ascertained facts, 
 that the different breeds of Pigeons, the Carriers, 
 Pouters, and Tumblers, might vary in any of their 
 internal and important structural characters to a 
 very great degree ; not only might there be changes 
 in the proportions of the skull, and the characters 
 of the feet and beaks, and so on ; but that there 
 misfht be an absolute difference in the number of 
 the vertebras of the back, as in the sacral vertebrae 
 of the Pouter ; and so great is the extent of the 
 variation in these and similar characters that I 
 pointed out to you, by reference to the skeletons 
 and the diagrams, that these extreme varieties 
 may absolutely differ more from one another in 
 their structural characters than do what naturalists 
 
XI PHENOMENA OF ORGANIC NATURE 419 
 
 call distinct Species of pigeons ; that is to say, 
 that they differ so much in structure that there is 
 a greater difference between the Pouter and the 
 Tumbler than there is between such wild and dis- 
 tinct forms as the Rock Pigeon or the Ring Pigeon, 
 or the Ring Pigeon and the Stock Dove ; and 
 indeed the differences are of greater value than 
 this, for the structural differences between these 
 domesticated pigeons are such as would be ad- 
 mitted by a naturalist, supposing he knew nothing 
 at all about their origin, to entitle them to con- 
 stitute even distinct genera. 
 
 As I have used this term Species, and shall prob- 
 ably use it a good deal, I had betterperhaps devote 
 a word or two to explaining what I mean by it. 
 
 Animals and plants are divided into groups, 
 which become gradually smaller, beginning with 
 a Kingdom, which is divided into Sub-Kingdoms ; 
 then come the smaller divisions called Provinces ; 
 and so on from a Province to a Class, from a 
 Class to an Order, from Orders to Families, 
 and from these to Genera, until we come at 
 length to 'the smallest groups of animals which 
 can be defined one from the other by constant 
 characters, which are not sexual ; and these are 
 what naturalists call Species in practice, whatever 
 they may do in theory. 
 
 If, in a state of nature, you find any two groups 
 of living beings, Avhich are separated one from the 
 other by some constantly-recurring characteristic. 
 
420 THE CAUSES OF THE xi 
 
 I don't care how slight and trivial, so long as it is 
 defined and constant, and does not depend on 
 sexual peculiarities, then all naturalists agree in 
 calling them two species ; that is what is meant 
 by the use of the word species — that is to say, it 
 is, for the practical naturahst, a mere question of 
 structural differences.' 
 
 We have seen now — to repeat this point once 
 more, and it is very essential that we should 
 rightly understand it — we have seen that breeds, 
 known to have been derived from a common stock 
 by selection, may be as different in their structure 
 from the original stock as species may be distinct 
 from each other. 
 
 But is the like true of the physiological charac- 
 teristics of animals ? Do the physiological differ- 
 ences of varieties amount in degree to those 
 observed between forms wliich naturalists call 
 distinct species ? This is a most important point 
 for us to consider. 
 
 As regards the great majority of physiological 
 characteristics, there is no doubt that they are 
 capable of being developed, increased, and modi- 
 fied by selection. 
 
 There is no doubt that breeds may be made as 
 different as species in many physiological charac- 
 ters. I have already pointed out to you very 
 
 ^ I lay stress here on the practical signification of " Species." 
 Whether a physiological test hetween species exist or not, it is 
 hardly ever applicable by the practical naturalist. 
 
XI PHENOMENA OF ORGANIC NATURE 421 
 
 briefly the diflferent habits of the breeds of 
 Pigeons, all of which depend upon their physio- 
 logical peculiarities — as the peculiar habit of 
 tumbling, in the Tumbler — the peculiarities of 
 flight, in the " homing " birds — the strange habi'o 
 of spreading out the tail, and walking in a peculiar 
 fashion, in the Fantail — and, lastly, the habit of 
 blowing out the gullet, so characteristic of the 
 Pouter. These are all due to physiological modifi- 
 cations, and in all these respects these birds differ 
 as much from each other as any two ordinary 
 species do. 
 
 So with Dogs in their habits and instincts. It 
 is a physiological peculiarity which leads the 
 Greyhound to chase its prey by sight — that enables 
 the Beagle to track it by the scent — that impels 
 the Terrier to its rat-hunting propensity — and 
 that leads the Retriever to its habit of retrieving. 
 These habits and instincts are all the results of 
 physiological differences and peculiarities, which 
 have been developed from a common stock, at 
 least there is every reason to believe so. But it 
 is a most lingular circumstance, that while you 
 may run through almost the whole series of 
 physiological processes, without finding a check to 
 your argument, you come at last to a point where 
 you do find a check, and that is in the reproduc- 
 tive processes. For there is a most singular cir- 
 cumstance in respect to natural species — at least 
 about some of them — and it would be sufficient 
 
422 THE CAUSES OF THE II 
 
 for the purposes of this argument if it were true 
 of only one of them, but there is, in fact, a great 
 number of such cases — and that is, that, similar 
 as they may appear to be to mere races or breeds, 
 they present a marked peculiarity in' the repro- 
 ductive process. If you breed from the male and 
 female of the same race, you of course have off- 
 spring of the like kind, and if you make the off- 
 spring breed together, you obtain the same result, 
 and if you breed from these again, you will still 
 have the same kind of offspring ; there is no 
 check. But if you take members of two distinct 
 species, however similar they may be to each other, 
 and make them breed together, you will find a 
 check, with some modifications and exceptions, 
 however, which I shall speak of presently. If 
 you cross two such species with each other, then 
 — although you may get offspring in the case of 
 the first cross, yet, if you attempt to breed from 
 the products of that crossing, which are what are 
 called Hybrids — that is, if you couple a male 
 and a female hybrid — then the result is that in 
 ninety-nine cases out of a hundred you will 
 get no offspring at all ; there will be no result 
 whatsoever. 
 
 The reason of this is quite obvious in some 
 cases ; the male hybrids, although possessing all 
 the external appearances and characteristics of 
 perfect animals, are physiologically imperfect and 
 deficient in the structural parts of the reproductive 
 
XI PHENOMENA OF ORGANIC NATURE 423 
 
 elements necessary to generation. It is said to 
 be invariably the case with the male mule, the 
 cross between the Ass and the Mare ; and hence 
 it is, that, although crossing the Horse with the 
 Ass is easy enough, and is constantly done, as far 
 as I am aware, if you take two mules, a male and 
 a female, and endeavour to breed from them, you 
 get no offspring whatever ; no generation will take 
 place. This is what is called the sterility of the 
 hybrids between two distinct species. 
 
 You see that this is a very extraordinary cir- 
 cumstance ; one does not see why it should be. 
 The common teleological explanation is, that it is 
 to prevent the impurity of the blood resulting 
 from the crossing of one species with another, but 
 you see it does not in reality do anything of the 
 kind. There is nothing in this fact that hybrids 
 cannot breed with each other, to establish such a 
 theory ; there is nothing to prevent the Horse 
 breeding with the Ass, or the Ass with the Horse. 
 So that this explanation breaks down, as a great 
 many explanations of this kind do, that are only 
 founded on mere assumptions. 
 
 Thus you see that there is a great difference 
 between " mongrels," which are crosses between 
 distinct races, and " hybrids," which are crosses 
 between distinct species. The mongrels are, so 
 far as we know, fertile with one another. But 
 between species, in many cases, you caimot suc- 
 ceed in obtaining even the first cross ; at any rate 
 
 66 
 
424 THE CAUSES OF THE XI 
 
 it is quite certain that the hybrids are often abso- 
 lutely infertile one with another. 
 
 Here is a feature, then, great or small as it may 
 be, which distinguishes natural species of animals. 
 Can we find any approximation to this in the 
 different races known to be produced by selective 
 breeding from a common stock ? Up to the 
 present time the answer to that question is abso- 
 lutely a negative one. As far as we know at 
 present, there is nothing approximating to this 
 check. In crossing the breeds between the Fan- 
 tail and the Pouter, the Carrier and the Tumbler, 
 or any other variety or race you may name — so far 
 as we know at present — there is no difficulty in 
 breeding together the mongrels. Take the Carrier 
 and the Fantail, for instance, and let them repre- 
 sent the Horse and the Ass in the case of distinct 
 species ; then you have, as the result of their breed- 
 ing, the Carrier-Fantail mongrel, — we will say the 
 male and female mongrel, — and, as far as we know, 
 these two when crossed would not be less fertile 
 than the original cross, or than Carrier with Car- 
 rier. Here, you see, is a physiological contrast 
 between the races produced by selective modifica- 
 tion and natural species. I shall inquire into the 
 value of this fact, and of some modifying circum- 
 stances by and by ; for the present I merely put 
 it broadly before you. 
 
 But while considering this question of the limi- 
 tations of species, a word must be said about what 
 
XI PHENOMENA OF ORGANIC NATURE 425 
 
 is called Recurrence — the tendency of races 
 which have been developed by selective breeding 
 from varieties to return to their primitive type. 
 This is supposed by many to put an absohite limit 
 to the extent of selective and all other variations. 
 People say, " It is all very well to talk about pro- 
 ducing these different races, but you know very 
 well that if you turned all these birds wild, these 
 Pouters, and Carriers, and so on, they would all re- 
 turn to their primitive stock." This is very com- 
 monly assumed to be a fact, and it is an argument 
 that is commonly brought forward as conclusive ; 
 but if you will take the trouble to inquire into it 
 rather closely, I think you will find that it is not 
 worth very much. The first question of course is, 
 Do they thus return to the primitive stock ? And 
 commonly as the thing is assumed and accepted, 
 it is extremely difficult to get anything like good 
 evidence of it. It is constantly said, for example, 
 that if domesticated Horses are turned wild, as 
 they have been in some parts of Asia Minor and 
 South America, that they return at once to the 
 primitive stock from which they were bred. But 
 the first answer that you make to this assumption 
 is, to ask who knows what the primitive stock 
 was ; and the second answer is, that in that case 
 the wild Horses of Asia Minor ought to be exactly 
 like the wild Horses of South America. If they 
 are both like the same thing, they ought mani- 
 festly to be like each other ! The best authorities, 
 
426 THE CAUSES OF THE XT 
 
 however, tell you that it is quite different. The 
 wild Horse of Asia is said to be of a dun colour, 
 with a largish head, and a great many other pe- 
 culiarities ; while the best authorities on the wild 
 Horses of South America tell you that there is no 
 similarity between their wild Horses and those of 
 Asia Minor; the cut of their heads is very differ- 
 ent, and they are commonly chestnut or bay- 
 coloured. It is quite clear, therefore, that as by 
 these facts there ought to have been two primitive 
 stocks, they go for nothing in support of the as- 
 sumption that races recur to one primitive stock, 
 and so far as this evidence is concerned, it falls to 
 the ground. 
 
 Suppose for a moment that it were so, and 
 that domesticated races, when turned wild, did 
 return to some common condition, I cannot see 
 that this would prove much more than that simi- 
 lar conditions are likely to produce similar results ; 
 and that when you take back domesticated ani- 
 mals into what we call natural conditions, you do 
 exactly the same thing as if you carefully undid 
 all the worlc you had gone through, for the pur- 
 pose of bringing the animal from its wild to its 
 domesticated state. I do not see anything very 
 wonderful in the fact, if it took all that trouble to 
 get it from a wild state, that it should go back in- 
 to its original state as soon as you removed the 
 conditions which produced the variation to the 
 domesticated form. There is an important fact, 
 
XI PHENOMENA OF ORGANIC NATURE 427 
 
 however, forcibly brought forward by Mr. Darwin, 
 which has been noticed in connection with the breed- 
 ing of domesticated pigeons ; and it is, that how- 
 ever different these breeds of pigeons may be from 
 each other, and we have abeady noticed the great 
 differences in these breeds, that if, among any of 
 those variations, you chance to have a blue pigeon 
 turn up, it will be sure to have the black bars 
 across the wings, which are characteristic of the 
 original wild stock, the Rock Pigeon. 
 
 Now, this is certainly a very remarkable cir- 
 cumstance ; but I do not see myself how it tells 
 very strongly either one way or the other. I 
 think, in fact, that this argument in favour of re- 
 currence to the primitive type might prove a great 
 deal too much for those who so constantly bring it 
 forward. For example, Mr. Darwin has very for- 
 cibly urged, that nothing is commoner than if you 
 examine a dun horse — and I had an opportunity 
 of verifying this illustration lately while in the 
 islands of the West Highlands, where there are a 
 great many dun horses — to find that horse exhibit 
 a long black stripe down his back, very often 
 stripes on his shoulder, and very often stripes on 
 his legs. I, myself, saw a pony of this description 
 a short time ago, in a baker's cart, near Rothesay, 
 in Bute : it had the long stripe down the back, 
 and stripes on the shoulders and legs, just like 
 those of the Ass, the Quagga, and the Zebra. 
 Now, if we interpret the theory of recurrence as 
 
428 THE CAUSES OF THE XI 
 
 applied to this case, might it not be said that here 
 was a case of a variation exhibiting the characters 
 and conditions of an animal occupying something 
 like an intermediate position between the Horse, 
 the Ass, the Quagga, and the Zebra, and from 
 which these had been developed ? In the same 
 way with regard even to Man. Every anatomist 
 will tell you that there is nothing commoner, m 
 dissecting the human body, than to meet with 
 what are called m^uscular variations — that is, if 
 you dissect two bodies very carefully, you will prob- 
 ably find that the modes of attachment and in- 
 sertion of the muscles are not exactly the same in 
 both, there being great peculiarities in the mode 
 in which the muscles are arranged ; and it is very 
 singular, that in some dissections of the human 
 body you will come upon arrangements of the 
 muscles very similar indeed to the same parts 
 in the Apes. Is the conclusion in that case 
 to be, that this is like the black bars in the case 
 of the Pigeon, and that it indicates a recurrence 
 to the primitive type from which the animals 
 have been probably developed ? Truly, I think 
 that the opponents of modification and variation 
 had better leave the argument of recurrence 
 alone, or it may prove altogether too strong for 
 them. 
 
 To sum up, — the evidence as far as we have 
 gone is against the argument as to any limit to 
 divergences, so far as structure is concerned ; and 
 
SI I'UJiJNOJW.JiJSA OJ>' OKGANIC STSTTJKE 429 
 
 in favour of a physiological limitation. By selec- 
 tive breeding we can produce structural diver- 
 gences as great as those of species, but we cannot 
 produce equal physiological divergences. For the 
 present I leave the question there. 
 
 Now, the next problem that lies before us — and 
 it is an extremely important one — is this : Does 
 this selective breeding occur in nature ? Because, 
 if there is no proof of it, all that I have been tell- 
 ing you goes for nothing in accounting for the 
 origin of species. Are natural causes competent 
 to play the part of selection in perpetuating 
 varieties ? Here we labour under very great 
 difficulties. In the last lecture I had occasion to 
 point out to you the extreme difficulty of obtain- 
 ing evidence even of the first origin of those 
 varieties which we know to have occurred in 
 domesticated animals. I told you, that almost al- 
 ways the origin of these varieties is overlooked, so 
 that I could only produce two or three cases, as 
 that of Gratio Kelleia and of the Ancon sheep. 
 People forget, or do not take notice of them until 
 they come to have a prominence ; and if that is 
 true of artificial cases, under our own eyes, and in 
 animals in our own care, how much more difficult 
 it must be to have at first hand good evidence of 
 the origin of varieties in nature ! Indeed, I do 
 not know that it is possible by direct evidence to 
 prove the origin of a variety in nature, or to prove 
 selective breeding ; but I will tell you what we 
 
430 THE CAUSES OF THE XI 
 
 can prove — and this comes to the same thing — 
 that varieties exist in nature within the limits of 
 species, and, -what is more, that when a variety has 
 come into existence in nature, there are natural 
 causes and conditions, which are amply competent 
 to play the part of a selective breeder ; and al- 
 though that is not quite the evidence that one 
 would like to have — though it is not direct testi- 
 mony — yet it is exceeding good and exceedingly 
 powerful evidence in its way. 
 
 As to the first point, of varieties existing 
 among natural species, I might appeal to the 
 universal experience of every naturalist, and of 
 any person who has ever turned any attention 
 at all to the characteristics of plants and animals 
 in a state of nature ; but I may as well take 
 a few definite cases, and I will begin with Man 
 himself. 
 
 I am one of those who believe that, at present, 
 there is no evidence whatever for saying, that man- 
 kind sprang originally from any more than a single 
 pair ; I must say, that I cannot see any good 
 ground whatever, or even any tenable sort of evi- 
 dence, for believing that there is more than one 
 species of Man. , Nevertheless, as you know, just 
 as there are numbers of varieties in animals, so 
 there are remarkable varieties of men. I speak 
 not merely of those broad and distinct variations 
 which you see at a glance. Everybody, of course, 
 knows the difference between a Negro and a white 
 
XI PHENOMENA OF ORGANIC NATURE 431 
 
 man, and can tell a Chinaman from an English- 
 man. They each have pecuhar characteristics of 
 colour and physiognomy ; but you must recollect 
 that the characters of these races go very far 
 deeper — they extend to the bony structure, and to 
 the characters of that most important of all organs 
 to us — the brain ; so that, among men belonging 
 to different races, or even within the same race, 
 one man shall have a brain a third, or half, or even 
 seventy per cent, bigger than another ; and if you 
 take the whole range of human brains, you will 
 find a variation in some cases of a hundred per 
 cent. Apart from these variations in the size of 
 the brain, the characters of the skull vary. Thus 
 if I draw the figures of a Mongol and of a Negro 
 head on the blackboard, in the case of the last the 
 breadth would be about seven-tenths, and in the 
 other it would be nine-tenths of the total length. 
 So that you see there is abundant evidence of 
 variation among men in their natural condition. 
 And if you turn to other animals there is just the 
 same thing. The fox, for example, which has a 
 very large geographical distribution all over 
 Europe, and parts of Asia, and on the American 
 Continent, varies greatly. There are mostly large 
 foxes in the North, and smaller ones in the South. 
 In Germany alone the foresters reckon some eight 
 different sorts. 
 
 Of the tiger, no one supposes that there is more 
 than one species ; they extend from the hottest 
 
432 THE CAUSES OF THE XI 
 
 parts of Bengal, into the dry, cold, bitter steppes 
 of Siberia, into a latitude of 50°,— so that they may 
 even prey upon the reindeer. These tigers have 
 exceedingly different characteristics, but still they 
 all keep their general features, so that there is no 
 doubt as to their being tigers. The Siberian 
 tiger has a thick fur, a small mane, and a longi- 
 tudinal stripe down the back, while the tigers of 
 Java and Sumatra differ in many important re- 
 spects from the tigers of Northern Asia. So lions 
 vary ; so birds vary ; and so, if you go further back 
 and lower down in creation, you find that fishes 
 vary. In different streams, in the same country 
 even, you vrill find the trout to be quite different 
 to each other and easily recognisable by those who 
 fish in the particular streams. There is the same 
 differences in leeches ; leech collectors can easily 
 point out to you the differences and the peculiari- 
 ties which you yourself would probably pass by ; 
 so with fresh-water mussels ; so, in fact, with every 
 animal you can mention. 
 
 In plants there is the same kind of variation. 
 Take such a case even as the common bramble. 
 The botanists are all at war about it ; some of 
 them wanting to make out that there are many 
 species of it, and others maintaining that they are 
 but many varieties of one species ; and they can- 
 not settle to this day which is a species and which 
 is a variety ! 
 
 So that there can be no doubt whatsoever that 
 
XI I'HjyjVOJMENA OF ORGANIC NATURE 433 
 
 any plant and any animal may vary in nature ; 
 that varieties may arise in the way I have described 
 — as spontaneous varieties — and that those varie- 
 ties may be perpetuated in the same way that I 
 have shown you spontaneous varieties are perpetu- 
 ated ; I say, therefore, that there can be no doubt 
 as to the origin and perpetuation of varieties in 
 nature. 
 
 But the question now is : — Does selection take 
 place in nature ? Is there anything like the 
 operation of man in exercising selective breeding, 
 taking place in nature ? You Avill observe that, 
 at present, I say nothing about species ; I wish to 
 confine myself to the consideration of the pro- 
 duction of those natural races which everybody 
 admits to exist. The question is, whetlier in 
 nature there are causes competent to produce 
 races, just in the same way as man is able to pro- 
 duce by selection, such races of animals as we 
 have already noticed. 
 
 When a variety has arisen, the CONDITIONS OF 
 Existence are such as to exercise an influence 
 which is exactly comparable to that of artificial 
 selection. By Conditions of Existence I mean 
 two things — there are conditions which are fur- 
 nished by the physical, the inorganic world, and 
 there are conditions of existence which are fur- 
 nished by the organic world. There is, in the first 
 place, Climate ; under that head I include only 
 temperature and the varied amount of moisture 
 
434 THE CAUSES OF THE xi 
 
 of particular places. In the next place there is 
 what is technically called Station, which means 
 — given the climate, the particular kind of place 
 in which an animal or a plant lives or grows ; for 
 examjDle, the station of a fish is in the water, of a 
 fresh-water fish in fresh water ; the station of a 
 marine fish is in the sea, and a marine animal 
 may have a station higher or deeper. So again 
 with land animals : the differences in their stations 
 are those of different soils and neighbourhoods ; 
 some being best adapted to a calcareous, and 
 others to an arenaceous soil. The third condition 
 of existence is Food, by which I mean food in 
 the broadest sense, the supply of the materials 
 necessary to the existence of an organic being ; in 
 the case of a plant the inorganic matters, such as 
 carbonic acid, water, ammonia, and the earthy 
 salts or salines ; in the case of the animal the in- 
 organic and organic matters, which we have seen 
 they require ; then these are all, at least the first 
 two, what we may call the inorganic or physical 
 conditions of existence. Food takes a mid-place, 
 and then come the organic conditions ; by which 
 I mean the conditions which depend upon the 
 state of the rest of the organic creation, upon the 
 number and kind of living beings, with which an 
 animal is surrounded. You may class these under 
 two heads : there are organic beings, which operate 
 as opponents, and there are organic beings which 
 oi^erate as helpers to any given organic creature. 
 
XI PHENOMENA OF ORGANIC NATURE 435 
 
 The opponents may be of two kinds : there are 
 the indirect opponents, which are what we may 
 call rivals; and there are the direct opponents, 
 those which strive to destroy the creature ; and 
 these we call enemies. By rivals I mean, of course, 
 in the case of plants, those which require for their 
 support the same kind of soil and station, and, 
 among animals, those which require the same kind 
 of station, or food, or climate; those are the in- 
 direct opponents ; the direct opponents are, of 
 course, those which pi'ey upon an animal or 
 vegetable. The helpers may also be regarded as 
 direct and indirect : in the case of a carnivorous 
 animal, for example, a particular herbaceous plant 
 may, in multiplying, be an indirect helper, by en- 
 abling the herbivora on which the carnivore preys 
 to get more food, and thus to nourish the carnivore 
 more abundantly ; the direct helper may be best 
 illustrated by reference to some parasitic creature, 
 such as the tape-worm. The tape-worm exists in 
 the human intestines, so that the fewer there are 
 of men the fewer there will be of tape-worms, 
 other things being alike. It is a humiliating re- 
 flection, perhaps, that we may be classed as direct 
 helpers to the tape-worm, but the fact is so : we 
 can all see that if there were no men there would 
 be no tape-worms. 
 
 It is extremely difficult to estimate, in a proper 
 way, the importance and the working of the Con- 
 ditions of Existence. I do not think there were 
 any of us who had the remotest notion of properly 
 
436 THE CAUSES OF THE 21 
 
 estimating them uatil the puhlication of Mr. 
 Darwin's work, which has placed them before ois 
 with remarkable clearness ; and I must endeavour, 
 as far as I can in my own fashion, to give you 
 some notion of how they work. We shall find it 
 easiest to take a simple case, and one as free as 
 possible from every kind of complication. 
 
 I will suppose, therefore, that all the habitable 
 part of this globe — the dry land, amounting to 
 about 51,000,000 square miles — I will suppose 
 that the whole of that dry laud has the same 
 climate, and that it is composed of the same kind 
 of rock or soil, so that there will be the same 
 station everywhere ; we thus get rid of the peculiar 
 influence of different climates and stations. I 
 will then imagine that there shall be but one 
 organic being in the world, and that shall be a 
 plant. In this we start fair. Its food is to be 
 carbonic acid, water and ammonia, and the saline 
 matters in the soil, which are, by the supposition, 
 everywhere alike. We take one single plant, 
 with no opponents, no helpers, and no rivals ; it is 
 to be a " fair field, and no favour." Now, I will 
 ask you to imagine further that it shall be a plant 
 which shall produce every year fifty seeds, which 
 is a very moderate number for a plant to produce ; 
 and that, by the action of the winds and currents, 
 these seeds shall be equally and gradually dis- 
 tributed over the whole surface of the land. I 
 want you now to trace out Avhat Avill occur, and 
 you will observe that I am not talking fallaciously 
 
XE 
 
 PHENOMENA OF ORGANIC NATURE 437 
 
 any more than a mathematician does when he ex- 
 poiinls his problem. If you show that the con- 
 ditions of your problem are such as may actually 
 occur in Nature and do not transgress any of the 
 known laws of Nature in working out your pro- 
 position, then you are as safe in the conclusion 
 you arrive at as is the mathematician in arriving 
 at the solution of his problem. In science, the 
 only way of getting rid of the complications with 
 which a subject of this kind is environed," is to 
 work in this deductive method. What will be 
 the result, then ? I will suppose that every plant 
 requires one square foot of ground to live upon ; 
 and the result will be that, in the course of nine 
 years, the plant will have occupied every single 
 available spot in the whole globe ! I have chalked 
 upon the blackboard the figures by which I arrive 
 at the result : — 
 
 Plants. Plants. 
 
 1 X 50 in 1st year = 50 
 
 50 X 50 ,, 2nd „ = 2,500 
 
 2,500 X 50 ,, 3rd „ = 125,000 
 
 125,000 X 50 „ 4th ,, = 6,250,000 
 
 6,250,000 X 50 ,, 5th „ = 312,500,000 
 
 312,500,000 X 50 ,, 6th „ = 15,625,000,000 
 
 15,625,000,000 x 50 „ 7th „ = 781,250,000,000 
 
 781,250,000,000 x 50 „ 8th „ = 39,062,500,000.000 
 
 39,062,500,000,000 x 50 „ 9th ,, = 1,953,125,000,000,000 
 
 51,000,000 square miles — the"\ 
 
 sq. ft. in 1 sq. mile J " 
 
 being 531,326,600,000,000 
 square feet less than would be required at the end of the ninth 
 year. 
 
438 THE CAUSES OF THE XI 
 
 You will see from this that, at the end of the 
 first year the single plant will have produced fifty 
 more of its kind ; by the end of the second year 
 these will have increased to 2,500 ; and so on. in 
 succeeding years, you get beyond even trillions ; 
 and I am not at all sure that I could tell you what 
 the proper arithmetical denomination of the total 
 number really is ; but, at any rate, you will under- 
 stand the meaning of all those noughts. Then 
 you see that at the bottom, I have taken the 
 51,000,000 of square miles, constituting the sur- 
 face of the dry land ; and as the number of square 
 feet are placed under and subtracted from the 
 number of seeds that Avould be produced in the 
 ninth year, yon can see at once that there would 
 be an immense number more of plants than there 
 would be square feet of ground for their accom- 
 modation. This is certainly quite enough to 
 prove my point; that between the eighth and ninth 
 year after being planted the single plant would have 
 stocked the Avhole available surface of the earth. 
 
 This is a thing which is hardly conceivable — it 
 seems hardly imaginable — yet it is so. It is 
 indeed simply the law of Malthus exemplified. 
 Mr. Malthus was a clergvman, who worked out 
 this subject most minutely and truthfully some 
 years ago ; he showed quite clearly — and although 
 he was much abused for his conclusions at the 
 time, they have never yet been disproved and 
 never will be — he showed that in consequence of 
 
XI ruii.JNUMJiJNA UK ORGANIC NATURE 439 
 
 the increase in the number of ortjanic beings in a 
 geometrical ratio, while the means of existence 
 cannot be made to increase in the same ratio, that 
 there must come a time when the number of or- 
 ganic beings will be in excess of the power of pro- 
 duction of nutriment, and that thus some check 
 must arise to the further increase of those organic 
 beings. At the end of the ninth year we have seen 
 that each plant would not be able to get its full 
 square foot of ground, and at the end of another 
 year it would have to share that space with fifty 
 othtrs the produce of the seeds which it would 
 give off. 
 
 What, then, takes place ? Every plant grows 
 up, flourishes, occupies its square foot of ground, 
 and gives off its fifty seeds ; but notice this, that 
 out of this number only one can come to anything; 
 there is thus, as it were, forty-nine chances to one 
 against its growing up ; it depends upon the most 
 fortuitous circumstances whether any one of these 
 fifty seeds shall grow up and flourish, or whether 
 it shall die and perish. This is what Mr. Darwin 
 has drawn attention to, and called the " Struggle 
 FOR Existence " ; and I have taken this simple 
 case of a plant because some people imagine that 
 the phrase seems to imply a sort of fight. 
 
 I have taken this plant and shown you that this 
 is the result of the ratio of the increase, the neces- 
 sary result of the arrival of a time coming for every 
 species when exactly as many members must be 
 5T 
 
440 THE CAUSES OF THE XI 
 
 destroyed as are born ; that is the inevitable ulti- 
 mate result of the rate of production. Now, what 
 is the result of all this ? I have said that there 
 are forty-nine struggling against every one ; and 
 it amounts to this, that the smallest possible start 
 given to any one seed may give it an advantage 
 which will enable it to get ahead of all the others ; 
 anything that will enable any one of these seeds to 
 germinate six hours before any of the others wiU, 
 other things being alike, enable it to choke them 
 out altogether. I have shown you that there is 
 no particular in which plants will not vary from 
 each other ; it is quite possible that one of our 
 imaginary plants may vary in such a character as 
 the thickness of the integument of its seeds ; it 
 might happen that one of the plants might pro- 
 duce seeds having a thinner integiiment, and that 
 would enable the seeds of that plant to germinate 
 a little quicker than those of any of the others, and 
 those seeds would most inevitably extinguish the 
 forty-nine times as many that were struggling 
 with them. 
 
 I have put it in this way, but you see the practi- 
 cal result of the process is the same as if some 
 person had nurtured the one and destroyed the 
 other seeds. It does not matter how the variation 
 is produced, so long as it is once allowed to occur. 
 The variation in the plant once fairly started tends 
 to become hereditary and reproduce itself; the 
 seeds would spread themselves in the same way 
 
XI PHENOMENA OF ORGANIC NATURE 441 
 
 and take part in the struggle with the forty-ninq 
 hundred, or forty-nine thousand, with which they 
 might he exposed. Thus, by degrees, this variety 
 with some slight organic change or modification, 
 must spread itself over the whole surface of the 
 habitable globe, and extirpate or replace the other 
 kinds. That is what is meant by Natural 
 Selection ; that is the kind of argument by which 
 it is perfectly demonstrable that the conditions of 
 existence may play exactly the same part for 
 natural varieties as man does for domesticated 
 varieties. No one doubts at all that particular 
 circumstances may be more favourable for one 
 plant and less so for another, and the moment you 
 admit that, you admit the selective power of 
 nature. Now, although I have been putting a 
 hypothetical case, you must not suppose that I 
 have been reasoning hypothetical! y. There are 
 plenty of direct experiments which bear out what 
 we may caU the theory of natural selection ; there 
 is extremely good authority for the statement that 
 if you take the seed of mixed varieties of wheat 
 and sow it, collecting the seed next year and sow- 
 ing it again, at length you will find that out of all 
 your varieties only two or three have lived, or per- 
 haps even only one. There were one or two 
 varieties which were best fitted to get on, and they 
 have killed out the other kinds in just the same 
 way and with just the same certainty as if you had 
 taken the trouble to remove them. As I have 
 
442 THE CAUSES OF THE xi 
 
 already said, the operation of nature is exactly 
 the same as the artificial operation of man. 
 
 But if this be true of that simple case, which I 
 put before you, where there is nothing but the 
 rivalry of one member of a species with others, 
 what must be the operation of selective conditions, 
 when you recollect as a matter of fact, that for 
 every species of animal or plant there are fifty or 
 a hundred species which might all, more or less, be 
 comprehended in the same climate, food, and sta- 
 tion ; — that every plant has multitudinous animals 
 which prey upon it, and which are its direct oppo- 
 nents ; and that these have other animals preying 
 upon them, — that every plant has its indirect 
 helpers in the birds that scatter abroad its seed, 
 and the animals that manure it with their dung ; — 
 I say, when these things are considered, it seems 
 impossible that any variation which may arise in 
 a species in nature should not tend in some way 
 or other either to be a little better or worse than 
 the previous stock ; if it is a little better it will 
 have an advantage over and tend to extirpate the 
 latter in this crush and struggle ; and if it is a 
 little worse it will itself be extirpated. 
 
 I know nothing that more appropriately ex- 
 presses this, than the phrase, " the struggle for 
 existence " ; because it brings before your minds, 
 in a vivid sort of way, some of the simplest pos- 
 sible circumstances connected with it. When a 
 struggle is intense there must be some who are 
 
XI PHENOMENA OF ORGANIC NATURE 443 
 
 sure to be trodden down, crushed, and overpowered 
 by others ; and there will be some who just 
 manage to get through only by the help of the 
 slisfhtest accident. I recollect reading an account 
 of the famous retreat of the French troops, under 
 Napoleon, from Moscow. Worn out, tired, and 
 dejected, they at length came to a great river over 
 which there was but one bridge for the passage of 
 the vast army. Disorganised and demoralised as 
 that army was, the struggle must certainly have 
 been a terrible one — every one heeding only him- 
 self, and crushing through the ranks and treading 
 down his fellows. The writer of the narrative, 
 who was himself one of those who were fortunate 
 enough to succeed in getting over, and not among 
 the thousands who were left behind or forced into 
 the river, ascribed his escape to the fact that he 
 saw striding onward through the mass a great 
 strong fellow, — one of the French Cuirassiers, who 
 had on a large blue cloak — and he had enough 
 presence of mind to catch and retain a hold of this 
 strong man's cloak. He says, " I caught hold of 
 his cloak, and although he swore at me and cut 
 at and struck me by turns, and at last, when he 
 found he could not shake me off, fell to entreating 
 me to leave go or I should prevent him from 
 escaping, besides not assisting myself, I still kept 
 tight hold of him, and would not quit my grasp 
 until he had at last dragged me through." Here 
 you see was a case of selective saving — if we may 
 
444 THE CAUSES OF THE rc 
 
 SO term it — depending for its success on the 
 strencjtli of the cloth of the Cuirassier's cloak. It 
 is the same in nature ; every species has its bridge of 
 Beresina ; it has to fight its way through and strug- 
 gle with other species ; and when well-nigh over- 
 powered, it may be that the smallest chance, some- 
 thing in its colour, perhaps — the minutest circum- 
 stance — will turn the scale one way or the other. 
 
 Suppose that by a variation of the black race it 
 had prodiiced the white man at any time — you 
 know that the Negroes are said to believe this to 
 have been the case, and to imagine that Cain 
 was the first Avhite man, and that we are his 
 descendants — suppose that this had ever hap- 
 pened, and that the first residence of this human 
 being was on the West Coast of Africa. There is no 
 great structural difference between the white man 
 and the Negro, and yet there is something so sin- 
 gulaidy different in the constitution of the two, 
 that the malarias of that country, which do not 
 hurt the black at all, cut off and destroy the white. 
 Then you see there would have been a selective 
 operation performed ; if the white man had risen 
 in that way, he would have been selected out and 
 removed by means of the malaria. Now there 
 really is a very curious case of selection of this 
 sort among pigs, and it is a case of selection of 
 colour too. In the woods of Florida there are a 
 great many I5igs, and it is a very curious thing that 
 they are all black, every one of them. Professor 
 
XI PHENOMENA OF ORGANIC NATURE 4i5 
 
 Wyman was there some years ago, and on noticing 
 no pigs but these black ones, he asked some of the 
 people how it was that they had no white pigs, 
 and the reply was that in the woods of Florida 
 there was a rot^t which they called the Paint 
 Root, and that if the white pigs were to eat any 
 of it, it had the effect of making their hoofs crack, 
 and they died, but if the black pigs ate any of it, 
 it did not hurt them at all. Here was a very 
 simple case of natural selection. A skilful breeder 
 could not more carefully develop the black breed 
 of pigs, and weed out all the white pigs, than the 
 Paint Root does. 
 
 To show you how remarkably indirect may be 
 such natural selective agencies as I have referred 
 to, I will conclude by noticing a case mentioned 
 by Mr. Darwin, and which is certainly one of the 
 most curious of its kind. It is that of the Humble 
 Bee. It has been noticed that there are a great 
 many more humble bees in the neighbourhood of 
 towns, than out in the open country ; and the ex- 
 planation of the matter is this : the humble bees 
 build nests, in which they store their honey and 
 deposit the larvae and eggs. The field mice are 
 amazingly fond of the honey and larvae ; therefore, 
 wherever there are plenty of field mice, as in the 
 country, the humble bees are kept down ; but in 
 the neighbourhood of towns, the number of cats 
 which prowl about the fields eat up the field mice, 
 and of course the more mice they eat up the less 
 
446 PHENOMENA OF ORGANIC NATURE XI 
 
 there are to prey upon the larvae of the bees — the 
 cats are therefore the indirect HELPERS of the 
 bees.^ Coming back a step farther we may say 
 that the old maids are also indirect friends of the 
 humble bees, and indirect enemies of the field 
 mice, as they keep the cats which eat up the 
 latter ! This is an illustration somewhat beneath 
 the dignity of the subject, perhaps, but it occurs 
 to me in passing, and with it I will conclude this 
 lecture. 
 
 ^ The humble bees, on the other hand, are direct helpers of 
 some plants, such as the heartsease and red clover, which are 
 fertilised by the visits of the bees ; and they are indirect helpers 
 of the numerous insects which are more or less completely sup- 
 ported by the heartsease and red clover. 
 
VI 
 
 A CRITICAL EXAMINATION OF THE POSITION OF 
 MR. DARWIN'S WORK, "ON THE ORIGIN OF 
 SPECIES," IN RELATION TO THE COMPLETE 
 THEORY OF THE CAUSES OF THE PHENOMENA 
 OF ORGANIC NATURE. 
 
 In the precedicg five lectures I have endeav- 
 oured to give you an account of those facts, and 
 of those reasonings from facts, which form the 
 data upon which all theories regarding the causes 
 of the phenomena of organic nature must be 
 based. And, although I have had frequent 
 occasion to quote Mr. Darwin — as all persons here- 
 after, in speaking upon these subjects, will have 
 occasion to quote his famous book on the " Origin 
 of Species," — you must yet remember that, wher- 
 ever I have quoted him, it has not been upon 
 theoretical points, or for statements in any way 
 connected with his particular speculations, but on 
 matters of fact, brought forward by himself, or 
 collected by himself, and which appear incidentally 
 in his book. If a man vnll make a book, pro- 
 
448 THE CAUSES OF THE x 
 
 fessing to discuss a single question, an encyclo- 
 paedia, I cannot help it. 
 
 Now, having had an opportunity of considering 
 in this sort of way the dififerent statements bear- 
 ing upon all theories whatsoever, I have to lay 
 before you, as fairly as I can, what is Mr. Darwin's 
 view of the matter and what position his theories 
 hold, when judged by the principles which I have 
 previously laid down, as deciding our judgments 
 upon all theories and hypotheses. 
 
 I have already stated to you that the inquiry 
 respecting the causes of the phenomena of organic 
 nature resolves itself into two problems — the first 
 being the question of the origination of living or 
 organic beings ; and the second being the totally 
 distinct problem of the modification and perpetua- 
 tion of organic beings when they have already 
 come into existence. The first question Mr. 
 Darwin does not touch ; he does not deal with it 
 at all ; but he says : — -" Given the origin of organic 
 matter — supposing its creation to have already 
 taken place, my object is to show in consequence 
 of what laws and what demonstrable properties of 
 organic matter, and of its environments, such 
 states of organic nature as those with which Ave 
 are acquainted must have come about." This, you 
 will observe, is a perfectly legitimate proposition ; 
 every person has a right to define the limits of 
 the inquiry which he sets before himself ; and yet 
 it is a most singular thing tTiat in all the multi- 
 
XI PHENOMENA OF ORGANIC NATURE 449 
 
 farious, and, not unfrequently, ignorant attacks 
 which have been made upon the " Origin of 
 Species," there is nothing which has been more 
 speciously criticised than this particular limitation. 
 If people have nothing else to urge against the 
 book, they say — " Well, after all, you see Mr. 
 Darwin's explanation of the ' Origin of Species ' 
 is not good for much, because, in the long run, he 
 admits that he does not know how organic matter 
 began to exist. But if you admit any special 
 creation for the first particle of organic matter 
 you may just as well admit it for all the rest ; five 
 hundred or five thousand distinct creations are 
 just as intelligible, and just as little difficult to 
 understand, as one." The answer to these cavils 
 is two -fold. In the first place, all human inquiry 
 must stop somewhere ; all our knowledge and all 
 our investigation cannot take us beyond the limits 
 set by the finite and restricted character of our 
 faculties, or destroy the endless unknown, which 
 accompanies, like its shadow, the endless procession 
 of phenomena. So far as I can venture to offer 
 an opinion on such a matter, the purpose of our 
 being in existence, the highest object that human 
 beings can set before themselves, is not the pursuit 
 of any such chimera as the annihilation of the 
 unknown ; but it is simply the unwearied endeav- 
 our to remove its boundaries a little further from 
 our little sphere of action. 
 
 I wonder if any historian would for a moment 
 
450 THE CAUSES OF THE XI 
 
 admit the objection, that it is preposterous to 
 trouble ourselves about the history of the Roman 
 Empire, because we do not know anything positive 
 about the origin and first building of the city of 
 Rome ! Would it be a fair objection to urge, 
 respecting the sublime discoveries of a Newton, or 
 a Kepler, those great philosophers, whose dis- 
 coveries have been of the profoundest benefit and 
 service to all men — to say to them — " After all 
 that you have told us as to how the planets re- 
 volve, and how they are maintained in their orbits, 
 you cannot tell us what is the cause of the origin 
 of the sun, moon, and stars. So what is the use 
 of what you have done ? " Yet these objections 
 would not be one whit more preposterous than 
 the objections which have been made to the 
 " Origin of Species." Mr. Darwin, then, had a 
 perfect right to limit his inquiry as he pleased, 
 and the only question for us — the inquiry being 
 so limited — is to ascertain whether the method of 
 his inquiry is sound or unsound ; whether he has 
 obeyed the canons which must guide and govern 
 all investigation, or whether he has broken 
 them ; and it was because our inquiry this 
 evening is essentially limited to that question, 
 that I spent a good deal of time in a former 
 lecture (which, perhaps some of you thought 
 might have been better employed), in endeavour- 
 ing to illustrate the method and nature of scien- 
 tific inquiry in general. We shall now have to 
 
XI PHENOMENA OF ORGANIC NATUKE 451 
 
 put in practice thie principles that I then laid 
 down. 
 
 I stated to you in substance, if not in words, that 
 wherever there are complex masses of phenomena 
 to be inquired into, whether they be phenomena 
 of the affairs of daily life, or whether they belong 
 to the more abstruse and difficult problems laid 
 before the philosopher, our course of proceeding 
 in unravelling that complex chain of phenomena 
 with a view to get at its cause, is always the same ; 
 in all cases we must invent an hypothesis ; we 
 must place before ourselves some more or less 
 likely supposition respecting that cause ; and then, 
 having assumed an hypothesis, having supposed a 
 cause for the phenomena in question, we must 
 endeavour, on the one hand, to demonstrate our 
 hypothesis, or, on the other, to upset and reject it 
 altogether, by testing it in three ways. We must, 
 in the first place, be prepared to prove that the 
 supposed causes of the phenomena exist in nature ; 
 that they are what the logicians call vera causm — 
 true causes ; — in the next place, we should be pre- 
 pared to show that the assumed causes of the 
 phenomena are competent to produce such pheno- 
 mena as those which we wish to explain by them ; 
 and in the last place, we ought to be able to show 
 that no other known causes are competent to pro- 
 duce these phenomena. If we can succeed in satis- 
 fying these three conditions we shall have demon- 
 strated our hypothesis ; or rather I ought to say 
 
452 THE CAUSES OF THE XI 
 
 we shall have proved it as far as certainty is pos- 
 sible for us ; for, after all, there is no one of our 
 surest convictions which may not be upset, or at 
 any rate modified by a further accession of know- 
 ledge. It was because it satisfied these condi- 
 tions that we accepted the- hypothesis as to the 
 disappearance of the tea-pot and spoons in the 
 case I supposed in a previous lecture ; we found 
 that our hypothesis on that subject was tenable 
 and valid, because the supposed cause existed in 
 nature, because it was competent to account for 
 the phenomena, and because no other known cause 
 was competent to account for them ; and it is upon 
 similar grounds that any hypothesis you choose to 
 name is accepted in science as tenable and 
 valid. 
 
 What is Mr. Darwin's hypothesis ? As I appre- 
 hend it — for I have put it into a shape more con- 
 venient for common purposes than I could find 
 fcrbatim in his book — as I apprehend it, I say, 
 it is, that all the phenomena of organic nature, 
 past and present, result from, or are caused by, 
 the inter-action of those properties of organic 
 matter, which we have called Atavism and Varia- 
 bility, with the Conditions of Existence, or, 
 in other words, — given the existence of organic 
 matter, its tendency to transmit its properties, and 
 its tendency occasionally to vary ; and, lastly, given 
 the conditions of existence by which organic mat- 
 ter is surrounded — that these put together are the 
 
XI PHENOMENA OF ORGANIC NATURE 453 
 
 causes of the Present and of the Past conditions of 
 Organic Nature. 
 
 Such is the hypothesis as I understand it. Now 
 let us see how it will stand the various tests which 
 I laid down just now. In the first place, do these 
 supposed causes of the phenomena exist in nature ? 
 Is it the fact that, in nature, these properties of 
 organic matter — atavism and variability — and 
 those phenomena which we have called the con- 
 ditions of existence, — is it true that they exist ? 
 Well, of course, if they do not exist, all that I have 
 told you in the last three or four lectures must be 
 incorrect, because I have been attempting to prove 
 that they do exist, and I take it that there is 
 abundant evidence that they do exist ; so far, 
 therefore, the hypothesis does not break down. 
 
 But in the next place comes a much more diffi- 
 cult inquiry : — Are the causes indicated compe- 
 tent to give rise to the phenomena of organic 
 nature ? I suspect that this is indubitable to a 
 certain extent. It is demonstrable, I think, as I 
 have endeavoured to show you, that they are per- 
 fectly competent to give rise to all the phenomena 
 which are exhibited by Races in nature. Further- 
 more, I believe that they are quite competent to 
 account for all that we may call purely structural 
 phenomena which are exhibited by Species in 
 nature. On that point also I have already en- 
 larged somewhat. Again, I think that the causes 
 assumed are competent to account for most of the 
 
454 THE CAUSES OF THE XI 
 
 physiological characteristics of species, and I not 
 only think that they are competent to account for 
 them, but I think that they account for many 
 things which otherwise remain wholly unaccount- 
 able and inexplicable, and I may say incompre- 
 hensible. For a full exposition of the grounds on 
 which this conviction is based, I must refer you to 
 Mr. Darwin's work ; all that I can do now is to 
 illustrate what I have said by two or three cases 
 taken almost at random. 
 
 I drew your attention, on a previous evening, to 
 the facts which are embodied in our systems of 
 Classification, Avhich are the results of the examin- 
 ation and comparison of the different members 
 of the animal kingdom one with another. I men- 
 tioned that the whole of the animal kingdom is 
 divisible into five sub-kingdoms ; that each of these 
 sub-kingdoms is again divisible into provinces ; 
 that each province may be divided into classes, 
 and the classes into the successively smaller groups, 
 orders, families, genera, and species. 
 
 Now, in each of these groups the resemblance 
 in structure among the members of the group is 
 closer in proportion as the group is smaller. Thus, 
 a man and a worm are members of the animal 
 kingdom in virtue of certain apparently slight 
 though really fundamental resemblances which 
 they present. But a man and a fish are members of 
 the same sub-kingdom Vertehrata, because they are 
 much more like one another than either of them 
 
SI PHENOMENA OF ORGANIC NATUKE 455 
 
 is to a worm, or a snail, or any member of the other 
 sub-kingdoms. For similar reasons men and horses 
 are arranged as members of the same Class, Mam- 
 malia ; men and apes as members of the same 
 Order, Primates ; and if there were any animals 
 more like men than they were like any of the 
 apes, and yet different from men in important and 
 constant particulars of their organisation, we should 
 rank them as members of the same Family, or of 
 the same Genus, but as of distinct Species. 
 
 That it is possible to arrange all the varied 
 forms of animals into groups, having this sort of 
 singular subordination one to the other, is a very 
 remarkable circumstance ; but, as Mr. Darwin re- 
 marks, this is a result which is quite to be ex- 
 pected, if the principles which he lays down be 
 correct. Take the case of the races which are 
 known to be produced by the operation of atavism 
 and variabiUty, and the conditions of existence 
 which check and modify these tendencies. Take 
 the case of the pigeons that I brought before you : 
 there it was shown that they might be all classed 
 as belonging to some one of five principal divi- 
 sions, and that within these divisions other sub- 
 ordinate groups might be formed. The members 
 of these groups are related to one another in just 
 the same way as the genera of a family, and the 
 groups themselves as the families of an order, or 
 the orders of a class ; while all have the same sort 
 of structural relations with the wild rock -pigeon, 
 
 58 
 
456 THE CAUSES OF THE XI 
 
 as the members of any great natural group have 
 with a real or imaginary typical form. Now, we 
 know that all varieties of i^igeons of every kind 
 have arisen by a process of selective breeding from 
 a common stock, the rock-pigeon ; hence, you see, 
 that if all species of animals have proceeded from 
 some common stock, the general character of their 
 structural relations, and of our systems of classifi- 
 cation, which express those relations, would be just 
 what we find them to be. In other words, the 
 hypothetical cause is, so far, competent to produce 
 effects similar to those of the real cause. 
 
 Take, again, another set of very remarkable 
 facts, — the existence of what are called rudi- 
 mentary organs, organs for which we can find 
 no obvious use, in the particular animal econ- 
 omy in which they are found, and yet which are 
 there. 
 
 Such are the spiint-like bones in the leg of the 
 horse, which I here show you, and which corre- 
 spond with bones which belong to certain toes and 
 fingers in the human hand and foot. In the horse 
 you see they are quite rudimentary, and bear 
 neither toes nor fingers ; so that the horse has 
 only one "finger'' in his fore-foot and one "toe" 
 in his hind-foot. But it is a very curious thing 
 that the animals closely allied to the horse show 
 more toes than he ; as the rhinoceros, for instance : 
 he has tliese extra toes well formed, and anatomi- 
 cal facts show very clearly that he is very closely 
 
SI fJUEJNOMENA OF ORGANIC NATURE 457 
 
 related to the horse indeed. So we may say that 
 animals, in an anatomical sense nearly related to 
 the horse, have those parts which are rudimentary 
 in him fully developed. 
 
 Again, the sheep and the cow have no cutting- 
 teeth, but only a hard pad in the upper jaw. That 
 is the common characteristic of ruminants in 
 general. But the calf has in its upper ja.w some 
 rudiments of teeth which never are developed, and 
 never play the part of teeth at all. Well, if 
 you go back in time, you find some of the older, 
 now extinct, allies of the ruminants have well- 
 developed teeth in their upper jaws ; and at the 
 present day the pig (which is in structure closely 
 connected with ruminants) has well-developed 
 teeth in its upper jaw ; so that here is another 
 instance of organs well-developed and very useful, 
 in one animal, represented by rudimentary organs, 
 for which we can discover no purpose whatsoever 
 in another closely allied animal. The whalebone 
 whale, again, has horny " whalebone " plates in its 
 mouth, and no teeth ; but the young foetal whale 
 before it is born has teeth in its jaws; they, how- 
 ever, are never used, and they never come to any- 
 thing. But other members of the group to which 
 the whale belongs have well-developed teeth in 
 both jaws. 
 
 Upon any hypothesis of special creation, facts of 
 this kind appear to me to be entirely unaccount- 
 able and inexplicable, but they cease to be so if 
 
458 THE CAUSES OF THE XI 
 
 you accept Mr. Darwin's hypothesis, and see reason 
 for believinof that the whalebone whale and the 
 whale with teeth in its mouth both sprang from a 
 whale that had teeth, and that the teeth of the 
 foetal whale are merely remnants — recollections, 
 if we may so say — of the extinct whale. So in 
 the case of the horse and the rhinoceros : suppose 
 that both have descended by modification from 
 some earlier form which had the normal number 
 of toes, and the persistence of the rudimentary 
 bones which no longer support toes in the horse 
 becomes comprehensible. 
 
 In the language that we speak in England, and 
 in the language of the Greeks, there are identical 
 verbal roots, or elements entering into the com- 
 position of words. That fact remains unintellig- 
 ible so long as we suppose English and Greek to 
 be independently created tongues ; but when it is 
 shown that both languages are descended from 
 one original, we give an explanation of that 
 resemblance. In the same way the existence 
 of identical structural roots, if I may so term 
 them, entering into the composition of widely 
 different animals, is striking evidence in favour of 
 the descent of those animals from a common 
 original. 
 
 To turn to another kind of illustration : — If you 
 regard the whole series of stratified rocks — that 
 enormous thickness of sixty or seventy thousand 
 feet that I have mentioned before, constituting the 
 
XI PHENOMENA OF ORGANIC NATURE 459 
 
 only record we have of a most prodigious lapse of 
 time, that time being, in all probability, but a 
 fraction of that of which we have no record; — if 
 you observe in these successive strata of rocks 
 successive groups of animals arising and dying 
 out, a constant succession, giving you the same 
 kind of impression, as you travel from one group 
 of strata to another, as you would have in travel- 
 ling from one country to another ; — when you 
 find this constant succession of forms, their 
 traces obliterated except to the man of science 
 — when you look at this wonderful history, and 
 ask what it means, it is only a paltering with 
 words if you are offered the reply — " They were 
 so created." 
 
 But if, on the other hand, you look on all 
 forms of organised beings as the results of the 
 gradual modification of a primitive type, the facts 
 receive a meaning, and you see that these older 
 conditions are the necessary predecessors of the 
 present. Viewed in this light the facts of palae- 
 ontology receive a meaning — upon any other 
 hypothesis I am unable to see, in the slightest 
 degree, what knowledge or signification we are 
 to draw out of them. Again, note as bearing 
 upon the same point, the singular likeness which 
 obtains between the successive Faunse and Florce, 
 whose remains are preserved on the rocks : you 
 never find any great and enormous difference 
 between the immediately successive Faunae and 
 
460 THE CAUSES OF THE SI 
 
 Florffi, unless you have reason to believe there 
 has also been a great lapse of time or a great 
 change of conditions. The animals, for instance, 
 of the newest tertiary rocks, in any part of the 
 world, are always, and without exception, found 
 to be closely allied with those which now live in 
 that part of the world. For example, in Europe, 
 Asia, and Africa, the large mammals are at pres- 
 ent rhinoceroses, hippopotamuses, elephants, lions, 
 tigers, oxen, horses, &c. ; and if you examine the 
 newest tertiary deposits, which contain the 
 animals and plants which immediately preceded 
 those which now exist in the same country, you 
 do not find gigantic specimens of ant-eaters and 
 kangaroos, but you find rhinoceroses, elephants, 
 lions, tigers, &c., — of different species to those now 
 living — but still their close allies. If you turn to 
 South America, where, at the present day, we have 
 great sloths and armadilloes and creatures of that 
 kind, what do you find in the newest tertiaries ? 
 You find the great sloth-like creature, the Mrgar 
 therium, and the great armadillo, the Glyptcdoii, 
 and so on. And if you go to Australia you find 
 the same law holds good, namely, that that con- 
 dition of organic nature which has preceded the 
 one which now exists, presents differences perhaps 
 of species, and of genera, but that the great types 
 of organic structure are the same as those which 
 now flourish. 
 
 What meaning has this fact upon any other 
 
xr PHENOMENA OF ORGANIC NATURE 461 
 
 hypothesis or supposition than one of successive 
 modification? But if the population of the 
 world, in any age, is the result of the gradual 
 modification of the forms which peopled it in the 
 preceding age — if that has been the case, it is in- 
 telligible enough ; because we may expect that 
 the creature that results from the modification of 
 an elephantine mammal shall be something like 
 an elephant, and the creature which is produced 
 by the modification of an armadillo-like mammal 
 shall be like an armadillo. Upon that supposition, 
 I say, the facts are intelligible ; upon any other, 
 that I am aware of, they are not. 
 
 So far, the facts of palaeontology are consistent 
 with almost any form of the doctrine of progressive 
 modification; they would not' be absolutely incon- 
 sistent with the wild speculations of De Maillet, 
 or with the less objectionable hypothesis of La- 
 marck. But Mr. Darwin's views have one peculiar 
 merit ; and that is, that they are perfectly con- 
 sistent with an array of facts which are utterly in- 
 consistent with, and fatal to, any other hypothesis 
 of progressive modification which has yet been 
 advanced. It is one remarkable peculiarity of 
 Mr. Darwin's hypothesis that it involves no neces- 
 sary progression or incessant modification, and 
 that it is perfectly consistent with the persistence 
 for any length of time of a given primitive stock, 
 contemporaneously with its modifications. To 
 return to the case of the domestic breeds of 
 
462 THE CAUSES OF THE XI 
 
 pigeons, for example ; you have the dove-cot 
 pigeon, which closely resembles the rock pigeon, 
 from which they all started, existing at the same 
 time with the others. And if species are developed 
 in the same way in nature, a primitive stock and 
 its modifications may, occasionally, all find the 
 conditions fitted for their existence ; and though 
 they come into competition, to a certain extent, 
 with one another, the derivative species may not 
 necessarily extirpate the primitive one, or vice 
 versd. 
 
 Now palaeontology shows us many facts which 
 are perfectly harmonious with these observed 
 effects of the process by which Mr. Darwin sap- 
 poses species to have originated, but which appear 
 to me to be totally inconsistent with any other 
 hypothesis which has been proposed. There are 
 some groups of animals and plants, in the fossil 
 world, which have been said to belong to " persist- 
 ent types," because they have persisted, with 
 very little change indeed, through a very great 
 range of time, while everything about them has 
 changed largely. There are families of fishes 
 whose type of construction has persisted all the 
 way from the carboniferous strata right up to the 
 cretaceous ; and others which have lasted through 
 almost the whole range of the secondary rocks, 
 and from the lias to the older tertiaries. It is 
 something stupendous this — to consider a genus 
 lasting without essential modifications through all 
 
Ai — jrni^iSvJVxJiiNA VH UKtfAISHJ iVIATUllE 463 
 
 Ihis enormous lapse of time while almost every- 
 thing else was changed and modified. 
 
 Thus I have no doubt that Mr. Darwin's hypo- 
 thesis will be found competent to explain the ma- 
 jority of the phenomena exhibited by species in 
 nature ; but in an earlier lecture I spoke cautiously 
 with respect to its power of explaining all the 
 physiological peculiarities of species. 
 
 There is, in fact, one set of these peculiarities 
 which the theory of selective modification, as it 
 stands at present, is not wholly competent to 
 explain, and that is the group of phenomena which 
 I mentioned to you under the name of Hybridism, 
 and which I explained to consist in the sterility of 
 the offspring of certain species when crossed one 
 with another. It matters not one whit whether 
 this sterility is universal, or whether it exists only 
 in a single case. Every hypothesis is bound to 
 explain, or, at any rate, not be inconsistent with, 
 the whole of the facts which it professes to account 
 for ; and if there is a single one of these facts 
 which can be shovm to be inconsistent with (I do 
 not merely mean inexplicable by, but contrary to) 
 the hypothesis, the hypothesis falls to the ground, 
 — it is worth nothing. One fact with which it is 
 positively inconsistent is worth as much, and as 
 powerful in negativing the hypothesis, as five 
 hundred. If I am right in thus defining the obli- 
 gations of an hypothesis, Mr. Darwin, in order to 
 place his views beyond the reach of all possible 
 
464 THE CAUSES OF THE XI 
 
 assault, ought to be able to demonstrate the possi- 
 bility of developing from a particiilar stock by se- 
 lective breeding, two forms, which should either 
 be unable to cross one with another, or whose 
 cross-bred offspring should be infertile with one 
 another. 
 
 For, you see, if you have not done that you have 
 not strictly fulfilled all the conditions of the prob- 
 lem ; you have not shown that you can produce, 
 by the cause assumed, all the phenomena which 
 you have in nature. Here are the phenomena of 
 Hybridism staring you in the face, and you cannot 
 say, " I can, by selective modification, produce 
 these same results.'' Now, it is admiitted on all 
 hands that, at present, so far as experiments have 
 gone, it has not been found possible to produce 
 this complete physiological divergence by selective 
 breeding. I stated this very clearly before, and I 
 now refer to the point, because, if it could be 
 proved, not only that this has not been done, but 
 that it cannot be done ; if it could be demonstrated 
 that it is impossible to breed selectively, from any 
 stock, a form which shall not breed with another, 
 produced from the same stock ; and if we were 
 shown that this must be the necessary and inevit- 
 able results of all exjDeriments, I hold that Mr, 
 Darwin's hypothesis would be utterly shattered. 
 
 But has this been done ? or Avhat is really the 
 state of the case ? It is simply that, so far as we 
 have gone yet with our breeding, we have not pro- 
 
XI i-illiJNOMJiNA OF OKUANIC NATURE 465 
 
 duced from a common stock two breeds which are 
 not more or less fertile with one another. 
 
 I do not know that there is a single fact which 
 would justify any one in saying that any degree of 
 sterility has been observed between breeds abso- 
 lutely known to have been produced by selective 
 breeding from a common stock. On the other 
 hand, I do not know that there is a single fact 
 which can justify any one in asserting that such 
 sterility cannot be produced by proper experiment- 
 ation. For my own part, I see every reason to 
 believe that it may, and will be so produced. For, 
 as Mr. Darwin has very properly urged, when we 
 consider the phenomena of sterility, we find they 
 are most capricious ; we do not know what it is 
 that the sterility depends on. There are some 
 animals which will not breed in captivity ; whether 
 it arises from the simple fact of their being shut 
 up and deprived of their liberty, or not, we do not 
 know, but they certainly will not breed. What an 
 astounding thing this is, to find one of the most 
 important of all functions annihilated by mere 
 imprisonment ! 
 
 So, again, there are cases known of animals 
 which have been thought by naturalists to be un- 
 doubted species, which have yielded perfectly fer- 
 tile hybrids ; while there are other species which 
 present what everybody believes to be varieties^ 
 
 ' And as I conceive with, very good reason ; but if any objec- 
 tor urges that we cannot prove that they have been produced by 
 
466 THE CAUSES OF THE XI 
 
 whicli are more or less infertile with one another. 
 There are other cases which are truly extraordi- 
 nary ; there is one, for examiDle, which has been 
 carefully examined, — of two kinds of sea-weed, of 
 which the male element of the one, which we may 
 call A, fertilises the female element of the other, 
 B ; while the male element of B will not fertilise 
 the female element of A ; so that, while the for- 
 mer experiment seems to show us that they are 
 varieties, the latter leads to the conviction that 
 they are S2Jccies. 
 
 When we see how capricious and uncertain this 
 sterility is, how unknown the conditions on which 
 it depends, I say that we have no right to affirm 
 that those conditions will not be better understood 
 by and by, and we have no ground for supposing 
 that we may not be able to experiment so as to 
 obtain that crucial result which I mentioned just 
 now. So that though Mr. Darwin's hy^iothesis 
 does not completely extricate us from this difficulty 
 at present, Ave have not the least right to say it 
 will not do so. 
 
 There is a wide gulf between the thing you can- 
 not explain and the thing that upsets you alto- 
 gether. There is hardly any hypothesis in this 
 world which has not some fact in connection with 
 it which has not been explained, but that is a very 
 different affair to a fact that entirely opposes your 
 
 artificial or natural selection, the objection must be admitted — 
 ultra-sceptical as it is. But in science, scepticism is a duty. 
 
XI PHENOMENA OF ORGANIC NATURE 467 
 
 hypothesis; in this case all you can say is, 
 that your hypothesis is in the same position as a 
 good many others. 
 
 Now, as to the third test, that there are no 
 other causes competent to explain the phenomena, 
 I explained to you that one should be able to say 
 of an hypothesis, that no other known causes than 
 those supposed by it are competent to give rise to 
 the phenomena. Here, I think, Mr. Darwin's 
 view is pretty strong. I really believe that the 
 alternative is either Darwinism or nothing, for I 
 do not know of any rational conception or theory 
 of the organic universe which has any scientific 
 position at all beside Mr. Darwin's. I do not 
 know of any proposition that has been put before 
 us with the intention of explaining the phenomena 
 of organic nature, which has in its favour a 
 thousandth part of the evidence which may be ad- 
 duced in favour of Mr. Darwin's views. Whatever 
 may be the objections to his views, certainly all 
 other theories are absolutely out of court. 
 
 Take the Lamarckian hypothesis, for example. 
 Lamarck was a great naturalist, and to a certain 
 extent went the right way to work ; he argued 
 from what was undoubtedly a true cause of some 
 of the phenomena of organic nature. He said it 
 is a matter of experience that an animal may be 
 modified more or less in consequence of its desires 
 and consequent actions. Thus, if a man exercise 
 himself as a blacksmith, his arms will become 
 
468 THE CAUSES OF THE XI 
 
 strong and muscular ; such organic modification is 
 a result of this particular action and exercise. 
 Lamarck thought that by a very simple supposi- 
 tion based on this truth he could explain the origin 
 of the various animal species : he said, for ex- 
 ample, that the short-legged birds Avhich live on 
 fish had been converted into the long-legged 
 waders by desiring to get the fish without wetting 
 their feathers, and so stretching their legs more 
 and more through successive generations. If 
 Lamarck could have shown experimentally that 
 even races of animals could be produced in this 
 way, there might have been some ground for his 
 speculations. But he could show nothing of the 
 kind, and his hypothesis has pretty well dropped 
 into oblivion, as it deserved to do. I said in an 
 earlier lecture that there are hypotheses and hy- 
 potheses, and when people tell you that Mr. Dar- 
 win's strongly-based hypothesis is nothing but a 
 mere modification of Lamarck's, you will know 
 what to think of their capacity for forming a 
 judgment on this subject. 
 
 But you must recollect that when I say I think 
 it is either Mr. Darwin's hypothesis or nothing ; 
 that either we must take his view, or look upon 
 the whole of organic nature as an enigma, the 
 meaning of which is wholly hidden from us ; you 
 must understand that I mean that I accept it 
 provisionally, in exactly the same way as 1 accept 
 any other hypothesis. Men of science do not 
 
SI ^THEmr5iEF3rTrE'-i7EGionc~ira7ruEE 469 
 
 pledge themselves to creeds ; they are bound by 
 carticles of no sort ; there is not a single belief that 
 it is not a bounden duty with them to hold with 
 a light hand and to part with cheerfully, the 
 moment it is really joroved to be contrary to any 
 fact, great or small. And if, in course of time I 
 see good reasons for such a proceeding, I shall have 
 no hesitation in coming before you, and pointing 
 out any change in my opinion without finding the 
 slightest occasion to blush for so doing. So I say 
 that we accept this view as we accept any other, 
 so long as it will help us, and we feel bound to 
 retain it only so long as it will serve our great 
 purpose — the improvement of Man's estate and 
 the widening of his knowledge. The moment 
 this, or any other conception, ceases to be useful 
 for these purposes, away with it to the four winds ; 
 we care not what becomes of it ! 
 
 But to say truth, although it has been my busi- 
 ness to attend closely to the controversies roused 
 by the publication of Mr. Darwin's book, I think 
 that not one of the enormous mass of objections 
 and obstacles which have been raised is of any 
 very great value, except that sterility case which 
 I brought before you just now. All the rest are 
 misunderstandings of some sort, arising either 
 from prejudice, or want of knowledge, or still 
 more from want of patience and care in reading 
 the work. 
 
 For you must recollect that it is not a book to 
 
470 THE CAUSES OF THE xi 
 
 be read with as mucli ease as its pleasant style 
 may lead you to imagine. You spin through it 
 as if it were a novel the first time you read it, and 
 think you know all about it ; the second time you 
 read it you think you know rather less about it ; 
 and the third time, you are amazed to find how 
 little you have really apprehended its vast scope 
 and objects. I can positively say that I never 
 take it up without finding in it some new view, or 
 light, or suggestion that I have not noticed before. 
 That is the best characteristic of a thorough and 
 profound book ; and I believe this feature of the 
 " Origin of Species " explains why so many per- 
 sons have ventured to pass judgment and criti- 
 cisms upon it which are by no means worth the 
 paper they are written on. 
 
 Before concluding these lectures there is one 
 point to which I must advert — though, as Mr. 
 Darwin has said nothing about man in his book, 
 it concerns myself rather than him ; — for I have 
 strongly maintained on sundry occasions that if 
 Mr. Darwin's views are sound, they apply as much 
 to man as to the lower mammals, seeing that it is 
 perfectly demonstrable that the structural differ- 
 ences which separate man from the apes are not 
 greater than those which separate some apes 
 from others. There cannot be the slightest doubt 
 in the world that the argument which apjjlies to 
 the improvement of the horse from an earlier 
 stock, or of ape from ape, applies to the improve- 
 
XI PHENOMENA OF OHGANIC NATURE 471 
 
 ment of man from some simpler and lower stock 
 than man. There is not a single faculty — func- 
 tional or structural, moral, intellectual, or instinc- 
 tive, there — is no faculty whatever that is not 
 capable of improvement ; there is no faculty what- 
 soever which does not depend upon structure, and 
 as structure tends to vary, it is capable of being 
 improved. 
 
 Well, I have taken a good deal of pains at 
 various times to prove this, and I have endeav- 
 oured to meet the objections of those who main- 
 tain, that the structural differences between man 
 and the lower animals are of so vast a character 
 and enormous extent, that even if Mr. Darwin's 
 views are correct, you cannot imagine this par- 
 ticular modification to take place. It is, in fact, 
 an easy matter to prove that, so far as structure is 
 concerned, man differs to no greater extent from 
 the animals which are immediately below him 
 than these do from other members of the same 
 order. Upon the other band, there is no one who 
 estimates more highly than I do the dignity of 
 human nature, and the width of the gulf in in- 
 tellectual and moral matters which lies between 
 man and the whole of the lower creation. 
 
 But I find this very argument brought forward 
 vehemently by some. " You say that man has 
 proceeded from a modification of some lower 
 animal, and you take pains to prove that the 
 structural differences which are said to exist in his 
 
 69 
 
4,72 THE CAUSES OF THE ZI 
 
 brain do not exist at all and you teach that all 
 functions, intellectual, moral, and others, are the 
 expression or the result, in the long run, of struc- 
 tures, and of the molecular forces which they 
 exert." It is quite true that I do so. 
 
 " Well, but," I am told at once, somewhat 
 triumphantly, " you say in the same hreath that 
 there is a great moral and intellectual chasm 
 between man and the lower animals. How is 
 this possible when you declare that moral and in- 
 tellectual characteristics depend on structure, and 
 yet tell us that there is no such gulf between the 
 structure of man and that of the lower animals ? " 
 
 I think that objection is based upon a miscon- 
 ception of the real relations which exist between 
 structure and function, between mechanism and 
 work. Function is the expression of molecular 
 forces and arrangements no doubt; but, does it 
 follow from this, that variation in function so 
 depends upon variation in structure that the former 
 is always exactly proportioned to the latter ? If 
 there is no such relation, if the variation in func- 
 tion which follows on a variation in structure may 
 be enormously greater than the variation of the 
 structure, then, you see, the objection falls to the 
 ground. 
 
 Take a couple of watches — made by the same 
 maker, and as completely alike as possible ; set 
 them upon the table, and the function of each — 
 which is its rate of going — will be performed in 
 
XI PHENOMENA OF ORGANIC NATURE 473 
 
 the same manner, and you shall be able to dis- 
 tinguish no difference between them ; but let me 
 take a pair of pincers, and if my hand is steadj 
 enough bo do it, let me just lightly crush together 
 the bearings of the balance-wheel, or force to a 
 slightly different angle the teeth of the escape- 
 ment of one of them, and of course you know the 
 immediate result will be that the watch, so treated, 
 from that moment will cease to go. But what 
 proportion is there between the structural altera- 
 tion and the functional result ? Is it not perfectly 
 obvious that the alteration is of the minutest kind, 
 yet that, slight as it is, it has produced an infinite 
 difference in the performance of the functions of 
 these two instruments ? 
 
 Well, now, apply that to the present question. 
 What is it that constitutes and makes man what 
 he is ? What is it but his power of language — 
 that language giving him the means of recording 
 his experience — making every generation some- 
 what wiser than its predecessor — more in accord- 
 ance with the established order of the universe ? 
 
 What is it but this power of speech, of record- 
 ing experience, which enables men to be men — 
 looking before and after and, in some dim sense, 
 understanding the working of this wondrous uni- 
 verse — and which distinguishes man from the 
 whole of the brute world ? I say that this func- 
 tional difference is vast, unfathomable, and truly 
 infinite in its consequences ; and I say at the same 
 
474 THE CAUSES OF THE XI 
 
 time, that it may depend upon structural differ- 
 ences which shall be absolutely inappreciable to 
 us with our present means of investigation. What 
 is this very speech that we are talking about ? I 
 am speaking to you at this moment, but if you 
 were to alter, in the minutest degree, the propor- 
 tion of the nervous forces now active in the two 
 nerves which supply the muscles of my glottis, I 
 should become suddenly dumb. The voice is pro- 
 duced only so long as the vocal chords are parallel ; 
 and these are parallel only so long as certain 
 muscles contract with exact equality ; and that 
 again depends on the equality of action of 
 those two nerves I spoke of. So that a change of 
 the minutest kind in the structure of one of these 
 nerves, or in the structure of the part in which it 
 originates, or of the supply of blood to that part, 
 or of one of the muscles to which it is distributed, 
 might render all of us dumb. But a race of dumb 
 men, deprived of all communication with those 
 who could speak, would be little indeed removed 
 from the brutes. And the moral and intellectual 
 difference between them and ourselves would be 
 practically infinite, though the naturalist should 
 not be able to find a single shadow of even specific 
 structural difference. 
 
 But let me dismiss this question now, and, in 
 conclusion, let me say that you may go away with 
 it as my mature conviction, that Mr. Darwin's 
 work is the greatest contribution which has been 
 
XI PHENOMENA Of OKUAJNIC JNATURE 475 
 
 made to biological science since the publication of 
 the " Regne Animal " of Cuvier, and since that 
 of ^the " History of Development," of Von Baer. 
 I believe that if you strip it of its theoretical part 
 it still remains one of the greatest encyclopcedias 
 of biological doctrine that any one man ever 
 brought forth ; and I believe that, if you take it 
 as the embodiment of an hypothesis, it is destined 
 to be the guide of biological and psychological 
 speculation for the next three or four genera- 
 tions. 
 
 END OF VOL. II. 
 
D. APPLETON & CO.'S PUBLICATIONS. 
 
 NEW EDITION- OF PROF. HUXLEY'S ESSAYS. 
 
 COLLECTED ESSA YS. By Thomas H. Huxley. 
 New complete edition, with revisions, the Essays being grouped 
 according to general subject. In nine volumes, a new Intro- 
 duction accompanying each volume. i2mo. Cloth, $1.25 per 
 volume. 
 
 Vol. I.— method AND RESULTS. 
 
 Vol. II.— DARWINIANA. 
 
 Vol. III.-SCIENCE AND EDUCATION. 
 
 Vol. IV.— SCIENCE AND HEBREW TRADITION. 
 
 Vol. v.— SCIENCE AND CHRISTIAN TRADITION. 
 
 Vol. VI.— HUME. 
 
 Vol. VII.— MAN'S PLACE IN NATURE. 
 
 Vol. VIII.— DISCOURSES, BIOLOGICAL AND GEOLOGICAL. 
 
 Vol. IX.— EVOLUTION AND ETHICS, AND OTHER ESSAYS, 
 
 " Mr. Huxley has covered a vast variety of topics during the last quarter of a 
 century. It gives one an agreeable surprise to look over the tables of contents and 
 note the immense territory which he has explored. To read these books carefully 
 and studiously is to become thoroughly acquainted with the most advanced thought 
 on a large number of topics." — New YorA Herald. 
 
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 problems of science better adapted to reading by the general public, and in this form 
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 tive utterances." — Chicago Times. 
 
 " It was inevitable that his essays should be called for in a completed form, and they 
 will be a source of delight and profit to all who read them. He has always commanded 
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