[page] 276

DARWIN'S DESCENT OF MAN.

THE effect of Mr. Darwin's long expected and lately published volumes will not be so much to startle friend or for by novel facts or transcendent theories as to consolidate, to fortity, and to push to a conclusion the scheme of ideas which the world has learned for years to associate with his name. Feeling himself secure in the hold which the essential principles of his system have obtained upon the scientific opinion of the day, he comes forward prepared with modifications in detail, in deference to the criticisms which have been brought to bear from this or that standing-point of specific inquiry; whilst, like a skilful general, he proceeds to cover the ground with fresh masses of fact or a greater breadth and weight of strategy. His conclusions now go the length which he had, in terms somewhat vague and tentative, set himself at the outset of his speculations. He claims to have brought man himself, his origin and constitution, within that unity which he had previously sought to trace through all lower animal forms. The growth of opinion in the interval, due in chief messure ot his own intermediate works, has placed the discussion of this problem in a position very much in advance of that held by it fifteen years ago. The problem of evolution is hardly any longer to be treated as one of first principles; nor has Mr. Darwin to do battle for a first hearing of his central hypothesis, upborne as it is by a phalanx of names full of distinction and promise in either hemisphere. The high antiquity of man may rest sufficiently upon the labours of a host of demonstrators, from M. Boucher de Perthes to Sir Charles Lyell, Sir John Lubbock, and fellow-workers without number at home and abroad. Under the hands of Professor Huxley all has been done that could be done to make the physiological differences between man and the anthropomorphous quadrumans disappear, "it having been conclusively shown that in every single visible character man differs less from the higher apes than these do from the lowest members of the same order of primates." Mr. Darwin's object in the present work is to establish, from a general survey of his whole nature, the eveidence of "man, like every other species, being descended from some preexisting from; secondly, the manner of his development; and, thirdly, the value of the differences between the so-called reaces of men." The third head of inquiry was found by him to run up ultimately, and to a highly important extent, into the question of sexual selection, which had dawned upon him early in his researches, and has been slightly referred to in the Origin of Species. It has since been developed in a very able manner by Profefssor Häckel, to whose authority and facts Mr. Darwin refers at many stages of his argument, and whose work, had it appeared prior to the conception of Mr. Darwin's present essay, would, our author modestly tells us, have probably withheld it from the would. The amplitude of detail to which it was found necessary to extend this portion of the inquiry, together with the important etghnological issues dependent upon it, caused the latter half of the present work to reach a length somewhat out of proportion to the first. It fills, in fact, half the first volume and the whole of the second. We reserve for another opportunity the discussion of that portion of the Descent of Man which traces his pedigreee in its later ramifications from the point where it begins to bifurcate from a common ancestry with lower animal forms.

In the Descent of Man Mr. Darwin covers much of the ground occupied by Mr. Mivart in his recent Genesis of Species. We find ourselves justified in the anticipation on which we ventured in our review of Mr. Mivart's work, that Mr. Darwin would be far from insisting on the principle of natural selection as the sole agent in the origination or modification of species, to the exclusion of those internal principles of development and change which are inherent in the organism itself. It is essentially and above all upon this very element of internal and spontaneous growth that Mr. Darwin claims to rest that tendency to vary which he describes as infinite, and which, unknown and indefinable as are its laws or causes, experience teaches us to recognise in all forms endued with life. What Mr. Darwin specifically urges as the basis of his present work, and fortifies with the width and depth of illustration so habitual to him, is that "man is variable in body and mind, such varistions being induced either directly or indirectly by the same general causes, and obeying the same general laws, as is the case with the lower animals." He is careful to acknowledge, and even to point out, many characteristics of the lower forms of life of which natural selection fails to give an explanation. But, not to speak of the pregnant theory of sexual selection which he holds in reserve, he is able to fall back upon the general idea of variations induced as early as the embryonic stage, and tending to endless subsequent differentiation. What other explanation, he asks, has ever been given of the marvellous fact that the embryo of a man, dog, seal, bat, reptile, &c., can at first in no degree be distinguished from each other? "In order to understand the existence of rudimentary organs, we have only to suppose that a former progenitor possessed the parts in question in a perfact state, and that under changed habits of life they became reduced either by simple disuse, or through the natural selection of those individuals which were least encumbered with a superfluous par, aided by the other means previously indicated." A novel and curious piece of evidence is brought in to illustrate the bearing of this natural process upon the descent, or, as it might be more correct to call it, the ascent, of man. A little peculiarity in the ear, both in men and women, has been brought to the author's notice by Mr. Woolner, the well-known sculptor, who has modelled it for illustration in the work before us. The artist's attention was first drawn to it whilst at work upon a figure of Puck, to whom he had given pointed ears. He was thus led to examine the ears of various monkeys, and subsequently, with increased care, those of men. The peculiarity consists in a little blunt point projecting towards the inner ear from the inwardly folded margin or helix:—

These points not only project inwards, but often a little outwards, so that they are visible when the head is viewed from directly in front or behind. They are variable in size and somewhat in position, standing either a little higher or lower; and they sometimes occur on one ear and not on the other. Now the meaning of these projections is not, I think, doubtful; but it may be thought that they offer too trifling a character to be worth notice. This thougt, however, is as false as it is natural. Every character, however slight, must be the result of some definite cause; and if it occurs in many individuals, deserves consideration. The belix obviously consists of the extreme margin of the ear folded inwards; and this folding appears to be in some manner connected with the whole external ear being permanently pressed backwards. In many monkeys, which do not stand high in the order, as baboons and some species of macacus, the upper portion of the ear is slightly pointed, and the margin is not at all folded inwards; but if the margin were to be thus folded, a slight point would necessarily project inwards and probably a little outwards. This could actually be observed in a specimen of the Ateles beelzebuth in the Zoological Gardens; and we may safely conclude that it is a similar structure—a vestige of formerly pointed ears—which occasionally reappears in man.

* The Descent of Man, and Selection in Relation to Sex. By Charles Darwin, M.A., F.R.S., &c. 2 vols. London: John Murray. 1871.

[page] 277

Many further correspondences of rudimentary structure are accumulated by Mr. Darwin. Such are the nictitating membrane, or third eyelid, with its necessary muscles and other appendages, which is especially developed in birds, and in a lesser degree in some reptiles and amphibians, and in certain fishes, as in sharks. It is fairly well represented in the two lower divisions of the mammalian series, the monotremata and marsupials; and in some of the higher mammals, as in the walrus. In man, and the quadrumana, it exists as a mere rudiment, called the semilunar fold. The os coccyx in man, as in some few of the quadrumana and other mammals, is the rudiment of what forms in other vertebrates an external tail. With this large class of facts Mr. Darwin proceeds to correlate those which are drawn from the generally homologous structure in man and the lower animals, both in bodily type, cerebral structure, and reproductive processes, as well as in the parasites with which they are infested. A third class of resemblances is drawn from their embryonic development, proving man, in respect to these earlier stages of his being, to be physically nearer to the apes than the apes are to the dog. Further proofs of community of origin are sought from the comparison of mental powers, Mr. Darwin's object being to show that no distinction in essence or in kind can be drawn between these faculties in man and the higher mammals. Immense as the distance between the ape and the lowest savage msv be in degree, it is, he contends, one of degree only. Cuvier's doctrine that instinct and intelligence stand in an inverse ratio to one another is made to yield to fuller and more exact observations like those of M. Pouchet. Memory, foresight, imagination and even reason are shared alike by man and other animal tribes. Wonder curiosity, imitation, the parental and filial instincts, even the sentiment of chivalry, are seen in both. Curious tales are told of the risks run by monkeys to rescue a comrade or to aid favourite keepers. The notion that no animal is capable of using a tool is set aside, the chimpanzee in a state of nature being known to crack a native fruit, somewhat, like a walnut, with a stone. Mr. Darwin has himself seen a young orang improvise out of a stick a lever for prising open a crevice or lifting heavy bodies. Schimper the Abyssinian traveller reported by Brehm, knew troops of baboons (C. Gelada) encounter those of another species (C. Hamadryas) by rolling down great stones upon them. The like strategy was encountered by Brehm in company with the Duke of Coburg-Gotha in the Mensa Pass, when the pass was actually closed for awhile against the caravan equipped with firearms. It is true, as urged by the Duke of Argylf, that no brute has got to the point of fashioning or polishing a tool or weapon. But neither probably had primeval man, as witnessed by his first rudimentary implements, any notion beyond the use of fragments accidentally splintered or made to hand. As regards architecture and dress, we have the anthropomorphous apes building for themselves platforms In the trees. The orang is known to cover itself at night with the leaves of the Pandanus: and Brehm states that one of his baboons used to protect itself from the heat of the sun by throwing a straw mat over its head. In articulate language man has, of course, left the highest brutes far behind. Yet much may be said for Archbishop Whately's remark, that "man not the only animal that can make use of language to express more or less what is passing in his mind, or understand what ia expressed by another," as well as for the arguments of Mr. Hensleigh Wedgwood, Mr. Farrar, and Professor Schleicher on the imitative origin of human language. In the case of the higher mental states, in acts of abstractive self-consciousness, individuality, or general ideas, who shall say, asks Büchner, how far the hard-worked wife of a degraded Australian savage, who uses hardly any abstract words, and cannot count above four, exerts her self-consciousness, or reflects upon the nature of her existence, any more than many an intelligent old dog may reflect upon the past pleasures of the chase, which he is known to recall in dreams?

In his treatment of the origin end growth of the moral sense in man, Mr. Darwin has still more emphatically taken up a stand-point of a far higher level than that which Mr. Mivart considered himself to have reached in his recent objections. It is by no means essential to the theory of evolution as enounced by Mr. Darwin to sink the ideas of moral right or virtue into a mere "kind of retrieving," a blind fetching and carrying, so to say, in obedience to the animal sense of utility, which, traditionally impressed upon the young, has grown into an organized code of enlightened selfinterest. According to Mr. Darwin's latent view, the moral sense is in its nature founded upon something wholly distinct from that form of selfishness on which philosophers of the darivative school have been wont to rest the foundation of morality. He divides himself here from Adam Smith and Mill, as he seems in fact to go deeper than Mr. Herbert Spencer into the organic nature of morals. Mr. Spencer has spoken of the experiences of utility organized and consolidated through all past generations of the human race, which by continued transmission and accumulation have become in us certain faculties of moral intution, "certain emotions responding to right and wrong conduct, which have no apparent basis in the individual experiences of utility." The moral sense, as traced by Mr. Darwin, is rooted deeper in the elementary acts and functions of life; it is fundamentally identical with the social instincts which are traceable in degree in all animals, and of which it would be absurd to speak as having been engendered in the lower animals out of selfishness, or from feelings for the general good. The rudiments at least of emotions or faculties, moral in the true sense, as distinct from any calculation of results, exist, he proceeds to show, through a wide range of animal life. They ultimately rest upon sympathy, a more diffusive form of, love, leading to habits of self-command, deference to others, devotion and chivalrous sacrifice of self, sociability, and the reciprocal sense of duties upon which the family and society itself is reared. Natural Selecton would come in to strengthen and perpetuate the community in which these principles were at work. "Even among the lower animals those individuals which took the greatest pleasure in society would best escape various dangers; whilst those that cared least for their commrades, and lived solitary, would perish in greater numbers." Out of the rude impulses which in their earliest form served as a rule of right and wrong, taught what ought to be done or avoided, and acted as an elementary conscience in man, as in many a form of brute, were thus developed, as man advanced in intellectual power and experience, the standard and code of morality. In this portion of his argument Mr. Darwin's unexampled grasp of facts, with his power of logical correlation, is, it seems to us, seen at its highest. The intellectual pleasure of following so exquisite a chain of philosophical deduction may almost compensate many minds for the shock which his ultimate conclusion will inflict on them. Drawing into one these separate threads of physical, mental, and, moral investigation, his argument tends to bind by one indissoluble bond what have long been held to be distinct families in the animal realm. Man's right to form a separage order is denied. He comes, indeed, from a long and obscure line of progenitors. But the proximate steps of his pedigree may be pretty clearly made out. Going back no further than the Simiadæ, we discern two groups, as divided by nearly all naruralists—the Catarhine or Old World, and the Platyrhine or New World, monkeys. To the former of these man stands unquestionably the nearest allied in his dentition, the structure of his nostrils, and many other respects. Here, then, Mr. Darwin considers he has at length found the missing link whereby man, the wonder and glory of the universe, is connected through the successive grades of Simiadæ Lemuridæ, placental and marsupial mammals, reptiles, and amphibians, with his earliest vertebrate ancestry, a group of marine animals resembling the larvæ of existing Ascidians:—

By considering the embryological structure of man—the homologies which he presents with the lower animals—the rudiments which be retains—and the revesions to which be is Hable, we can partly recall in imagination the former condition of our early progentores; and can approximately place them in their proper position in the zoological series. We thus learn that man is descended from a hadry quadruped, furnished with a tail and pointed ears, probably arboreal in its habits, and an in habitant of the Old World. This creature, if its whole structure had been examined by a naturallist, would have been classed amongst the Quadrumann, as surely as would the common and still more ancient progenitor of the Old and New World monkeys. The Quadrumens and all the higheer mammals are probably derived from an ancient marsupdal animal, and this throught a long line of diversified forms, either from some reptile-like or some amphibian-like creature, and this again from some fish-like animal. In the dim obsecurity of the past we can see that the early progenitor of all the Vertebrate must have been an aqustie animal, provided with branchiæ, with the two sexes united in the same individual, and with the most important organs of the body (such as the brain and heart) imperfectly developed. This animal seems to have been more like the larvæ of our exixting marine Accidians thany any other known form.

(To be continued.)