FIG. 15.-Front and side views of the bony pelvis of Man, the Gorilla and Gibbon; reduced from drawings made from nature, of the same absolute length, by Mr. Waterhouse Hawkins. Not only, however, does Man occasionally possess thirteen pair of ribs, but the Gorilla sometimes has fourteen pairs, while an Orang-Utan skeleton in the Museum of the Royal College of Surgeons has twelve dorsal and five lumbar vertebræ, as in Man. Cu vier notes the same number in a Hylobates. On the other hand, among the lower Apes, many possess twelve dorsal and six or seven lumbar vertebræ; the Douroucouli has fourteen dorsal and eight lumbar, and a Lemur (Stenops tardigrades) has fifteen dorsal and nine lumbar vertebræ. The vertebral column of the Gorilla, as a whole, differs from that of Man in the less marked character of its curves, especially in the slighter convexity of the lumbar region. Nevertheless, the curves e present, and are quite obvious in young skeletons of the Gorilla and Chimpanzee which have been prepared without removal of the ligaments. In young Orangs similarly preserved, on the other hand, the spinal column is either straight, or even concave forward, through out the lumbar region. Whether we take these characters then, or such minor ones as those which are deriv able from the proportional length of the spines in the cervical vertebræ, and the like, there is no doubt whatsoever as to the marked difference between Man and the Gorilla: but there is as little, that equally marked differences, of the very same order, obtain between the Gorilla and the lower apes. The pelvis, or bony girdle of the hips, of Man is a strikingly human part of his organi 84 cubic inches. Let us assume, for simplicity's sake, that the lowest Man's skull has twice the capacity of the highest Gorilla. No doubt this is a very striking difference, but it loses much of its apparent systematic value when viewed by the light of certain other equally indubitable facts respecting cranial capacities. zation; the expanded haunch-bones affording support for his viscera during his habitually erect posture, and giving space for the attachment of the great muscles which enable him to assume and to preserve that attitude. In these respects the pelvis of the Gorilla differs very considerably from his (Fig. 15). But go no lower than the Gibbon, and see how vastly more he differs The first of these is, that the difference in from the Gorilla than the latter does from the volume of the cranial cavity of different Man, even in this structure. Look at the races of mankind is far greater, absolutely, flat, narrow haunch bones--the long and than that between the lowest Man and the narrow passage-the coarse, outwardly highest Ape, while, relatively, it is about curved, ischiatic prominences on which the the same. For the largest human skul Gibbon habitually rests, and which are measured by Morton contained 114 cubic coated by the so-called callosities," dense inches--that is to say, had very nearly patches of skin, wholly absent in the Gorilla. in the Chimpanzee, and in the Orang, as in Man! In the lower Monkeys and in the Lemurs the difference becomes more striking still, the pelvis acquiring an altogether quadru pedal character. But now let us turn to a nobler and more characteristic organ-that by which the hunan frame seems to be, and indeed is, so strongly distinguished from all others-I mean the skull. The differences between a Gorilla's skull and a Man's are truly immense (Fig. 16). In the former, the face, formed largely by the massive jaw-bones, predominates over the brain-case, or crani. um proper in the latter, the proportions of the two are reversed. In the Man, the occipital foramen, through which passes the great nervous cord connecting the brain with the nerves of the body, is placed just behind the centre of the base of the skull, which thus becomes evenly balanced in the erect Posture; in the Gorilla it lies in the posterior third of that base. In the Man, the surZace of the skull is comparatively smooth, ar the supraciliary ridges or brow promineuces usually project but little-while, in the Gorilla, vast crests are developed upon the skull, and the brow ridges overhang the cavernous orbits, like great penthouses. Sections of the skulls, however, show that some of the apparent defects of the Gorilla's cranium arise, in fact, not so much from deficiency of brain-case as from excessive development of the parts of the face. The cranial cavity is not ill-shaped, and the forehead is not truly flattened or very retreating, its really well-formed curve being simply disguised by the mass of bone which is built up against it (Fig. 16). But the roofs of the orbits rise more obiquely into the cranial cavity, thus diminishing the space for the lower part of the anterior lobes of the brain, and the absolute capacity of the cranium is far less than that of Man. So far as I am aware, no human cranium belonging to an adult man has yet been observed with a less cubical capacity than 62 cubic inches, the smallest cranium observed in any race of men by Morton, measuring 63 cubic inches; while, on the other hand, the most capacious Gorilla skull yet measured has a content of not more than double the capacity of the smallest; while its absolute preponderance of 52 cubic inches is far greater than that by which the low est adult male human cranium surpasses the largest of the Gorillas (62 341 274). Secondly, the adult crania of Gorillas which have as yet been measured differ among themselves by nearly one third, the maximum capacity being 34.5 cubic inches, the minimum 24 cubic inches; and, thirdly, after making all due allowance for differ ence of size, the cranial capacities of some of the lower apes fall nearly as much, relatively, below those of the higher Apcs as the latter fall below Man. Thus, even in the important matter of cranial capacity, Men differ more widely from one another than they do from the Apes, while the lowest Apes differ as much, in proportion, from the highest, as the latter does from Man. The last proposition is still better illustrated by the study of the modifications which other parts of the cranium undergo in the Simian series. It is the large proportional size of the facial bones and the great projection of the jaws which confers upon the Gorilla's skull its small facial angle and brutal character. But if we consider the proportional size of the facial bones to the skull proper only, the little Chrysothrix (Fig. 16) differs very widely from the Gorilla, and in the same way as Man does; while the Baboons (Cynocephalus, Fig. 16) exaggerate the gross proportions of the muzzle of the great Anthropoid, so that its visage looks mild and human by comparison with theirs. The difference between the Gorilla and the Baboon is even greater than it appears at first sight; for the great facial mass of the former is largely due to a downward development of the jaws; an essentially human character, superadded upon that almost purely forward, essentially brutal, development of the same parts which characterizes the Baboon, and yet more remarkably distinguishes the Lemur. Similarly the occipital foramen of Mycetes (Fig. 16), and still more of the Lemurs, is situated completely in the posterior face of the skull, or as much farther back than that of the Gorilla as that of the Gorilla is further back than that of Man; while, as if to render patent the futility of the attempt to base any broad classificatory distinction on such a character, the same group of Platyrhine, or American monkeys, to which the Mycetes belongs, contains the Chrysothrix, whose occipital foramen is situated far more forward than in any other ape, and nearly approaches the position it holds in Man. thrix, the cranium is as smooth and rounded as that of Man himself. What is true of these leading characteristics of the skull holds good, as may be imagined, of all minor features; so that for every constant difference between the Gorilla's skull and the Man's a similar constant difference of the same order (that is to say, consisting in excess or defect of the same quality) may be found between the Gorilla's skull and that of some other ape. So that, for the skull, no less than for the skeleton in THE RELATIONS OF MAN Again, the Orang's skull is as devoid of excessively developed supraciliary prominences as a man's, though some varieties exhibit great crests elsewhere (seep.208); and in some of the Cebine apes and in the Chryso FIG. 16.-Sections of the skulls of Man and various Apes, drawn so as to give the cerebral cavity the same length in each case, thereby displaying general, the proposition holds good that the differences between Man and the Gorilla are of smaller value than those between the Gorilla and some other Apes. In connection with the skull, I may speak of the teeth-organs which have a peculiar classificatory value, and whose resemblances and differences of number, form, and succession, taken as a whole, are usually regarded as more trustworthy indicators of affinity than any others. Man is provided with two sets of teethmilk teeth and permanent teeth. The former consist of four incisors, or cuttingteeth; two canines, or eye-teeth; and four molars, or grinders, in each jaw, making twenty in all. The latter (Fig. 17) comprise four incisors, two canines, four small grinders, called premolars or false molars, and six large grinders, or true molars in each jaw making thirty-two in all. The internal incisors are larger than the external pair, in the upper jaw, smaller than the external pair, in the lower jaw. The crowns of the upper molars exhibit four cusps, or bluntpointed elevations, and a ridge crosses the crown obliquely, from the inner, anterior, cusp to the outer, posterior cusp (Fig. 17 m2). The anterior lower molars have five cusps, three external and two internal. The premolars have two cusps, one internal and one external, of which the outer is the higher. In all these respects the dentition of the Gorilla may be described in the same terms as that of Man; but in other matters it_exhibits many and important differences (Fig. 17). Thus the teeth of man coustitute a regular and even series-without any break and without any marked projection of one tooth above the level of the rest; a peculiarity which, as FIG. 17.-Lateral views, of the same length, of the upper jaws of various Primates. i, incisors; c, canines; pm, premnolars; m, molars. A line is drawn through the first molar of Man, Gorilla, Cynocephalus, and Cebus, and the grinding surface of the second molar is shown in each, its anterior and internal angle being just above the m of m2. And Cuvier long ago showed, is shared by no the Gorilla; but, notwithstanding this, their other mammal save one-as different a crea- dentition is very different, for they have four ture from man as can well be imagined- more false molars, like the other American namely, the long extinct Anoplotherium. monkeys-but as they are four fewer truc The teeth of the Gorilla, on the contrary, ex- molars, the total remains the same. hibit a break, or interval, termed the diaste- passing from the American apes to the ma, in both jaws in front of the eye-tooth, Lemurs, the dentition becomes still more or between it and the outer incisor, in the completely and essentially different from upper jaw; behind the eye-tooth, or be that of the Gorilla. The incisors begin to tween it and the front false molar in the vary both in number and in form. The lower jaw. Into this break in the series, in molars acquire, more and more, a manyeach jaw, fits the canine of the opposite iaw, pointed, insectivorous character, and in one the size of the eye-tooth in the Gorilla being Genus, the Aye-Aye (Cheiromys), the canines so great that it projects, like a tusk, far be- disappear, and the teeth completely simulate yond the general level of the other teeth. those of a Rodent (Fig. 17). The roots of the false molar teeth of the Hence it is obvious that, greatly as the Gorilla, again, are more complex than in dentition of the highest Ape differs from Man, and the proportional size of the molars that of Man, it differs far more widely from is different. The Gorilla has the crown of that of the lower and lowest Apes. the hindmost grinder of the lower jaw more complex, and the order of eruption of the Whatever part of the animal fabric-whatpermanent teeth is different, the permanent ever series of muscles, whatever viscera canines making their appearance before the might be selected for comparison-the result second and third molars in Man, and after would be the same-the lower Apes and the them in the Gorilla. Gorilla would differ more than the Gorilla Thus, while the teeth of the Gorilla closely and the Mar. I cannot attempt in this place resemble those of Man in number, kind, and to follow out all these comparisons in detail, in the general pattern of their crowns, they and indeed it is unnecessary I should do so. exhibit marked differences from those of Man But certain real, or supposed, structural disin secondary respects, such as relative size, tinctions between man and the apes remain, number of fangs, and order of appearance.upon which so much stress has been laid But if the teeth of the Gorilla be compared that they require careful consideration in with those of an Ape, no further removed order that the true value may be assigned to from it than a Cynocephalus, or Baboon, it those which are real, and the emptiness of will be found that differences and resem- those which are fictitious may be exposed. blances of the same order are easily observa. I refer to the characters of the hand, the ble; but that many of the points in which foot, and the brain. the Gorilla resembles Man are those in which Man has been defined as the only animal it differs from the Baboon, while various respects in which it differs from Man are exaggerated in the Cynocephalus. The number and the nature of the teeth remain the same in the Baboon as in the Gorilla and in Man. But the pattern of the Baboon's upper molars is quiet different from that described above (Fig. 17), the canines are proportionally longer and more knife-like; the anterior premolar in the lower jaw is specially modified; the posterior molar of the lower jaw is still larger and more complex than in the Gorilla. Passing from the old-world Apes to those of the new world, we meet with a change of much greater importance than any of these. In such a genus as Cebus, for example (Fig. 17), it will be found that while in some secondary points, such as the projection of the canines and the diastema, the resemblance to the great ape is preserved; in other and most important respects, the dentition is extremely different. Instead of 20 teeth in the milk set, there are 24; instead of 32 teeth in the permanent set, there are 36, the false molars being increased from eight to twelve. And in form the crowns of the molars are very unlike those of the Gorilla, and differ far inore widely from the human pattern. The Marmosets, on the other hand, exhibit the same number of teeth as Man and possessed of two hauts terminating his fore limbs, and of two feet ending his hind limbs, while it has been said that all the apes possess four hands; and he has been affirmed to differ fundamentally from all the apes in the characters of his brain, which alone, it has been strangely asserted and reasserted, exhibits the structures known to anatomists as the posterior lobe, the posterior cornu of the lateral ventricle and the hippocampus minor. are That the former proposition should have gained general acceptance is not surprising indeed, at first sight, appearances much in its favor; but, as for the secondi, one can only admire the surpassing courage of its enunciator, seeing that it is an innova tion which is not only opposed to generally and justly accepted doctrines, but which is directly negatived by the testimony of all original inquirers, who have specially investigated the matter; and that it neither has been, nor can be, supported by a single anatomical preparation. It would, in fact, be unworthy of serious refutation, except for the general and natural belief that deliberate and reiterated assertions must have some foundation. Before we can discuss the first point with advantage we must consider with some attention, and compare together, the structure |