Anthropoid apes

Transcriber’s Note: Italics are enclosed in _underscores_; references to specific area within illustrations, originally printed in smaller point-size numbers, are enclosed in ~tildes~.

Additional notes will be found near the end of this ebook.

The International Scientific Series.

Vol. LIII.

Anthropoid Apes

By Robert Hartmann

Professor In The University Of Berlin

With Sixty-Three Illustrations

London Kegan Paul, Trench & Co., 1, Paternoster Square 1885

(_The rights of translation and of reproduction are reserved_)

Contents.

Chapter Page

I. The Development Of Our Acquaintance With Anthropoid Apes 1

II. The External Form Of Anthropoid Apes 11

III. THE EXTERNAL AND ANATOMICAL STRUCTURE OF ANTHROPOID APES, COMPARED WITH THE HUMAN STRUCTURE 55

IV. On Varieties In The Form Of Anthropoids 210

V. GEOGRAPHICAL DISTRIBUTION, HABITS IN A STATE OF NATURE, AND NATIVE NAMES OF ANTHROPOIDS 225

VI. Life In Captivity 257

VII. Position Of Anthropoids In The Zoological System 285

VIII. A SUMMARY, TOGETHER WITH SOME FURTHER CONSIDERATIONS OF THE ANTHROPOMORPHISM OF THE GORILLA, CHIMPANZEE, ORANG, AND GIBBON 290

Appendix 309

Index 321

List Of Illustrations.

Fig. Page

1. Aged male gorilla 14

2. Ear of a male adult gorilla 17

3. The young male gorilla, from the specimen in the Berlin Aquarium of 1876–77 22

4. The same animal at a still earlier age 23

5. Ear of chimpanzee 31

6. Young chimpanzee 33

7. Head and shoulders of an aged male orang-utan 38

8. Ear of the orang-utan 39

9. Adult male orang-utan 40

10. Head of the white-handed gibbon 47

11. Ear of the white-handed gibbon 48

12. Left hand of _Hylobates albimanus_ 49

13. Left foot of the same animal 50

14. A wauwau in the left foreground (_Hylobates agilis_); in the background to the right, two slender apes (_Semnopithecus entellus_) 51

15. Skull of an aged male gorilla in profile 56

16. Front view of the skull of an aged male gorilla 57

17. Skeleton of an aged male gorilla 65

18. Skull of an aged male chimpanzee 69

19. Skull of a very young female chimpanzee 73

20. Skeleton of the forearm and hand of the Central African bam-chimpanzee 74

21. Skeleton of foot of the Central African bam-chimpanzee 76

22. Skull of middle-aged female orang 77

23. Skeleton of young orang-utan 79

24. The Zulu king, Ketchwayo, in fighting array, with two of his men 85

25. Aidanill, hairless Australian 88

26. The same in profile 88

27. Dewan, Aidanill’s sister 90

28. Human ear 93

29. Magot (_Innuus ecaudatus_) 94

30. Capucin ape (_Cebus capucinus_) 98

31. Hand of a very aged male gorilla 103

32. Hand of a Hammegh from Roseres, on the Blue Nile 104

33. Satan’s ape (_Pithecia Satanas_). Shows the formation and mode of using the feet in apes of the New World 106

34. Human skull 108

35. The Neanderthal skull 115

36. Lower jaw of Moulin-Quignon 119

37. Naulette lower jaw 120

38. Lower jaw of chimpanzee 120

39. Sagittal section through the skull of a bam-chimpanzee 123

40. Human skeleton 132

41. Skeleton of an aged male gorilla 133

42. Skeleton of human hand, back view 136

43. Section through a platycnemic tibia from Cro-Magnon 138

44. Section through the tibia of a male gorilla 138

45. Section through the tibia of a male chimpanzee 138

46. Skeleton of the human foot, seen from above 140

47. Coaita (_Ateles paniscus_) 142

48. Muscles of the head and face of a European 151

49. Head-muscles of a Monjalese negro 152

50. Head-muscles of gorilla presented in Fig. 3 153

51. Palmar muscles of man 168

52. Palmar muscles of gorilla 169

53. Muscular system of the back of a gibbon’s hand 170

54. Muscular system of the human foot 177

55. Muscles on the upper side of chimpanzee’s foot 178

56. The brain of an orang, seen from the side 191

57. Brain of the chimpanzee, seen from above 192

58. Brain of gorilla, side view 193

59. Brain of orang, seen from above 194

60. Longitudinal section of a gorilla’s brain 196

61. Mafuca 216

62. The home of the gorilla 230

63. Climbing orang-utan, seen from behind 244

Anthropoid Apes.

Chapter I.

The Development Of Our Acquaintance With Anthropoid Apes.[1]

Our first acquaintance with the great anthropoid apes dates from the times of remote antiquity. The West Coast of Africa, which is the abode of these animals, was known to the Carthaginians as early as B.C. 500. In B.C. 470 Hanno set out with sixty fifty-oared galleys, laden with colonists and merchandise, on a grand expedition across Morocco to Upper Guinea. The object in view was partly mercantile, partly undertaken with the purpose of establishing a colony. It seems that at that time pioneering expeditions had previously taught them how far the coast was adapted for colonization. The Carthaginians met with “_gorillai_” on the lower range of the mountains of the Isle of Sherboro, and in the mountainous district of Sierra Leone(1). These are described as hairy sylvan creatures who replied to the attacks of the seafarers by throwing stones at them. Three of these monsters, of the female sex, were captured, but they bit and scratched so furiously that it was necessary to kill them on the spot. Pliny relates that at the time of the Roman invasion, B.C. 146, two of the skins obtained on this occasion were still preserved at Carthage, in the temple of Astarte(2). It was subsequently shown that chimpanzees, not true gorillas, were described in these “gorillai.” The latter animals are not now found so far north.

[1] A list of the numerous authorities for the substance of this chapter is placed at the end of the volume.

An old representation of the chimpanzee, in mosaic, was found on the pavement of the temple of Fortuna at Præneste (now Palestrina). This mosaic is now in a museum at Rome, and has been described by several authors. It represents a scene in tropical Africa, probably on the Upper Nile. I find it difficult to recognize the chimpanzee on the mosaic amid the giraffes, hippopotami, crocodiles, and the other representatives of the animal world of tropical Africa(3). But it is well known that these large apes are found on some of the streams of the Upper Nile, as in Niam-Niam and Uganda. Pliny writes of these animals: “On the Indian mountains to the south, in the land of the Catharcludi, there are satyrs. These are the swiftest of creatures, sometimes going on all fours, sometimes upright like men, and they are so active that they can only be captured when old or sick”(4). These satyrs have been identified with the orang-utan, but the gibbon may also be intended, which is swifter and more agile, when in an upright position, than the orang-utan.

Subsequent to the remote period which we have cited, there is a long silence respecting these remarkable animals. Only at the time when Portugal became subject to the power of Spain, we hear something about them from Congo and Angola. The sailor Eduardo Lopez gave an account of the chimpanzee, which was published by Pigafetta in 1598 (5). There are later accounts of very large apes in the writings of Pedro da Cintra (6), Father Merolla of Sorrento (7), Froger (8), and William Smith (9).

Smith gives a representation of the chimpanzee under the erroneous name of the mandril (_Cynocephalus Maimon_). The illustration is bad, but it may be recognized by his description. In 1641 the Dutch anatomist N. van Tulpe (Tulpius) gave a better illustration of this anthropoid (10). This naturalist observed that the animal in question, _Homo sylvestris_ or orang-utan (_Satyrus indicus_), is called quojas morrou by the Africans. An anatomical description of the chimpanzee, which is still of great value, was given by Tyson in 1699 (11). The anatomical illustrations included in this work are remarkably well executed for that time.

Our biological acquaintance with the West African anthropoids is considerably increased by the account given in the sixteenth century by the adventurer Battel, of Leigh, in Essex. This man passed through the forests of Lower Guinea, as sergeant of the Portuguese troops under the command of the Governor of Angola, Don Manuel Silveira Pereira. In 1613 Battel’s account was published by his neighbour Purchas in his _Pilgrims_ (12). Battel speaks of two kinds of large apes, the engeco and the pongo, which inhabited the forest on the banks of the Banna and the Mayombe. The engeco corresponds to the ndjéko or nschégo (chimpanzee), the pongo to the n’pungu of Loango, or the gorilla. Battel’s description of the habits of these animals affords some characteristic touches which will concern us presently. We may date our earliest acquaintance with the largest of all the anthropoids from this adventurer’s career.

The Dutch physician Oliver Dapper published in 1668 a detailed description of Africa (13), in which there is much of value, and he mentions the large apes, called quojas morrau or morrou, which inhabit the kingdom of Congo (14). By these he apparently means the chimpanzee.

Some account, unfortunately rather vague, of the gorilla has been recently given by Bowdich in his very interesting work on the “Mission of the Anglo-African Company to Ashanti” (15). He says that there are several remarkable species of apes in the territory of the Gaboon, among which the ingenu (gorilla) is the strangest. The natives asserted that this animal is much larger than the orang-utan, generally five feet tall, and four feet broad from shoulder to shoulder.

In 1847 Dr. Savage, a Protestant missionary on the Gaboon, reported to the distinguished anatomist Owen that there was an ape in that country larger than the chimpanzee. In addition to this information, he sent some drawings of skulls by the wife of an English missionary, Prince, in which the supra-orbital arch is strongly developed. Savage gave to the animal the name of _Troglodytes Gorilla_, to distinguish it from _Troglodytes niger_, the chimpanzee. Owen also described two skulls of gorillas, sent to him from the Gaboon (16). The skull of a gorilla, sent to Boston by the missionary Wilson, was drawn and described by Professor Jeffreys Wyman, and with it the notes of the donor were also published (17). In 1851 the skeleton of a gorilla reached Philadelphia through the medical missionary H. A. Ford, who also published the latest accounts of the new anthropoid (18). In 1849 some remains of a gorilla reached Paris through Gautier Laboulaye, and this valuable contribution to natural history was received by de Blainville and Isidore Geoffroy Saint-Hilaire. In 1851 and 1852 more perfect remains were presented to the Museum in Paris by Dr. Franquet and Admiral Penaud. In the finely illustrated works by de Blainville (19), Is. Geoffroy Saint-Hilaire (20), and Duvernoy (21), they are represented with great care. A splendid illustration of one of these specimens, excellently stuffed, consisting of an adult male, adorns the _Photographie zoologique_, by L. Rousseau and A. Devéria, which has, so far as I am aware, been published without any text (22). This illustration is so true to nature that I made use of it in one of my earlier publications (23).

Paul Belloni du Chaillu, born in North America of French parents, and reared in his father’s mercantile house on the Gaboon, spent the years 1855–65 in roaming through the lands bordering on the Gaboon, the Ogōwē, and the Fernāo Vaz; he professed to have taken part in gorilla-hunts, and he published several books about his travels (24). Critical light has been thrown upon these works, especially by A. E. Brehm and Winwood (25); the illustrations are defective, and the text is full of tales of adventure. Du Chaillu’s information respecting the African anthropoids was published in the _Proceedings of the Zoological Society of London_ (26). His remarkable collection of the remains of apes has been described by Jeffreys Wyman (27), to whom we are also indebted for a notice of the materials collected by Savage (17).

Owen has published instructive anatomical treatises on the gorilla and the chimpanzee, in addition to those already cited. This English professor had the opportunity of dissecting a young male gorilla, imperfectly preserved in spirits of wine (28). The travellers Burton (29), de Compiègne (30), Savongnan de Brazza (31), Lenz (32), the members of the German-African Loango Expedition (33), and Von Koppenfels (34) have also contributed some information respecting the gorilla in a wild state. Other works on the zoology and anatomy of this animal have been published by Duvernoy, already cited, Dahlbom (35), Haeckel (36), Flower (37), Issel (38), Giglioli (39), Chapman (40), Mivart (41), Macalister (41A), Von Aeby (42), Lucae (43), Ecker (44), Bolau (45), Pansch (46), Lenz (47), A. B. Meyer (48), R. Meyer (49), Bischoff (50), Ehlers (51), Virchow (52), Von Bär (53), by the author of this work (54), etc. Duvernoy, Chapman, Bischoff, Bolau, Ehlers, and I have, like Owen, been able to dissect perfect specimens of the gorilla. Two of the specimens which came into my hands were unquestionably in the best condition, since I obtained them immediately after their deaths in Berlin. A larger specimen of a female, 1000 mm. tall, was in worse preservation, yet still quite available for the purposes of study.

The list of anatomical treatises on the gorilla is not yet exhausted. Valuable information may be found in the anthropological works by C. Vogt (55), in the writings of Pruner-Bey (56), and Magitot (57), in Darwin’s works (58), in _Histoire Naturelle des Mammifères_, by Gervais (59), in Huxley’s _Anatomy of Vertebrated Animals_ (60), in Flower’s _Osteology of the Mammalia_ (61), in Giebel’s _Odontographie_ (62), and in many other handbooks and treatises on natural history, which want of room forbids me to mention.

In 1860, so far as I am aware, the first living gorilla reached England. It survived its arrival seven months, and a good illustration of this creature, accompanied by a brief description, has been recently published in the _Proceedings of the Zoological Society of London_ (63). In 1876, towards the end of June, Dr. Falckenstein brought the second living gorilla from Loango to Berlin. It had been kept in confinement in that country at the German station Chinchoxo since 1874, and it died on November 13, 1877, at the Berlin Aquarium. Dr. Hermes obtained a third specimen in September, 1881, which died soon after its arrival in Berlin. In 1883 a fourth still survived in the Berlin Aquarium.

The chimpanzee became the more general object of zoological and anatomical study at an earlier period, since the species occupied a wider area than the gorilla, and is more easily captured. I have already mentioned Hanno’s observations on the subject, and the animal described by von Tulpe. In 1740 Buffon had seen a young specimen of the chimpanzee, and another was in existence in London at the same time. In vol. 35, pl. 2, of his Natural History, Buffon gives an illustration of the chimpanzee, and pl. 3 represents an orang-utan, not very true to nature, but still recognizable (64). It is commonly supposed that the Dutch traveller Bosman, cited by Buffon, was acquainted both with the gorilla and the chimpanzee. He speaks of an ape about five feet high, living near Fort Wimba “d’une couleur fauve” (65). Although Buffon was acquainted with the names chimpanzee and chimpezée, as well as with Battel’s surmises about the pongo and the enjeco, yet he regarded the jockos, pongos, and orangs as animals all belonging to one species. The young African animals observed by him and von Tulpe (chimpanses) must have been young pongos (66). The name pongo was afterwards applied to the old misshapen orang-utan. The skin and skeleton of the chimpanzee observed by Buffon when still alive, was preserved in the Zoological Museum in Paris as late as 1842 (67). There is a beautiful illustration of a young female which lived in the menagerie of the Jardin des Plantes in Paris in 1838 in the catalogue of this noble institution (68). This illustration, in which the animal is represented on all fours, has since been frequently copied. Copies have also been made of the drawings of the same individual in a walking position, and swinging by one arm, which originally appeared in Vélins’ famous catalogue of the Museum of Paris. Is. Geoffroy Saint-Hilaire and Dahlbom have given good illustrations of the head and body of an old male chimpanzee (69). Numerous, and for the most part correct, pictures of the chimpanzee have been given in several modern works and illustrated papers (70). Undoubtedly the best representations of the chimpanzee, corrected from photographs taken from life, are found in my osteological treatise on the gorilla which appeared in 1880, and also in the little book which preceded it (71). The form and mode of life of this species of ape are fairly well described by Bischoff (72), as well as in the books already mentioned, and especially in those by Temminck (73), Gervais, Reichenbach, and Brehm. Recently the opportunities of describing the bodies of chimpanzees have been frequent. Remarks on the anatomy of this animal may also be found in the works of Tyson (11), Vrolik (74), Champneys (75), Brühl (76), and Schroeder van der Kolk and Vrolik (77), as well as in the works we have already mentioned by Owen, Duvernoy, Bischoff, Issel, Giglioli, Lenz, etc. Du Chaillu (26), Duvernoy (78), Bischoff (50), Gratiolet and Alix (79), A. B. Meyer (80), and the author of this work (81) have treated of the external form and internal structure of new species of apes, and varieties of the chimpanzee.

Much has been written about the orang-utan since Vosmaer’s (82) day, among others by Rademacher (83), Wurmb (84), Griffith (85), Temminck (86), Schlegel and S. Müller (87), Is. Geoffroy Saint-Hilaire (88), Brooke (89), Abel (90), and Wallace (91). Camper (92), Owen (93), J. Müller (94), Schlegel and S. Müller (95), Heusinger (96), Dumortier (97), Brühl (98), Bischoff, Langer (99), etc., have studied the anatomy of this animal. Good illustrations of the orang-utan are found in Vélins’ catalogue, copied by Chenu (100) and Gervais (101), and in Wallace; also in the designs by Mützel (102) and Max (103), and in my work on the Gorilla, already cited.

It had been already shown by Tilesius (104) and Cuvier (105) that Wurmb’s young pongo is identical with the orang of Linnæus. We now know certainly that the name pongo (n’pungu in Loango) should only be applied to the gorilla.

The fourth and smallest species of anthropoid apes, the Indian long-armed apes or gibbons, have been recently described, with reference to their form and mode of life, by various travellers and naturalists, especially by Duvaucel (106), Bennet (107), Martin (108), Lewis (109), S. Müller (110), Diard (111); also by Buffon (112), Is. Geoffrey Saint-Hilaire (113), and Blyth (114), etc. Gulliver (115), Bischoff (116), and the author of this work have studied the anatomy of these creatures.

Chapter II.

The External Form Of Anthropoid Apes.

In the gorilla, the chimpanzee, and the orang-utan the external form is subject to essential modifications, according to the age and sex. The difference between the sexes is most strongly marked in the gorilla, and these differences are least apparent in the gibbon.

When a young male gorilla is compared with an aged animal of the same species, we are almost tempted to believe that we have to do with two entirely different creatures. While the young male still displays an evident approximation to the human structure, and develops in its bodily habits the same qualities which generally characterize the short-tailed apes of the Old World, with the exception of the baboon, the aged male is otherwise formed. In the latter case the points of resemblance to the human type are far fewer; the aged animal has become a gigantic ape, retaining indeed in the structure of his hands and feet the characteristics of the primates, while the protruding head is something between the muzzle of the baboon, the bear, and the boar. Simultaneously with these remarkable alterations of the external structure there occurs a modification of the skeleton. The skull of an aged male gorilla becomes more prognathous, and the incisor teeth have almost attained the length of those of lions and tigers. On the upper part of the skull, which is rounded in youth, great bony crests are developed on the crown of the head and on the occiput, and these are supported by the high, spinous processes of the cervical vertebræ, and thus supply the starting-point for the powerful muscles of the neck and jaw. The supra-orbital arches are covered with wrinkled skin, and the already savage, and indeed revolting, appearance of the old gorilla is thereby increased. A comparison of the two illustrations (Figs. 1 and 3) which accompany the text, will make this clear.

These distinctions are not so striking in the female as in the male gorilla. Although there is much which is bestial in the appearance of an aged female, yet the crests, so strongly marked in the male, the projecting orbits, and strong muscular pads are absent in the female, as well as the prognathous form of the skull and the length and thickness of the canine teeth. The aged female gorilla is not, in her whole structure, so far removed from the condition of the same sex in youth as is the aged male. The structure of the female has on the whole more in common with the human form. It has been said, and indeed on good authority, that the female type should take the foremost place in the study of the animal structure, since it is the more universal. But H. von Nathusius maintains that we must take both sexes into consideration in the study of domestic animals, since both are needed to determine the breed.[2] I accept this condition in the scientific study and description of wild animals also, of every kind and species. All that is said of the universal type of the female animal is and must remain in my eyes a mere phrase. Only the accurate observation of males and females, and of young individuals of both sexes, can throw sufficient light on the history of the race. The male animal is the larger, and predominant with respect to the complete development of certain peculiarities of form in the specific organism, since these are doubtfully present in the adult female, and are either altogether absent in the immature young, or only rudimentary.

Let us now consider, in the first place, the prototype of the species, the aged male gorilla in the full strength of his bodily development (Fig. 1). This animal, when standing upright, is more than six feet in height, or 2000 mm. The head is 300 mm. in length. The occiput appears to be broader below than above, since the upper part slopes like a gabled roof towards the high, longitudinal crest of the vertex. The projecting supra-orbital arches start prominently from the upper and central contour of the skull. In this species, as in other apes, and indeed among mammals generally, and especially in the case of the carnivora, ruminants, and multi-ungulates, eyebrows are present. In the gorilla these consist of a rather scanty growth of coal-black bristles, about 40 mm. in length. Beneath the projecting supra-orbital arches are the eyes, opening with somewhat narrow slits, and with lids which display many and deep longitudinal folds. The upper lid is set with longer and thicker eyelashes than the lower. The dark eyes glow between the lids with a ferocious expression.

[Illustration: Fig. 1.--Aged male gorilla.]

The bridge of the nose rises gradually outwards from between the inner corners of the eyes, and is keel-shaped in the centre. This part of the head is from 70 to 80 mm. in length, longer and narrower in one individual, shorter and wider in another. The skin in this region is covered with a network of wrinkles of varying size. The end of the nose and the nostrils are high, conical, and very wide at the base. This part of the nose, attached to the very projecting forehead, has the effect of an altogether snout-like muzzle. It is intersected by a central longitudinal furrow, which divides the whole tip of the nose into two symmetrical halves. This furrow is more strongly marked in the case of adult animals than in the young. The aperture of the nostrils is large and triangular, with the cartilaginous point turned upwards, and the edges applied to the bridge of the nose and to the cheeks have a somewhat retreating appearance. The lateral margins of this part of the nostril take an arched form, first diverging in different directions, then gradually converging again towards the upper lip. The lip is short, and this, combined with the large nose, gives a certain resemblance to the mouth of an ox. This resemblance is the more striking, as the whole of this region is covered with glandular skin of a deep black colour, which is either glabrous or provided with a few scattered hairs, but furnished with small flattened warts.

Below the eyes the cheeks are broad and very round, dwindling away and becoming depressed in the lower part of the face. They are seamed with curved wrinkles of varying depth, which tend downwards in the same direction as the wrinkles on the lower eyelids. The short upper lip is provided with oblique folds which converge outwards in the centre. The points of the strong canine teeth, which in many individuals are from 38 to 40 mm. long, and 20 mm. wide, diverge a little from each other, and stretch the upper lip in an oblique direction, so that this part of the face takes the form of a triangular, bevelled surface, with its prominent base-line between the canine teeth. It may also be observed that in many individuals of this species the nose is not very deeply set on the upper lip; that in others, again, the nose is decidedly raised, and the lip only presents a small hem below the nose. In many such cases the prognathism of the face is strongly marked, so as to give a baboon-like effect. In other specimens, again, this debased type is not allied with strongly marked prognathism.

If we take a front view of the skull of an aged male gorilla we see that the upper edges of the great supra-orbital arches are bevelled off below and at the sides. This bevelled form is repeated in the broad cheek-bones, as we see them in front. The front view of the head, and indeed of the whole animal, presents a strongly projecting contour, an impression which is strengthened by the puffed cheeks, with their lateral pads of fat. The lower jaw, with its scarcely indicated chin, retreats in the centre and dwindles into a triangular form. This contour is characteristic of the species. The whole skin of the face is glossy, set with few hairs, and of a deep black colour.

[Illustration: Fig. 2.--Ear of a male adult gorilla.]

The ear (Fig. 2) averages 60 mm. in length, and from 36 to 40 mm. in width. It seems to be fastened to the head by the back and upper part, is generally of an oval shape, and furnished with a strongly marked helix. The helix varies in width in different individuals, and often terminates on its inner edge in the projecting peaked excrescence described by Darwin, of which I shall have more to say presently. The anti-helix, tragus, and anti-tragus, and the cleft which lies between these two latter parts (_incisura inter tragica_) are generally fully developed; the lobule is more rarely present. Individual variations in the special structure of these parts may frequently be observed.

The strong trapezoid muscles are prominent on the neck, and when the head is stretched they stand out like pillars on the sides of the neck. Owing to the great development of the spinous processes of the cervical vertebræ and of the muscles attached to them, and to the occipital bones of the skull, the neck is very powerful, almost like that of a bull. The shoulders are remarkable for their breadth, and the pectoral muscles for their large size. The nipples of the breast, which are not surrounded by any visible _areolæ_, stand out in youth, and afterwards assume a horny texture which stiffens into a kind of bone. When one of these animals is gorged with food the navel is still apparent on the tun-shaped, rounded belly, of which the sides fall in when the stomach is empty.

On the upper and forearms the plastic form of the strongly developed flexor and extensor muscles is very apparent, testifying to the enormous strength of the upper extremities. The hands are large, and very wide, with short, thick fingers. The thumb, of which the extremity takes a conical form, is short, extending little beyond the middle of the second metacarpal bone. The extremities of the otherwise broad fingers are somewhat laterally compressed. The fore-finger is not materially shorter than the middle finger. The third finger is sometimes shorter than, sometimes of the same length as, the first, and the fourth is decidedly shorter. The back of the wrist is covered with deep oblique folds. A network of wrinkles, oblique or curved, also covers the skin on the back of the fingers, on which there are callosities up to the first joint. The gorilla closes the fingers when going on all fours, and turns the back of the hand on the ground, thus producing this thickening of the upper skin on the joints. Callosities of the same nature, although not so extensive, are not rare on the second finger-joints. The palm of the hand is covered with a hard, horny skin, generally beset with warts, especially at the roots of the fingers. In spite of the blackness of the skin which covers them, these characteristics are still apparent.

The fingers are united by a strong web, reminding us of the membrane found on the otter and other web-footed animals, and reaching nearly to the first finger-joint. A thick coat of hair extends to the root of the fingers, although on the backs of the fingers there are only a few isolated hairs.

The trunk of the body of a gorilla, seen from behind, somewhat resembles a trapezium in form, of which the longer of the two parallel sides extends between the shoulders, and the shorter between the two halves of the pelvis. The longitudinal sides, which are not parallel, correspond to the sides of the back. The arrangement of all the lower part of the trunk, on which the bones of the pelvis stand out prominently in an oblique direction, somewhat resembles a four-sided pyramid with its apex reversed. The gluteal muscles are not strongly developed. The tuberosity of the ischium projects in a somewhat angular form.

While the external sexual organs of the male are so covered by the wrinkled skin of the abdomen that they are not prominent in their passive condition, those of the female are, on the contrary, very apparent; the external lips of the vagina, provided with large nymphæ, and a large clitoris, are only apparent when the sexual instinct is excited.

The thighs are covered with strong muscles, which appear to be smoothed off on the inner side, and somewhat arched on the outside. The lower part of the leg is also muscular, and its section is of a long-oval form; the region of the calf is more strongly developed than in other anthropoids. The bones of the foot are not at all prominent, and the same remark applies to those of the hand. The contour of the back of the long, broad foot is flat; the sole is convex, covered with strong muscles, and padded with layers of fat. When the animal puts the sole of the foot on the ground, its muscles go back to the region of the heel, and forward into the inner side of the foot, thus presenting the primitive formation of a heel.

The great toe, as in all apes, is detached like a thumb from the other toes, and can be used as such. The metatarsus serves as a base for its projection, in the same manner as the thumb starts from the fore part of the contour of the wrist. The great toe sometimes extends as far as the joint between the first and second phalanges of the second toe, sometimes nearly as far as the middle of the second phalanx. This characteristic varies in different individuals. At the point of union of the first metatarsal bone with the hinder extremity of the first phalanx of the great toe, there is a round projection on the inner side of the foot. The great toe is very broad at its root, then becomes smaller, and widens again into a broad final phalanx. With its strong lateral ridges of skin, which cover the sinews and cushions of fat, all this part of the foot appears to be wide and flattened off from the back to the sole.

The second, third, fourth, and fifth toes are more slender than the great toe. The second toe is in most cases rather shorter than the third. The third and fourth toes are almost of the same length, and only a little longer than the second toe.[3] The fifth toe is considerably shorter than the fourth. The last phalanges of the toes taper in front, and are furnished on their lower surface with long, laterally compressed pads. The section of such a phalanx is almost trapezoidal, with a long upper parallel side. The upper part of the foot, although generally flat, rises a little in the neighbourhood of the first metatarsal bone, and slopes thence to its outer edge.

The hair grows thickly on the back of the foot as far as the extremity of the metatarsal bones, more sparsely on the back of the toes. There are strongly marked oblique furrows on this part of the foot, especially on the joints, often combined with horny callosities, since the animal sometimes doubles up the toes and runs upon the back of them. The nails of the hands and feet are black, like the whole of their skin-covering, distinctly grooved, very much arched, and generally somewhat wider at the base than in front.

[Illustration: Fig. 3.--The young male gorilla, from the specimen in the Berlin Aquarium of 1876–77.]

On the sole of the foot we find the region of the heel, the ball of the great toe, in this case resembling the ball of a thumb, the roots and tips of the toes, together with pads consisting of muscles, tendons, and skin. The several divisions of these padded balls are separated from each other by furrows which are longitudinal, oblique, and transverse, and more or less distinct from each other. The black skin which covers the sole of the foot is thick and horny, but provided with a series of papillæ. The whole skin of an aged animal is of a deep black colour, somewhat glossy, and covered with intersecting wrinkles.

[Illustration: Fig. 4.--The same animal at a still earlier age.]

The young male gorilla does not essentially differ from the old male in its general and external appearance. Its skull is, however, without the crest which characterizes the latter animal, and is still of a rounded form in the region of the crown and occiput. At this age the head is not so high at the back and on the top as in aged males. The orbits are less prominent, the general aspect of the face is not so decidedly prognathous, and the bridge of the nose is shorter. The lines of the body in the young male are softer and less exaggerated, and the expression of the face is less ferocious than in an aged male. The horny callosities on the hands and feet are altogether wanting or only faintly indicated, and the hands, fingers, and toes have not arrived at the powerful development which we observe in the older animal. (Comp. Figs. 3 and 4.)

Considerable differences may be observed in the whole structure of the adult female gorilla. The animals of this sex are smaller and weaker than males of the same age. The skull of the female is smaller and more rounded than that of the male, and the great bony crests are also absent. The orbits are less prominent, and a front view of the head gives the impression of a trapezoidal form. The coronal arch rises above this trapezoid. In the male, on the contrary, the crown seems to lengthen above and behind into a pyramidal form. In the aged female the bridge of the nose is generally shorter than in the aged male, but even in this particular there is great variation in different individuals. Sometimes the bridge of the nose in a female is much depressed, and then the interval between the orbits and the end of the nose is shorter: I intentionally avoid the term _tip_ of the nose, on account of the blunted form of this organ. Even when the bridge of the nose is more prominent, the interval between its end and the orbits is sometimes very short.

The aged female gorilla usually has wider cheeks, a smaller nose, and a higher upper lip. This last peculiarity is shown in the correct and well-stuffed specimens in the museums at Paris and Lübeck. Although, in the process of drying, the skin of the nose may have shrunk a little, yet there is still room for the upper lip, provided with folds which are either vertical and parallel or diverge like a fan. Owen and Mützel[4] have given satisfactory illustrations of these parts. In the aged female the shape of the neck is not, as in the aged male, strong and bulging, so as to resemble a cowl. Yet it is enlarged in conformity with the not inconsiderable development of the spinous processes of the cervical vertebræ, and with that of the powerful cervical muscles. Even in a young male, of the age of the specimen which was kept in the Berlin Aquarium, between July, 1876, and November, 1877, this enlargement of the neck was present in a marked degree. In still younger individuals, however, under a year old, in which the spinous processes of the vertebræ have not yet been developed, there is no such enlargement, but, on the contrary, this region of the neck takes a concave form.

In conformity with the smaller size of the body, the shoulders, arms, and thighs of the adult female are smaller than those of the full-grown male, but they are still very powerful. While giving suck, the breasts of the female are swelled in the form of a half-cone, instead of assuming the convex shape which is observed in many European women, and still more frequently in those of the negro, Indian, and South Sea races. The nipple is cylindrical rather than conical in shape, and covered with finely wrinkled black skin, which is sometimes hard and horny. When not giving suck, the breasts hang slackly down, like short empty pouches. The belly swells in the neighbourhood of the crest of the ilium, and increases in thickness at the groin. The external sexual organs, in the period of excitement, swell in a manner resembling the lips of a woman’s pudenda.

In a young female the cranium is rounded, and the face is only slightly prominent. In aged specimens, especially in those of the male sex, there is a somewhat typical prolongation of that part of the face which lies between the eyes and the end of the nose, and this is to a slight extent apparent in the young female. Variations in form and in the extent of the prolongation are, however, apparent even at this early period. The trunk and limbs are more slenderly built than in a male of the same age.

The hairy coat of the gorilla consists of long, thick, straight or stiffly curved bristles, and also of shorter, thinner, and curled woolly hair. On the crown of the head the hair is somewhat stiff, from 12 to 20 mm. in length, and it becomes erect under the influence of anger. While the sides and fore-part of the chin are only clothed with short, stiff hairs, they grow thickly on the back part of the chin, like a beard or forelock. The hairs which turn outwards from the sides of the face and on the neck are 30 or more mm. in length. On the shoulders the hair is from 130 to 150 mm. long, hanging down on the upper arms and the back. In the middle of the upper arm the hair is from 50 to 70 mm. long, growing downwards as far as the bend of the elbow. At this point it generally begins to grow in an upward direction. On the back of the forearm it again grows downwards. In the middle of the forearm on its inner side, a parting of the hairs takes place, as one portion goes in front of the radius, while the other portion turns behind the ulna. On the back of the wrist a tuft of curved hair turns upwards; a middle tuft goes directly back; and the lower tuft, also curved, turns outwards. On the back of the hand the hairs turn towards the fingers. On the breast and belly the hairs are shorter and grow more sparsely. On the breast their direction is as a rule upwards and outwards. On the belly they converge from the ribs towards the centre and the navel. On the thighs the hairs are about 160 mm. long, and here, as on the lower part of the leg, they tend outwards, while on the back of the foot they grow towards the toes. On the back, shoulders, and on the thigh and leg, the bristles are slightly curved. This quality increases the general impression of shagginess and fleeciness which is produced by the hairy coat of these creatures. The woolly hair does not grow very thick, and is not much matted.

The colour of the hair not only differs on different parts of the body, but also in different individuals. On the crown of the head it is of a reddish brown, or rarely of a decided brown or black. The hairs in this region are sometimes dun-coloured at the root, greyish white in the centre, and brownish red, shading into the dark brown tip. The hair on the lips is sometimes of a blackish brown, sometimes whitish, or both colours are found together. The hair growing at the sides of the face is grey below, dark brown or almost black above. On the neck and shoulders the hair is of a grey colour at the root, and gradually becomes lighter towards the tip. In the centre it is brown, shading into a lighter colour at either end, but this ringed form of colour is not universal. The tips of the hair are dark, sometimes brown or reddish. The hair on the back, on the upper arms and thighs, is whitish or light grey for half its length, with a blackish brown ring towards the tip, which is of a dark grey colour. Many of these hairs on the back have two brown rings on them. The forearms, hands, shanks, and feet are covered with hairs which are grey at the root, brownish grey, dark brown, or black at the tip. Round the posteriors there is a circle of white, grey, or brownish yellow hairs from 10 to 20 mm. in length. In both sexes variations from the colour of the coat here described are not rare. It has been already observed that the brownish red colour of the hair on the head is sometimes exchanged for another shade. In many individuals the neck, shoulders, and back are of a dark grey, brown, or even black colour. In others the forearms, hands, shanks, and feet are covered, like the rest of the body, with grey and brown hair intermingled.

The second species of anthropoid apes is the chimpanzee. In this case also we must consider successively the aged and young male, and the aged and young female animals.

The full-grown chimpanzee is smaller than the adult gorilla. In this species also the male is larger than the female. The chimpanzee is, speaking generally, of a slighter build than the gorilla.

The head of the aged male chimpanzee fundamentally differs from that of the aged male gorilla, since the skull of the former has a depressed crown, and the transverse occipital ridge is only faintly indicated. Since the orbits are also less strongly developed than in the aged male gorilla, and the spinous processes of the cervical vertebræ do not assume the same elevated form which is characteristic of the latter species, the countenance of the chimpanzee is not of a square shape, and there is not space for the strong muscular system arching over the neck like a cowl, which is so characteristic of the gorilla. The head of the chimpanzee displays, both in aged and young specimens, the concave neck which is common among apes, that is to say, a depression between the head and the throat. In an aged male the crown of the head presents a rounded, arched contour, since, as we have already said, the prominent bony processes are wanting. Although the supra-orbital arches are not so excessively prominent as in a gorilla of the same age, they are strongly developed, covered with wrinkled skin, and in this case also there is a species of eyebrow, stiff and bristly, with shorter hairs between. The large, wrinkled lids are furnished with thick eyelashes. The inner angle of the eye somewhat resembles that of the gorilla.

A general physiognomical distinction between the gorilla and the chimpanzee consists in the fact that the bridge of the nose is shorter in the latter than in the former. In the chimpanzee this part of the organ is depressed, yet the depression is of a conical and convex form, and is covered with a network of wrinkles of varying depth. In the chimpanzee the interval between the inner angle of the eye and the upper lateral contour of the cartilaginous end of the nose is shorter than in the gorilla. There is also some difference in the form of the nose: it is on the whole flatter, the tip is less apparent, the nostrils are not so widely opened nor so thickly padded. (Fig. 3.) In the chimpanzee, as well as in the gorilla, a central and vertical furrow directly divides the triangular nostrils, and these are likewise divided from the rest of the face by the broad pear-shape furrow which surrounds them. The upper lip is generally high, sometimes as high as 30 mm.; but in some individuals it is much lower. As in the gorilla, the chin forms a triangle of equal sides, with its apex reversed.

The external ear of the chimpanzee has on the whole less resemblance to the human ear, and its contour is larger than that of the gorilla. But this organ varies so much in individuals that it is difficult to lay down any rule for its average size. It ranges from 59 to 77 mm. in length, and from 42 to 80 mm. in width. Many individuals have a distinct lobule to the ear, others not. (Fig. 5.) In this example the helix and anti-helix are developed, in others they are wanting. The tragus and anti-tragus are more or less apparent in different individuals, as well as the other modifications of the external cartilage of the ear.

[Illustration: Fig. 5.--Ear of chimpanzee.]

An aged male chimpanzee has broad, rather rounded shoulders, a powerful chest, long muscular arms, reaching to the knees, and a long hand, which seems to be very slender in comparison with that of the gorilla. The thumbs vary in length, for the most part reaching as far as the metacarpal phalanges, but not in all cases. The middle finger is longer than the other three; the first and third fingers are shorter by the length of the last phalanx, the third is a little longer than the first, and the fourth is again shorter. A web, which reaches to the middle of the first row of phalanges, stretches between the bases of the four fingers. There are horny callosities on the back of the hand of the aged male, since the chimpanzee, like the gorilla, supports himself on the backs of his closed fingers. The fingers are laterally compressed, but slightly arched on the back of the hand, and more decidedly so on the palm. A network of furrows covers the back of the hand, and these are more deeply impressed on its palm. The thumb is separated from the palm by a distinct furrow; and from four to six furrows of varying depth cross the centre of the palm. The finger-nails are short, wide, and arched, very convex at their free edges.

In the aged male the sides of the belly are compressed, the thighs are broad and muscular, and somewhat flattened both on the inner and outer sides. The knees are rather prominent, the shanks are somewhat laterally compressed, and the calf of the leg is very slightly developed. As in the gorilla, the long, wide feet have a thumb-like formation of the great toes, which are of considerable size. They extend, when drawing anything towards them, as far as the second phalanx of the second toe. The four other toes are more slender and only a little longer than the great toe. The heel is but slightly developed, and slopes away below. The joint between the first phalanx of the great toe and the first metatarsal bone is marked by an angular projection on the inner edge of the foot. The back of the foot is very slightly convex. The last phalanx of the great toe is very much sloped off on its upper surface, but this is less apparent in the other parts of this member. The last phalanges of the other laterally compressed toes are strongly arched on the under surface. Considerable convexities may also be observed under the metacarpo-phalangeal joint of the great toe and under its last phalanx. The shape of the toe-nails resembles that of the fingers. Large callosities are not unfrequently found on the backs of the toes, since the animal sometimes supports himself on these parts. A connective web is found between all the toes except the great toe and its neighbour, but it does not extend so far as that between the roots of the fingers.

[Illustration: Fig. 6.--Young chimpanzee.]

Although the young male chimpanzee is distinguished from the aged male of the same species by differences in the structure of many of its parts, yet these distinctions are not so characteristic as those between the young and aged male gorillas. The skull of the younger animal, which is altogether devoid of the prominent bony crest and ridges, is shaped almost like a truncated cone in the region of the crown; in some individuals of only a few years old, the bony development of the orbits has already begun, starting from the principal part of the frontal bone, and covered with pads of wrinkled skin. The short and depressed bridge of the nose becomes longer and higher, the cartilaginous end of the nose becomes larger, and the prognathism of the face increases with each successive stage of growth. The strength of the trunk and limbs is early developed. The sexual characteristics are gradually and plainly developed; but the male gorilla far exceeds the chimpanzee in demoniacal ferocity.

The adult female is smaller, and has a smaller head, with an oval crown to the skull. The orbits are not so strongly developed as in the aged male, the nasal parts are less prominent, and the teeth are not nearly so strong. The body of an animal of this sex is rounder in all its parts; and the belly, with its wider pelvis, is more tun-shaped than in the aged male. Neither do the limbs display the same angular formation of muscles.[5] The hands and feet of the female are also smaller and slenderer. In a young female the characteristics here described are presented in the mitigated form which corresponds with its youthful condition. But the female sometimes becomes a very strong and even violent creature. This was often proved in the Hamburg Zoological Garden, where a female specimen, in splendid condition, survived for several years under the faithful care of old Siegel.[6]

The skin of the chimpanzee is of a peculiar light, yet muddy flesh colour, which sometimes verges upon brown. Spots, varying in size and depth of colour, sometimes isolated, sometimes in groups, and of a blackish brown, sooty, or bluish black tint, are found on different parts of the body of many individuals, especially on the face, neck, breast, belly, arms and hands, thighs and shanks; more rarely on the back. The face, which is soon after birth of a flesh colour, merging into a yellowish brown, assumes a darker shade with the gradual development of the body. The hairy coat is sleek, or only in rare cases slightly curled, and the coarser and bristly hair is generally stiff and elastic. The parting on the forehead is often so regular that it might have been arranged by the hairdresser’s art (see Fig. 6). Close behind that part of the head at which the projecting supra-orbital ridges of the gorilla generally meet, there is in the chimpanzee an altogether bald place, or only a few scattered hairs. Round the face the growth of hair streams downwards like a beard. On the neck it is from 60 to 80 or 100 mm. in length, and it falls in the same long locks over the shoulders, back, and hips. The hair on the limbs is not so long, and takes a downward direction on the upper arm, and an opposite direction on the forearm, while there is often a longitudinal parting on the centre of the inner surface of this part of the limb. On the back of the wrist the hair grows in a kind of whorl; the upper hairs turn upwards and backwards, the middle ones turn backwards, the lower ones backwards and downwards. The backs of the hands and the roots of the fingers are hairy. On the front of the thigh the hair takes a downward direction, while behind it grows backwards. On the shank it grows downwards in the region of the tibia, and turns back on the inside of the leg. The back of the foot and the roots of the toes are likewise hairy. There is a shorter growth of these scattered hairs on the face, chin, and ears. On the supra-orbital arches there are from eight to twenty, or even more, stiff, scattered hairs, after the manner of eyebrows; and eyelashes are likewise present.

In most cases the hair of the true chimpanzee is of a black colour. Short whitish hairs may be observed on the lower part of the face and chin, as well as round the posteriors. Sometimes the colour of the hair is shot throughout with reddish or brownish black.

The orang-utan, the chief representative of the anthropoids in Asia, differs from the African forms of this group, almost at the first glance, in the height of his skull, of which the fore-part is compressed and shortened in a backward direction. In the aged male it is, however, provided with high and erect bony crests, which give a prognathous appearance to the countenance. We take an aged male as the type of our description.

The forehead is high and erect, not retreating like that of the chimpanzee; it is open, and has moderately convex frontal eminences. From the centre of the forehead a round or bluntly oval eminence sometimes projects. The supra-orbital ridges are strongly arched, yet not so prominent as that of the aged male chimpanzee, setting aside that of the gorilla. The eyes are not widely opened, nor are their lids large and furrowed, but on the lower lids there are deep wrinkles. The small bridge of the nose is generally much depressed, but sometimes assumes a slightly conical form as it issues from the central longitudinal depression of the face. The end of the nose, further removed from the eyes than is generally the case in the chimpanzee, is not so broad as it is in the latter animal and in the gorilla. The wings of the nose are narrow and highly arched in their upper part, divided from each other by a vertical furrow, and the nostrils are small and oval, separated by a thin partition. The upper lip is high, broad, and projecting, and seldom much wrinkled. It is divided from the cheeks and from the upper part of the face by a deep depression; and behind the cheeks two large and long-shaped or sometimes triangular pads of fat often project forwards and downwards.

[Illustration: Fig. 7.--Head and shoulders of an aged male orang-utan.]

The very mobile lips are furrowed, and not remarkably thick. The chin is very retreating, but somewhat uniformly rounded in front (Fig. 7). The small ear averages 55 mm. in length, and 12 mm. in width, and has a general resemblance in structure to the human ear (Fig. 8). On the fore-part of the short, thick neck there are irregular, and in some places very deep circular folds of skin. The throat-pouch distends part of this slack, wrinkled skin, which hangs down in front like a great empty wallet (see Figs. 7 and 9).

[Illustration: Fig. 8.--Ear of the orang-utan.]

The structure of the other parts of the body lacks even to some extent the powerful and symmetrical formation which we observe in the gorilla, and indeed in the chimpanzee. The trunk, with broad yet rather angular and sloping shoulders, with flattened breast, rounded back, and still more rounded belly, is tun-shaped, and gives the impression of a want of proportion. In lean individuals the gluteal region resembles the projecting rump of a fowl, and this may also be observed in the young gorilla and chimpanzee. The long, muscular arms reach to the ankles when the animal is in an erect position, and are altogether out of proportion with the rest of the body. The powerful upper arm is shorter than the lean forearm. The hand is long and narrow. The thumb, which reaches as far as the metacarpo-phalangeal joint, has a displeasing and almost rudimentary effect. A web unites the fingers, sometimes extending along a third of the first phalanx, sometimes along half. The middle finger is somewhat longer than the first and third fingers, and the third is next to it in length. The fourth finger is comparatively long. The palm of the hand is flat, only marked by a few deep furrows. The long, slender fingers are laterally compressed, and the nails on their tapering ends are arched.

[Illustration: Fig. 9.--Adult male orang-utan.]

The thighs, somewhat compressed on the inner side, are, however, very muscular, but become much smaller on their back side. The calf of the leg is less developed than in the gorilla, or even than in the chimpanzee. The feet are, like the hands, long and slender. The narrow, flat heels project very slightly behind. The great toes are short, with wide extremities, rounded above, and provided on the sole with thick, fatty skin. In old age these animals not only often lose the nails of their great toes, but sometimes even the last phalanges themselves. This is not merely a disease produced by confinement, as is the case with sea-cat monkeys, hyenas, etc., which in this condition lose portions of their tails or toes, but it also occurs among orang-utans in their wild state. The middle toe is the longest, and the fourth toe is the shortest. Layers of fat may be observed on the under side of all but the great toe, where they rarely occur. The backs of the hands and feet are covered with very ribbed and wrinkled skin, and on the hands there are callosities.

This animal, of a quieter and more phlegmatic disposition than the gorilla and chimpanzee, has a very strange appearance, with its projecting head and short neck; its face widening in the middle and tapering towards the forehead and chin; its tun-shaped trunk, long, thin extremities, and shaggy coat. It differs widely from the chimpanzee and gorilla in these particulars. In the young male the compression of the forehead is less marked than in aged animals, and the bony crests which conduce to raise the coronal arch in its upper and hinder part are also absent. The supra-orbital arches are less strongly developed, the jaws are less prominent, and the layers of fat upon the cheeks are absent. The head is more detached from the neck, the structure of the whole body is slenderer, the expression of the countenance is milder. A small, conical nail, blunted at the end, may generally be observed on the great toe.

In the adult female, as I have pointed out elsewhere, the physical characteristics of the young male are repeated in an exaggerated form. The skull, displaying only very small bony crests, is indeed high, but more rounded than in the aged male; the face is prominent, but the head is more detached from the neck than in the latter case. On account of the greater width of the pelvis, the body is still more tun-shaped than in the aged male. When giving suck, the breasts are distended in the form of a half cone, but when this condition ceases they fall together and only present two short, wrinkled, slightly prominent folds of skin; the small, horny nipples are almost cylindrical; and the areola, of which the traces are scanty at all times, altogether disappears. The throat-pouch is less strongly developed than in the aged male, but the limbs are as fully developed. The head of the young female is still more rounded, with a more flattened though still projecting face, and the limbs are slenderer, and thus still more out of proportion with the thick trunk than is the case with a young male.

The orang-utan’s skin is of a greyish blue colour, sometimes mixed with brown, but the greyish blue shade is predominant. A yellowish or brownish grey is less common. Round the eyes, nostrils, upper lips, and chin there is often a ring of a dirty, yellowish brown colour, forming a strange contrast with the general bluish grey tone of the face. The arms, legs, hands, and feet are black or greyish black, more rarely brown or reddish brown.

The hairy coat of the orang-utan consists of long, curved, waving bristles, and some scanty downy hairs. On the back of the head, on the shoulders, back, and hips I have measured hairs from 220 to 235 mm. in length. In other individuals they were, however, much shorter--20, 40, or 60 mm. long. There is often a natural parting of the hair of the head, which falls asunder on either side. In some cases there is no parting, and the hair streams wildly down; and in others, again, it stands upright, stiffening from the sides and top of the head in a demoniacal manner (Figs. 7 and 9). A beard frequently encircles the cheeks and chin. The hair grows upwards and outwards on the neck and fore-part of the throat, on the shoulders, back, breast, belly, upper arms, and thighs, while it takes the opposite direction on the forearm. On the wrist the hair grows in the manner described in the case of the gorilla. There is only a scanty growth of hair on the breast and belly, and it is also short and weak on the face, ears, and backs of the hands and feet. I have not observed eyebrows on the animals I have seen, but they may occur, and the eyelashes are fully developed.

The hair is of a reddish brown colour, something like burnt sienna, and the hair-tips on the back parts of the body are generally brown. In some individuals the hair is darker, of a russet or blackish brown; in others it is lighter, and in the latter case the breast and belly are of a yellowish white. The beard is sometimes dark yellow. Some individuals almost devoid of hair have been observed.

The gibbons, or long-armed apes (_Hylobates_), constitute the fourth group of anthropoids. Many kinds of this group are known, and I feel bound to describe, at any rate, a few of them, in order to be able to give an idea of their structure. With respect to these animals, I cannot only rely on the materials which are accessible to me, but must also make use of the descriptions given by others.[7]

The gibbons have as a rule very long arms, reaching to their ankles when they stand upright. The face is not very prognathous, the crown of the head is rounded off, and the nails are flat. There are small callosities on their posteriors, which are absent in the gorilla, the chimpanzee, and the orang-utan.

The largest species of these animals, which inhabit part of the continent and of the islands of Asia, is the siamang (_Hylobates syndactylus_, F. Cuvier).[8] According to Diard, its arms are not quite so long as those of the wauwau (_H. agilis_, F. Cuvier). This animal’s head is small, with a somewhat retreating forehead, a long, moderately arched crown to the head, and a slightly arched occiput. The base of the nose is depressed, the region of the jaws is only slightly prognathous in the aged male. According to Diard, the eyes are deeply set, the nostrils are very wide, the cheeks fall in below the zygomatic arch, the mouth opens widely, the chin is of insignificant size. It is the only one of the gibbons which possesses the throat-pouch, already described as common to the other forms of anthropoids, and in aged animals it hangs slackly down, almost bare in front. The second and third toes are connected together by a thin web, reaching to the last joint in the male, and to the penultimate joint in the female. The hairs on the forearm turn their points upward, and form a kind of whorl on the wrist. The animal is of a glossy black colour, with a thick and tolerably long coat of hair on the body and limbs. According to Bock, the face is encircled by a grey or white beard. This animal is about a metre in height, and inhabits the woods of Sumatra.

The lar (_Hylobates Lar_, Illig) is another species of gibbon. The structure of the body is much more slender than that of the animal just described; the head is round, the eyes are large, the nose projects from its depressed surroundings with only a very slight ridge, and the cartilaginous end is shaped like a triangle with unequal sides. This triangular end is divided by a longitudinal furrow, and the small nostrils converge downwards and inwards, and are divided from each other by a thin partition. The structure of the upper lip is peculiar. In the centre, just below the base of the nasal partition, it is depressed, and divided into two symmetrical lateral halves by a vertical furrow. Each of these halves forms a rounded edge, overhanging the small lower lip. Above the upper lips, between them and the zygomatic arch, which slopes away below the lower eyelids, there are the flat, depressed cheeks. The small chin presents itself below the central cleft of the upper lips and their convex rims. The face of this gibbon, of which the general appearance is very singular, is surrounded by a circle of thick hair, which resembles the circular hood of an Eskimo. This characteristic form of the head, both generally and in detail, is not confined to the lar, but applies to other species of gibbons, including the siamang (see Figs. 11 and 15). It is a feature which distinguishes the long-armed apes, almost at the first glance, from the other forms of anthropoids already described. The colour of the lar’s face is reddish brown or tawny; the hair which surrounds it is of a light grey: the body is of a dark grey, with short, light grey hair on the backs of the hands and feet. The black ears are almost hairless. The lar has up to this time seldom found a place in our zoological collections. It is found in Malacca and Siam.

[Illustration: Fig. 10.--Head of the white-handed gibbon.]

The white-handed gibbon (_Hylobates albimanus_, Vigors and Horsfield) is often confounded with _H. Lar_. But _H. albimanus_ has a black face, and the general colour of the skin is black, including the inside of the hands and feet. Thick white hair encircles the face, and the backs of the hands and feet are covered with short white or light grey hairs, while the rest of the coat is quite black. The hair of the forearm grows downwards, towards the wrist. The ears of these apes are almost of the shape of an equilateral triangle. The helix of the ear runs like a flap round its free outer edge. The anti-helix passes through the centre of the slightly depressed external surface of the ear, of which the whole arrangement does not essentially differ from that of the ear of other anthropoids. The cartilaginous substance of the organ is a good deal inflected, broad behind and in the upper part, dividing into two limbs in front and below. There are indications of the tragus and anti-tragus. The detached lobule of the ear is absent (Fig. 11). This structure of the external ear is common to other species of gibbons, although in many cases the upper part of the helix is wrinkled, and the anti-helix is sometimes more fully developed, and more like that of the human ear.

[Illustration: Fig. 11.--Ear of the white-handed gibbon.]

The face in this species is small. The supra-orbital arches are strongly developed, and almost join in the centre. The eyes are large, dark, and have a mild and placid expression. The cheeks are prominent in the region of the zygomatic arch, and depressed below it. The bridge of the nose is imbedded between the cheeks, which, especially when seen in profile, take a slightly conical form. The nose is covered with cross-folds. Its cartilage is of the shape described in the former species, and so are the upper lip and chin (Fig. 10). Long, bristly hairs stand out on the supra-orbital arches and upper lip, and short, thin hairs cover the end of the nose. The white hairs which encircle the face grow like a beard on the chin. The whole face has a melancholy, almost tearful expression. The neck is short, the trunk drawn out. On the long, narrow hand there is a short thumb, laterally compressed, which does not quite reach to the metacarpo-phalangeal joint. The ball of the last phalanx forms a thick, rounded pad, which is repeated in a lesser degree on the under side of the first phalanx of the thumb, and on its ball. The thumb-nail is bent back, as unlike a claw as the flattened, long, and narrow nails of the other fingers. The middle finger is only a little longer than the first, and the fourth not much shorter than the third finger (Fig. 12).

[Illustration: Fig. 12.--Left hand of _Hylobates albimanus_.]

The foot is neatly made, short and narrow, without a projecting heel. The great toe is very long, reaching almost to the last phalanx of the second toe. The sole of the foot, and the under side of the great toe, especially its last joint, are provided with thick, rounded pads. The middle toe is not much longer than the second, the fourth is shorter again, and the fifth is only half as long as the fourth. There is only a very short web between the roots of the fingers, but it extends much further on the toes (Fig. 13). This species of ape is found in Further India.

[Illustration: Fig. 13.--Left foot of the same animal.]

The wauwau (_Hylobates agilis_, F. Cuvier, Fig. 14), an ape of a rare species, may, according to Duvaucel, be recognized by his prominent supra-orbital arches, sunken eyes, a moderately flat nose, and large nostrils with lateral openings. The face of the male is hairless, and of a bluish black; that of the female is brown. The face is encircled by thick, whitish hair, through which the ears are only partly visible. There are a few black hairs on the chin. In the male the head, belly, inner surface of the arms and of the thighs are dark brown. The neck and shoulders are of a lighter shade, and the hair on the heels is dun or whitish. The backs of the hands and feet are dark brown. The sides of the posteriors and the backs of the thighs are brown, chestnut, or white. In the female the white hair which encircles the face is shorter, and verges on dun colour. The young animals are light yellow or brown. This animal inhabits the island of Sumatra.

[Illustration: Fig. 14.--A wauwau in the left foreground (_Hylobates agilis_); in the background to the light, two slender apes (_Semnopithecas entellus_).]

The grey gibbon (_Hylobates leuciscus_, Kuhl) is covered with a thick, long, and woolly coat, with scattered hairs which are curly, and have two or three rings of dark colour on a light ground. The upper part of the head is black; light, or sometimes white, hair encircles the blackish face. The general colour is dun. The front of the throat, the breast, and belly are of a lighter shade; while the back of the neck, the shoulders, upper arms, and thighs are darker. A brown or black stripe runs down the breast and belly from the armpits. The insides of the hands and feet are black. The colour of young specimens is more uniformly grey or dun. This animal is found in Java and Sumatra.

The hulock, otherwise called yulock or yoluck (_Hylobates Hoolock_, Harlan), has, in its adult condition, a prognathous face with prominent supra-orbital arches, a long, low bridge to its nose, with high, narrow nostrils, and a very small upper lip. In aged animals there are two oblique folds over the eyes, of a light grey colour. The rest of the hairy coat, the face, hands, and feet are black, or, in the younger animals, brownish black, with grey extremities. A line of grey extends from the breast downwards over the belly. This animal inhabits the mountainous district of Assam.

The unko (_Hylobates Rafflesii_, Is. Geoff. Saint-Hilaire) is of a black colour, shading into reddish brown on the back and sides. Hair, of a grey colour in the male and white in the female, encircles the face. This ape is a native of Sumatra.

The dun-coloured gibbon (_Hylobates entelloides_, Is. Geoff. Saint-Hilaire) is so called from its coat, which is thick and woolly, and furnished with long hairs of a greyish yellow or dun colour. This coat is somewhat darker on the inner surface of the arms and on the neck, where it shades into reddish yellow. The growth of hair surrounding the face is lighter, verging upon white. The female is generally more yellow in colour than the male, and the hair on her face is of a reddish yellow rather than white, but not without a trace of white hairs. The face and the bare places on the hands and feet are black. Between the second and third toes there is a connective web reaching as far as the first joints. This animal inhabits the Malacca peninsula. The name of the species is derived from its assumed likeness to the Indian hanuman (_Semnopithecus Entellus_, F. Cuvier), of which an illustration is given in the background to the right of Fig. 14.

The white-bearded gibbon (_Hylobates leucogenys_, Ogilby[9]) is remarkable for the long, erect hairs which grow on the upper and back part of the scalp, and for the long white beard on the cheeks and chin, which joins the thick growth above the eyes. The rest of the body is dark black. Its native place is doubtful.

The general colour of the tufted gibbon (_Hylobates pileatus_, J. E. Gray) is black, shading into grey on the shoulders, back, and thighs. A white ring surrounds the hands, feet, face, and scalp; and there is also a patch of white on the sexual organs, and often a patch of black on the breast. The whiskers are black. In other respects the animal varies according to its sex and age. It is found in Siam and Kambodja.[10]

The dark grey gibbon (_Hylobates funereus_, Is. Geoff. Saint-Hilaire) is of an ashen grey colour on the upper and outer side of its limbs, verging into brown; and on the under side it is dark brown. There is a narrow strip of light grey round the face, with a darker band round the back of the head. It is found in the island of Sulu.[11]

In addition to these species of gibbons of which we have given a brief account, there are several others--as, for example, _Hylobates concolor_ (Harlan), from Borneo; _H. Muelleri_ (L. Martin), from the same place; _H. choromandus_ (Ogilby), from India, and many others. But since our space is limited, the description given above must suffice for a diagnosis of the species.

Chapter III.

THE EXTERNAL AND ANATOMICAL STRUCTURE OF ANTHROPOID APES, COMPARED WITH THE HUMAN STRUCTURE.

In order to complete as far as possible the description which we propose to give of the general natural history of these remarkable animals, it is necessary to examine their anatomical structure. Yet it is not so much our aim to give a detailed and exhaustive description of their anatomy, as to glance rapidly at those peculiarities of their inner structure which catch the eye. It seems to me expedient in this case to follow the method of systematic and descriptive anatomy, and to take the several natural organs in succession. This method, which has long prevailed for studying the structure of the human body, should also be our guide in our researches in comparative anatomy. Our readers need scarcely be told that the anatomy of anthropoids is only a small branch of the comparative anatomy of vertebrate animals in general.

I begin by considering the bony structure of anthropoids, and, in particular, of the gorilla. And it will be well to note the important differences between the structure of the skull of a young and aged male, and of a young and aged female gorilla.

[Illustration: Fig. 15.--Skull of an aged male gorilla in profile.]

The skull of the aged male animal is large and heavy. Its average weight is one and a quarter kilogrammes. The longitudinal diameter, from the alveolar point of the upper jaw to the occipital point, may be as much as 294 mm. The overhanging orbits are high in front, and flattened off behind, and their upper edges unite to form a ridge in the middle of the face. To these the back parts of the orbits are attached, in shape like a truncated cone, round and prominent in front, and narrowing into bony capsules in the direction of the brain-pan. They open directly in front, and the aperture is generally in the form of a regular square. The edges are seldom so blunted off as to present a figure somewhat approaching to a circle (comp. Figs. 15, 16). The frontal bone, which in the young of both sexes is high, broad, and arched, becomes depressed in the centre in the aged male. The temporal ridges, thickened to a hem, pass over this to the coronal crest.

[Illustration: Fig. 16.--Front view of the skull of an aged male gorilla.]

This crest is highly characteristic. It begins in the region of the frontal bone, and, rising abruptly, unites itself with the transverse occipital crest. It is of varying height,[12] but is rarely altogether absent in an adult male animal. On the top of this coronal crest we may see the two well-developed bony ridges which almost touch each other, and which indicate the upper limits of the temporal muscles on either side. In young animals these ridges tend downwards over the sides of the head, below the vertex of the skull. Their position and direction vary with the growth of the skull, and correspond with that of the coronal crest. The transverse occipital crest is of considerable height in the case of aged and vigorous animals, and is frequently somewhat concave in front, and convex at the back. The fore surface of this crest is formed of the two parietal bones, the hinder surface of the squamose portion of the occipital bone. The lambdoidal suture is on the top of this occipital crest, and in this case, as in that of other mammals, including man, it unites the parietal bones with those of the occiput. The point of union between the coronal and occipital crests divides the latter into two symmetrical lateral halves, curving outwards and downwards. The high, wide squamose portion of the occipital bone is somewhat flattened behind, or more rarely arched, while it is abrupt at its base and in some degree in front. Six curved lines, three on either side, opposite each other, sometimes mark the limits of the attachments of the cervical muscles on the head. The mastoid process of the temporal bone is present, but Brühl could find no trace of a styloid process on the skulls of gorillas and chimpanzees.

The squamous portion of the temporal bone is often connected with the frontal bone by the process termed Virchow’s frontal process of the temporal bone. The nasal bones are high, very narrow in their upper part, and widening below. When they are united in the centre of the nasal bridge, a sloping, keel-shaped projection may often be observed. The inferior turbinated bones of the nasal cavity are remarkable for their size. In the skulls of young animals the inter-maxillary bones, which are in all anthropoids early united with those of the same region, stand up high and peaked between the nasal bones and those of the upper jaw.

The crowns or prominent external surfaces of the enormous canine teeth project in the centre of the face on either side like pillars, just below the nostrils, and extend above and below the row of teeth in the two upper jaws (see Fig. 16). In this way the crowns of the canine teeth form a retreating triangular space, of which the base-line of the equilateral triangle corresponds with the row of teeth. The chin part of the lower jaw, in a front view, also takes the form of an equilateral triangle. In the latter case the base-line is covered by that section of the row of teeth containing the incisor teeth. The sides of the triangle are covered by the converging canine teeth (see again Fig. 17). The incisor teeth, enclosed between the latter, in that part of the lower jaw already described, are retreating. The rami of the lower jaw are high and very wide. The angle of the lower jaw is obtuse (Fig. 15). The front or coronoid process and the back or condyloid process of the ramus of this bone are separated from each other by a deep, hollow cleft. The condyloid process projects abruptly above, but is less marked behind.

When we consider the internal form of the skull of an aged male gorilla, the first thing that strikes us is the marked development of the frontal sinuses, and especially their width in the region of the nasal portion of the frontal bone. We next observe the wings of the sphenoid bone, and that these large concave apophyses are provided with spaces only slightly separated from each other. These sinuses are not only plainly connected with each other, but with the sphenoidal sinuses. There is a broad sinus in the malar bone, provided with vestibules, and this has a deep communication with the maxillary sinus, or antrum of Highmore, embedded in the body of the upper maxillary bone. There are, finally, sinuses at the point of junction between the coronal and occipital crests.

The maxillary region of the cranium of the young male gorilla is already somewhat prognathous, and the keel-shaped elevation of the bridge of the nose is also very apparent, but the development of these parts is not nearly so advanced as in the aged male. The whole contour of the cranium is oval, and without the high crests so characteristic of the aged male animal. It is well known that the Swedish anatomist and anthropologist Anders Retzius has classified the skulls of different races of men as long-headed (_dolichocephali_) and short-headed (_brachycephali_). In the former class, the length is considerably greater than the height; while in the latter, the difference is either slight or non-existent. The skulls of the _dolichocephali_ are long and oval; those of the _brachycephali_ are short, round, or square. In addition to this division, which is of great value in the rapid and superficial, yet sound classification of racial skulls, Retzius has constituted another. He has characterized skulls of which the profile is straight, or nearly straight, as _orthognathous_ (_rechtzähnige_); and those of which the maxillary region is very prominent, as _prognathous_ (_schiefzähnige_). These orthognathous and prognathous skulls may be either dolichocephalic or brachycephalic.[13]

In applying this classification by Retzius to anthropoids, the gorillas and chimpanzees have been characterized as dolichocephalic and prognathous, the orang-utans and the gibbons as brachycephalic and prognathous. Several scientific men have sought to establish the noteworthy distinction that dolichocephalic anthropoids are found in Africa, and brachycephalic anthropoids in Asia. This distinctive characteristic is held to agree with the geographical and ethnological conditions of the continents in question.[14] Virchow remarks in a later work that the skull of a gorilla becomes longer with every year of life, but that this is not so much due to the cranium as such, as to its bony outworks, such as the strongly developed supra-orbital arches, the enlargement of the frontal sinuses, etc. Measurements rather tend to show that the young gorilla is brachycephalic, but that this characteristic diminishes with increasing age, at any rate, if the external excrescences are taken into account. But it is quite otherwise when the furthest point of measurement is taken from the frontal arch, not from the nasal prominence. In such a case the increase of the brachycephalic condition is established.[15]

In the skulls of such young males as those here mentioned, the temporal ridges, which in aged animals are in close proximity in the region of the developed bony crests, have already in some cases begun to approach each other, but they are still far apart. In young specimens we can distinguish, on each side of the parietal bones, two temporal ridges, opposite each other, and taking a nearly parallel course. The upper ridge, which loses itself on the external surface of the mastoid process, which is already developed, corresponds to the junction of the fascia of the cranial muscles (_Galea aponeurotica musculi epicranii_) with the fascia enclosing the large temporal muscles. The lower ridge, which is gradually merged in the upper edge of the zygomatic process of the temporal bone, forms the demarcation of the fleshy origin of the temporal muscle. This corresponds to the spot at which the two layers of the temporal fascia unite. In a very young male these temporal ridges can be only faintly traced; they become more strongly marked as his growth advances, and as they approximate more closely to each other on the vertex of the cranium. I have examined a skull of which the sutures were still open, and could already trace the development of the coronal crest in two divisions, separated from each other by a longitudinal furrow. The upper edges of these divisions corresponded to the two temporal ridges, which were in close proximity to each other. If the animal had not died at this stage of its development, it is probable that, with advancing growth, the two divisions of the crest would have been welded into one structure. Such a condition only characterizes a transitory stage of development, repeated in each individual.

In the centre of the vertex of the cranium, where the longitudinal crest of which we have so often spoken is subsequently developed, we may often observe on the sagittal suture of the cranium of a young male a longitudinal swelling, which increases very gradually. In the region of the two upper semicircular curved lines (_lineæ semicirculares s. nuchæ supremæ_), on the squamous occipital portion, or between these and the two central cervical lines, a transverse swelling is early developed; this swelling sometimes extends to the lambdoidal suture, or, at any rate, to its neighbourhood. This bony excrescence, of which the anatomical term is _Torus occipitalis transversus_, corresponds to the first layer of the transverse occipital crest so characteristic of the old male gorilla (see Fig. 15).

In several skulls of young gorillas, in the region of the coronal suture, a small, insulated, intermediate bone may be observed (Virchow’s _os epiptericum_) between the squamous portion of the temporal bone and the greater wing of the sphenoid, with which it is sometimes completely welded. In this case there is, above the _os epiptericum_, a direct connection between the temporal and frontal bones by means of the frontal process (Virchow’s _processus frontalis squamæ temporalis_), which is not rare in anthropoids.[16] This process often owes its origin to the _os epiptericum_, which is in its early stages attached to the temporal bone. I shall have to refer again to this frontal process.

The orbits are more rounded in young than in aged skulls; in the latter they are always angular, although the angles, especially the upper and external angles, may be more or less blunted. Virchow remarks that in the skull of a very young gorilla the height of the orbit exceeds its width, and that at that age the skull is therefore high. In the aged male gorilla the height of the orbit, according to the several measurements I have taken, varies between 39 to 52 mm., and the width between 37 to 45 mm.

[Illustration: Fig. 17.--Skeleton of an aged male gorilla.[17]]

The rest of the skeleton of the aged male gorilla corresponds in its powerful and massive form with the general structure of the body, which is remarkable for its height and strength (see Fig. 16). In the skeleton of the trunk there are seven cervical, thirteen dorsal, and four lumbar vertebræ, thirteen ribs, and, even in aged animals, a sternum composed of several pieces of bone. The cervical vertebræ display long spinous processes, which are most strongly developed between the fourth and seventh vertebræ. The extremities of this colossal structure, combined with the elevation of the occipital region, present a convex outline when seen from behind. This structure provides the point of insertion and support for the powerful cushion of cervical muscles. The dorsal vertebræ, which increase in height, width, and depth as they stand lower on the column, taper, and are keel-shaped at their junction with the cervical vertebræ. The central parts of the widely arched ribs, which are thirteen or sometimes fourteen in number, are very thick and powerful in the aged male. Only seven pairs of ribs are attached by the costal cartilages to the sternum, and two other costal cartilages are in proximity with them. The other cartilages are only rudimentary, and the terminations in the muscular system of the belly are free. There are, indeed, variations from the type here established, and from ten to eleven ribs are sometimes attached to the sternum by thread-like strips of ligament or cartilage.

The formation of the pelvic girdle in this animal is of special interest. The chief parts of this portion of the skeleton--that is, the hip, pelvic, or innominate bones--are high, tapering in their lower part, and broad and flat above, where they terminate in the crest of the ilium, which describes a quarter of a circle. There is, for the most part, only one small superior iliac spine, and the ischii are somewhat turned outwards, and furnished with broad, rounded tuberosities, and for the most part with only a single large sacro-sciatic notch. The horizontal rami of the pubes are narrow, while the descending rami are wide. The os sacrum is narrow, and shaped like a protracted cone, turning abruptly outwards, and resembling the basal joint of a true tail. The coccyx appears to be the rudiment of a genuine tail.

The bones of the shoulder-girdle present interesting peculiarities. The clavicles are long and slender, with a leaf-shaped, flattened end articulating with the scapula, and a thickened end articulating with the sternum. The scapula is a very large triangular bone, resembling the human scapula in its general form, and the supra- and infra-spinous fossæ are not strongly marked. The long and powerful humerus has its head inclined at an angle of sixty degrees towards the axis of the shoulder. Frequently, but not invariably, the lower, flattened extremity of the humerus is pierced on one or both sides above its rounded eminence, and this is termed by Darwin the intercondyloid foramen.

The radius has a powerful head, and a shaft considerably curved outwards, while it is, on the other hand, curved backwards and inwards at the elbow. The bones of the carpus, metacarpus, and phalanges are remarkably long, broad, and deep. The development of the femur corresponds to that of the whole skeleton. Its middle piece or shaft is curved in front and flattened behind. The shaft of the tibia is generally rounded off, but is sometimes rather laterally compressed.

The os calcis of the foot is slender, curved outwards in the centre and inwards behind the astragalus. The head, with its cuneiform extremity, is of a transverse oval shape, turned inwards. The scaphoid bone, which is generally in connection with this projection, takes the same direction towards the inner side of the foot. This peculiar contortion causes the tarsus of the gorilla to appear almost as if it had been subjected to a deviation or fracture of its longitudinal axis.

In young and adult males, as well as in young females, the structure of the bones is generally less massive than in aged males. In the female skeleton the strongly developed depressions and ridges, especially in the bones of the extremities, are absent. The head of the ulna is, for example, less deeply set in the case of a female, and its projections are smaller than in the male animal. In the female, also, the head of the radius is smaller, and the triangular shape of its shaft is less strongly marked. The pelvic bones of a female gorilla are wider, flatter, and less concave on their very projecting inner surface. They diverge more widely from each other, and this is also the case with the tuberosities of the ischium. The pubic arch is less depressed than in the male gorilla. Although the spinous processes of the vertebræ attain to some length and thickness, their development in the female is not so great as it is in the male sex.

The bony structure of the chimpanzee offers many points of resemblance to that of the gorilla, while it differs in certain particulars from the structure of other anthropoids. And first, the size of the skeleton is smaller than that of the gorilla, which is in agreement with the smaller relative size of the body of the chimpanzee.

[Illustration: Fig. 18.--Skull of an aged male chimpanzee.]

We must begin with a general view of the skull of the chimpanzee. In both sexes the frontal regions are smaller, while the coronal region is more rounded than in the gorilla. The high bony crests and prominent supra-orbital arches are wanting in the chimpanzee; the peculiar character of the bony ridges, projecting like tubes from the other parts of the skull, is less marked, and they belong more directly to the frontal region (see Fig. 18). The bony bridge of the nose is more concave in the chimpanzee; the jaw-bones are smaller and less compressed in the centre than they are in the gorilla.

When we undertake to describe the skull of the chimpanzee in detail, it becomes necessary to consider separately the skulls of aged and young males, and of aged and young females; for in this case also the distinctions of sex and age are very evident. On the skull of an aged male chimpanzee the temporal ridges are not much developed on the coronal arch. They meet on this arch from 60 to 90 mm. behind the orbits, and form only a small coronal crest. The transverse occipital crest is somewhat developed, and at its point of union with the coronal crest the temporal ridges divide to form its upper edges. This is the case not only with the Rio Quillu skull, from which Fig. 18 is taken, but with that of the so-called troglodyte Tschègo given by Duvernoy.[18] In some other specimens belonging to aged male animals the presence of a coronal crest cannot, however, be detected. In these the temporal ridges are very small, and more or less distant from each other. While the transverse occipital crest maintains an almost uniform height on the gorilla skull, like a detached ridge, it is only slightly elevated behind in those chimpanzee skulls in which the crest is partially developed. In the gorilla male this ridge divides the squamous occipital portion, which is sometimes bevelled, sometimes slightly convex; in the male chimpanzee this part is more decidedly arched, and takes the form of a half-oval. The mastoid processes are also present in the chimpanzee. The external occipital crest and the curved lines are generally apparent. The styloid processes are more plainly traced than in the gorilla. In the latter, as well as in the chimpanzee, there is a blunt, tubular process of the temporal bone, opposite to another bony process, issuing from the occipital bone. This has been observed by Virchow, and is termed by him the carotid process (_Processus caroticus_).

The orbits of the chimpanzee are generally more rounded, with a distinctly circular rim, while the nasal bones are as long and narrow as in the gorilla. The region of the jaws is very prognathous; the external nasal openings are rounder and smaller than in the gorilla. The crowns of the canine teeth project in the same pillar-shaped form (Fig. 18). The triangular space enclosed by these and by the row of teeth in the upper jaw is often very wide and projecting, even more so than in the gorilla. But whereas in the latter the canine teeth are shaped almost like a three-sided pyramid, in the chimpanzee they are more rounded and conical. In the general structure of the teeth of both species there are certain differences of which we shall speak presently.

The brain-pan of a young male chimpanzee is still more arched than it is in aged animals. The temporal ridges are still far apart. The transverse occipital crest displays near the mastoid process well-defined wing-shaped indentations. In the skulls of very young males the transverse occipital swelling of which we have spoken (_Torus occipitalis transversus_) is already developed. The orbits are distinctly detached from the skull; the bridge of the nose is depressed; the crowns of the canine teeth are, in conformity with the still slight development of the teeth themselves, less marked, and the triangular space enclosed by the teeth is less convex than in older animals.

The skull of the adult chimpanzee is, in its coronal and occipital parts, more uniformly arched, narrower, and more elongated than in aged males. The transverse occipital ridge usually develops itself in the region of the upper curved lines, or in the bony parts enclosed between these and the central lines. The nasal and upper maxillary region is depressed. That section of the upper jaw which contains the incisor and canine teeth is small. In the skulls of all chimpanzees, of whatever sex or age, the body of the lower jaw is comparatively small, with two low but wide rami, of which the coronoid and condyloid processes are divided from each other by a comparatively wide cleft. The rami of the chimpanzee’s lower jaw are still more abruptly retreating than is usually the case in the gorilla.

The skull of a very young female gorilla is shaped almost like a half-sphere. The orbits are scarcely detached from the forehead; the want of elevation of the orbital arch, and the slighter prognathism of the jaw, is marked by the deep depression between it and the nose and forehead (Fig. 20).

The cancellous texture of the bones of the chimpanzee’s skull admits of a whole system of cavities communicating with each other, which are of the nature of the so-called sinuses present in the frontal, sphenoid, ethmoid, and maxillary bones of the human skull. In the chimpanzee, however, the sinuses are more extensive than in man, or even than in the gorilla. The large cavities of the forehead communicate with those of the nose and jaws. The sphenoidal sinuses and ethmoidal cells are large and deep. The greater wings of the sphenoid bone and its pterygoid processes are provided with considerable cavities. The mastoid cells of the temporal bones are in connection with the cells of the greater wings and pterygoid processes of the sphenoid bone, and also extend through the squamous portions and zygomatic processes of the temporal bones, losing themselves in their upper part in the smaller cells of cancellous bone which are found between the outer and inner walls of the skull. These are of more uniform shape and size.

[Illustration: Fig. 19.--Skull of a very young female chimpanzee.]

The skeleton of the chimpanzee, in accordance with the smaller size of the species, is relatively of a slenderer build than that of the gorilla. The spinous processes of the seven cervical vertebræ are more slightly developed, and have undivided extremities. The transverse processes of the fifth and sixth cervical vertebræ are almost of the same shape as cervical ribs. There are thirteen dorsal vertebræ, somewhat laterally compressed: this compression is greater than in man and in the gorilla. The four lumbar vertebræ of the chimpanzee are furnished with long, thin, riblike transverse processes. The so-called mammillary processes of the final vertebra are strongly developed in the male. The intervertebral foramina are small, as they are also in the gorilla and orang-utan. The thirteen ribs of the chimpanzee remind us of the human structure. The collar-bone is slightly curved, as in the gorilla. There is a marked difference between the sexes in the structure of the scapula which is broad and three-sided in the male, small and leaf-shaped in the female.

[Illustration:

Fig. 20.--Skeleton of the forearm and hand of the Central African bam-chimpanzee. _a_, Ulna. _b_, Radius. _c_, Scaphoid bone. _d_, Semi-lunar bone. _e_, Cuneiform bone. _f_, Pisiform bone. _g_, Trapezium. _h_, Os magnum. _j_, Trapezoid. _k_, Unciform bone. _l_, Phalanges of thumb. _m_, Metacarpal bones. _n_, Phalanges. ]

The humeri have slender shafts, with well-developed condyles and ridges. The bones of the forearm are much curved, so that the interval between them is, as in the gorilla, somewhat wide. From the wrist to the final phalanges the hand is more slender than in the gorilla.

The pelvis in this species of ape has high, narrow ilia, spreading in their upper parts, and projecting forwards, so as to form the cavity of the abdomen, and, especially in the male sex, the anterior spines of the ilium are more strongly developed than in the gorilla and orang-utan. The ischiatic tuberosities are of a spreading form, and diverge considerably from each other. The pubic arch is deeply hollowed, but the point of juncture is elevated. As in the gorilla, the os sacrum resembles the basis of a tail, but it is less developed and less conical in form.

In the chimpanzee, as well as in other anthropoids, the coccyx gives altogether the impression of a laterally compressed and rudimentary tail. This is especially the case in young animals, in which the coccyx always appears to be very narrow and prolonged. In older animals this part gradually widens, yet without losing its resemblance to a rudimentary tail.

The head of the femur resembles a section of a sphere, of which the upper part is sometimes wanting. Its shaft, which is curved in front, is much slenderer in the female than the male. The patella is oval. In the tibia the narrow shaft is laterally compressed, and bent inwards. The bones on the inner side of the foot take a backward direction, while those on the outer side, attached to the fibula, turn outwards.

In the ankle-joint the head of the astragalus is much arched, and turned inwards. The scaphoid bone is thick and deeply hollowed. The metatarsal bones and phalanges have a considerable upward convexity (Fig. 21).

[Illustration: Fig. 21.--Skeleton of foot of the Central African bam-chimpanzee. _a_, Astragalus. _b_, Os calcis. _c_, Scaphoid bone. _d_, _e_, _f_, Cuneiform bones. _g_, Cuboid bone. _h_, First metatarsal bone. _j_, Second to fifth metatarsal bones. _k_, Phalanges.]

The skeleton of the orang has also its special characteristics. We have already remarked, in describing the external form of the heads of these animals, that the skull is high and projecting, and retreating in its hinder part. In the old male orang this part of the bony structure is of smaller size than in the old male gorilla. The arch of the cranium is shorter and rounder than in that animal and in the chimpanzee. The central longitudinal crest of the vertex is present, but in accordance with the more spherical shape of the coronal part of the cranium, this crest is more arched above than in the gorilla, in which it slopes gently upward to the transverse occipital crest, which rises high and peaked from the back of the head. This latter crest is indeed developed in the orang, but it is not so high, and is more retreating. In consequence of this formation, the upper posterior part of the gorilla-skull appears in profile to be much more abrupt and peaked than that of the orang. In the latter, also, the orbital arches are not so high and abrupt, and not so much detached from the rest of the skull. In the orang the squamous occipital portion declines abruptly in front and below, yet it is generally more arched than in the gorilla. The orbits of the orang, which are sometimes rounded, sometimes more square, are divided from each other by a narrow partition. The space between them and the anterior nares is not so great as in the gorilla. While in the last-named animal the space between the root of the nose and the teeth of the upper jaw-bone is convex, in the chimpanzee it is generally vertical, and in the orang it is depressed (Fig. 22). The maxillary parts, furnished with strong canine teeth, are very prognathous, yet hardly to the same extent as in the chimpanzee. The body of the lower jaw is high, and its rami are high and wide. The bony crests of which we have spoken are absent in the female. The coronal part and the squamous occipital parts are arched; the upper jaw is smaller, and the lower jaw is also less massive, than in the male animal. In very young animals the predominance of the strongly arched cranium over the countenance is apparent, and the increase of size in the latter occurs gradually (Fig. 23).

[Illustration: Fig. 22.--Skull of middle-aged female orang.]

The anterior nares are narrow at the top, and wide at their base. They are more decidedly pear-shaped (_Apertura pyriformis_) than those of the gorilla and chimpanzee. In the latter animals these apertures are generally wider and more uniformly rounded. Bischoff justly observes that the bony part below the orbits, which in the gorilla is wide above, tapering away in the lower part of the face, is narrower and more vertical in the orang. The nasal bones of the orang are high and of moderate width. Brühl mentions the styloid process of the orang’s skull, which is, however, somewhat abortive when we compare it with that of the human skull. It has its origin in a tolerably deep groove. On the other hand, Brühl, as we have already observed, can find no trace of the styloid process in the skulls of the gorilla and the chimpanzee![19]

[Illustration:

Fig. 23.--Skeleton of young orang-utan. _a_, Sternum. _b_, Radius. _c_, Ulna. _d_, Tibia. _e_, Metacarpus. _f_, Phalanges. _g_, Great toe. _h_, Fibula. _j_, Hip-bones. _k_, Coccyx. _l_, Vertebral column. _m_, Scapula. _n_, Femur. ]

There are many large-celled bony cavities in the orang’s skull. These may be observed in the greater wings and pterygoid processes of the sphenoid bone, in the mastoid and squamous parts of the temporal bones, in the lachrymal bones, in the body, and in the condyles of the occipital bone, and in the zygomatic arch. The larger fore-cells on the squamous part of the temporal bones are connected by a wide aperture with the sinuses of the greater wings and pterygoid processes of the sphenoid bone. A sinus which may be observed on the greater wing generally communicates by a large round hole with the temporal cells. There is generally, but not always, a communication between the sinuses of the greater wing and pterygoid process and the nasal cavity. These cavities sometimes communicate with each other through a wide aperture at the base of the nose. The squamous part of the temporal bones has a cellular sinus, which communicates with the cells of the mastoid process, in its lower part with the tympanum, and in its fore-part with the ossicles of the lower wall of the tympanum. The maxillary sinuses are in connection with the cells of the lachrymal bone. There is nothing in the orang’s skull corresponding to the Vidian canal of the sphenoid bone, but it may be traced in the gorilla and the chimpanzee.

The vertebral column of the orang has not the same colossal spinous processes which distinguish that of the gorilla. It differs also in many other, though less striking, particulars both from the gorilla and the chimpanzee. In the orang there are generally twelve dorsal vertebræ, tapering in their lower parts; while their long, thick, transverse processes, which are full of knots, take an upward direction. The upper articular processes of the four lumbar vertebræ present short and rather insignificant mammillary processes. The sternum of the young orang is generally formed of one large upper bone, with six smaller bones below. In older animals the body of the sternum appears to consist of a tier of three bones connected together. The ribs resemble those of the human skeleton, the clavicle is long and straight, and the scapula also resembles that of a man in form. The flat pelvic bones of the orang also turn outwards; the ischiatic bones are short, with spatula-shaped tuberosities; the pubic arch is high, and the obturator foramen is narrow and oval. The sacrum and coccyx do not resemble a rudimentary tail so much as in the case of the anthropoids we have already described. We are reminded of the human structure in the humerus, of which the shaft is much curved behind, and on its outer side. The ulna is very slender, and provided with a protracted, jagged styloid process. The neck of the radius is tapering, while its shaft is arched like that of the ulna, and the anterior border and oblique line are sharp. The wrist, metacarpus, and fingers are long and narrow.

The femur of the orang is remarkable for its large head, shaped like a section of a sphere, and its slender shaft. The latter is less bent than in the gorilla. The patella, which, in my opinion, should be classed among the so-called sesamoid bones, is in this case of an irregular form. The shank and foot-bones are remarkably slender. The scaphoid is tapering; the head of the astragalus does not turn inward so much as in the gorilla. The hinder surfaces of the metatarsal bones and of the phalanges turn decidedly outwards.

We have now to consider the bony structure of gibbons, in which there are many specific variations which our space will not allow us to consider in detail, but a slight sketch of their organic system must be given. The brain-pan of this animal’s skull is of an oval shape, without the crests so characteristic of other anthropoids, and even in the aged males of this species their development is so slight as to be scarcely perceptible. The occipital bone of male animals is, indeed, generally rounded, and the whole occipital portion is somewhat compressed in a downward direction, while the coronal region is at the same time flattened. The cranium gradually widens behind, so that, when seen from above, its form is somewhat pear-shaped. In aged males the orbits project from the low, retreating frontal bone, and are surrounded by a bony, circular rim.

The face is not very prognathous, and the short wide nasal-bones form a wide, depressed partition between the orbits. The edges of the jaw-bones describe a parabolic curve and are considerably elongated. The palate is consequently long and narrow. The rami of the lower jaw are wide and low, and their coronoid processes are only slightly developed. In aged males the teeth, and especially the canine teeth, are long and projecting; yet, comparatively speaking, they never attain to the great development of those of other anthropoids.

The number of vertebræ seems to be subject to considerable variation even in the same species, and various estimates are given by different naturalists. Müller, for example, has said that in several species (_Hylobates syndactylus_, _H. leuciscus_, _H. variagatus_, and _H. concolor_) there are thirteen dorsal, five lumbar, six sacral, and four coccygeal vertebræ. Cuvier counted in the siamang, thirteen dorsal, five lumbar, four sacral, and three coccygeal vertebræ. In _Hylobates agilis_ I counted thirteen dorsal, six lumbar, five sacral, and four coccygeal vertebræ. _Hylobates syndactylus_ has long coccygeal bones, and an elongated os sacrum, which gives the impression of serving for the application of a short tail, or, indeed, of being in itself a rudimentary tail. In other respects the cervical, dorsal, and lumbar vertebræ differ little in structure from those of man.

The ribs on the sternum, which widens abruptly outwards, are strongly arched. The lowest of these project, owing to the width of the shaft. In the sternum there is a want of proportion between the smallness of its body and the size and width of its extremity. The ensiform appendix of this bone is long and wide, and spatula-shaped at its lower extremity. In the shoulder-girdle the clavicles are very slender, and much arched. The scapulæ, on the other hand, are high and narrow, spatula-shaped, and provided with a steeply projecting acromion process, a strongly developed coracoid process, and deep glenoid cavities. The upper limbs are, in conformity with the general structure of these apes, very slender; the shafts of the bones of the upper and forearm are elongated, with small extremities. The condyles are small, especially those of the elbow. The bones of the wrist, the metacarpus, and the fingers are also long and slender.

In the pelvis we note that the ilia are narrow below, and expand in the form of a spatula above, and that their position is almost vertical. Their inner surfaces are only slightly concave, and are directed somewhat forwards. The ischiatic bones are low, with wide, flattened, rugged tuberosities, and rounded _foramina obturatoria_. The ischiatic rami project forwards in an almost horizontal direction. There are large prominences on the pubic arch of the siamang.

The leg-bones are much shorter than those of the arm. The heads of the femurs stand out plainly from their short necks and large trochanters, as segments of perfect spheres. In this case, as in that of other anthropoids, the third trochanter (_trochanteres tertii_), often so apparent in the human femur, is barely indicated. The shank-bones are arched. The tibia is often laterally compressed, so that its transverse section forms a scalene triangle. The malleoli are compressed from before backwards. The elongated heel-bones appear to be laterally compressed. The canal between the astragalus and the os calcis (_Sinus tarsi_) is very wide. The metatarsal bones and phalanges have large bases, long slender shafts, and heads projecting on the under side. Even the final phalanges are long and slender.

[Illustration: Fig. 24.--The Zulu king, Ketchwayo, in fighting array, with two of his men.]

We shall now find it profitable to compare the external characters of anthropoids with those of man. We are sometimes disposed to see the true likenesses of anthropoid apes in dark-skinned, naked savages. These savages are often insufficiently fed, the skin is wrinkled, the face, even at an early age, is deeply furrowed, and their general appearance is neglected. The dark silhouette of such people stands out so distinctly against a clear background, their habit of life is so rude, their attitudes impress us so disagreeably, that we are involuntarily led to make such a comparison. This tendency unfortunately gives a wide field for exaggeration among dilettanti naturalists, and such as are zealous to establish a preconceived theory. A conscientious inquirer must, however, be cautious, and avoid too great generalization in such comparisons. For instance, much has been said of the pithecoid structure of all African negroes, yet this only applies to some peculiarly hideous races, in a state of physical degradation. There are many negro tribes in different parts of Africa which are remarkable for their well-formed bodies, and for a not ignoble bearing. The warlike demeanour of the natives of Ashanti, Dahomey, and Ibos is well known. Although the Hausanese are flat-nosed and thick-lipped, yet when armed and dressed in uniform, as we see in the photographs of Captain Glover’s force, their military bearing is very apparent. The tribes of Schilluk, Nuehr, Bari, Niam-Niam, and A-Bantu present examples of distinguished warriors, however rude and savage. Dabulamanzi, commander of the Zulus at the butcheries of Isandlhwana and Ulundi, and his chiefs, give me, in a photograph in my possession, the impression of gallant warriors, however uncivilized. In all these cases it is difficult to establish the resemblance to anthropoid apes (see also Fig. 24).

The Papuans, especially on the Australian continent, are generally classed with the African negroes in such comparisons. We admit that a horde of Australian blacks, degraded by hunger and fatigue, emaciated and dirty, may, as they roam through the shadeless woods, the steppes and thick scrub of their native country, present a strange and brute-like appearance. And if the foreign intruder takes a coarse pleasure in giving drink to these savages, their immodest gestures may afford a revolting impression of their bestial nature. Yet the habits even of these dark-skinned savages are altogether different under more favourable conditions. Although of small stature, they are not badly proportioned, and their manners and bearing are capable of improvement, so that they can act as native police, messengers, etc. This was the case also with the natives of Queensland, Australia, whom I saw in the Zoological Gardens, Berlin, throwing the boomerang. Even in these tamed savages, however, we must note the projecting orbits, the deep depression between the forehead and nose, and the flatness of the latter organ. There are aged, wrinkled bushmen, negroes, Papuans, Malays, Japanese, and Mongols of inland Asia whose countenances are altogether pithecoid. And such a cast of face may even be found in Europe.

Some years ago, Mr. Bond, a land-surveyor in British India, asserted that he had found the missing link between man and apes in the mountainous district of the Western Ghauts. And indeed, the race he describes seems to have a strong resemblance to apes. “The forehead is low and retreating. The lower part of the face projects like the muzzle of an ape; the legs are short and bent outwards. The trunk and arms are comparatively long. The hands and fingers are contracted so that the latter cannot be freely extended; a thick skin covers the hollow of the hand and the fingers, especially their tips; the nails are small and imperfect; the feet are broad, and covered both on their backs and soles with a thick skin. This tribe seems to worship nature. They have no fixed dwellings; they live chiefly on roots and honey, and exchange the latter, together with wax and other productions of their forests, for tobacco, clothes, and rice.”[20]

Nothing more, so far as I am aware, has been published concerning this race. The description given above leaves much to be desired. The assertion respecting the contracted fingers is obscure, and such a condition is directly opposed to any resemblance with the flexible hand of apes.

[Illustration:

Fig. 25. Aidanill, hairless Australian.

Fig. 26. The same in profile. ]

Let us turn from a tribe of which the existence is still dubious, to consider the portraits we subjoin of a man and woman, aborigines of Queensland, in a district watered by the Ballone. These are Aidanill, the brother, and Dewan, the sister, members of a hairless family. The indefatigable Miklucho-Maclay went to Gulnarber, 140 miles from Tulba, in order to examine them, and took the photographs from which our illustrations are taken.[21]

A likeness to the chimpanzee, when deprived of its hair, may be traced in the keel or roof-shaped form of the skull; in the prominence of the supra-orbital arches; in the deep depression between the forehead and nose, of which only the centre of the bridge has a slight vertical elevation; in the broad, flattened nostrils, bounded by deep furrows; in the wide, fleshy mouth, and the large, laterally projecting ears. Gratiolet and Alix give such a head in their treatise on _Troglodytes Aubryi_ (Figs. 25, 26, 27). When we add to this the dark brown skin, the deeply furrowed countenance, and the dark brown eyes, as they are described by Miklucho-Maclay, the external resemblance between many of the Australian aborigines and apes becomes more marked.

[Illustration: Fig. 27.--Dewan, Aidanill’s sister.]

Projecting ears are common among men of different races, and I have observed them in Europeans who are otherwise well formed. Even in this latter case the effect is ape-like. Much has been said of the resemblance which may often be observed between the human ear and that of apes. It is admitted that hardly any part of the organism varies so much in its characteristics as the external ear. This is the case with anthropoids, and almost more frequently with men. Individuals of all nations are found with defective development of this or that characteristic helix, angle tragus, notch concha, and fossa, with lobules imperfectly formed or altogether absent. I have frequently observed such misshapen ears, which vary from the perfect type, and bear a certain resemblance to the ear of apes, among the hard-featured peasantry of Germany, Switzerland, France, Italy, and Poland, who cannot be said to count beauty as part of their inheritance. In Africa I found this defective formation more common among the Maltese, Greeks, and Turks who were living in the country, than among the fellaheen, Berbers, and negroes. The latter have been unjustly charged with the possession of “hideous ape-like ears,” whereas, among the African races, these organs are, in the majority of cases, of a pleasing form. With respect to the Australian blacks, and to the Malay, Mongolian, and Indian races, I cannot rely on my personal observation. According to my very limited experience, there is much individual variation among these races, and ears of the hideous, ape-like formation might be sought for with success. The specific resemblance to apes can, indeed, only be ascertained by one who is accurately acquainted with the organism of these animals. These and similar ideas are often expressed by the unlearned, who do not really understand the characteristics in question.

Darwin speaks of the anthropoid form of the ear in the chimpanzee and orang.[22] “The ears of the chimpanzee and orang are curiously like those of man, and I am assured by the keepers in the Zoological Gardens that these animals never move or erect them, so that they are in an equally rudimentary condition, as far as that function is concerned, as man. Why these animals, as well as the progenitors of man, should have lost the power of erecting their ears, we cannot say. It may be, though I am not quite satisfied with this view, that owing to their arboreal habits and great strength they were but little exposed to danger, and so during a lengthened period moved their ears but little, and thus gradually lost the power of moving them. This would be a parallel case with that of those large and heavy birds, which from inhabiting oceanic islands have not been exposed to the attacks of beasts of prey, and have consequently lost the power of using their wings for flight.

“The celebrated sculptor, Mr. Woolner, informs me of one little peculiarity in the external ear which he has often observed both in men and women, and of which he perceived the full signification. His attention was first called to the subject whilst at work on his figure of Puck, to which he had given pointed ears. He was thus led to examine the ears of various monkeys, and subsequently more carefully those of man. The peculiarity consists in a little blunt point, projecting 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 thought, 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 helix 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.”

[Illustration: Fig. 28.--Human ear.]

I subjoin an illustration of the human ear, in which the pointed tip mentioned by Darwin may be easily discovered. This point may also be perceived in the ears of anthropoids, and especially in those of the orang-utan. Meyer has attempted to show that this Darwinian pointed tip is only due to the abortive development of part of the helix, and in this case we should not regard the occurrence as an ape-like pointing of the helix, but rather as its partial interruption owing to the pathological condition of that organ.[23] In a later edition of his work, Darwin admits, in reply to Meyer, that this explanation may apply to many cases in which there are several very small points, or when the whole of the helix is sinuate. In one case, photographed by Darwin, the prominence was so large that, if we were to assume with Meyer that the ear would have been normal if the cartilage had been uniformly developed along the whole extent of the helix, the latter must have occupied a third part of the ear. Two cases were mentioned to Darwin in which the upper edge of the ear had no inner fold, and was so pointed that it was very like that of an ordinary mammal. The ear of the fœtus of an orang given in Darwin’s illustration appears to be pointed, although in the adult animal that organ is very like the human ear. The Darwinian tip may also be seen in the fœtus of an orang described and illustrated by Salvatore Trinchese in the _Annali del Museo civico di Storia Naturale di Genova_ (1870). The tip of the helix is pointed in very young individuals of the gibbon species, especially in _Hylobates Lar_. Among the lower apes the pointed ear is very common (see Fig. 29).

[Illustration: Fig. 29.--Magot (_Innuus ecaudatus_).]

The eyelids of anthropoids greatly resemble those of man in their structure. In adult gorillas and chimpanzees there is always a semilunar fold (_plica semilunaris_) corresponding to the _membrana nictitans_, or third eyelid of birds. In man there exists, instead of this, only a rudimentary apparatus, the _caruncula lachrymalis_. In some individuals it attains to a considerable size, as I have observed in the fellaheen, Berbers, Shillook, and other tribes. On the other hand, the conversion of the caruncula into a true, although only rudimentary, _plica semilunaris_ has not been observed by me in the human eye. Miklucho-Maclay describes the caruncula in Melanesians (the Papuans of New Guinea), in the Orang-Sakay (of the Malay peninsula), and in the Mikronesians (of the island of Japan and of the Palau archipelago), as two or three times as wide as that of the average European.[24]

The eye of the young male gorilla which was kept alive in the Berlin Aquarium from 1876–77 was carefully examined by me in June, 1877. I found that the sclerotic membrane of the eyeball was whitish, surrounded by a dark brown ring. A second darker ring, sharply defined, surrounded the cornea. The iris was of a yellowish brown. The sclerotic membrane, however, gradually deepens in colour so as to give the effect of a uniform dark brown. The iris retains a light brown colour for a longer period, but it darkens with age. In an aged animal there is no brightness in the eye, except from reflected light. In the chimpanzee the iris is light brown, verging on yellow; and this is also the case in the orang.

The expressionless, indifferent look of anthropoids has often been observed, and undoubtedly chimpanzees and orangs generally gaze placidly before them. I have, however, observed an animated expression in the eyes of the former species, and W. L. Martin has also observed a flash and brightening of their eyes. I shall never forget the expression of malicious anger in the eyes of the female animal Mafuca, at Dresden, as soon as she was teased. The expression of the eyes of the gorilla in the Berlin Aquarium also changed frequently, especially when he was about to perform some mischievous trick, or when he was provoked to anger. The expression of this animal was very human, but necessarily it could only recall the darkly coloured eyes of negroes and other black races. In 1876 there were two very young orangs in the Berlin Aquarium, one hairy and the other hairless. These animals clung together in a close embrace. If they were separated, their eyes became bright and restless, and they again sought to embrace each other while uttering plaintive cries. On tickling one of the animals under the chin, it made a most absurd grimace, and its eyes brightened, as Martin has observed in similar cases. The eyes of the gibbons which I have observed had a thoroughly mild and placid expression, rarely animated by any fire.

The instance we have mentioned of hairless Australians is the more remarkable since these aborigines are for the most part distinguished for their luxuriant growth of hair. The Australian blacks and the Ainos of Yedo are, as a rule, perhaps the most hairy races in the world. It is known, however, that in all countries and climates exceptional cases are found of individuals whose bodies are wholly or partially covered with hair, and these conditions sometimes affect whole families. Interesting historical and morphological researches respecting these hairy men have recently been made by von Siebold, Ecker, Virchow, Bartels, and Ornstein. In many of these cases we are presented with decidedly brute-like phenomena. The Mexican woman Julia Pastrana displays the strongest resemblance to apes. Other hairy men remind us at the first glance of some of the canine species. In all races the women are less hairy than the men. Darwin states that in the females of some species of apes the under side of the body is less hairy than in the males, and this is also the case with anthropoids, especially with the chimpanzee.

The beard is, as we know, common to man and apes. Among apes it is more strongly developed in the male than in the female, and this is also the case in the human species. Darwin points out that the growth of the beard both of men and apes occurs at the period of their sexual maturity, and also that there is a remarkable parallel between men and apes in its colour. For when the human beard varies in colour from the hair of the head, which is frequently the case, it is, without exception, of a lighter, and generally of a reddish hue. Darwin observed this in England, and Hooker found no exception to the rule in Russia. J. Scott carefully observed the numerous races which are to be found in Calcutta, as in other parts of India, namely, the two Sikh races, the Bhoteas, Hindus, Burmese, and Chinese. Although most of these races have very little hair on the face, Scott found that in all cases without exception, in which there was any difference in colour between the hair of the head and the beard, the latter was of a lighter shade. In apes the colour of the beard often differs widely from that of the hair of the head, and in such cases it is always of a lighter shade, often white, sometimes yellow or reddish.

[Illustration: Fig. 30.--Capucin ape (_Cebus capucinus_).]

“It is well known,” says Darwin, “that the hair on our arms tends to converge from above and below to a point at the elbow. This curious arrangement, so unlike that in most of the lower mammals, is common to the gorilla, chimpanzee, orang, some species of Hylobates, and even to some few American monkeys. But in _Hylobates agilis_ the hair on the forearm is directed downwards or towards the wrist in the ordinary manner; and in _Hylobates lar_ it is nearly erect, with only a very slight forward inclination; so that in this latter species it is in a transitional state. It can hardly be doubted that with most mammals the thickness of the hair and its direction on the back is adapted to throw off the rain; even the transverse hairs on the forelegs of a dog may serve for this end when he is coiled up asleep. Mr. Wallace remarks that the convergence of the hair towards the elbow on the arms of the orang (whose habits he has so carefully studied) serves to throw off the rain, when, as is the custom of this animal, the arms are bent, with the hands clasped round a branch or over its own head. We should, however, bear in mind that the attitude of an animal may perhaps be in part determined by the direction of the hair; and not the direction of the hair by the attitude. If the above explanation is correct in the case of the orang, the hair on our forearms offers a curious record of our former state; for no one supposes that it is now of any use in throwing off the rain, nor in our present erect condition is it properly directed for this purpose.”[25]

Darwin also remarks that it is erroneous to deny that apes have eyebrows. In fact, long bristly eyebrows are present in all anthropoids--not growing thickly together like those of men, but scattered among the shorter and thicker growth of hair which clothes the parts above the orbits; nor do they maintain any definite direction. In the white-handed gibbon, these eyebrows are remarkable for their length and stiffness. A growth of hair corresponding to eyebrows may, indeed, be observed above the upper eyelids of all mammals, including seals and pachydermata. On the upper lip of gorillas, chimpanzees, and orangs we may also observe a number of somewhat longer, stiff, and bristly hairs which stand apart from the otherwise short hairs on the lips, and give the impression of a cat’s “whiskers.” In _Hylobates albimanus_ I observed that these _vibrissæ_ attain to a considerable length (Fig. 10).

The external form of the trunk of anthropoids, taken as a whole, does not greatly differ from that of man. We have not, indeed, the well-formed human torso, with its graceful lines; and the formation of the posteriors, together with a want of expansion about the hips, displeases us in its departure from the human type (see Figs. 1 and 6). We shall not be disposed to compare the torso of the Apollo Belvedere, or of the Olympian Hermes with that of a gorilla or chimpanzee. Yet the torso of a powerful male gorilla, from which the hair has been removed, may be favourably compared with that of one of the large-bellied, lean-armed weaklings who are everywhere to be found as living caricatures of the human species.

The neck of anthropoids is generally short and thick. In the gorilla that part of the body has a great backward convexity, owing, as we have said, to the great development of the spinous processes of the cervical vertebræ, and of the muscles attached to them. A short, thick throat, and considerable development of the neck, a bull-neck, as it is called, is also not unfrequent in man. This peculiarity is sometimes supposed to be one of the national characteristics of the African blacks. Burmeister says that “the negro’s thick neck is the more striking, since it is generally allied with a short throat. In measuring negroes from the crown of the head to the shoulder I found the interval to be from nine and a quarter to nine and three-quarter inches. In Europeans of normal height, this interval is seldom less than ten inches, and it is more commonly eleven inches in women, and twelve in men. The shortness of the neck, as well as the relatively small size of the brain-pan, and the large size of the face may the more readily be taken as an approximation to the simian type, since all apes are short-necked, and the relative distance of these animals is somewhat further from the negro than that of the negro from the European. This shortness of the neck in the negro explains his greater carrying power, and his preference for carrying burdens on his head, which is much more fatiguing to the European on account of his longer and weaker neck.”[26]

Burmeister’s assumption on this subject is, however, much too general. It does not apply to many of the negro races--at any rate, not to those of the Upper Nile valley. A long, thin neck is the characteristic of the Funje, Shillooks, Denkas, Baris, and other large tribes of those regions. Among these people the interval between the top of the head and the shoulder is from ten to eleven, and even from eleven to twelve inches (240 to 260 mm., and 260 to 286 mm.). Burmeister has been thinking exclusively of the Brazilian blacks. Yet I am unable to trace the typical short neck, either in the well-known portraits of slaves by Maurice Rugendas,[27] or in the collection of photographs of Brazilian negroes which is in my possession. This characteristic is also absent, even in many portraits of West African and Mozambique blacks, tribes from which the slave population of Brazil has been chiefly drawn. Many Mongolians, Malays, Papuans, and Polynesians have short, thick necks, but this characteristic is more rare among the American aborigines and among Europeans. If we are to recognize an approximation to the simian type in this formation, it is one common to several nations, and it is not confined only, nor even chiefly, to the negro races.

The remarkable elongation of the upper limbs of anthropoid apes cannot be compared with the length of the corresponding limbs in men. For although among negroes and the members of other primitive peoples we may occasionally observe unusually long arms, yet these are individual peculiarities which are also found among Europeans, and cannot be counted among racial characteristics.

[Illustration: Fig. 31.--Hand of a very aged male gorilla.]

The hand of the orang and the gibbon is too long and narrow to be directly compared with the human hand. The chimpanzee and the gorilla, especially the latter, have hands more like those of man. In the case of an adult male gorilla the first glance at this member reminds us of the knotty fist of a black dock labourer or lighterman, like those who, at Rio de Janeiro, Bahia, or La Guayra, lift the heavy bags of coffee and place them on their heads or on their herculean shoulders. Much has been said of the enlargement of the connective skin between the bases of the fingers of a negro hand, and of the pointed extremities of the fingers. Van der Hoeven, in his well-known treatise, _De Natuurlijke Geschiedenis van den Negerstam_, has described and drawn the hand of an Ashanti boy, formed in this manner. Hence there is a disposition to recognize in this peculiarity an important characteristic of the negro race. As in the hand of the gorilla, the connective web between the bases of the fingers is also extensive, and the ungual phalanges taper at their extremities, there is also an inclination to ascribe an expressly anthropoid character to the negro hand. Yet this structure of the fingers is by no means universal among the negroes. An enlargement of the connective web is not indeed uncommon, but its extent varies considerably. Nor is it wanting in the fingers of other races. An attentive observer will be able to trace it in the labouring population of country districts in Europe. I have myself frequently observed this characteristic in Canton Wallis, and in the Lombard and Genoese provinces, through which I travelled on foot in 1869 and 1871, when I devoted special attention to this point. In Fig. 32 I give a negro hand of a type which seems to be common among the blacks in the inland districts of North-eastern Africa. It can hardly be denied that the form of this hand, which is certainly not flattered, possesses the characteristics of a thoroughly human organization.

[Illustration: Fig. 32.--Hand of a Hammegh from Roseres, on the Blue Nile.]

With respect to other primitive peoples besides negroes, we have not at present sufficient information, and we ought therefore to beware of premature generalization. The thin shanks, with imperfectly developed calves, found among many primitive races, and especially among the African and Australian blacks, are often and not unjustly adduced as an instance of their ape-like formation. In fact, the general uncomeliness of these parts in the races in question is one of their significant characteristics.

[Illustration: Fig. 33.--Satan’s ape (_Pithecia Satanas_). Shows the formation and mode of using the feet in apes of the New World.]

The anthropoid foot resembles in structure those of other apes, including those of the New World, and as a rule it differs from the human foot in the flexibility of the great toes. It has, however, been justly observed that many individuals of different races have been able to use the great toe almost as if it were a thumb. Such persons may be found everywhere. Men who have been born without arms, or who have been deprived of them during life, have been able to use their feet like hands, as some compensation for this privation. The most surprising instance of our time has occurred in the violinist without arms, whose performances are heard in various continental capitals. Another, mentioned by Bär, was able to write with his feet. But even people who have the full use of their upper limbs can often grasp with the great toe as if it were a thumb, so as to pick up small objects from the ground, or draw them towards them. Constant practice in such feats produces a certain dexterity. Negroes, Malays, Polynesians, and Indians make use of their outstretched great toes in climbing with as skilful a gripe as our schoolboys and sailors are also able to do in gymnastics, or in climbing up the masts. Among such people the distinction between the foot of man and apes is less marked, since, even when at rest, the great toe is apt to be somewhat detached from the others. This may be seen in A. Buchta’s excellent photographs of individuals of the Central African tribe, the Makraka. Haeckel justly observes that there is no marked physiological distinction between the hand and foot which can be established on a scientific basis. In order to make such a distinction it is necessary to consider their morphological characteristics.[28]

[Illustration:

Fig. 34.--Human skull. _a_, Nasal bone. _b_, Upper jaw. _c_, Lower jaw. _d_, Occipital bone. _e_, Temporal bone. _f_, Parietal bone. _g_, Frontal bone. _h_, Malar bone. ]

_Structure of the skeleton._--In comparing the skulls of anthropoids with those of men, we should, in the case of the gorilla, chimpanzee, and orang-utan, content ourselves with young specimens rather than with the skulls of adults. In aged apes of these species, the colossal development of the bony crests of the skull, as well as that of the jaws, the prominence of the orbital rim, and the flattening of the occipital bone, present distinctions of such a searching character that we are greatly hindered in the pursuit of the comparative method. But during the process of development the anthropoid skeleton admits of a direct comparison with that of man. In a young animal the rounded skull suggests a parallel between it and the human head. It must be admitted that we find, especially in primitive peoples, many human skulls which in their whole plastic form differ little from the skulls of young gorillas, chimpanzees, and orangs. Even in the way the occipital bone is rounded off, young anthropoids and men are often found in a similar stage of development. The squamous occipital portion in a young negro, Papuan and Malay, is indeed often flatter and more bevelled than it is in a young gorilla or chimpanzee.

We must not, however, assume that the two individuals brought into comparison are of precisely the same age, since such a point cannot easily be ascertained, even when subjects for examination are afforded by one of our larger museums. Savages are seldom able to give their precise age, and the attempt to do so often relies on insufficient data. The direct examination of the skull will afford some information on this point; but the conditions of growth in anthropoids are not so well known as to admit of an accurate estimate. We have to rely on the state of the teeth, on the stage at which the development of the bony crests has arrived, etc., in order to form an approximate estimate of the age of the skull.

On the squamous occipital portion the arrangement of the curved lines which are the boundaries to the attachments of the cervical muscles, is common to men, to anthropoids, and to other apes. Only indications of these lines are to be found in the lower order of mammals. In the human skull there is sometimes a formation belonging to the squamous occipital portion which has a distinctly pithecoid or ape-like character. This is the occipital swelling we have already described (_Torus occipitalis transversus_), which may be either enclosed by the two upper curved lines, or lie between these and the central curved lines, or may be altogether in the region of the latter. This swelling extends in a gradual manner above and below its bony support. Its edge may be more or less sharp, more or less like a crest in its development, wider or narrower, with or without a central eminence, but its appearance is always striking. In young male and female gorillas, orangs, and chimpanzees this formation represents the completely formed transverse occipital crests, which are found for the most part in aged male animals of these species. These swellings may also be observed on the skulls of adult men of all times and all nations. They are by no means rare in the skulls which are in ordinary use at the Berlin School of Anatomy, and they are remarkably common in many groups of skulls. They are frequent among the skulls, for the most part without their lower jaws, which the late Dr. Sachs disinterred in a Mohammedan burial-ground of the thirteenth century, near Cairo. These are the remains of Mohammedans of different ranks, but, for the most part, of the peasantry or fellaheen. Ecker was able to trace the sagittal crest in the skulls of Australian males, while it is absent in the females. Similar indications of the bony crest have been observed by me in the roof-shaped or scaphocephalic skulls of many negroes, but in these cases I am not aware whether there is a corresponding distinction of sex. It can hardly be denied that this bony prominence is a human characteristic.

Broca has given the term pterion to the H-shaped connection formed by the sutures between the parietal bone, the greater wing of the sphenoid bone, the squamous portion of the temporal bone, and the frontal bone. One of the most common disturbances in the symmetry of the connecting suture, as we have already briefly mentioned, arises from the insertion of a frontal process of the squamous portion of the temporal bone between the lower angle of the parietal bone, the fore-part of the frontal bone, and the greater wing of t