CHAPTER XIV

THE ORDER PRIMATES

This order in the system of Linnæus includes Man, the Monkeys, the Lemurs, and the Bats. By common consent of all zoologists the last-named animals have been removed into a distinct order; but with regard to the association of the others there has been, and still is, much difference of opinion.

That all the Monkeys, from the highest Anthropoid Apes to the lowest Marmosets, form a natural and tolerably homogeneous group seems never to have been questioned; but whether the Lemurs on the one hand and Man on the other should be united with them in the same order are points of controversy. If, in accordance with the traditional views of zoologists, the former are still considered to be members of this order, they must form a suborder apart from all the others, with which they have really very little in common except the opposable hallux of the hind foot, a character also met with in the Opossums, and which is therefore of very secondary importance.[640]

Using the term Primates in this wider sense it is not easy to give any precise definition of the order. The dentition is diphyodont and heterodont; the number of incisors being very generally ²⁄₂, and that of the molars, with the exception of the _Hapalidæ_, being ³⁄₃. The cheek-teeth are adapted for grinding, the molars being more complex than the premolars, and usually having four main tubercles, which may be either subconical or more or less compressed. The orbit is invariably surrounded by a ring of bone; the clavicles are well developed; and the radius and ulna are never united. The scaphoid and lunar of the carpus, and commonly also the centrale, remain distinct from one another. There are usually five digits furnished with well-developed nails in both the manus and the pes; but the pollex may be rudimentary or wanting. The hallux, except in Man, is opposable to the other digits, and has a flat nail (absent in _Simia_); and the pollex, when present, is usually also more or less opposable. The terminal phalanges of the digits are flattened (except in the second digit of the pes of the Lemuroidea), and not cleft at their extremities. The fingers and toes generally do not taper towards their extremities, but (except in _Chiromys_) are dilated, flattened, and rounded at their tips. The humerus has no entepicondylar foramen, nor the femur a third trochanter. In the alimentary canal (Fig. 324) the stomach is generally simple, although sacculated in the subfamily _Semnopithecinæ_ of the _Cercopithecidæ_; and there is always a cæcum, which is generally of large size. The placenta may be either non-deciduous, or discoidal and deciduous. There are always two mammæ in the pectoral region, except in _Chiromys_; and the testes descend into a scrotum.

[Illustration: FIG. 324.—Alimentary canal of _Galago_, the greater part of the small intestine being omitted. _d_, duodenum; _i_, ileum; _cm_, cæcum; _r_, rectum.]

The Lemuroidea are decidedly low in the scale of organisation, their placentation being of a lower type than that of the Insectivora; and all the Primates retain generalised features in their pentadactylate limbs and more or less bunodont cheek-teeth. In respect to cerebral characters and other features the higher representatives of the order have, however, acquired a specialisation clearly indicating their right to occupy the highest position in the animal kingdom. So far as the available material admits of forming an opinion, fossil forms appear to indicate an intimate connection between the Lemuroidea and Insectivora, so that in some cases it is almost impossible to determine whether an extinct type should be referred to the former or to the latter group. It is noteworthy that while in all existing Primates the upper molars are of a quadrituberculate type, in the extinct Lemuroid genus _Anaptomorphus_ they are trituberculate.

_Suborder_ LEMUROIDEA.

The Latin term _Lemur_ was applied by Linnæus to the typical representatives of the present group of Primates, having been suggested by the nocturnal habits and strange ghost-like appearance of some of its members. As these animals had previously no vernacular appellation in English, this name has been generally adopted, and is now completely anglicised, making “Lemurs” in the plural. The French call them _Makis_, and the Germans _Halbaffen_, in allusion to their forming a transition from monkeys to ordinary quadrupeds. For the same reason they are called _Prosimiæ_ by some systematic writers. When the name was bestowed by Linnæus only five species were known, of which one, _L. volans_, Linn. (_Galeopithecus volans_ of modern writers), is now removed by common consent from the group. Notwithstanding the discovery of many new and curious forms, the Lemurs remain a very natural and circumscribed division of the animal kingdom, though no longer considered a single genus, but divided up into many genera and even families.

The existing species are not numerous, and do not diverge widely in their organisation or habits, being all of small or moderate size, all adapted to an arboreal life, climbing with ease, and, as they find their living, which consists of fruits, leaves, birds’ eggs, small birds, reptiles, and insects, among the branches of the trees, they rarely have occasion to descend to the ground. None are aquatic, and none burrow in the earth. Many of the species, although by no means all, are nocturnal in their habits, spending the day in sleeping in holes, or rolled up in a ball, perched on a horizontal branch, or in the fork of a tree, and seeking their food by night. Their geographical distribution is very peculiar; by far the larger proportion of species, including all those to which the term “Lemur” is now especially restricted, being exclusively inhabitants of Madagascar, where they are so abundant and widely distributed that it is said by M. Grandidier, who has contributed more than any other traveller to enrich our knowledge of the structure and manners of these animals, that there is not a little wood in the whole island in which some of them cannot be found. From Madagascar as a centre a few species less typical in character extend through the African continent westward as far as Senegambia, and others are found in the Oriental region as far east as the Philippine Islands and Celebes.

The following are the essential characters by which the suborder as a whole is distinguished from the Anthropoidea. Skull with the orbit opening freely into the temporal fossa beneath the postorbital bar (except in _Tarsius_); and the lachrymal foramen situated externally to the margin of the orbit (Fig. 327). The pollex and hallux are always well developed, the latter being especially large; the second or index digit of the manus may be rudimentary; while in the pes the second digit invariably terminates in a long pointed claw. The cerebral hemispheres do not completely overlap the cerebellum, and are but slightly convoluted. The uterus is bicornuate. The placenta is non-deciduate, and either diffused or bell shaped—the whole of the chorion except the cephalic pole being covered with villi; and the allantois is of very great size. There may be abdominal mammæ. Except in _Chiromys_, the first pair of upper incisors are separated in the middle line. In marked contrast to the Anthropoidea, the middle or transverse portion of the colon is almost always folded or convoluted on itself. (See Fig. 324.)

In subdividing the group for the purpose of a more detailed description of the different animals of which it is composed it must first be noted that there are two very aberrant forms, each represented by a single species—the little _Tarsius_ of the Indian archipelago, and the singular _Chiromys_ or Aye-aye, which, though an inhabitant of Madagascar, the headquarters of the suborder, and living in the same forests and under the same external conditions as the most typical Lemurs, exhibits a most remarkable specialisation in the structure of its limbs and teeth, the latter being modified so as to resemble, at least superficially, those of the Rodents, in which order it was once placed. The differences between these two forms and the remaining Lemurs are so great that the whole suborder naturally divides itself into three families, the first of which may be again divided into four subfamilies.

_Family_ LEMURIDÆ.

Upper incisors two on each side, small and separated by an interval in the middle line. Upper canine large, conical, compressed, and pointed. Premolars two or three, molars three on each side above and below, with numerous more or less pointed cusps. In the front of the lower jaw are on each side two or three closely approximated, long, slender teeth lying almost horizontally and projecting forwards. These are generally considered to represent the incisors and canine, but there is some doubt about their homologies, and they may be all considered as incisors, the canine being absent. The first lower premolar larger than those behind it, and shaped like a canine, of which it performs the function (Fig. 327). The orbit and temporal fossa widely continuous beneath the bar of bone (formed by the frontal and jugal) constituting the posterior boundary of the former cavity. The fibula well developed and distinct from the tibia. All the digits of both feet (except the second of the hind foot) with flat nails, and corresponding form of ungual phalanges.

Subfamily =Indrisinæ=.—The dentition of the adult consists of thirty teeth, usually expressed by the formula _i_ ²⁄₁, _c_ ¹⁄₁, _p_ ²⁄₂, _m_ ³⁄₃; but, as indicated above, they may be _i_ ²⁄₂, _c_ ¹⁄₀, _p_ ²⁄₂, _m_ ³⁄₃. In the milk-dentition there are twenty-two teeth, the true molars of course not being represented, but there are two additional teeth in the fore part of the lower jaw which have no successors in the permanent series. Hind limbs greatly developed, but the tarsus normal. Hallux of large size, and very opposable. The other toes united at their base by a fold of skin, which extends as far as the end of the first phalanx. Mammæ two, pectoral. Cæcum very large, and colon extremely long and spirally coiled.

The animals of this group are, as their organisation indicates, essentially arboreal, and feed exclusively on fruit, leaves, buds, and flowers. They are restricted geographically to the island of Madagascar. Among them are the largest members of the suborder. A detailed and beautifully illustrated account of their characters, external and internal, and distribution and habits, is given in the _Histoire Naturelle de Madagascar_, by A. Grandidier and Alphonse Milne-Edwards (1875). The species are not numerous and are distributed into three genera.

_Indris._[641]—Upper incisors subequal in size. Upper canine larger than the first premolar. Muzzle moderately long. Ears exserted. Carpus without an os centrale. Tail rudimentary. Vertebræ: C 7, D 12, L 9, S 4, C 9.

The only well-established species is the Indris (_I. brevicaudata_, Fig. 325), discovered by Sonnerat in 1780. It is the largest of the Lemurs, the length of the head and body being about 2 feet, and the tail 2 inches. It is very variable in colour, for although usually nearly black, marked with whitish spots principally in the lumbar region and forearm, individuals have been found quite white. It inhabits exclusively the forests of a part of the east coast of Madagascar, living in small troops of four or five in number, and resembling in most of its habits the animals of the next genus.

_Propithecus._[642]—Second upper incisor much smaller than the first. Upper canine larger than the first premolar. Muzzle rather short. Ears short, concealed by the fur. An os centrale in the carpus. Tail long. Vertebræ: C 7, D 12, L 8, S 3, C 28.

[Illustration: FIG. 325.—Indris (_Indris brevicaudata_). From Milne-Edwards and Grandidier, _Mammifères de Madagascar_, pl. 12.]

The species are all subject to great variations in colour, which has led to much difficulty in discriminating them, and to much confusion of synonymy. Grandidier and Milne-Edwards recognise three as certainly distinct—_P. diadema_, _P. verreauxii_, and _P. coronatus_ (Fig. 326). Some of these are to be found in almost every part of the island of Madagascar, living in the woods in small bands of six or eight together, and feeding exclusively on buds, flowers, and berries. Their powerful hind limbs enable them to leap from tree to tree, often to a distance of 10 yards, without any apparent effort, and thus seeming to fly through the air. When obliged to descend to the ground to pass from one clump of trees to another they do not run on all fours, but stand erect, and throwing their arms above their heads progress by a series of short jumps, producing an effect which is described by travellers who have seen them thus in their native haunts as exceedingly ludicrous. They are not nocturnal, but most active in the morning and evening, remaining seated or coiled up among the branches during the heat of the day. They are naturally of a quiet and gentle disposition, and do not show much intelligence. All the species are also less vociferous than the true Lemurs, only when alarmed or angered making a noise which has been compared to the clucking of a fowl. Like the rest of the subfamily they never have more than a single young one at a time.

[Illustration: FIG. 326.—_Propithecus coronatus._ (From Milne-Edwards and Grandidier, _Mammifères de Madagascar_, pl. 7.)]

_Avahis._[643]—Second upper incisor larger than the first. Upper canine scarcely larger than the first premolar. Muzzle very short. Ears very small and hidden in the fur, which is very soft and woolly. Carpus without an os centrale. Tail long. Vertebræ: C 7, D 11, L 9, S 3, C 23.

One species, _A. laniger_, the Woolly Lemur, or Avahis, considerably smaller than any of the last genus. It differs from them in its habits, being quite nocturnal, and not associating in small troops, but being always met with either alone or in pairs. It is very slow in its movements, and rarely descends to the ground, but when it does it walks upright like the other _Indrisinæ_. It is found throughout the forests which clothe the mountains on the east coast of Madagascar, and also in a limited district on the north-west coast, the specimens from the latter locality being of smaller size and rather different in colour.

Subfamily =Lemurinæ=.—The dentition in the adult consists of thirty-six teeth, which, as usually enumerated, are _i_ ²⁄₂, _c_ ¹⁄₁, _p_ ³⁄₃, _m_ ³⁄₃. In the fore part of the lower jaw are on each side three elongated, compressed, procumbent teeth, of which the outer, usually considered the homologue of the canine, is larger than the others. All the forms have long tails. Hind limbs not of the same disproportionate size as in the last group; and the cæcum much less developed. Tarsus but slightly elongated, the calcaneum being always less than one-fourth the length of the tibia. Toes of the hind feet free to the base. Habitat, Madagascar, and some of the adjacent Comoro Islands.

[Illustration: FIG. 327.—Skull of Ring-tailed Lemur (_Lemur catta_). × ⅓; _uc_, Upper canine; _lc_, lower canine; _pm_, premolars; _m_, molars.]

This group contains the typical Lemurs, or rather those to which the term is now chiefly restricted. Two somewhat aberrant members make it necessary to divide it into three genera.

_Lemur._[644]—Upper incisors separated by an interval in the middle, and not in contact with each other or the canine, in front of which they are both placed. Muzzle elongated. Ears conspicuous and tufted. Mammæ two, pectoral. Vertebræ: C 7, D 12, L 7 (or D 13, L 6), S 3, C 27.

[Illustration: FIG. 328.—The Ring-tailed Lemur (_Lemur catta_).]

Animals much about the size of a common Cat, with Fox-like faces, soft thick fur, and long tails well clothed with hair. Not having the same disproportionate size of the limbs as the last group, they are much more quadrupedal in their actions, walking on the ground or running along the branches of trees on all four feet, but also jumping with marvellous agility. They are gregarious, living in small troops, are diurnal in their habits, but most active towards evening, when they make the woods resound with their loud cries. They feed not only on fruits and buds, but also on eggs, young birds, and insects. When at rest or sleeping they generally coil their long, bushy tails around their bodies, apparently for the sake of the warmth it affords. They have either one or two young ones at a birth, which are at first nearly naked, and are carried about, hanging close to and almost concealed by the hair of the mother’s belly. After a while they change their position and mount upon the mother’s back, where they are carried about until they are able to climb and leap by themselves. Though no member of the _Indrisinæ_ has as yet lived long enough in captivity to be brought alive to Europe, various species of _Lemurinæ_ are commonly seen in menageries, and often breed in England. They present a great tendency to variation in their colouring, in consequence of which many nominal species have been made. The most distinct, and at the same time most beautiful, is the Ring-tailed Lemur (_L. catta_, Fig. 328), of a delicate gray colour, and with a long tail marked with alternating rings of black and white. This is said by Mr. G. A. Shaw[645] to be an exception to all the other Lemurs in not being arboreal, but living chiefly among rocks and bushes. Pollen, however, says that it inhabits the forests of the south-west parts of Madagascar, living, like its congeners, in considerable troops, and not differing from them in its habits. He adds that it is extremely gentle, and active and graceful in its movements, and utters at intervals a little plaintive cry like that of a domestic cat. All the others have the tail of uniform colour. The largest species is _L. varius_, the Ruffed Lemur, sometimes black and white, and sometimes reddish-brown, the variation apparently not depending on sex or age, but on the individual. In _L. macaco_ the male is black and the female red. _L. mongoz_, _L. collaris_, and _L. albifrons_ are other well-known species.

_Hapalemur._[646]—Upper incisors very small, subequal, separated widely in the middle line. Those of either side in contact with each other and with the canine, the posterior one being placed on the inside, and not in front of the latter. Muzzle very short and truncated. Mammæ four. There is apparently but one species, _H. griseus_, smaller than any of the true Lemurs, of a dark gray colour, with round face and short ears. It is quite nocturnal, and lives chiefly among bamboos, subsisting on the young shoots. A second species has been named _H. simus_, but it is doubtful if it is more than a variety.

_Lepidolemur._[647]—Upper incisors absent or rudimentary. Muzzle more elongated than in the last. No distinct os centrale in the carpus. _L. mustelinus_ is the best-known species. It has, at all events when adult, no upper incisors. It is rare, and like _Hapalemur_ nocturnal in its habits. A second closely allied species, but with better developed premaxillæ, containing a pair of small styliform incisors, has been described by Peters[648] under the name of _Myxocebus caniceps_.

Subfamily =Galaginæ=.—Dentition as in _Lemurinæ_, from which the members of this subfamily are distinguished by the elongation of the tarsus, caused by a peculiar modification of the calcaneum and the navicular, the distal portion of the former and the whole of the latter having the form of almost cylindrical rods placed side by side, while the other bones retain nearly their normal form and proportion.

_Chirogaleus._[649]—Last upper premolar very much smaller than the first molar, with only one external cusp. The animals included under this name appear to form a transition between the true Lemurs and the Galagos. The genus was originally established by Geoffroy St. Hilaire in 1812 for the reception of three species only known at that time by drawings made in Madagascar by the traveller Commerson. Subsequent discoveries have brought to light several others that may be referred to it, including one or two which are sometimes considered as forming a genus apart under the name of _Microcebus_. They are all small, some being less than a rat in size, long-tailed, and nocturnal in their habits. One of the largest, _C. furcifer_, is of a reddish-gray colour, and distinguished by a dark median stripe on its back which divides on the top of the head into two branches, one of which passes forwards above each eye. The most interesting peculiarity of these animals, a knowledge of which we owe to M. Grandidier, is that certain species (_C. samati_, _C. gliroides_, _C. milii_, etc.) during the dry season coil themselves up in holes of trees and pass into a state of torpidity like that of the hibernating animals in the winter of northern climates. Before this takes place an immense deposit of fat accumulates upon certain parts of the body, especially upon the basal portion of the tail, which has then dimensions corresponding to that of the well-known fat-tailed Sheep of the Cape, but which by the time they emerge from their torpor has acquired its normal proportions. The smallest species, to which many names have been given (_C. pusillus_, _rufus_, _smithi_, etc.), lives among the small branches on the tops of the highest trees, feeding on fruit and insects, and making nests which resemble those of birds.

_Galago._[650]—Last upper premolar with two large external cusps, and nearly equalling the first molar in size. Calcaneum about one-third the length of the tibia, and the navicular much longer than the cuboid. Vertebræ: C 7, D 13, L 6, S 3, C 22-26. Tail long, and generally bushy. Ears large, rounded, naked, and capable of being folded at the will of the animal. Mammæ four, two pectoral and two inguinal.

The Galagos differ from all the Lemuroids previously mentioned, inasmuch as they are inhabitants, not of Madagascar, but of the African continent, being widely distributed in the wooded districts from Senegambia in the west to Abyssinia in the east, and as far south as Natal. They pass the day in sleep, but are very active at night, feeding on fruit, insects, and small birds. When they descend to the ground they sit upright, and move about by jumping with their hind legs, like jerboas and kangaroos. They are pretty little animals, varying in size from that of a small cat to less than a rat, with large eyes and ears, soft woolly fur, and long tails. There are several species, of which _G. crassicaudatus_, from Mozambique, is the largest. A similar species, or perhaps variety, from Angola is _G. montieri_. _G. garnetti_, _alleni_, _maholi_, _demidoffi_, and _senegalensis_ are other recognised species. The last-mentioned was the first known to science, having been brought from Senegal by Adanson, and described in 1796 by Geoffroy, who adopted the name _Galago_, by which it was said to be called by the natives.

Subfamily =Lorisinæ=.—Dental formula as in _Lemurinæ_. Index finger very short, sometimes rudimentary and nailless. Fore and hind limbs nearly equal in length. Tarsus not specially elongated. Pollex and hallux diverging widely from the other digits, the hallux especially being habitually directed backwards. Tail short or quite rudimentary. Mammæ two, pectoral.

A small group of very peculiar animals, of essentially nocturnal habits, and remarkable for the slowness of their movements. They are completely arboreal, their limbs being formed only for climbing and clinging to branches, not for jumping or running. They have rounded heads, very large eyes, short ears, and thick, short, soft fur. They feed not only on vegetable substances, but, like many of the _Lemuridæ_, on insects, eggs, and also birds, which they steal upon while roosting at night. None of the species are found in Madagascar. One of the greatest anatomical peculiarities of these animals is the breaking up of the large arterial trunks of the limbs into numerous small parallel branches, constituting a _rete mirabile_, which is found also in the Sloths, with which the Loris are sometimes confounded on account of the slowness of their movements. The animals of this group are usually divided into four genera, though the characters by which they are separated are very trivial. There are more properly two natural divisions.

_A._ Characterised by the index finger being small, but having the complete number of phalanges, and by their Asiatic habitat.

These form the genus _Loris_ of Geoffroy St. Hilaire (1796), _Stenops_ of Illiger (1811), but they were in 1812 divided by Geoffroy into two genera, _Nycticebus_ and _Loris_, a division which has been accepted by most modern zoologists.

_Nycticebus._[651]—First upper incisor larger than the second, which is often early deciduous. Inner margins of the orbits separated from each other by a narrow flat space. Nasal and premaxillary bones projecting but very slightly in front of the maxillæ. Body and limbs stout. No external tail. Vertebræ: C 7, D 17, L 6, S 3, C 12. The species are _N. tardigradus_, the common Slow Lemur or Loris, of the Malay Countries, Sumatra, and Borneo; _N. javanicus_, of Java; and _N. cinereus_ (Fig. 329) of Siam and Cochin China. The habits of all are much alike. They lead a solitary life in the recesses of large forests, chiefly in mountainous districts, where they sleep during the day in holes or fissures of large trees, rolled up into a ball, with the head between the hind legs. On the approach of evening they awake; and during the night they ramble among the branches of trees, slowly and quietly, in search of their food, which consists of tender leaves and fruit, small birds, insects, and mice. When in quest of living prey they move noiselessly till quite close, and then suddenly seize it with one of their hands. The female produces but one young one at a time. _L. tardigradus_ was placed by Linnæus at the head of the list of species of his genus _Lemur_, and its habits doubtless suggested the generic name which was transferred by Geoffroy to the less nocturnal and spectre-like Madagascar members of the group.[652]

[Illustration: FIG. 329.—The Gray Loris (_Nycticebus cinereus_). From A. Milne-Edwards, _N. Archives du Muséum_, vol iii. pl 3.]

_Loris_.[653]—Upper incisors very small and equal. Orbits very large, and only separated in the middle line above by a thin vertical plate of bone. Nasals and premaxillæ produced forwards considerably beyond the anterior limits of the maxillæ, and supporting a pointed nose. Body and limbs slender. No external tail. Vertebræ: C 7, D 14, L 9, S 3, C 6. This genus is represented only by the Slender Loris (_L. gracilis_) of Southern India and Ceylon (Fig. 330). This species is common in some of the forest regions of Southern India, and may be purchased in the bazaars at Madras, its eyes being regarded as a remedy by the natives for ophthalmic diseases. It is a strange-looking creature, about the size of a squirrel, of a yellowish-brown colour, with large, prominent eyes, pointed nose, long thin body, long, angularly bent, slender limbs, and no tail. Its habits, according to Mr. W. T. Blanford,[654] are “very similar to those of _Nycticebus tardigradus_, except that the Slender Loris is rather quicker in its movements, though still slow in general. Like its ally, it is purely nocturnal and arboreal, living upon shoots and young leaves, insects, birds’ eggs, birds, and lizards. It is said to be very fond of honey or syrup. It sleeps rolled up in a ball with its head between its legs, grasping its perch with its arms.”

[Illustration: FIG. 330.—The Slender Loris (_Loris gracilis_). From Blanford, _Mammalia of British India_, p. 47.]

_B._ Index fingers reduced to a mere tubercle without nail. Both the known species are from West Africa.

_Perodicticus._[655]—A short tail, about a third of the length of the trunk. Two or three of the anterior dorsal vertebræ have very long slender spinous processes which in the living animal project beyond the general level of the skin, forming distinct conical prominences, covered only by an exceedingly thin and naked integument. The Potto, _P. potto_, is one of the oldest known members of the lemuroid group, having been described in 1705 by Bosman, who met with it in his voyage to Guinea. It was, however, lost sight of until 1825, when it was rediscovered in Sierra Leone, and fully described by Bennett in 1830 under the name of _Perodicticus geoffroyi_. Bennett’s generic name has been retained, but the specific name bestowed by Gmelin, adopted from Bosman, has been restored. It is also found in the Gaboon. It is strictly nocturnal, and slower in its movements even than _Nycticebus tardigradus_, which otherwise it much resembles in its habits.

A second species, the Awantibo (_P. calabarensis_), rather smaller and more delicately made, with smaller hands and feet and rudimentary tail, constitutes the genus _Arctocebus_ of Gray. It is found at Old Calabar, and is very rare, only a few individuals having as yet been met with. Vertebræ: C 7, D 15, L 7, S 3, C 9.[656]

_Family_ TARSIIDÆ.

Dentition: _i_ ²⁄₁, _c_ ¹⁄₁, _p_ ³⁄₃, _m_ ³⁄₃; total 34. The first upper incisor large, and in contact with its fellow of the opposite side. Canine of moderate size. Molars with numerous pointed cusps. Lower canine semi-erect, its apex diverging from that of the single incisor. First lower premolar smaller than those behind it. Orbit to a large extent separated from the temporal fossa by a bony partition. Fibula slender, with its lower half confluent with the tibia. Second and third digits of the hind foot with compressed claws; all the other digits of both feet with flat nails. Calcaneum and navicular bone of the foot elongated as in the Chirogales and Galagos, but to a still greater extent. Colon short and not folded. Vertebræ: C 7, D 13, L 6, S 3, C 27.

_Tarsius._[657]—The family contains the single genus _Tarsius_, of which but one species is known, _T. spectrum_, the Tarsier, a very singular little animal, rather smaller than an English squirrel, with very large eyes and ears, a long thin tail, tufted at the end, and immensely elongated tarsal portion of the foot, in allusion to which its generic name was given to it. It inhabits the forests of many of the islands of the Indo-Malayan archipelago, including Sumatra, Borneo, Celebes, and some of the Philippines, feeds chiefly on insects and lizards, sleeps during the day, but is tolerably active at night, moving chiefly by jumping from place to place, an action for which the structure of its hind legs, which present a curious resemblance to those of a frog, seems particularly well adapted. It is rare, not more than two being generally found together, and only brings forth one young at a time.[658]

_Family_ CHIROMYIDÆ.

Dentition of adult: _i_ ¹⁄₁, _c_ ⁰⁄₀, _p_ ¹⁄₀, _m_ ³⁄₃; total 18. Incisors very large, compressed, curved, with persistent pulps and enamel only in front, as in Rodents. Teeth of cheek series with flat, very indistinctly tuberculated crowns. In the young the first set of teeth more resemble those of the normal lemurs, being _i_ ²⁄₂, _c_ ¹⁄₀, _m_ ²⁄₂, all very small. Orbit surrounded by a ring of bone posteriorly, beneath which it communicates freely with the temporal fossa. Fibula well developed and distinct from the tibia. All the digits of both feet with pointed rather compressed claws, except the hallux, which has a flattened nail. Middle digit of the hand excessively attenuated. Vertebræ: C 7, D 12, L 6, S 3, C 27.

[Illustration: FIG. 331.—Skull of Aye-aye (_Chiromys madagascariensis_). × ⅙ Mus. Roy. Coll. Surgeons.]

_Chiromys._[659]—This family, like the last, is formed for the reception of a single genus, _Chiromys_,[660] containing one species, _C. madagascariensis_, the Aye-aye, an animal about the size of a cat, with a broad rounded head, short face, and large and naked ears. It has very large hands and long thin fingers with pointed claws, one of which (the middle or third) is remarkable for its extreme slenderness. The foot resembles that of the other lemurs in its large opposable hallux, with a flat nail, but all the other toes have pointed compressed claws, like that of the second toe in the _Lemurinæ_ and the second and third in the _Tarsiidæ_. Tail long and bushy. General colour dark brown, the outer fur being long and rather loose, with a woolly undercoat. Mammæ two, inguinal in position. It is a native of Madagascar, where it was discovered by Sonnerat in 1780. The specimen brought to Paris by that traveller was the only one known until 1860. Since then many others have been obtained, and they may frequently be seen living in the gardens of the Zoological Society of London. Like so many of the Lemurs, the Aye-aye is completely nocturnal in its habits, living either alone or in pairs, chiefly in the bamboo forests. Observations upon captive specimens have led to the conclusion that it feeds principally on succulent juices, especially of the sugar-cane, which it obtains by tearing open the hard woody circumference of the stalk with its strong incisor teeth. It is said also to devour certain species of wood-boring caterpillars, which it obtains by first cutting down with its teeth upon their burrows, and then picking them out of their retreat with the claw of its attenuated middle finger. It constructs large ball-like nests of dried leaves, lodged in a fork of the branches of a tree with the opening on one side. The resemblance of its teeth to those so characteristic of the Rodentia caused it to be placed formerly in that order, and it was only when its anatomical characters were fully known that its true affinities with the Lemurs became apparent.[661]

_Extinct_ LEMUROIDS.

The discoveries of the last few years have revealed the former existence, both in Europe and North America, of a number of extinct animals more or less closely allied to the living Lemurs, which are of especial interest as showing in some instances characters of a more generalised type than is the case with the living representatives of the suborder. It is, however, in some cases very difficult to determine whether these extinct forms should be referred to the Lemuroidea or Insectivora; and if those naturalists are right who regard these groups as survivors of a very generalised ancestral type of mammalian organisation, it is to be expected that as we recede in time we should find that the two groups show more and more marked signs of a natural connection. The earliest reference of one of these extinct Upper Eocene types to the Primates was made in 1862 by Professor L. Rütimeyer, of Basle, who described part of an upper jaw with three teeth from the so-called Bohnerz of Egerkingen, near Soleure in Switzerland, under the name of _Cænopithecus lemuroides_, regarding the animal to which the specimen belonged as partaking of the characters both of the Lemurs and the American Monkeys. Most other palæontologists refused, however, to accept this determination, and it was not until many years later that the researches of Gaudry and Filhol showed not only that _Cænopithecus_ was indeed a true Lemuroid, but also that it was either identical with or closely allied to a form described by Cuvier in the early part of this century under the name of _Adapis_ and regarded as referable to the Ungulata. Later researches have brought to light other Lemuroids in the Tertiaries of both the Old and the New World; and it is very noteworthy that all these types seem to have disappeared from both regions with the close of the upper portion of the Eocene period.

[Illustration: FIG. 332.—The last five right upper cheek-teeth of _Microchœrus antiquus_ (_A_) and _Microchœrus erinaceus_ (_B_). Twice natural size, and natural size.]

Among the more interesting of the forms which are generally regarded as true Lemuroids we may first mention a small species from the Quercy Phosphorites, of which the hinder cheek-teeth are shown in Fig. 332, _A_, which was originally described as _Necrolemur antiquus_, but appears to be generically identical with _Microchœrus erinaceus_, of the upper Eocene of Hampshire, of which the corresponding teeth are shown in _B_ of the same figure. In this genus, according to Dr. Schlosser, the dental formula is _i_ ²⁄₁, _c_ ¹⁄₁, _p_ ³⁄₃, _m_ ³⁄₃, or the same as in the existing _Tarsius_; but it is not improbable that in some instances the first lower premolar may have been developed. The upper molars of _M. erinaceus_ differ from those of _M. antiquus_ by the simpler structure of their columns and the smaller size of the external cingulum, which lacks the median cusp found in the latter. The angle of the mandible is produced into a large hook-like flange which at once distinguishes the genus from all existing Lemurs; and the anterior lower premolar is not canine-like. _M. antiquus_ is of very small size, but the larger _M. edwardsi_ of the same deposits comes nearer in dimensions to _M. erinaceus_. The upper molars decrease in size from the first to the third, the first and second having a median cusp in the external cingulum, by which they are readily distinguished from the corresponding teeth of the under-mentioned genus _Hyopsodus_. The third upper molar differs from that of _Hyopsodus_ by its small size and the abortion of its posterior columns. The skull approximates to that of the living genus _Galago_, exhibiting the same inflation of the auditory bulla. The upper molars are also not unlike one species of that genus, but the fourth upper premolar has but one outer cusp, as in _Chirogaleus_.

The small _Anaptomorphus_, from the North American Eocene, has a skull of about the same size as that of the smallest species of _Microchœrus_, but the dental formula is _i_ ²⁄₂, _c_ ¹⁄₁, _p_ ²⁄₂, _m_ ³⁄₃, and the upper molars are of the tritubercular type.

[Illustration: FIG. 333.—The left upper cheek-teeth of _Adapis magna_, from the Upper Eocene of Hampshire.]

The well-known _Adapis_ (_Aphelotherium_ or _Palæolemur_), of the Upper Eocene of France and England, differs from all existing Lemuroids in possessing four premolars[662]; the dental formula being _i_ ²⁄₂, _c_ ¹⁄₁, _p_ ⁴⁄₄, _m_ ³⁄₃. The fourth upper premolar has two outer cusps, and the upper molars (Fig. 333) resemble those of _Lepidolemur_ and _Hapalemur_, while the lower canine is a well-developed tooth performing the usual function of biting against the canine of the upper jaw. The lower incisors have upright, spatulate crowns, as in the true Apes. The skull is said to approximate in contour to that of _Propithecus_. The typical _A. parisiensis_ is of comparatively small size, but the species of which the upper cheek-teeth are shown in the woodcut is of much larger dimensions. The skull of _A. magna_, which measures upwards of 4 inches in length, resembles that of _A. parisiensis_ in its general characters, but is modified much in the way that the skulls of larger animals differ from the smaller ones of the same natural group. Thus the brain-chamber and orbits are relatively smaller, the face larger, the muscular crests more developed, and the constriction between the cerebral and the facial portion of the skull more marked. These modifications remove the skull in its general characters still farther from the existing Lemurs—so much so that M. Filhol refers it and the other species of _Adapis_ to a distinct zoological type, intermediate between the lemurs and the pachyderms, to which he gives the name of _Pachylemuriens_, but later researches do not support this view. As mentioned above, it has been suggested that _Cænopithecus lemuroides_ is inseparable from _Adapis parisiensis_, but the postero-internal column of the upper molars is said to be larger. The genera _Tomitherium_ and _Notharctus_, of the Eocene of the United States, appear to be allied to _Adapis_, but the second has a larger lower canine. The same deposits have also yielded more or less imperfect remains of other forms departing more widely from the existing Lemuroid type. Of these _Hyopsodus_, of the Wasatch and Bridger Eocene of the United States, has the dental formula _i_ ²⁄₂, _c_ ¹⁄₁, _p_ ⁴⁄₄, _m_ ³⁄₅. The quadrituberculate upper molars have well-developed accessory intermediate columns (protoconule and metaconule), and thus resemble those of _Microchœrus_; the external surfaces of the outer columns of their teeth being flattened, with vertical ridges and a distinct cingulum. The third upper molar has its postero-internal column (hypocone) partly aborted, but is otherwise as well developed as the preceding molars. _Microsyops_, of the North American Eocene, appears to have been an allied form in which there were probably only three premolars.

[Illustration: FIG. 334.—The right upper cheek-teeth of _Plesiadapis remensis_; from the Lowest Eocene of Rheims. × ³⁄₂. _p_, 3, 4, premolars; _m_, 1, 2, 3, molars. (From Osborn.)]

The genera _Protoadapis_ and _Plesiadapis_, from the lowest Eocene of Rheims, may not improbably be regarded as primitive Lemuroids. The lower molars are quinquetubercular, and not unlike those of _Microsyops_; the dental formula of the lower jaw is _i_ 2, _c_ 1, _p_ 3-4, _m_ 3 in the first-named genus, but in the second the dentition is reduced to _i_ ²⁄₁, _c_ ¹⁄₀, _p_ ²⁄₂, _m_ ³⁄₃. In _Plesiadapis_ the lower and the first upper incisor are enlarged, the upper molars (Fig. 334) tritubercular, and the lower quadritubercular. _Indrodon_, of the lowest Eocene of the United States, resembles _Plesiadapis_ in its tritubercular upper molars, and appears to have a nearly similar dental formula. _Mixodectes_, of the same deposits, was probably a more or less closely allied type. _Pelycodus_ of the Wasatch Eocene of North America, in which the hallux was not opposable, and _Cryptopithecus_ of the German Eocene, may be regarded as very generalised Lemuroids.

_Bibliography._—Besides the works and memoirs on particular families and genera referred to above, see St. G. Mivart, “Notes on the Crania and Dentition of the _Lemuridæ_,” in _Proc. Zool. Soc._ 1864 (pp. 611-648) and 1867 (pp. 960-975); Mivart and Murie, “On the Anatomy of the _Lemuroidea_,” in _Trans. Zool. Soc._ 1872, vol. vii. pp. 1-113; W. Turner, “On the Placentation of the Lemurs,” in _Phil. Trans._ vol. clxvi. pp. 569-587; F. Pollen and D. C. Van Dam, _Recherches sur la Faune de Madagascar_. 2ᵐᵉ parte, “Mammifères,” 1868. For the fossil types see M. Schlosser, “Die Affen, Lemuren, etc., des Europäischen Tertiärs,” in _Beitr. Pal. Œstr-Ungar_, 1888.

_Suborder_ ANTHROPOIDEA.

This suborder includes the whole of the remaining members of the Primates, namely, those animals commonly known as Marmosets, Monkeys, Baboons, and Apes, together with Man himself. The characters by which the Anthropoidea are distinguished as a whole from the Lemuroidea may be summarised as follows. Skull with the orbit separated from the temporal fossa by a vertical plate of bone joining the postorbital bar, and the lachrymal foramen situated within the margin of the orbit. Pollex sometimes rudimentary or absent; second digit of manus always well developed, and that of the pes usually with a flattened nail (not so in _Hapalidæ_). The cerebral hemispheres of the brain either completely or almost completely cover the cerebellum, and are much convoluted. Uterus not bicornuate. The placenta is deciduate and discoidal; and the allantois is small. There are never abdominal mammæ. As additional points of distinction from the Lemuroidea, it may be mentioned that the anterior cornu of the hyoid is shorter than the posterior; the inner pair of upper incisors are in contact in the middle line; and the transverse portion of the colon extends uninterruptedly across the abdomen.

The Anthropoidea may be divided into the five families—_Hapalidæ_, _Cebidæ_, _Cercopithecidæ_, _Simiidæ_, and _Hominidæ_, of which the first and second are confined to the New, and the third and fourth to the Old World.

In noticing some of the salient features in the external and internal structure of the Anthropoidea it will be found convenient to allude to all the members of the first four families as Apes, in contradistinction to Man. In respect to relative size the extremes are found in the Gorilla on the one hand and _Hapale_ on the other; the difference in this respect between these two forms being greater than that between Man and a Squirrel. The relative proportions between the limbs and the body, and also between the fore and hind limbs, are subject to great variation. Thus in _Hylobates_ and _Ateles_ both pairs of limbs are much elongated; in the former case the pectoral being much longer than the pelvic pair (Fig. 335). In other cases, as in the Orang (Fig. 354), while the arms are very long, the legs are short; but in the subfamily _Cercopithecinæ_ both pairs are short and subequal. Only in the _Hapalidæ_ and some of the _Cebidæ_ are the legs proportionately as long as in Man.

The tail is as much as three times the length of the body in _Ateles_; while in the _Simiidæ_ it is totally absent. In the majority of genera it is long in all the species; but in some cases, as in _Macacus_, it may be either long, short, or absent in the different species of a single genus.

Equally marked variations occur in the shape of the head. Thus in _Ateles_ it is rounded; while in the Orang it is elevated vertically; in _Chrysothrix_ it is produced posteriorly; and in the Baboons (_Cynocephalus_) it is characterised by the great production of the muzzle and the terminal position of the nostrils, whereby a characteristic Dog-like form is assumed. The eyes are always directed forwards, and are never more separated from one another than in Man, although, as in _Chrysothrix_, they may be closer together. They are of very large size in _Nyctipithecus_, while in the Baboons they are relatively small in proportion to the size of the head. The ears are invariably well developed, and are usually pointed at their postero-superior angle. Those of man are characterised by the soft depending portion known as the “lobule,” of which there is a rudiment in the Gorilla. In the majority of Apes the nose is but very slightly prominent; but it attains an extraordinary development in _Nasalis larvatus_, and is scarcely less remarkable in _Semnopithecus roxellanæ_ (Fig. 349). Among the Gibbons the Hoolock has a distinctly aquiline nose. The nostrils are terminal in the true Baboons; and while in all the Old World Apes they are approximated, in those of the New World they are separated by a broad septum. With the exception of the Orang, the lips of the Apes are thin.

The pollex makes a nearer approach in form to the human thumb in the Chimpanzee than in any other Ape. Man differs from all the Apes in having the hallux frequently longer instead of shorter than the other digits of the foot. The hallux of the Orang is peculiar in having no nail, but in other cases the nail is flat; the nails of the other digits of the Apes are never quite flat, and in some of the _Cebidæ_ they are decidedly compressed laterally, while in the _Hapalidæ_ they assume the form of sharp and curved claws.

All the Apes have the greater part of the body well clothed with hair. In the Gibbons and the _Cercopithecidæ_ the buttocks have naked ischiatic callosities, which attain their greatest development in _Cynocephalus_ and its allies. The male of the Orang has a well-developed beard, and in _Cercopithecus diana_ there is long hair on the cheeks and chin, while in _Macacus silenus_ the face is surrounded by a fringe of long hair, separated by an interval on the forehead. Long hair is found on the head in _Hapale œdipus_ and in some species of _Semnopithecus_; while in the Bonnet Monkey (_Macacus sinicus_) it radiates in all directions from a central point on the vertex. Long hair clothes the shoulders in _Cynocephalus hamadryas_ and _Hapale humeralifer_; and the end of the tail has a tuft in two species of _Cynocephalus_ and in _Macacus sinicus_. Many of the African _Colobi_ and some species of the Howlers have very long hair on the flanks; and in _Pithecia_ this development of hair extends to the greater part of the body and the tail, _P. satanas_ also having a long beard. In all the lower Apes the hairs on the arm and forearm are directed towards the hand quite down to the wrist; and the same arrangement obtains in _Hylobates_. In the other _Simiidæ_, however (as in man), the points of the hairs of the arm and forearm converge at the elbow. Darwin’s explanation of this peculiarity is that these Apes are accustomed to sit with the arms bent, so that the rain is thus enabled to run off at the elbow.

In one species of _Hapale_ the hair is of a silky texture, and in the South American _Eriodes_, and _Macacus tibetanus_ (as in all the mammals inhabiting the arid and severe climate of Tibet) it becomes woolly.

The development of very brilliant colours on the naked parts of the body, such as the face, sexual organs, and ischiatic callosities is a marked feature of many of the _Cercopithecidæ_ and some other Apes.

With the exception of the long tail found in most forms, the general structure of the skeleton of the Apes is very similar to that of man, but there are marked differences in the form of the jaws and of the innominate bones. The proportion of the facial to the cranial region of the skull varies with the shape of the head, of which brief mention has already been made; the greatest development of the facial portion being in the Baboons. Curiously enough, some of the lower American Monkeys, and more especially _Chrysothrix_, have the greatest relative development of the cranial part of the skull of all the Apes; this character being, however, one common to all the smaller representatives of particular groups, and obviously necessary to provide the requisite amount of brain-space. In the convexity of the frontal region of the skull the American forms, and more especially _Pithecia_, make the nearest approximation to man, and the same is true with regard to the occipital production, which is most developed in _Chrysothrix_. Most of the _Simiidæ_ exhibit, however, a distinct convexity of the occiput, and thereby differ markedly from the _Cercopithecidæ_, in which this region is flat. The rotundity of the cranium is obscured in the larger Apes, such as the Orang (Fig. 353) and Gorilla, by the development of prominent bony ridges for muscular attachment; these attaining their maximum in the males of the species last named, where the sagittal crests and the supraorbital ridges are very prominent. The mastoid process is always smaller in the Apes than in Man, and as it diminishes in size the petrosal tends to assume an inflated or bullate condition. The orbits in shape are most like that of Man in the Gorilla; and, in accordance with the size of the eyes, they are of enormous dimensions in _Nyctipithecus_.

The angle formed by the plane of the foramen magnum with that of the basicranial axis is subject to variation according to the degree of convexity of the occiput, but is generally smaller than in Man, although larger in _Chrysothrix_. There is an external bony meatus auditorius in Man, the _Simiidæ_, and the _Cercopithecidæ_, but none in the _Cebidæ_ and _Hapalidæ_.

The premaxillæ of the Apes are always large; and, except in the Chimpanzee, the premaxillo-maxillary suture persists until after the permanent dentition has been developed. The nasals are smaller and flatter than in Man, but are largest in _Mycetes_. The two rami of the mandible are invariably completely ankylosed at the symphysis in the adult. The Siamang (_Hylobates syndactylus_) is the only ape in which the mandibular symphysis slows a slight projection in front corresponding to the human chin. In _Mycetes_ the angle of the mandible attains an enormous development (Fig. 338) to protect the huge inflated basihyal. The frontal sinuses, though present, in the _Simiidæ_, are generally replaced in the _Cercopithecidæ_ by a coarse diploë, but they are present in the _Cebidæ_ and _Hapalidæ_, being especially large in _Cebus_. In fully adult individuals the cranial sutures become obliterated, the internasal suture disappearing at an early age in the _Simiidæ_ and most of the _Cercopithecidæ_. As in many Carnivora, the tentorium, or membrane separating the cerebrum from the cerebellum, may become ossified in some of the American forms.

The number of the teeth in the Old World Apes is invariably the same as in Man, namely _i_ ²⁄₂, _c_ ¹⁄₁, _p_ ²⁄₂, _m_ ³⁄₃, total 32; but in the _Cebidæ_ the cheek-teeth are _p_ ³⁄₃, _m_ ³⁄₃, and in the _Hapalidæ_ _p_ ³⁄₃, _m_ ²⁄₂. It is probable that the two pairs of incisors correspond to the first and third of the typical series of three. In all Apes the dental series is interrupted by a diastema, and the canines of the males are large. Man alone has an uninterrupted dental series of a horse-shoe-form, without prominent canines.

According to recent researches the Chimpanzee and some of the other _Simiidæ_ exhibit a more or less close approximation to the sigmoid curvature of the vertebral column which is so characteristic of Man, and there is also some approach to it in the Baboons. The number of dorsal vertebræ in the Apes may vary from eleven, as in some species of _Cercopithecus_ and _Macacus_, to fourteen in certain forms of _Hylobates_, and to fifteen in _Nyctipithecus_. The _Cebidæ_ generally have thirteen; and the same number obtains in the Chimpanzee and Gorilla, while the Orang resembles Man in having but twelve. The lumbar vertebræ show a range in number of from four to seven. In the _Simiidæ_ there are four or five of these vertebræ, the length of the lumbar region being shorter in this family than in the other Apes, with the exception of _Ateles_. The shortness of the lumbar region in the last-named genus is compensated by the relative length of the dorsal region, as is shown in Fig. 335.

[Illustration: FIG. 335.—Skeleton of the Black-handed Spider Monkey (_Ateles geoffroyi_). From De Blainville.]

The sacrum is longest in the _Simiidæ_ and Man, its greatest absolute length occurring in the Gorilla, and the relative greatest length being found in _Hylobates_. The _Simiidæ_ never have less than five, and may have six sacral vertebræ; while in the lower forms there are generally only two or three, although occasionally four in some of the American forms. The Orang and some of the Baboons make the nearest approximation to Man in the marked angle formed at the junction of the sacrum with the lumbar vertebræ. Except in the _Simiidæ_ and _Macacus inuus_, the number of caudal vertebræ in the Apes always exceeds four, but they may be reduced to five in the Mandrill (_Cynocephalus maimon_). In _Macacus_ and _Uacaria_ the shortness of the tail is attained by the small size of the vertebræ themselves, the number of which may be from fifteen to seventeen. Other forms usually have from twenty to thirty-three caudals, the latter number occurring in _Ateles_ (Fig. 335), where the tail is relatively the longest. The tail is, however, absolutely longest in _Semnopithecus_, _Colobus_, and their allies, the length being partly due to the size of the component vertebræ. Chevron bones are present in all forms having a distinct tail; and, together with other processes for muscular attachment, attain their greatest development in _Ateles_.

The vertebral processes known as metapophyses and anapophyses, which are generally inconspicuous in Man, and are but small in the _Simiidæ_, attain a large development in the lower forms. The metapophyses generally commence in the eighth or ninth dorsal, and continue to the anterior caudals, where they gradually merge in the prezygapophyses. The anapophyses, which are most developed in the _Cebidæ_, project outwards and backwards from one vertebra to embrace the prezygapophyses of the succeeding one. They occur generally in the same region as the metapophyses, but usually cease at the penultimate lumbar, although in some cases they can be traced on to the posterior cervicals and anterior caudals, in the latter region passing into the transverse processes.

In most Apes the sternum is narrow, and consists of a more or less enlarged manubrium, followed by a chain of subequal and antero-posteriorly elongated bones, from three to six in number. In the _Simiidæ_ alone is there a broad sternum, or one consisting of a manubrium, followed by a single bone only, as in _Hylobates_. The Orang presents a peculiarity, in that the sternum long remains made up of ossifications arranged in pairs, side by side, successively. The true ribs are seven in number on each side in the highest forms, but in _Hylobates_ there are sometimes eight. In _Ateles_ there are sometimes nine pairs. In _Hapale_ the number varies from six to eight, and it is seven or eight in the other genera. The angles of the ribs are never so marked as in Man; although most marked in _Hylobates_. _Pithecia_ is distinguished by the greater relative breadth of the ribs. In no Ape is the thorax half as broad again as it is deep from back to breast; but in the _Simiidæ_ its transverse diameter exceeds its depth by from about one-fourth to a little under one-third of the latter. In _Ateles_, and sometimes in _Mycetes_, the thorax is wider than deep, but in all the rest it is deeper than wide.

In regard to the appendicular skeleton it may be observed that the Gorilla and Orang make the nearest approach to Man in the form of the scapula; and that the supraspinous fossa of this bone is largest in _Gorilla_ and _Mycetes_, being remarkably small in _Simia_. The _Cebidæ_ have a distinct suprascapular notch which is often converted by a bar of bone into a foramen; this bar in _Mycetes_ giving rise to a peculiar flat process. The acromion and coracoid processes are most developed in the _Simiidæ_ and _Ateles_.

The relative length of the fore and hind limbs has been already briefly touched upon. The humerus closely resembles that of Man throughout the suborder; the nearest approximation occurring in the _Simiidæ_. As in the Lemuroidea, this bone never has an entepicondylar foramen, but in many of the American forms it has a supracondylar perforation. The radius and ulna, like the tibia and fibula, are always perfectly distinct throughout their length; and the hand can be pronated and supinated upon the forearm. Man, the Gorilla, and the Chimpanzee differ from other forms in having no os centrale in the carpus.

The brain of Apes is always much smaller in absolute dimensions than in Man. Thus, according to Professor Mivart,[663] “the cranial capacity is never less than 55 cubic inches in any normal human subject, while in the Orang and Chimpanzee it is but 26 and 27½ cubic inches respectively. The relative size of the brain varies inversely with the size of the whole body, but this is the case in warm-blooded vertebrates generally. The extreme length of the cerebrum never exceeds, as it does in Man, two and a quarter times the length of the basicranial axis. The proportion borne by the brain to its nerves is less in the Apes than in Man, as also is that borne by the cerebrum to the cerebellum. In general structure and form the brain of Apes greatly resembles that of Man. Each half of the cerebrum contains a triradiate lateral ventricle, and though in some _Cercopithecidæ_ the posterior cornu is relatively shorter than in man, it again becomes elongated in the _Cebidæ_, and in many of the latter it is actually longer relatively than it is in man. The posterior lobes of the cerebrum are almost always so much developed as to cover over the cerebellum, the only exceptions being the strangely different forms _Mycetes_ and _Hylobates syndactylus_. In the latter the cerebellum is slightly uncovered, but it is so considerably in the former. In _Chrysothrix_ the posterior lobes are much more largely developed relatively than they are in man. The cerebrum has almost always a convoluted external surface. In this group, however, as in mammals generally, a much-convoluted cerebrum is correlated with a considerable absolute bulk of body. Thus in _Hapale_ (and there only) we find the cerebrum quite smooth, the only groove being that which represents the Sylvian fissure. In _Simia_ and _Gorilla_ and _Anthropopithecus_, on the contrary, it is very richly convoluted. A hippocampus minor is present in all Apes, and in some of the _Cebidæ_ it is much larger relatively than it is in Man, and is absolutely larger than the hippocampus major. Of all Apes, the Orang has a brain which is most like that of Man; indeed, it may be said to be like Man’s in all respects, save that it is much inferior in size and weight, and that the cerebrum is more symmetrically convoluted and less complicated with secondary and tertiary convolutions. If the brain of _Simia_ be compared with that of _Gorilla_ and _Anthropopithecus_, we find the height of the cerebrum in front greater in proportion in the former than in the latter; also the bridging convolutions, though small, are still distinguishable, while they are absent in the Chimpanzee. Nevertheless this character cannot be of much importance, since it reappears in _Ateles_, while two kinds of the genus _Cebus_ (so closely allied as to have been sometimes treated as one species) differ strangely from each other in this respect. The corpus callosum, in Apes generally, does not extend so far back as in Man, and it is very short in _Pithecia_. In the Orang and Chimpanzee there are, as in Man, two corpora albicantia, while in the lower Monkeys there is but one. The vermis of the cerebellum is larger in the _Cebidæ_ than in the _Simiidæ_ and _Cercopithecidæ_. In all Apes below the _Simiidæ_ each lateral lobe of the cerebellum gives off a small lobule, which is received into a special fossa of the petrous bone. Certain prominences of the medulla oblongata, termed corpora trapezoidea, which are found in lower mammals, begin to make their appearance in the _Cebidæ_.”

The organs connected with the functions of alimentation, circulation, and excretion, as well as the muscles, conform generally to the type obtaining in Man, of which full description will be found in works on human anatomy. The tongue is longer in Apes than in Man; and a uvula is generally present, although rudimentary in the _Cebidæ_. The peculiar sacculation of the stomach in the subfamily _Semnopithecinæ_ has been already mentioned; this sacculation is most developed at the cardiac extremity, where it somewhat resembles a colon spirally coiled. In _Hylobates_ the stomach is very like that of Man, differing only in the more elongated and distinct pylorus. _Pithecia_ has a more globular stomach, while in _Hapale_ the cardiac and pyloric apertures are approximated. The intestine of Apes is devoid of valvulæ conniventes, and it is only in Man and the _Simiidæ_ that the colon is furnished with a vermiform appendage. The colon varies from a fully sacculated form in _Hylobates_ to a smooth one in _Cebus_.

The liver of Apes is subject to a considerable amount of variation. In the _Simiidæ_ it comes more or less close to the human type; that of the Orangs being usually divided only into two principal lobes by the umbilical vein, and showing no trace of lateral fissures. In the Gorilla these fissures are present, so as to produce right and left lateral and central lobes. _Hylobates_ has a liver (Fig. 352) which perhaps is nearer to the human than that of any of the other _Simiidæ_. In the _Cercopithecidæ_ the liver differs from that of the _Simiidæ_ by the deeply cleft lateral fissures, and has a comparatively small and pointed caudate lobe. The enormous size of the stomach in _Colobus_ causes the liver to be very narrow, and pushed to the left side. The liver of the _Cebidæ_ (Fig. 336) and _Hapalidæ_, in addition to the deeply cleft lateral fissures, is characterised by the great size and quadrangular form of the caudate lobe (_c_), which attains its maximum development in _Ateles_. The gall-bladder is always present.

[Illustration: FIG. 336.—Under surface of the liver of the Black-handed Spider Monkey (_Ateles melanochir_). _u_, Umbilical fissure; _vc_, vena cava; _ll_, left lateral lobe; _lc_, left central lobe; _rc_, right central lobe; _rl_, right lateral lobe; _s_, Spigelian lobe; _c_, caudate lobe; _g_, gall-bladder.]

The larynx is in many Apes furnished with sac-like appendages, which are variable in different species as regards number, size, and situation. They may be dilatations of the laryngeal ventricle, as in _Simia_, _Gorilla_, and _Anthropopithecus_, or they may open above the false vocal chords so as to be extensions of the thyro-hyoid membrane, as in _Hylobates_. There may be but a single median opening in the front part of that membrane at the base of the epiglottis, as in the _Cercopithecidæ_. There may be a single median opening at the back of the trachea, just below the cricoid cartage, as in _Ateles_; there may be but a single sac, or there may be five, as sometimes in _Mycetes_. These may be enormous, meeting in the middle line in front and extending down to the axillæ, as in the Gorilla and Orang. A sac may occupy the cavity of the expanded body of the hyoid, as in _Mycetes_.

The hyoid has its basilar part generally somewhat more convex and enlarged than in Man; but in _Mycetes_ it becomes greatly enlarged and deeply excavated, so as to form a great bony bladder-like structure. The posterior cornua of the hyoid (thyrohyals) are never entirely absent, but the anterior or lesser cornua may be so, as in _Mycetes_. The anterior cornua never exceed the posterior cornua in length; but they may be (_e.g._ in _Cercopithecus_) more largely developed relatively than in Man, and may even be jointed, as in _Lagothrix_.

The lungs have generally the form of those of man; but the right lung may have four lobes, as in _Hylobates_. The great arterial trunks in _Simia_, _Gorilla_, and _Anthropopithecus_ are arranged as in Man. In _Hylobates_ and the lower Apes, however, the left carotid artery may take its origin from the innominate artery.

In regard to their distribution in time the earliest record that we as yet have of the occurrence of Apes is in the Middle Miocene of Europe, where forms are met with apparently so closely allied to some of the higher existing types that it is evident we must look much farther back before we can get any clue to the origin of the suborder. Since all the known fossil Old World Apes are referable to the _Simiidæ_ or _Cercopithecidæ_, and no representatives of these families have been obtained from the Tertiaries of America, it would appear that the distinction of the Apes of the Old World from those of the New is of very old standing.

At the present day Apes are mainly confined to tropical and subtropical regions. In the Old World _Macacus inuus_ is found as far north as Gibraltar, _M. tibetanus_ and _Semnopithecus roxellanæ_ inhabit western Tibet, while in Japan we have _M. speciosus_. In the New World one species of _Ateles_ is known to occur as far north as latitude 19° in Southern Mexico, and may range a few degrees higher. To the southward species are found near the Cape, in Timor, and the Malay Archipelago; while in America they range in Brazil and Paraguay to about latitude 30°. The Tibetan species are found at a very high elevation; and in the outer Himalaya the Langurs (_Semnopithecus_) may be seen in winter and spring leaping from bough to bough of snow-covered pines.

Apes are very abundant in the Ethiopian and Oriental regions, as well as in that part of America which extends from Panama to Southern Brazil. Ceylon, Borneo, Sumatra, and Java may be mentioned as islands where Ape-life attains great development; but they are unknown in Madagascar and the West Indian Islands, and of course in the Australasian region.

We have already alluded to the circumstance that while the _Simiidæ_ and _Cercopithecidæ_ are exclusively confined to the Old World, the _Cebidæ_ and _Hapalidæ_ are equally restricted to the New, and we may accordingly proceed to notice a few points in relation to generic distribution. Of the larger _Simiidæ_ the Gorilla and Chimpanzee are confined to Equatorial Africa, and the Orang to Malayana; but there is evidence of the former existence of a species of Chimpanzee (_Anthropopithecus_) and not improbably of an Orang (_Simia_) in Northern India. The Gibbons (_Hylobates_) are now exclusively Oriental. Europe has only _Macacus inuus_ of Gibraltar, also found in Africa north of the Sahara, and therefore strictly Palæarctic in distribution. The Ethiopian region includes in the _Cercopithecidæ_ the genus _Colobus_ (the African analogue of _Semnopithecus_), _Cercopithecus_, and the Baboons (_Cynocephalus_, etc.) The Baboons range, however, into Arabia and Syria, and also existed during the Pliocene epoch in Northern India. _Semnopithecus_ and _Macacus_ are very characteristic of the Oriental region; but, as already mentioned, outlying species extend into various parts of the Palæarctic region. _Macacus_ has indeed a very wide distribution, extending from Gibraltar and North Africa to Japan. The allied _Cynopithecus_, represented only by _C. niger_ of Celebes, approximates to the Baboons; while the one species of _Nasalis_ is peculiar to Borneo. Remains of _Semnopithecus_ and _Macacus_ occur in the Tertiaries of India and Europe, which also yield allied extinct types noticed in the sequel.

In America, north of Panama, the genera known to be represented are _Chrysothrix_, _Nyctipithecus_, _Cebus_, _Ateles_, _Mycetes_ and _Hapale_ in Veragua; _Nyctipithecus_, _Cebus_, _Ateles_, and _Mycetes_ in Costa Rica and Nicaragua; _Ateles_ and _Mycetes_ in Guatemala; and _Ateles_ in Southern Mexico. Brazil is the headquarters of the American Apes; but different portions of that vast region have a somewhat distinct Ape fauna. Thus the genus _Eriodes_ appears in South-Eastern Brazil to represent the species of _Ateles_ inhabiting the more northern and western parts of the empire. Southwards, the genera _Cebus_, _Mycetes_, _Chrysothrix_, and _Callithrix_ extend farthest; but they do not probably all extend to the farthest limit yet known, namely 30° S. The species found farthest south are _Mycetes caraya_, _Cebus fatuellus_, and _Callithrix personatus_.

_Family_ HAPALIDÆ.

Dentition: _i_ ²⁄₂, _c_ ¹⁄₁, _p_ ³⁄₃, _m_ ²⁄₂; total 32. No bony external auditory meatus, a broad internarial septum, and no cheek-pouches. Tail non-prehensile; no ischiatic callosities. Pollex not opposable; a long, curved, and pointed claw to all the digits except the hallux.

This family, which includes the smallest representatives of the suborder, commonly known as Marmosets, is confined to the New World. In addition to the diagnostic characters given above, it may be mentioned that the pollex is elongated and the hallux very small, while the pectoral limbs are not longer than the pelvic pair; and the tail is long and more or less thickly covered with elongated hairs.

The dentition of the Marmosets sufficiently distinguishes them from all other members of the suborder, although they are evidently nearly allied to the _Cebidæ_. The small size of the hallux, and the total incapacity of the pollex to oppose itself in the least degree to the other digits, as well as the presence of claws on all the digits of the manus, are, however, equally characteristic features. These animals (Fig. 337) are not larger than Squirrels, and are of active arboreal habits, living in small companies, and adding insects to the ordinary fruit diet. Frequently, as in the figured species, the head is furnished on either side with a long tuft of hair projecting outwards and backwards. They give birth to as many as three young ones at a time, and thereby differ from all other members of the suborder, in which one is the normal number. They are divided into two genera, according to the proportionate size of the lower canine to the incisors; but some species present an intermediate condition, so as to render this distinction of somewhat doubtful value.

_Hapale._[664]—Lower canine not longer than the incisors. A number of species have been described, among which may be mentioned _H. jacchus_, _H. albicollis_, _H. aurita_, and _H. humeralifer_. Remains of species of this genus have been found in the cavern-deposits of Brazil.

[Illustration: FIG. 337.—The Golden Marmoset (_Midas chrysoleucas_). From _Proc. Zool. Soc._ 1868, pl. 24.]

_Midas._[665]—Lower canine considerably longer than the incisors. No less than twenty-four species of this genus have been named, among which the Silky Marmoset (_M. rosalia_) of Columbia, the Pinche Monkey (_M. œdipus_) of South-Eastern Brazil, and the Golden Marmoset (_M. chrysoleucas_, Fig. 337) are well-known types.

_Family_ CEBIDÆ.

Dentition: _i_ ²⁄₂, _c_ ¹⁄₁, _p_ ³⁄₃, _m_ ³⁄₃; total 36. Tail frequently prehensile; digits with nails; other characters as in the _Hapalidæ_.

The members of this American family are at once distinguished by the dental formula, which is numerically higher than in any other Apes. The various species range over the whole of tropical America, but are most abundant in the dense forest regions of Brazil, where they live a completely arboreal life, to which the prehensile tails of many of them are so specially adapted. They are in most respects closely allied to the _Hapalidæ_, but the pollex diverges somewhat from the plane of the other digits; while the retention of the third molar is a very distinctive feature. None of the species attain the dimensions of the larger _Cercopithecidæ_ of the Old World. The genera are usually arranged in five subfamilies.

Subfamily =Mycetinæ=.—Lower incisors vertical; hyoid bones enormously inflated; tail long and prehensile, naked beneath at the end; pollex well developed.

[Illustration: FIG. 338.—Side view of skull and hyoid bone of the Red Howling Monkey (_Mycetes seniculus_). From De Blainville.]

_Mycetes._[666]—The sole representatives of this subfamily are the well-known Howling Monkeys, all of which are included in the genus _Mycetes_. They are of more bulky build, and have more produced muzzles than the other members of the family. The truncated occipital region, and the extraordinary development of the rami of the mandible, especially of their angular and ascending portions, are the chief peculiarities by which the skulls (Fig. 338) of the members of this genus are characterised. The last named character, which is more marked in the male than in the female sex, is related to the enormous size of the vocal organs, which the rami of the mandible enclose and protect. The inflated hyoid bone, which forms a deep cup, is shown in the figure. The Howlers are subject to great individual and sexual variation of colours, so that the discrimination of species from local races is difficult. In one species the male is black and the female straw-coloured; and several of the species have bright red or golden hair on the flanks. In disposition these creatures are sluggish and stupid, but their chief characteristic is their prodigious power of voice. Mr. Bates, in his _Naturalist on the Amazons_, observes that “when Howlers are seen in the forest there are generally three or four of them mounted on the topmost branches of a tree. It does not appear that their harrowing roar is emitted from sudden alarm; at least it was not so in captive individuals. It is probable, however, that the noise serves to intimidate their enemies.”

Several species have been described, the Red Howler (_M. seniculus_) and the Ursine Howler (_M. ursinus_) being well-known forms. Remains of this genus probably referable to existing types are found fossilised in the cavern-deposits of Brazil. An allied fossil form from the South American Pleistocene has been described as _Protopithecus_.

Subfamily =Pitheciinæ=.—Lower incisors inclined forward at their summits; hyoid bone normal; tail long or short, non-prehensile; pollex well developed. Two genera are included in this subfamily, readily distinguished by the length of the tail.

_Pithecia._[667]—The Sakis, as the representatives of this genus are commonly termed, are readily characterised by the length of the tail; the angle of the mandible is expanded, although less so than in _Mycetes_. A number of species have been described, the Black Saki (_P. satanas_) of the Lower Amazons, being one of the best known. While some species, like _P. hirsuta_, have long hair covering the whole of the head, body, and tail, in others only the head, or the cheeks and chin, are so clothed.

_Uacaria._[668]—The Uakari Monkeys differ from all the other _Cebidæ_ by their short Baboon-like tail. The Bald Uakari (_U. calva_) of the Rio Negro, and the closely allied _U. rubicunda_ of the Upper Amazons, are remarkable for their scarlet face, which forms a striking contrast to the long, silky, whitish hair covering the body. According to Mr. Bates, the Uakaris live in forests which are inundated during a great part of the year, and never descend to the ground; they appear to be rare and of local distribution. The third species, _U. melanocephala_, differs considerably from both the others. The cæcum of _U. calva_, according to Mr. F. E. Beddard, measures upwards of “10 inches along the greater curvature; it is separated from the colon by a very marked constriction; it is not sacculated, and when fully distended with air is curved on itself into a little less than a circle; it is furnished with a well-developed median frenum carrying blood-vessels.” A similar type of cæcum is also found in _Callithrix_ and _Pithecia_.

Subfamily =Nyctipithecinæ=.—Lower incisors vertical; hyoid normal; tail long, non-prehensile; pollex well developed.

Three genera are included in this subfamily, the species being partly insectivorous.

[Illustration: FIG. 339.—The Moloch Teetee (_Callithrix moloch_). From _Archives du Muséum_, vol. iv. pt. 3.]

_Callithrix._[669]—Head small, depressed, and not elongated; nares widely separated; canines small; angle of mandible expanded as in _Pithecia_; tail with long hair.

This genus comprises several small species, mostly from Brazil and the Amazons, and commonly known as Teetees, one of the best-known species (_C. moloch_, Fig. 339) being represented in the accompanying woodcut. The smaller eyes and the more widely separated nostrils distinguish them from _Nyctipithecus_; while the small canines and the bushy tail readily mark their distinction from _Chrysothrix_. Remains of _Callithrix_ have been found in the Brazilian caves.

_Chrysothrix._[670]—Head greatly elongated; orbits large and closely approximated; canines well developed; tail with comparatively short hair.

[Illustration: FIG. 340.—The Lemurine Douroucouli (_Nyctipithecus lemurinus_). From _Archives du Muséum_, vol. iv, pl. 2.]

The small Squirrel Monkeys, of which four species have been described, are characterised by the great backward projection of the occipital region of the skull, and by orbits approximating in size to those of the next genus.

_Nyctipithecus._[671]—Head rounded; orbits very large, separated by a narrow septum; nares somewhat approximated.

The Douroucoulis (Fig. 340), as the members of this genus are called, are of nocturnal habits, in association with which the eyes are of enormous dimensions, as in the Lemuroid genus _Loris_. The following account, of two species of this genus is taken from Mr. Bates’s _Naturalist on the Amazons_: “They sleep all day long in hollow trees, and come forth to prey on insects and eat fruit only in the night. They are of small size, the body being about a foot long, and the tail 14 inches, and are thickly clothed with soft gray and brown fur, similar in substance to that of the Rabbit. Their physiognomy reminds one of the Owl or Tiger-Cat; the face is rounded and encircled by a ruff of whitish fur; the muzzle is not at all prominent; the mouth and chin are small; the ears are very short, scarcely appearing above the hair of the head; and the eyes are large and yellowish in colour, imparting the staring expression of nocturnal birds of prey. The forehead is whitish, and decorated with black stripes, which in one of the species (_N. trivirgatus_) continue to the crown, and in the other (_N. felinus_) meet on the top of the forehead. _N. trivirgatus_ was first described by Humboldt, who discovered it on the banks of the Cassiquiare, near the headquarters of the Rio Negro.”

Subfamily =Cebinæ=.—Lower incisors vertical; hyoid bone normal; tail long and prehensile; pollex present or absent.

This subfamily includes the typical members of the family, which are arranged in four genera.

_Ateles._[672]—Form slender; limbs very long; fur not woolly; pollex absent; tail naked beneath distally; nails not much laterally compressed and pointed.

This genus includes the well-known Spider Monkeys (Fig. 341), which by their long limbs and tail are admirably adapted to a purely arboreal life, although they lack the active and agile habits of the Old World Gibbons. The tail with the under surface of its extremity naked affords the most completely prehensile type of this organ, and can sustain the weight of the whole body. Objects are not unfrequently grasped by it and brought within reach of the hand or mouth. Owing to the absence of the pollex the power of grasping is very imperfect in the hand. At least fourteen species of this genus have been described, among the best-known being _A. melanochir_ (Fig. 341), _A. paniscus_ of Guiana, _A. geoffroyi_ of Central America, _A. ater_ of Eastern Peru, and _A. hybridus_ of Colombia.

_Eriodes._[673]—Form slender; limbs very long; fur woolly; internasal septum narrower than usual in the family; pollex rudimentary; tail naked beneath distally; nails exceedingly compressed laterally, and pointed.

This genus is represented by three species from South-East Brazil, which, while closely allied to the true Spider Monkeys, differ by their woolly hair, the narrow internasal septum, the presence of a rudimentary pollex, and the great compression of the nails. The species are _E. arachnoides_, _E. hemidactylus_, and _E. hypoxanthus_.

_Lagothrix._[674]—Form rather robust; limbs moderate; fur woolly; pollex well developed; tail distally naked beneath.

[Illustration: FIG. 341.—The Black-handed Spider Monkey (_Ateles melanochir_). From _Proc. Zool. Soc._ 1871, pl. 15.]

The Woolly Monkeys differ from the preceding genera by the presence of a well developed pollex. They resemble _Eriodes_ in their fur and compressed nails, but differ in the more widely separated nares. The tail resembles that of the preceding genera. Speaking of these Monkeys Mr. Bates observes that “the Barrigudos are very bulky animals, whilst the Spider Monkeys are remarkable for the slenderness of their bodies and limbs. I obtained specimens of what have been considered two species, one (_L. olivaceus?_) having the head clothed with gray, the other (_L. humboldti_, Fig. 342) with black fur. They both live together in the same places, and are probably only differently coloured individuals of one and the same species. I sent home a very large male of one of these kinds, which measured 27 inches in length of trunk, the tail being 26 inches long; it was the largest monkey I saw in America, with the exception of a black Howler, whose body was 28 inches in height. The skin of the face in the Barrigudo is black and wrinkled, the forehead is low, with the eyebrows projecting.... In the forests the Barrigudo is not a very active animal; it lives exclusively on fruits, and is much persecuted by the Indians on account of the excellence of its flesh as food.” Five species are usually recognised, viz. _L. canus_, _L. humboldti_, _L. castelnaui_, _L. tschudii_, and _L. geoffroyi_.

[Illustration: FIG. 342.—Humboldt’s Lagothrix (_Lagothrix humboldti_). From _Proc. Zool. Soc._ 1863, pl. 31.]

_Cebus._[675]—Form rather robust; limbs moderate; fur not woolly; pollex well developed; tail not naked beneath distally.

This, the typical, genus includes the Sapajous or Capuchins (Fig. 343), which are so commonly seen in this country in captivity, being the favourite Monkeys of itinerant musicians. They are smaller and stouter in build than the Spider Monkeys, from which they are readily distinguished by the well-developed pollex, and the absence of a naked under surface to the extremity of the tail. At least twenty species have been described (_C. fatuellus_, _C. lunatus_, _C. capucinus_, _C. albifrons_, _C. hypoleucus_, etc.), but it is probable that some of these are not entitled to stand, since there is a large amount of individual variation. Fossil remains of species of _Cebus_ have been described from the Pleistocene cavern-deposits of Brazil.

[Illustration: FIG. 343.—The White-cheeked Sapajou (_Cebus lunatus_). From _Proc. Zool. Soc._ 1865, pl. 45.]

_Family_ CERCOPITHECIDÆ.

Dentition: _i_ ²⁄₂, _c_ ¹⁄₁, _p_ ²⁄₂, _m_ ³⁄₃; total 32. Crowns of molars elongated antero-posteriorly, with the tubercles forming a pair of imperfect transverse ridges, and the last lower molar usually with a hind talon. A bony external auditory meatus. A narrow internarial septum. Tail non-prehensile. Ischiatic callosities present. Cheek-pouches present or absent. Pollex, when present, opposable. Pelvic limbs never much longer than pectoral. Sternum narrow. Cæcum without vermiform appendage.

This family includes all the Old World Apes, with the exception of the _Simiidæ_, and may be divided into the subfamilies _Cercopithecinæ_ and _Semnopithecinæ_.

Subfamily =Cercopithecinæ=.—Pelvic and pectoral limbs approximately equal; tail variable; cheek-pouches present; stomach simple.

This subfamily comprises, the African Baboons, the common Indian Monkeys constituting the genus _Macacus_, together with the African _Cercopithecus_ and _Cercocebus_ and a few allied types.

_Cynocephalus._[676]—Muzzle much elongated (Fig. 344), with the nostrils terminal; ischial callosities very large; tail more or less short; muzzle swollen by enlargement of the maxillæ. Now confined to Africa and Arabia.

[Illustration: FIG. 344.—Skeleton of the Chacma Baboon (_Cynocephalus porcarius_). From De Blainville.]

This genus comprises the typical Baboons, and we may select the well-known Mandrill (_C. maimon_), of tropical West Africa, as a good illustrative example. It may be mentioned in passing that the name Mandrill appears to have been first introduced into English literature by William Smith in his _New Voyage to Guinea_, published in 1744, wherein he mentions among the animals of Sierra Leone one “called by the white men in this country Mandrill,” but adds, “why it is so called I know not.”[677] Smith gives sufficiently accurate details to show that his animal is not that now called Mandrill, but the Chimpanzee. Buffon, however, while quoting Smith’s description, transferred the name to the very different species now under consideration, and to that it has been attached ever since.

The Baboons generally are distinguished from most other Monkeys by the comparative equality of the length of their limbs, which with the structure of the vertebral column adapts them rather for quadrupedal progression on the ground than for climbing among the branches of trees; and some of them, like the South African Chacma (_C. porcarius_), of which the skeleton is shown in Fig. 344, live habitually among rocks, and are much less completely frugivorous than other Apes. They are also remarkable for the great size of their face and jaws as compared with the part of the skull which encloses the brain. The Mandrill, in addition to these characters, is distinguished by the heaviness of its body, stoutness and strength of its limbs, and exceeding shortness of its tail, which is a mere stump, not 2 inches long, and usually carried erect. It is, moreover, remarkable for the prominence of its brow ridges, beneath which the small and closely approximated eyes are deeply sunk; the immense size of the canine teeth; the great development of a pair of oval bony prominences on the maxillary bones in front of the orbits, rising on each side of the median line of the face, and covered by a longitudinally ribbed naked skin; and more especially for the extraordinarily vivid colouring of some parts of the skin. The body generally is covered with a full soft coating of hair of a light olive-brown above and silvery-gray beneath, and the chin is furnished underneath with a small pointed yellow beard. The hair of the forehead and temples is directed upwards so as to meet in a point on the crown, which gives the head a triangular appearance. The ears are naked and of a bluish-black colour. The hands and feet are naked and black. A large space around the greatly developed ischial callosities, as well as the upper part of the insides of the thighs, are naked and of a crimson colour, shading off on the sides to lilac or blue, which, depending not upon pigment but upon injection of the superficial blood-vessels, varies in intensity according to the condition of the animal—increasing under excitement, fading during sickness, and disappearing after death. But it is in the face that the most remarkable disposition of vivid hues occur, more resembling those of a brilliantly coloured flower than what might be expected in the cutaneous covering of a mammal. The cheek-prominences are of an intense blue, the effect of which is heightened by deeply sunk longitudinal furrows of a darker tint, while the central line and termination of the nose are a bright scarlet. Notwithstanding the beauty of these colours in themselves, the whole combination, with the form and expression of features, quite justifies Cuvier’s assertion that “il serait difficile de se figurer un être plus hideux que le Mandrill.”

It is only to fully adult males that this description applies. The female is of much smaller size, and of more slender make; and, though the general tone of the hairy parts of the body is the same, the prominences, furrows, and colouring of the face are very much less marked. The young males have black faces. At the age of three the blue of the cheeks begins to appear, but it is not until they are about five, when they cut their great canine teeth, that they acquire the characteristic red of the end of the nose.

[Illustration: FIG. 345.—The Yellow Baboon (_Cynocephalus babuin_). From _Archives du Muséum_, Vol. ii. pl. 34.]

The Mandrills, especially the old males, are remarkable for the ferocity of their disposition, as well as for other disagreeable qualities, which are fully described in Cuvier’s account of the animal in _La Ménagerie du Muséum d’Histoire Naturelle_ (1801), but when young they can easily be tamed. Like the rest of the Baboons, they appear to be rather indiscriminate eaters, feeding upon fruit, roots, reptiles, insects, scorpions, etc., and inhabit open rocky ground rather than forests. Not much is known of the Mandrill’s habits in the wild state, nor of the exact limits of its geographical distribution. The specimens brought to Europe all come from the west coast of tropical Africa, from Guinea to the Gaboon.

An allied species, the Drill (_C. leucophæus_), which resembles the Mandrill in size, general proportions, and shortness of tail, but wants the bright colouring of the face which makes that animal so remarkable, inhabits the same district. Other well-known species are the Yellow Baboon (_C. babuin_), of West Africa (Fig. 345); the Arabian Baboon (_C. hamadryas_), of Arabia and Abyssinia; and the Anubis Baboon (_C. anubis_), of West Africa.

It is very noteworthy from a distributional point of view, as showing the former intimate connection between the faunas of the Oriental and Ethiopian regions, that fossil remains of Baboons have been found in the Pleistocene cavern-deposits of Madras, and also in the older Pliocene beds of the Siwalik Hills in Northern India; the two species from the latter deposits having been described as _C. subhimalayanus_ and _C. falconeri_.

_Theropithecus._[678]—Distinguished from _Cynocephalus_ by the nostrils not being terminal, but situated as in _Macacus_. This genus is represented by the Abyssinian Gelada (_T. gelada_) and the allied _T. obscurus_.

_Cynopithecus._[679]—The Black Ape of Celebes (_C. niger_) forms a connecting link between the Baboons and the genus _Macacus_; the skull differing from that of the latter in the development of longitudinal ridges on the sides of the upper surface of the maxillæ, as in some of the species of _Cynocephalus_. The muzzle is also more produced than in _Macacus_.

[Illustration: FIG. 346.—The Tibetan Macaque (_Macacus tibetanus_). From Milne-Edwards, _Recherches des Mammifères_, pl. 34.]

_Macacus._[680]—Muzzle considerably produced; nostrils not terminal; cheek-pouches and ischial callosities well developed; tail long, short, or absent; a distinct talon to the third lower molar.

With the exception of the Barbary Ape (_M. inuus_) of Northern Africa and Gibraltar, the Macaques are now exclusively Asiatic, one species (Fig. 346) occurring in Tibet, and another (_M. speciosus_) being found in Japan. All these Monkeys are of stout build, and it is chiefly by the greater production of the muzzle, the larger ischiatic callosities, and the frequent shortness of the tail that they are distinguished from the under-mentioned African genera. The transition from the longer-tailed to the short-tailed forms is so complete that the proposed generic separation of the latter as _Innus_ is impracticable. In _M. innus_ the tail is wanting; in _M. tibetanus_ (Fig. 346) and _M. nemestrinus_ of Tenasserim it is short; in the common Bengal Monkey (_M. rhesus_) it is about one-half the length of the head and body, while in _M. cynomolgus_ and its allies it is still longer. In the Indian Lion-tailed Monkey (_M. silenus_) it is tufted at the end.

The following summary of the habits of the Macaques is taken from Mr. W. T. Blanford’s _Mammals of British India_: “The species of the present genus resemble each other in their habits; they are found in flocks, often of considerable size, and generally composed of individuals of both sexes and of all ages. They are active animals, though less rapid in their movements, whether on trees or on the ground than the _Semnopitheci_. Their food is varied, most of the species, if not all, eating insects as well as seeds, fruits, etc., and one kind feeding partly on crustacea. They have occasionally been known to devour lizards, and, it is said, frogs also. All have the habit of cramming food into their cheek-pouches for mastication at leisure—a practice that must be familiar to any one who has fed monkeys in confinement. The voice and gestures of all the species are similar, and differ entirely from those of both the Gibbons and _Semnopitheci_.... The majority of the species are very docile when young. They thrive well, and several of them have bred in confinement. The period of gestation is almost seven months, only a single young one, as a rule, being produced at a birth. They become adult at the age of four or five years, but breed earlier.”

The Common Indian _M. rhesus_ is found in the Himalaya at an elevation of over 8000 feet.

Fossil remains of _Macacus_ are found in India in the Pleistocene of Madras and the Pliocene of the Punjab; and they also occur in the Pliocene of France and Italy, those from the latter deposits having been incorrectly separated as _Aulaxinuus_. Part of the jaw of a Monkey from the Pleistocene of Essex has been described as _Macacus pliocenus_, and is very interesting as showing the presence of Apes in Europe at that late period.

_Cercocebus._[681]—An African genus agreeing with _Macacus_ in the presence of a hind talon to the third lower molar, but with the other characters of _Cercopithecus_. The species of this genus are known as Mangabeys, or White-eyelid Monkeys, and include _C. collaris_, _C. fuliginosus_, _C. æthiops_, and _C. albigena_; all being from West Africa.

_Cercopithecus._[682]—Muzzle more or less short; ischial callosities moderate; tail long; no talon to third lower molar. Build more slender than in _Macacus_. Confined to Africa.

The members of this and the last genus include those Monkeys which in their comparative slender build and length of tail make the nearest approach to the next subfamily. There are numerous species, among which the Green Monkey (_C. cullitrichus_), the Grivet (_C. griseo-viridis_), the Vervet (_C. lalandi_), the Pluto Monkey (_C. pluto_, Fig. 347). The Patas (_C. ruber_), the Diana Monkey (_C. diana_), and the Mona Monkey (_C. mona_) are well-known types.

Subfamily =Semnopithecinæ=.[683]—Pelvic limbs longer than the pectoral, tail very long; no cheek-pouches; stomach sacculated. Build slender.

[Illustration: FIG. 347.—The Pluto Monkey (_Cercopithecus pluto_). From Gray, _Proc. Zool. Soc._ 1848, p. 57.]

This subfamily is represented by three genera, of which one is African and two are Asiatic. Mr. W. T. Blanford, in his _Mammals of British India_, observes that “the members of this subfamily are readily distinguished by their slender form, and by the absence of cheek-pouches. They are more purely herbivorous than the Macaque Monkeys, and a considerable portion of their food consists of leaves and young shoots. In consequence probably of the nature of their food, these Monkeys are more delicate than the species of _Macacus_, and are thus less easily kept in captivity. They are consequently far less well represented in European museums, and have been less studied by European naturalists. Very little is known of their general life-history or of their feeding habits.”

Their digestive organs are much modified, the stomach attaining an extraordinary complexity, which may be described as follows. An ordinary stomach must be supposed to lie immensely elongated, and gradually tapering from the cardiac end to a very prolonged, narrow, pyloric extremity. Then two longitudinal muscular bands, corresponding in situation to the greater and lesser curvatures of an ordinary stomach—the former commencing just below the fundus, and the latter at the cardiac orifice, and both proceeding towards the pylorus—are developed, so as to pucker up the cavity into a number of pouches, exactly in the same principle as the human colon is puckered up by its three longitudinal bands. These pouches are largest and most strongly marked at the œsophageal end, and becoming less and less distinct, quite cease several inches before the pylorus is reached, the last part of the organ being a simple smooth-walled tube. The fundus, or cardiac end of the stomach, is formed by a single large sac, slightly constricted on its under surface by the prolongation of the interior longitudinal band, or that corresponding to the great curvature. The œsophagus enters into the upper part of the left, or pyloric end of this sac, or rather at the point of junction between it and the second (also a very large) sacculus. Furthermore, the whole of this elongated sacculated organ is, by the brevity, as it were, of the lesser curvature, coiled upon itself in an irregularly spiral manner, so that when _in situ_ the pylorus comes to be placed very near the œsophageal entrance.

[Illustration: FIG. 348.—Lateral view of the skull and palatal aspect of the cranium of _Semnopithecus nemæus_. (From De Blainville.)]

_Nasalis._[684]—Skull resembling that of the _Cercopithecinæ_ in that the lower border of the nasal bones extends considerably below the lower border of the orbits, whereas in the other _Semnopithecinæ_ the aperture of the nares extends upwards between the orbits. Nose produced into a large proboscis. Other characters as in _Semnopithecus_.

This genus includes only the Proboscis Monkey (_N. larratus_) of Borneo, remarkable for the great prolongation of the nose in the adult. In young animals the nose is relatively much shorter, and bent upwards after the manner of that of _Semnopithecus roxellanæ_ (Fig. 349).

[Illustration: FIG. 349.—_Semnopithecus roxellanæ._ (From Milne-Edwards, _Recherches des Mammifères_, pl. 36.)]

_Semnopithecus._[685]—Pollex small; narial aperture extending upwards between the orbits. Now confined to Asia.

This genus is characteristic of South-Eastern Asia from the Himalaya southwards, the Oriental region being its headquarters. The development of the muzzle is less than in the Macaques, and the facial angle is higher, but it does not appear that this indicates greater intellectual capacity. The outlying _S. roxellanæ_[686] (Fig. 349), of the highlands of Eastern Tibet and Kansu, is remarkable for the peculiar upturned nose, in which respect, as already mentioned, it recalls the young of _Nasalis larvatus_. The genus is represented in India and Burma by no less than fourteen species, of which the common Indian Langur, or Hanuman Monkey (_S. entellus_) and the larger Himalayan Langur (_S. schistaceus_) are two of the best known. In the former the length of the head and body is about 24, and that of the tail 38 inches in adult males. This monkey, owing to the veneration in which it is held by the Hindus, is a great pest in many parts of India, frequently pilfering grain from the shops in the native bazaars. According to Mr. Blanford, it “is usually found in smaller or larger communities, composed of individuals of both sexes and of all ages, the youngest clinging to their mothers and being carried by them, especially when alarmed. An old male is occasionally found solitary, as with so many other mammals.... Apart from villages, the high trees on the banks of streams or of tanks, and, in parts of Central India, rocky hills are the favourite haunts of these monkeys. Whether on trees, on rocks, or on the ground, they are exceedingly active.” The closely allied _S. schistaceus_ attains a larger average size, full grown males attaining a length of 30 inches, the tail measuring 36 inches. In the spring and winter this species may be observed in the Kashmir Himalaya leaping among the snow-laden trees of the forest. In a fossil state _Semnopithecus_ occurs in the Pleistocene and Pliocene of India, and it has also been recorded from the Pliocene of France and Italy.

_Colobus._[687]—This African genus differs from _Semnopithecus_ in that the pollex is absent or reduced to a small tubercle, which may or may not carry a nail. About eleven species have been described, some of which are remarkable for the beautiful mantle of long silky hair which hangs down from each side of the body, and for their tufted tails. In _C. guereza_ from Abyssinia these are white, and the rest of the body and limbs black. Others (as _C. satanas_) are entirely black. The skins of the long-haired species are largely imported into Europe for the manufacture of ladies’ muffs, etc.

_Extinct Genera._—Certain types of Apes from the European Tertiaries indicate genera referable to the _Cercopithecidæ_, but distinct from any of those now living. Of these _Mesopithecus_,[688] from the Lower Pliocene Pikermi beds of Attica, is known by almost complete skeletons, and resembles _Macacus_ in the shortness and stoutness of the limbs, but agrees with _Semnopithecus_ in the characters of the skull and teeth. An allied Monkey from the Lower Pliocene of Perpignan, in France, differs from _Mesopithecus pentelici_ by its superior size, proportionately more produced muzzle, and larger hind talon to the last lower molar; it has been described under the name of _Dolichopithecus_.[689]

The genus _Oreopithecus_[690] was founded upon the remains of an Ape from the Middle Miocene of Monte Bamboli, in Tuscany, of somewhat larger size than a Gibbon, and apparently presenting characters connecting the _Cercopithecidæ_ and _Simiidæ_. According to Dr. Ristori,[691] it resembles the former, especially _Cynocephalus_ and _Semnopithecus_, in the long dental series and the elongation of the last molars; but in the shortness of the face, rounding of the chin, and the diagonal arrangement of the molar tubercles, it approximates to the _Simiidæ_, of which it may have been an ancestral type.

_Family_ SIMIIDÆ.

Crowns of molars relatively wide, with the angles more or less rounded off, the tubercles not forming transverse ridges, and the last lower molar without a hind talon. No tail. No cheek-pouches. Ischiatic callosities, if present, small. Pectoral limbs much longer than pelvic. Sternum broad. Cæcum with vermiform appendage. Centrale of carpus sometimes absent. Other characters as in _Cercopithecidæ_.

This family contains the true Anthropoid Old World Apes, namely the Gibbons, Orangs, Chimpanzees, and Gorillas, which are the most highly organised of all the Apes, and thus make the nearest approach to Man.

_Hylobates._[692]—Skull not produced at the vertex; body and limbs slender, the pectoral limbs being so elongated that the hands reach the ground when walking upright; hallux well developed; a centrale in the carpus; and small ischiatic callosities. Size smaller than in the following genera, the height of the largest species (_H. syndactylus_) not much exceeding 3 feet. Now confined to Asia.

The Gibbons, or Long-armed Apes (Figs. 350, 351), are readily distinguished from the remaining members of the family by the characters given above, as well as by the circumstance that they are the only Apes which habitually walk in an upright position. It is in these animals that we meet with the last traces of the ischial callosities so largely developed in the _Cercopithecidæ_. The species are now restricted to South-Eastern Asia, being especially abundant in the Malay Archipelago and adjacent regions.

The largest species is the Sumatran Siamang (_H. syndactylus_), which attains a height of 3 feet, and has been generically separated by some writers as _Siamanga_. It is remarkable as having a better developed chin and wider sternum than any other Ape, and differs from the other members of the genus by the circumstance that the second and third digits of the pes are united by skin as far as their last joints. Exclusive of this species, the Gibbons differ but little from one another in size and general conformation, and since the colour of individuals undoubtedly referable to a single species is remarkably variable, there is much uncertainty about the number of species, and much confusion in the nomenclature. Among well-marked species we may mention the Hoolock (_H. hoolock_), ranging from the South of Assam through Sylhet and Cachar to the Irawadi Valley near Bhamo, the White-handed Gibbon (_H. lar_, Fig. 350), which is found in Tenasserim and throughout Malayana, the Dun-coloured Gibbon (_H. entelloides_, Fig. 351) of Malayana, and the Tufted Gibbon (_H. pileatus_) of Siam and Cambogia.

[Illustration: FIG. 350.—The White-handed Gibbon (_Hylobates lar_). From Blanford, _Mammals of British India_, p. 8.]

The following account of the habits of the Gibbons is taken from Mr. W. T. Blanford’s _Mammals of British India_. “Gibbons are thoroughly arboreal, and Hoolocks are almost, if not entirely, confined to hill-forest. They move chiefly by means of their long arms, by which they swing themselves for prodigious distances from branch to branch and from tree to tree. They descend hillsides at a surprising pace, their descent being accomplished by grasping bamboos or branches that bend beneath their weight, and allow them to drop until they can seize the ends of other bamboos or branches lower on the slope, and take another mighty swing downwards. They also ascend with great rapidity, swinging themselves from tree to tree. When walking on the ground the Hoolock rests on its hind feet alone, with the sole flat on the ground, and the great toe widely separated from the other digits. The arms are usually held upwards, sometimes horizontally, their great length giving the animal a very peculiar aspect. Gibbons walk rather quickly, with a waddling gait, and can easily be overtaken by men when on the ground. The food of these Apes consists of fruit, leaves, young shoots, spiders (of which they are very fond), insects, birds’ eggs, and almost certainly of young birds, if not of any birds they can capture. Anderson found that small birds were killed and devoured by Hoolocks in confinement with a method and eagerness that showed this prey to be the natural food of the Apes. The Hoolock drinks with its lips, putting its head down to the water as Monkeys do. All species of _Hylobates_ have a powerful voice, and the common name of the Hoolock is taken from its peculiar double call, which is repeated several times. At a distance the sound much resembles a human voice; it is a peculiar wailing note, audible from afar, and in the countries inhabited by these animals is one of the most familiar forest sounds. The calls commence at daybreak, and are continued till 9 or 10 A.M., several of the flock joining in the cry, like hounds giving tongue. After 9 or 10 o’clock in the morning the animals feed or rest, and remain silent throughout the middle of the day, but recommence calling towards evening, though to a less extent than in the earlier part of the day.”

[Illustration: FIG. 351.—The Dun-coloured Gibbon (_Hylobates entelloides_). From _Archiv. du Muséum_, vol. ii. pl. 29.]

The skull of the Gibbons, although agreeing with that of other Apes in its prognathism, presents a somewhat human appearance, and the molar teeth are also very like diminutive human molars. In the anterior inward inclination of the two series of cheek-teeth and the inward position of the upper premolars the Gibbons make an approach to the human type unknown in other Apes.

The figure of the liver of one species of this genus is introduced to show the general absence of lateral fissures and the small size of the caudate lobe (_c_) characteristic of the liver of all the _Simiidæ_, except _Gorilla_ (see p. 706), as well as that of Man. Another specimen of the liver of the same species showed scarcely any trace of a caudate lobe.

[Illustration: FIG. 352.—Under surface of the liver of _Hylobates lar._ _u_, Umbilical fissure; _p_, portal fissure; _vc_, vena cava; _l_, left lobe; _r_, right lobe; _s_, Spigelian lobe; _c_, caudate lobe; _g_, gall-bladder.]

A fossil Ape from the Middle Miocene of France, originally described as _Pliopithecus_, indicates an extinct Gibbon which does not appear to be generically separable from _Hylobates_.

_Simia._[693]—Skull (Fig. 353) produced at the vertex; body and limbs massive; the pectoral limbs reaching to the ankle; a centrale in the carpus; hallux very small; sixteen dorso-lumbar vertebræ, and twelve pairs of ribs; no ischiatic callosities. Oriental.

[Illustration: FIG. 353.—Side view of the skull of adult Orang (_Simia satyrus_). From _Trans. Zool. Soc._ vol. i. pl. 53.]

This genus includes the large red-haired Apes from Sumatra and Borneo commonly known as Orangs, or Orang-Utans,[694] of which there is probably only a single species (_S. satyrus_). These animals inhabit the swampy forests near the coasts; and the males attain a height of about 4 feet 4 inches. The body is very bulky and the legs exceedingly short, but the arms are very long, reaching in the erect posture down to the ankles. The Orang walks resting on the knuckles of the hands and the outer sides of the feet, with the soles of the latter turned mainly inwards, as in Fig. 354. Its movements appear to be slow and deliberate, and in those specimens which have been kept in captivity in this country the demeanour is languid and melancholy, although this is far from being the case with those shown in the more congenial climate of the Zoological Gardens at Calcutta. The habits of these animals are arboreal, and they build a kind of shelter or nest of boughs and leaves; their food appears to consist mainly of fruits, and is exclusively of a vegetable nature. The whole of the body is clothed with long hair of a reddish-brown colour, and full-grown males have a well developed beard; the males not unfrequently also develop a large warty protuberance, formed of fibro-cellular tissue, on either side of the face. The hands are long, and are characterised by the small size of the pollex, which does not reach to the end of the metacarpal of the index finger. The feet have a similar structure, the hallux only reaching to the middle of the proximal phalange of the adjacent toe, and being often destitute not only of a nail, but likewise of the terminal phalange. The presence of a centrale in the carpus is a feature in which _Simia_ agrees with _Hylobates_ and the lower Apes, and differs from the two following genera and Man. With very rare exceptions the number of dorso-lumbar vertebræ is sixteen, of which twelve carry ribs, and therefore belong to the dorsal series, while the remaining four are lumbar. The distinction between the last lumbar and the first sacral vertebræ is clearly marked in young skeletons by the additional pleurapophysial ossifications (sacral ribs) in the transverse processes of the latter. Thus though _Simia_ presents a closer resemblance to Man than does _Anthropopithecus_ in the number of ribs, it differs in the more important characters of that of the whole series of trunk-vertebræ.[695] The hemispheres of the brain are much convoluted; the whole brain being more human-like than in any other Ape. The larynx is remarkable for having a prolongation from each ventricle, which in the adult become of enormous dimensions, and unite in front of the trachea to form one large sac extending downwards between the muscles to the axilla.

[Illustration: FIG. 354.—The Orang-Utan (_Simia satyrus_). From Mr. Wolf’s sketch at the Zoological Gardens.]

The skull of the Orang (Fig. 353) is characterised by its highly vaulted cranial portion, which is comparatively short (brachycephalic). The sagittal crest is well developed on the vertex, and has a highly convex contour; the superciliary ridges are but moderately developed, and do not stand out in the prominent manner so characteristic of the Gorilla. The aperture of the nares in the skull is more pear-shaped than in the two following genera.

The canines of the male Orang attain a great development; and the molars are characterised by the complex structure of their cusps and the numerous rugosities on the crown surface. The outer border of the upper premolars is placed in the same line as that of the molars.

The broken canine tooth of a large Anthropoid Ape from the Lower Pliocene of the Siwalik Hills probably indicates the existence at that period of a species of _Simia_ in Northern India.

_Gorilla._[696]—Skull not produced at the vertex; body and limbs massive, the pectoral limb not reaching below the middle of the lower leg (Fig. 355); no centrale in the carpus: hallux well developed; seventeen dorso-lumbar vertebræ, of which thirteen carry ribs; no ischiatic callosities. Male much larger than female, and with very strongly marked cranial ridges, which are wanting in the latter. Mandibular symphysis long. Ethiopian.

The well-known Gorilla (Fig. 356), of which there seems to be only one species (_G. savagei_), is found in Western Equatorial Africa, chiefly or entirely in the district enclosed by the Cameroon and Congo rivers. It is the largest of all the Apes, its bulk considerably exceeding that of man, although from the shortness of the legs it appears never to attain a greater height than 5½ feet. The first introduction of this animal to the notice of zoologists was made in 1847 by Dr. Thomas Savage, but it was not fully known till many years later.

[Illustration: FIG. 355.—Skeleton of the Gorilla. (From De Blainville.)]

The skin of the Gorilla is entirely black, the hair being blackish, but turning more or less gray in old individuals. The arms reach down as far as the middle of the lower leg; while the pollex extends only a short distance beyond the base of the first phalange of the index finger, and the hallux reaches nearly as far as the distal extremity of the corresponding digit of the foot. The digits of both the hand and foot are united together by integument as far as the distal extremities of the first phalanges. The larynx has very capacious air-sacs, which meet in front of the trachea and communicate with the ventricles; and in advanced age these sacs may extend to the axilla. The ears are relatively small. The skull is of an elongated or dolichocephalic type; that of the adult male being characterised by the enormous development of the supraorbital ridges, which form a kind of penthouse over the eyes, and contribute to the peculiarly ferocious appearance of the animal. The sagittal crest is also very large. The canine teeth of the male are very large, and are inclined outwards in both jaws. In the cheek-teeth the upper premolars are of considerable antero-posterior extent, with their outer border placed in the same line as that of the molars; and the third upper molar is larger than either of the others.

[Illustration: FIG. 356.—The Gorilla (_Gorilla savagei_). From _Trans. Zool. Soc._ vol. iv. pl. 43.]

The posterior cervical vertebræ are characterised by the great height of their neural spines, which thus form a strong basis for the powerful cervical muscles supporting the massive skull. In some instances the fourth lumbar vertebra becomes ankylosed to the sacrum, as is occasionally found to be the case in some of the lower human races.

In the absence of a centrale to the carpus, and also in the number of the dorso-lumbar vertebræ, the present and following genus resemble man; although they both differ in having thirteen in place of twelve pairs of ribs.

The brain of the Gorilla, according to Dr. Hartmann, resembles that of the Orang in the complexity of its convolutions, and is thereby distinguished from that of the Chimpanzee. In form it is of the long oval characteristic of Man; the brain of the Chimpanzee and Orang being more rounded.

Gorillas live in family parties in the depths of the dense forests of Western Equatorial Africa, seeking their food during the day, while at night it is said that the female and young ascend a tree at the foot of which the male sleeps. They walk with the backs of their closed hands and the flat soles of the feet placed on the ground. Although there has been much exaggeration on this point, it appears certain that the male Gorilla is an extremely ferocious and dangerous animal when brought to bay, but the statements as to its making unprovoked assaults on men do not appear authentic. They utter deep guttural sounds, which on some occasions may be described as grunts and at others as a roar.

_Anthropopithecus._[697]—One of the most important differences of this genus from the preceding is the absence of any marked disparity between the two sexes, either in the size or the conformation of the skull, although the male can always be distinguished by the larger size of the canine teeth. The mandibular symphysis is also much shorter. Differences in the characters of the teeth are described below. The genus is confined at the present day to the Ethiopian region.

The Chimpanzees (Fig. 357) inhabit Western and Central Equatorial Africa; and there has been much discussion whether they should all be included under one specific name (_A. troglodytes_), or whether there are really two or more species. A female specimen now living in the London Zoological Gardens, characterised among other distinctive features by the nearly bald head, clearly indicates, however, a second species, which probably corresponds to the imperfectly defined _A. calvus_ of Du Chaillu.

The region inhabited by the Chimpanzees extends from the Gambia to the Benguela, reaching as far inland as 28° E. long. The Common Chimpanzee is a smaller animal than the Gorilla, its height not exceeding 5 feet. In colour it is darker than the latter, and the ears are relatively larger. In the upright position the arms reach only a short distance below the knee, in which respect the Chimpanzee is more human-like than any of the other Apes. The face is furnished with distinct whiskers, eyebrows, and eyelashes. The pollex reaches nearly or quite to the base of the first phalange of the index finger, and the hallux to the base of the second phalange of the corresponding digit of the foot. The laryngeal sacs are as largely developed as in the Gorilla.

[Illustration: FIG. 357.—The Chimpanzee (_Anthropopithecus troglodytes_). From Mr. Wolf’s drawing of a young individual in the Zoological Society’s Gardens.]

Although the skull of the Chimpanzee has distinct superciliary ridges, yet the high bony crests of the calvarium of the male Gorilla are wanting, and the whole coronal region of the skull is more rounded and far less rugged.

The canine teeth of the male Chimpanzee are relatively much smaller than in the Gorilla and Orang. The upper molars are characterised by the third one being smaller than either of the other two, as well as by the presence of an indistinct cingulum on their inner surfaces. The upper premolars differ from those of the other genera of the family by the shortness of their antero-posterior diameter, and also by the larger size of their external as compared with their internal cusps; while the outer border of these teeth is placed internally to that of the upper molars. In all these respects the teeth of the Chimpanzee make a decided approximation to the human type.

Many young individuals of the Chimpanzee have been brought to Europe, but they appear to succumb sooner or later to the effects of an unsuitable climate. All these examples show that the disposition of this Ape is gentle, lively, and intelligent, and in all respects markedly opposite to that of the Orang. In a wild state these Apes are essentially forest-dwellers, and are more arboreal in their habits than the Gorilla. They live either in families, or in small parties of several families. Frequently at least they construct a kind of nest in the trees as a sleeping-place; the male being said to sleep on a forked branch below the level of this nest. In walking the Chimpanzee usually supports himself on the backs of his closed fingers, and either on the soles of the feet or on the closed toes.

From a distributional point of view the discovery of a fossil Ape in the Pliocene of the Punjab, apparently closely allied to the Chimpanzee, is of great interest. This determination rests upon the evidence of an imperfect palate originally described under the name of _Palæopithecus_, but subsequently referred to the present genus. The teeth of this jaw present all the essential characters of those of the Chimpanzee, but the two series of cheek-teeth have a slight anterior convergence, the premolars are shorter in the antero-posterior direction than is usually the case in that species, and the outer incisor is relatively narrower than in the latter. In these features the extinct _A. sivalensis_ makes a nearer approximation to the human type than is the case with its living congeners.

_Dryopithecus._[698]—The extinct _Dryopithecus_ of the Middle Miocene of France is represented by a single species of the approximate size of the Chimpanzee, and appears to be the most generalised member of the family. According to the recent observations of Professor Gaudry,[699] while it resembles the Gorilla in that the two series of lower cheek-teeth diverge anteriorly and the penultimate premolar is larger than the last of that series, it differs in having a much longer and narrower mandibular symphysis, and thus indicates a transition to the _Cercopithecidæ_. A gradual transition in the form of the mandible may, indeed, be traced from _Dryopithecus_, through _Gorilla_, to _Anthropopithecus_; the latter having a short and wide symphysis, with the two series of cheek-teeth slightly converging anteriorly, and the penultimate premolar being not larger than the last. In all these specialised characters the jaw of the Chimpanzee approximates to that of Man, in which the symphysis is still further shortened and widened, and the anterior convergence of the cheek-teeth so much increased as to produce a horse-shoe-like form in the whole dental series.

_Family_ HOMINIDÆ.

In the _Systema Naturæ_ of Linnæus Man was separated only generically from the Apes, but in the next great work which exercised a widespread influence over the progress of zoological science, the _Règne Animal_ of Cuvier, he forms a distinct order under the name of Bimana, the Monkeys and Lemurs being associated together as Quadrumana. This has been the prevailing arrangement in the zoological systems of the present century, though in the classification of Owen his position is still farther removed from that of the Monkeys, as in it the genus _Homo_ forms one of the four primary divisions or subclasses of the Mammalia, called Archencephala, the Quadrumana being united with the Carnivora, Ungulata, and others in another division called Gyrencephala. On the other hand, the tendency of most modern systematists, for reasons which have been fully stated by Professor Huxley,[700] is to revert towards the Linnæan position.

Considering solely the facts of Man’s bodily structure, it can be clearly demonstrated that the points in which he differs from the Ape most nearly resembling him are not of greater importance than those by which that Ape differs from other universally acknowledged members of the group; and therefore, in any natural system, if Man is to be made a subject of zoological classification upon the same principles as those applied elsewhere, he must be included in the order which comprises the Monkeys. We say upon the same principles as are applied elsewhere, since zoological classification has never taken into consideration the psychological characteristics which distinguish the subjects of its investigations, but only their tangible and physical structure, otherwise endless confusion would result, at all events with our very imperfect knowledge of animal psychology. The essential attributes which distinguish Man, and give him a perfectly isolated position among living creatures, are not to be found in his bodily structure, and should therefore either be left entirely out of consideration, or have such weight given to them as would remove him completely out of the region of zoological classification. To profess to classify Man as if he were one of the animals (as in all points of the structure and functions of his organs he undoubtedly is), to place him in the class Mammalia, and then to allow other considerations to influence the judgment as to the particular position he should occupy in the class, is most illogical.

Man, therefore, considered from a zoological point of view, must be included in the order Primates, even if the Lemurs be removed from it, since his structural affinities with the Monkeys are far closer than are those of the so-called “Half-Apes.” We may, without treading upon debatable ground, go farther, and say that the differences between Man and the Anthropoid Apes are really not so marked as those which separate the latter from the American Monkeys. This being admitted, perhaps the best exposition relating to the present condition of the order will be to regard Man as representing a fifth family of the Anthropoidea, which should be known as the _Hominidæ_. In thus ranking Man as one of the five principal families or sections of the suborder it should, however, be observed that this course does not in the least degree imply that such families are precisely equivalent to one another, or that the intervals by which they are separated are of equal importance; all that we commit ourselves to being that they are five perfectly distinct groups, all branches from a common stem, and in the present state of nature not united by any intermediate types.

The distinctions between the _Hominidæ_ and _Simiidæ_ are chiefly relative, being greater size of brain and of brain-case as compared with the facial portion of the skull, smaller development of the canine teeth of the males, complete adaptation of the structure of the vertebral column to the vertical position, greater length of the lower as compared with the upper extremities, and greater length of the hallux or great toe, with almost complete absence of the power of bringing it in opposition to the other four toes. The last feature together with the small size of the canine teeth are perhaps the most marked and easily defined distinctions that can be drawn between the two groups.

Man is universally admitted to form a single genus, _Homo_ of Linnæus, but a question of considerable importance in treating of him from a zoological point of view, and one which has been a subject of much controversy, is whether all men should be considered as belonging to a single or to several species. This question is perhaps of less importance now than formerly, when those who maintained a plurality of species associated with the hypothesis plurality of origin. One of the strongest arguments against the view that the various races of Man represent more than one species is that none of those who have maintained it have been able to agree as to how many distinct specific modifications can be defined, almost every number from three to twenty or more having been advocated by different authors. If the distinguishing characters of the so-called species had been so marked, there could not be such a remarkable diversity of opinion upon them. Again, the two facts—(1) that, however different the extremes of any two races may be in appearance (and it must be admitted that, as advocated by many polygenists, the differences are greater than many which are considered specific among other animals), every intermediate gradation can be found through which the one passes into the other, and (2) that all races are fertile _inter se_—are quite conclusive in favour of considering Man as representing a single species in the ordinary sense in which the word is now used, and of treating of all his various modifications as varieties or races.

The great problem at the root of all zoology, the discovery of a natural classification which shall be an expression of our knowledge of the real relationship or consanguinity of different forms, is also applicable to the study of the races of Man. When we can satisfactorily prove that any two of the known groups of mankind are descended from the same common stock, a point is gained. The more such points we have acquired the more nearly shall we be able to picture to ourselves, not only the present, but also the past distribution of the races of Man upon the earth, and the mode and order in which they have been derived from one another. But the difficulties in the way of applying zoological principles to the classification of Man are vastly greater than in the case of most animals. When groups of animals become so far differentiated from each other as to represent separate species, they remain isolated; they may break up into further subdivisions—in fact, it is only by further subdivision that new species can be formed; but it is of the very essence of species, as now universally understood by naturalists, that they cannot recombine, and so give rise to new forms. With the varieties of Man it is otherwise. They have never so far separated as to answer to the physiological definition of species. All races, as said above, are fertile with one another, though perhaps in different degrees. Hence new varieties have constantly been formed, not only by the segmentation of portions of one of the old stocks, but also by various combinations of those already established.

Without entering into the difficult question of the method of Man’s first appearance upon the world, we must assume for it vast antiquity,—at all events as measured by any historical standard. Of this there is now ample proof. During the long time Man existed in a savage state—a time compared to which the dawn of our historical period is as yesterday—he was influenced by the operation of those natural laws which have produced the variations seen in other regions of organic nature. The first Men may very probably have been all alike; but when spread over the face of the earth and subjected to all kinds of diverse external conditions,—climate, food, competition with members of their own species or with wild animals,—racial differences began slowly to be developed through the potency of various kinds of selection acting upon the slight variations which appeared in individuals in obedience to the tendency planted in all living things. These differences manifested themselves externally in the colour of the skin, the colour, quality, and distribution of the hair, the form of the head and features, and the proportions of the limbs, as well as in the general stature.

Geographical position must have been one of the main elements in determining the formation and permanence of races. Groups of Men isolated from their fellows for long periods, such as those living on small islands, to which their ancestors may have been accidentally drifted, would naturally, in course of time, develop a new type of features, of skull, of complexion, or hair. A slight set in one direction in any of these characters would constantly tend to intensify itself, and so new races would be formed. In the same way different intellectual or moral qualities would be gradually developed or transmitted in different groups of Men. The longer a race thus formed remained isolated the more strongly impressed and the more permanent would its characteristics become, and less liable to be changed or lost when the surrounding circumstances were altered or under a moderate amount of intermixture from other races—the more “true,” in fact, would it be. On the other hand, on large continental tracts, where no mountain ranges or other natural barriers form obstacles to free intercourse between tribe and tribe, there would always be a tendency towards uniformity, from the amalgamation of races brought into close relation by war or by commerce. Smaller or feebler races would be destroyed or absorbed by others impelled by superabundant population or other causes to spread beyond their original limits; or sometimes the conquering race would itself disappear by absorption into the conquered.

Thus for untold ages the history of Man has presented a shifting kaleidoscopic scene: new races gradually becoming differentiated out of the old elements, and, after dwelling a while upon the earth, becoming either suddenly annihilated or gradually merged into new combinations; a constant destruction and reconstruction; a constant tendency to separation and differentiation, and a tendency to combine again into a common uniformity—the two tendencies acting against and modifying each other. The history of these processes in former times, except in so far as they may be inferred from the present state of things, is a difficult study, owing to the scarcity of evidence. If we had any approach to a complete palæontological record, the history of Man could be reconstructed; but nothing of the kind is forthcoming. Evidence of the anatomical characters of Man as he lived on the earth during the time when the most striking racial characteristics were being developed, during the long ante-historic period in which the Negro, the Mongolian, and the Caucasian were being gradually fashioned into their respective types, is entirely wanting, or if any exists it is at present safely buried in the earth, perhaps to be revealed at some unexpected time and in some unforeseen manner. Even the materials from which a history of the modifications of the human species as known to our generation must be constructed are rapidly passing away, since the age in which we live is an age in which, in a far greater degree than any previous one, the destruction of races, both by annihilation and absorption, is going on. Owing to the rapid extension of maritime discovery and commerce, changes such as have never been witnessed before are now taking place in the ethnology of the world—changes especially affecting the island populations among which, more than elsewhere, the solution of many of those problems may be looked for. The subject is, however, attracting the attention of observers of all countries to a greater degree than it ever has before, and such progress has been made in perfecting the methods of investigation of racial characteristics that we are beginning to learn what lines of research are profitable and what are barren, so that we may hope the time is not far distant when we may get some clear insight into the knowledge of the natural classification and relationships of the races of Man.

The following is a brief summary of the principal results which appear to have been attained up to the present time by the study of this somewhat difficult subject.[701]

The most ordinary observation is sufficient to demonstrate the fact that certain groups of men are strongly marked from others by definite characters common to all members of the group, and transmitted regularly to their descendants by the laws of inheritance. Thus the Chinaman and the Negro, the native of Patagonia and the Andaman Islander, are as structurally distinct from each other as are many of the so-called species of any natural group of animals. Indeed, it may be said with truth that their differences are even greater than those which mark the groups called genera by many naturalists of the present day. Nevertheless the difficulty of parcelling out all the individuals composing the human species into certain definite groups, and of saying of each man that he belongs to one or other of such groups, is insuperable. No such classification has ever been, or, indeed, can ever be obtained. There is not one of the most characteristic and most extreme forms, like those just named, from which transitions cannot be traced by almost imperceptible gradations to any of the other equally characteristic and equally extreme forms. Indeed, a large proportion of mankind is made up, not of extreme or typical, but of more or less generalised or intermediate forms, the relative numbers of which are continually increasing, as the long-existing isolation of nations and races breaks down under the ever-extending intercommunication characteristic of the period in which we live.

The difficulties of framing a natural classification of Man, or one really representing the relationship of the various minor groups to each other, are well exemplified by a study of the numerous attempts which have been made from the time of Linnæus and Blumenbach onwards. Even in the first step of establishing certain primary groups of equivalent rank there has been no accord. Thus four primitive types were sketched out by Linnæus—the European, Asiatic, African, and American. These were expanded into five by Blumenbach by the addition of the Malay,[702] and reduced by Cuvier to three by the suppression of the last two. Many later writers have largely increased the number of these so-called primary divisions, but the conclusion, so often arrived at by various anthropologists, and so often abandoned for some more complex system, that the primitive man, whatever he may have been, has in the course of ages divaricated into three extreme types, represented by the Caucasian of Europe, the Mongolian of Asia, and the Ethiopian of Africa, and that all existing individuals of the species can be ranged around these types, or somewhere or other between them, seems, on the whole, to give the clearest view of the facts of the case. Large numbers are doubtless the descendants of direct crosses in varying proportions between well-established extreme forms; for, notwithstanding opposite views formerly held by some authors on this subject, there is now abundant evidence of the wholesale production of new races in this way. Others may be the descendants of the primitive stock before the strongly marked existing distinctions had taken place, and therefore present, though from a different cause from the last, equally generalised characters. In these cases it can only be by most carefully examining and balancing all characters, however minute, and finding out in what direction the preponderance lies, that a place can be assigned to them. It cannot be too often insisted on that the various groups of mankind, owing to their probable unity of origin, the great variability of individuals, and the possibility of all degrees of intermixture of races at remote or recent periods of the history of the species, have so much in common that it is extremely difficult to find distinctive characters capable of strict definition by which they may be differentiated. It is more by the preponderance of certain characters in a large number of members of a group, than by the exclusive or even constant possession of these characters in each of its members, that the group as a whole must be characterised.

Bearing these principles in mind, we may endeavour to formulate, as far as they have as yet been worked out, the distinctive features of the typical members of each of the three great divisions, and then show into what subordinate groups each of them seems to be divided.

We begin with the Ethiopian, Negroid, or Melanian, or “black” type. It is characterised by a dark, often nearly black, complexion; black hair, of a kind called “frizzly” or, incorrectly, “woolly,” _i.e._ each hair is closely rolled up on itself, a condition always associated with a more or less flattened or elliptical transverse section; a moderate or scanty development of beard, an almost invariably dolichocephalic skull; small and moderately retreating jugal bones (mesopic face); a very broad and flat nose, platyrhine in the skeleton; moderate or low orbits; prominent eyes; thick, everted lips; prognathous jaws; large teeth (macrodont); a narrow pelvis (index in the male 90 to 100); a long forearm (humero-radial index 80); and certain other proportions of the body and limbs which are being gradually worked out, and reduced to numerical expression as material for so doing accumulates.

The most characteristic examples of the second great type, the Mongolian or Xanthous, or “yellow,” have a yellow or brownish complexion; black coarse straight hair, without any tendency to curl, and nearly round in section; on all other parts of the surface except the scalp scanty and late in appearing; a skull of variable form, mostly mesocephalic (though extremes both of dolichocephalism and brachycephalism are found in certain groups of this type); a broad and flat face, with prominent, anteriorly-projecting jugal bones (platyopic face); nose small, mesorhine or leptorhine; orbits high and round, with very little development of glabella or supraciliary ridges; eyes sunken, and with the aperture between the lids narrow; in the most typical members of the group with a vertical fold of skin over the inner canthus, and with the outer angle slightly elevated; jaws mesognathous; teeth of moderate size (mesodont). The proportions of the limbs and form of the pelvis have yet to be worked out, the results at present obtained showing great diversity among different individuals of what appear to be well-marked races of the group, but this is perhaps due to the insufficient number of individuals as yet examined with accuracy.

The last type, which, for want of a better name, we must still call by the misleading one that has the priority, Caucasian, or “white,” has usually a light-complexioned skin (although in some, in so far aberrant cases, it is as dark as in the Negroes); hair fair or black, soft, straight, or wavy, in section intermediate between the flattened and cylindrical form; beard fully developed; form of cranium variable, mostly mesocephalic; jugal bones retreating; face narrow and projecting in the middle line (pro-opic); orbits moderate; nose narrow and prominent (leptorhine); jaws orthognathous; teeth small (microdont); pelvis broad (pelvic index of male 80); forearm short, relatively to humerus (humero-radial index 74).

In endeavouring to subdivide into minor groups the numerous and variously-modified individuals which cluster around one or other of these great types—a process quite necessary for many practical or descriptive purposes—the distinctions afforded by the study of physical characters are often so slight that it becomes necessary to take other considerations into account, among which geographical distribution and language hold an important place.

I. The Ethiopian or Negroid races may be primarily arranged as follows:—

A. African or Typical Negroes.—Inhabitants of all the central portion of the African continent, from the Atlantic on the west to the Indian Ocean on the east, greatly mixed all along their northern frontier with Hamitic and Semitic Melanochroi, a mixture which, taking place in various proportions and under varied conditions, has given rise to many of the numerous races and tribes inhabiting the Sudan.

A branch of the African Negroes are the Bantu—distinguished chiefly, if not entirely, by the structure of their language. Physically indistinguishable from the other negroes with whom they come in contact in the Equatorial regions of Africa, the Southern Bantu, or Kaffirs, as they are generally called, show a marked modification of type, being lighter in colour, having a larger cranial capacity, less marked prognathism, and smaller teeth. Some of these changes are probably due to crossing with other races.

B. The Negrillos—diminutive sub-brachycephalic tribes, inhabiting the dense forests of Central and Western Equatorial Africa—represent a distinct section of the Negro race. They form the only exceptions to the general dolichocephaly of the African branch of the Negroid division, and when found in a pure state are the smallest of all known human races, averaging scarcely more than 4 feet in height. The colour of their skin is yellowish rather than black.

C. The Bushmen (Bosjesmen, men of the woods, of the Dutch colonists of South Africa) constitute a very distinct modification of the Negro type. The hair shows the extreme of the frizzly character; being shorter and less abundant than that of the ordinary Negro, it has the appearance of growing in separate tufts, which coil up together into rounded balls compared to “peppercorns.” In their yellow complexion, wide cheek-bones, and peculiar form of the eyes they so much resemble some of the Mongolian races that anthropologists have been inclined to trace affinities to or admixture with them, although the character of the hair makes such a supposition almost inadmissible. The width of the cheek-bones and the narrowness of the forehead and chin give a lozenge shape to the front view of the face. The forehead is prominent and straight; the nose extremely flat and broad, more so than in any other race; the lips prominent and thick, although the jaws are less prognathous than in the true Negro races. The cranium has many special characters by which it can be easily distinguished from that of any other race. The average height of the males is about 4 feet 8 inches. There is every reason to believe that the Bushmen represent the earliest race of which we have any knowledge inhabiting the southern part of the African continent, but that long before the advent of Europeans upon the scene they had been invaded from the north by Negro tribes, who, being superior in size, strength, and civilisation, had taken possession of the greater part of their territories, and, mingling freely with the aborigines, had produced the mixed race called Hottentots, who retained the culture and settled pastoral habits of the Negroes, with many of the physical features of the Bushmen. These in their turn, encroached upon by the Kaffirs from the north and by Europeans from the south, are now greatly diminished, and threatened with the same fate which will surely soon befall the scanty remnant of the early inhabitants who still retain their primitive type.

D. Oceanic Negroes or Melanesians.—These include the Papuans of New Guinea and the majority of the inhabitants of the islands of the Western Pacific, and form also a substratum of the population, greatly mixed with other races, of regions extending far beyond the present centre of their area of distribution.

They are represented, in what may be called a hypertypical form, by the extremely dolichocephalic Kai Colos, or mountaineers of the interior of the Fiji Islands, although the coast population of the same group has lost the distinctive characters by crossing. In many parts of New Guinea and the great chain of islands extending eastwards and southwards ending with New Caledonia they are found in a more or less pure condition, especially in the interior and more inaccessible portions of the islands, almost each of which shows special modifications of the type recognisable in details of structure. Taken altogether, their chief physical distinction from the African Negroes lies in the fact that the glabella and supraorbital ridges are generally well developed in the males, whereas in Africans this region is usually smooth and flat. The nose also, especially in the northern part of their geographical range, New Guinea, and the neighbouring islands, is narrower (often mesorhine) and prominent. The cranium is generally higher and narrower. It is, however, possible to find African and Melanesian skulls quite alike in essential characters.

The now extinct inhabitants of Tasmania were probably pure, but aberrant, members of the Melanesian group, which had undergone a modification from the original type, not by mixture with other races, but in consequence of long isolation, during which special characters had been gradually developed. Lying completely out of the track of all civilisation and commerce, even of the most primitive kind, they were little liable to be subject to the influence of any other race; and there is in fact nothing among their characters which could be accounted for in the way above suggested, as they were intensely, even exaggeratedly, Negroid in the form of nose, projection of mouth, and size of teeth, typically so in character of hair, and aberrant chiefly in the width of the skull in the parietal region. A cross with any of the Polynesian or Malay races sufficiently strong to produce this would, in all probability, have also left some traces on other parts of their organisation.

On the other hand, in many parts of the Melanesian region there are distinct evidences of large admixture with Negrito, Malay, and Polynesian elements in varying proportions, producing numerous physical modifications. In many of the inhabitants of the great island of New Guinea itself and of the islands lying around it this mixture can be traced. In the people of Micronesia in the north and New Zealand in the south, although the Melanesian element is present, it is completely overlaid by the Polynesian, but there are probably few, if any, of the islands of the Pacific in which it does not form some factor in the composite character of the natives.

The inhabitants of the continent of Australia have long been a puzzle to ethnologists. Of Negroid complexion, features, and skeletal characters, yet without the characteristic frizzly hair, their position has been one of great difficulty to determine. They have, in fact, been a stumbling-block in the way of every system proposed. The solution, supported by many considerations too lengthy to enter into here, appears to lie in the supposition that they are not a distinct race at all, that is, not a homogeneous group formed by the gradual modification of one of the primitive stocks, but rather a cross between two already-formed branches of these stocks. According to this view, Australia was originally peopled with frizzly-haired Melanesians, such as those who still do, or did before the European invasion, dwell in the smaller islands which surround the north, east, and southern portions of the continent, but that a strong infusion of some other race, probably a low form of Caucasian Melanochroi, such as that which still inhabits the interior of the southern parts of India, has spread throughout the land from the north-west, and produced a modification of the physical characters, especially of the hair. This influence did not extend across Bass’s Straits into Tasmania, where, as just said, the Melanesian element remained in its purity. It is more strongly marked in the northern and central parts of Australia than on many portions of the southern and western coasts, where the lowness of type and more curly hair, sometimes closely approaching to frizzly, show a stronger retention of the Melanesian element. If the evidence should prove sufficiently strong to establish this view of the origin of the Australian natives, it will no longer be correct to speak of a primitive Australian, or even Australoid, race or type, or look for traces of the former existence of such a race anywhere out of their own land. Absolute proof of the origin of any race is, however, very difficult, if not impossible, to obtain, and there is nothing to exclude the possibility of the Australians being mainly the direct descendants of a very primitive human type, from which the frizzly-haired Negroes may be an offset. This character of hair is probably a specialisation, for it seems very unlikely that it was the attribute of the common ancestors of the human race.

E. The fourth branch of the Negroid race consists of the diminutive round-headed people called Negritos, still found in a pure or unmixed state in the Andaman Islands, and forming a substratum of the population, though now greatly mixed with invading races, especially Malays, in the Philippines, and many of the islands of the Indo-Malayan Archipelago, and of some parts of the southern portion of the mainland of Asia. They also contribute to the varied population of New Guinea, where they appear to merge into the taller, longer-headed, and longer-nosed Melanesians proper. They show in a very marked manner some of the most striking anatomical peculiarities of the Negro race, such as the frizzly hair, the proportions of the limbs, especially the humero-radial index, and the form of the pelvis; but they differ in many cranial and facial characters, both from the African Negroes on the one hand, and the typical Oceanic Negroes, or Melanesians, on the other, and thus form a very distinct and well-characterised group. Wherever they are still found they are obviously holding their own with difficulty, if not actually disappearing, and there is much about their condition of civilisation and the situations in which they occur to induce us to look upon them, as in the case of the Negrillos of Central and the Bushmen of South Africa, as the remains of a population which occupied the land before the incoming of the present dominant races.

II. The principal groups that can be arranged round the Mongolian type are as follows:—

A. The Eskimo appear to be a branch of the typical North Asiatic Mongols, who in their wanderings northwards and eastwards across the American continent, where they have been isolated almost as perfectly as an island population would be, hemmed in on one side by the eternal Polar ice, and on the other by hostile tribes of American Indians, with which they rarely, if ever, mingled, have gradually developed characters, most of which are strongly-expressed modifications of those seen in their allies who still remain on the western side of Behring Strait. It has also been shown that these special characteristics gradually increase from west to east, and are seen in their greatest perfection in the inhabitants of Greenland, at all events in those where no crossing with the Danes has taken place. A typical Eskimo skull presents a combination of characters by which it can be at once distinguished from that of any other of the groups of mankind. Such scanty remains as have yet been discovered of the earliest inhabitants of Europe do not present any structural affinities to this type, and there is therefore no justification for the supposition that they belonged to the same race, although it is not unlikely that similar external conditions may have led them to adopt similar modes of life.

B. The typical Mongolian races constitute the present population of Northern and Central Asia. They are not very distinctly, but still conveniently for descriptive purposes, divided into a Northern and a Southern group.

_a._ The members of the former, Mongolo-Altaic or Sibiric group, are united by the affinities of their language. These people, from the cradle of their race in the great plateau of Central Asia, have at various times poured out their hordes upon the lands lying to the west, and thence penetrated almost to the heart of Europe. The Lapps, Finns, the Magyars, and the Turks are each the descendants of one of these waves of incursion, but they have for so many generations intermingled with the peoples through whom they have passed in their migrations, or whom they have found in the countries in which they have ultimately settled, that their original physical characters have been completely modified. Even the Lapps, that diminutive tribe of nomads inhabiting the most northern parts of Europe, supposed to be of Mongolian descent, show so little of the special attributes of that branch that it is difficult to assign them a place in it in a classification based upon physical characters. The Japanese are said by their language to be allied rather to the Northern than to the following branch of the Mongolian stock.

_b._ The southern Mongolian or Sinitic group, divided from the former chiefly by language and habits of life, includes the greater part of the population of China, Tibet, Burma, and Siam.

C. The next great division of Mongoloid people is the Malay, forming the bulk of the population of the Indo-Malayan Archipelago and (mixed with the Negro) of Madagascar, subtypical it is true, but to which an easy transition can be traced from the most characteristic members of the type.

D. The brown Polynesians, Malayo-Polynesians, Mahoris, Sawaioris, or Kanakas, as they have been variously called, seen in their greatest purity in the Samoan, Tongan, and Eastern Polynesian Islands, are still more modified, and possess less of the characteristic Mongolian features; but yet it is difficult to place them anywhere else in the system. The large infusion of the Melanesian element throughout the Pacific must never be forgotten in accounting for the characters of the people now inhabiting the islands—an element in many respects so diametrically opposite to the Mongolian that it would materially alter the characters, especially of the hair and beard, which has been with many authors a stumbling-block to the affiliation of the Polynesian with the Mongolian stock. This mixture is physically a fine one, and in some proportions produces a combination, as seen, for instance, in the Maories of New Zealand, which in all definable characters approaches quite as near, or nearer, to the Caucasian type than to either of the stocks from which it may be presumably derived. This resemblance has led some ethnologists to infer a real extension of the Caucasian element at some very early period into the Pacific Islands, and to look upon their inhabitants as the product of a mingling of all the three great types of men. Though this is a very plausible theory, it rests on little actual proof, since the combination of Mongolo-Malayan and Melanesian characters in different degrees, together with the local variations certain to arise in communities so isolated from each other and exposed to such varied conditions as the inhabitants of the Pacific Islands, would probably account for all the modifications observed among them.

E. The native population (before the changes wrought by the European conquest) of the great continent of America, excluding the Eskimo, present, considering the vast extent of the country they inhabit and the great differences of climate and other surrounding conditions, a remarkable similarity of essential characters with much diversity of detail.

The construction of the numerous American languages, of which as many as twelve hundred have been distinguished, is said to point to unity of origin, as, though widely different in many respects, they are all, or nearly all, constructed on the same general grammatical principle—that called _polysynthesis_—which differs from that of the languages of any of the Old World nations. The mental characteristics of all the American tribes have much that is in common, and the very different stages of culture to which they had attained at the time of the conquest, as that of the Incas and Aztecs and the hunting or fishing tribes of the north and south, which have been quoted as evidence of diversities of race, were not greater than those between different nations of Europe, as Gauls and Germans on the one hand, and Greeks and Romans on the other, in the time of Julius Cæsar. Yet all these were Aryans, and in treating the Americans as one race it is not intended to imply that they are more closely allied than the different Aryan peoples of Europe and Asia. The best argument that can be used for the unity of the American race—using the word in a broad sense—is the great difficulty of forming any natural divisions in it founded upon physical characters. Thus there is no difference throughout the whole continent in the important character of the hair, this being always straight and lank, long and abundant on the scalp, but sparse elsewhere. The colour of the skin, notwithstanding the enormous differences of climate under which many members of the group exist, varies but little. It is true that in the features and cranium certain special modifications prevail in different districts, but the same forms reappear at widely separated parts of the continent. Thus skulls almost undistinguishable from one another may be met with from Vancouver’s Island, from Peru, and from Patagonia.

Naturalists who have admitted but three primary types of the human species have always found a difficulty with the Americans, hesitating between placing them with the Mongolian or so-called “yellow” races, or elevating them to the rank of a primary group. Cuvier, indeed, does not seem to have been able to settle this point to his own satisfaction, and leaves it an open question. Although the large majority of Americans have in the special form of the nasal bones, leading to the characteristic high bridge of the nose of the living face, in the well-developed superciliary ridge and retreating forehead, characters which distinguish them from the typical Asiatic Mongol, yet in many other respects they resemble them so closely that, while still admitting the difficulties of the case, we are inclined to include them as aberrant members of the Mongolian type.[703] It is, however, quite open to any one adopting the Negro, Mongolian, and Caucasian groups as primary divisions to place the Americans apart as a fourth.

Now that the high antiquity of man in America—perhaps as high as that which he has in Europe—has been discovered, the puzzling problem, from which part of the Old World the people of America have sprung, has lost its significance. It is, indeed, quite as likely that the people of Asia may have been derived from America as the reverse. However this may be, the population of America, except at the extreme north, was, before the time of Columbus, practically isolated from the rest of the world. Such visits as those of the early Norsemen to the coasts of Greenland, Labrador, and Nova Scotia, or the occasional accidental stranding of a canoe containing survivors of a voyage across the Pacific or the Atlantic, can have had little appreciable effect upon the characteristics of the people. It is difficult, therefore, to look upon the anomalous and special characters of the American people as the effects of crossing, as was suggested in the case of the Australians—a consideration which gives more weight to the view of treating them as a distinct primary division.

III. The Caucasian, Eurafrican, or white division, includes the two groups called by Professor Huxley Xanthochroi and Melanochroi, which, though differing in colour of eyes and hair, agree so closely in all other anatomical characters, so far, at all events, as has at present been demonstrated, that it seems preferable to consider them both as modifications of one great type than as primary divisions of the species. Whatever their origin may have been, they are now intimately blended, though in different proportions, throughout the whole of the region of the earth they inhabit; and it is to the rapid extension of both branches of this race that the great changes now taking place in the ethnology of the world are mainly due.

A. The Xanthochroi, or blonde type, with fair hair, eyes, and complexion, chiefly inhabit Northern Europe (Scandinavia, Scotland, and North Germany), but, although much mixed with the next group, they also extend as far as Northern Africa and Afghanistan. Their mixture with Mongoloid people has given rise to the Lapps, Finns, and some of the tribes of Northern Siberia.

B. Melanochroi, with black hair and eyes, and skin of almost all shades from white to black. They comprise the great majority of the inhabitants of Southern Europe, Northern Africa, and South-West Asia, and consist mainly of the Aryan, Semitic, and Hamitic families. The Dravidians of India, the Veddahs of Ceylon, and probably the Ainos of Japan, and the Maoutze of China, also belong to this race, which may have contributed something to the mixed character of some tribes of Indo-China and the Polynesian Islands, and, as before said, have given at least the characters of the hair to the otherwise Negroid inhabitants of Australia. In Southern India they are largely mixed with a Negrito element, and in Africa, where their habitat becomes coterminous with that of the Negroes, numerous cross-races have sprung up between them all along the frontier line. The ancient Egyptians were nearly pure Melanochroi, though often showing in their features traces of their frequent intermarriages with their Ethiopian neighbours to the south. The Copts and fellahs of modern Egypt are their little-changed descendants.

In offering this scheme of classification of the varieties of the human species, it is not suggested that it is one universally accepted by anthropologists, or that it is likely to be final. Whatever care be bestowed upon the arrangement of already acquired details, or whatever judgment be shown in their due subordination one to another, the acquisition of new knowledge may at any time call for a complete or partial rearrangement of the system. The difficulties which encompass the subject have, indeed, been already indicated, and will be found abundantly illustrated in the writings of those authors who have specially devoted themselves to its elucidation.

_Bibliography._—P. Topinard, _Éléments d’Anthropologie Générale_, 1885; A. de Quatrefages, _Histoire Générale des Races Humaines_ (1. _Questions Générales_, 1887; 2. _Classification des Races Humaines_, 1889); Quatrefages and Hamy, _Crania Ethnica_ (1873-1879); D. G. Brinton, _Races and Peoples_, 1890.

FOOTNOTES

[1] Galton’s _South Africa_, p. 187.

[2] L. F. E. Rousseau, _Anatomie comparée du Système dentaire chez l’Homme et chez les principaux Animaux_, 2d ed., 1839; F. Cuvier, _Des Dents des Mammifères considérées comme caractères zoologiques_, 1822-25; R. Owen, _Odontography_, 1840-45; C. G. Giebel, _Odontographie_, 1855; C. S. Tomes, _Manual of Dental Anatomy, Human and Comparative_, 3d ed., 1889.

[3] The lower incisors of some species of Shrews are, however, said to become ankylosed to the jaw in adult age.

[4] The teeth of the extinct Dinosaurian reptile _Triceratops_ have two distinct roots, placed transversely to the axis of the jaws.

[5] This and other questions concerning the homologies, notation, and succession of the teeth of mammals are more fully developed in two memoirs by one of the present writers:—“Remarks on the Homologies and Notation of the Teeth of the Mammalia,” in the _Journal of Anatomy and Physiology_, vol. iii. p. 262, 1869; and “Notes on the First or Milk Dentition of the Mammalia,” in the _Trans. Odontological Society of Great Britain_, 1871. See also an important memoir by Oldfield Thomas on the “Homologies and Succession of the teeth in the Dasyuridæ,” _Phil. Trans._ 1887, pp. 443-462.

[6] By many writers the letters indicating the different kinds of teeth are printed in capitals, as _I_, _C_, _P_, and _M_; while very frequently the symbol _Pm_ is employed in place of _p_.

[7] According to Mr. G. E. Dobson there are four upper incisors in some of the _Soricidæ_.

[8] See for the principal modifications of the skeleton of the class, the large and beautifully illustrated _Ostéographie_ of De Blainville, 1835-54; the section devoted to the subject in Bronn’s _Klassen und Ordnungen des Thier-Reichs_, by Giebel, 1874-79; and _An Introduction to the Osteology of the Mammalia_, by W. H. Flower, 3d ed., 1885.

[9] This and many of the following figures in this chapter are taken from Flower’s _Osteology of the Mammalia_.

[10] For the sake of uniformity, in all the following descriptions of the vertebral column, the long axis of the body is supposed to be in the horizontal position.

[11] The opinion has recently been expressed by Baur that bone termed radiale in Fig. 17 is really a second centrale, and that the radiale is represented by a minute bone generally known as the radial sesamoid. The mammalian scaphoid is accordingly also regarded as a second centrale. In the same communication, Dr. Baur expresses his disbelief in the existence of remnants of a prepollex and of a seventh digit in mammals and other vertebrates. (See _Anat. Anzeiger_, vol. iv. pp. 49-52, 1889.)

[12] On the Præpollex and Præhallux, etc., _Proc. Zool. Soc._ 1889, pp. 259-262.

[13] Cope and Baur consider that the astragalus corresponds only with the intermedium, and that the tibiale may exist as a distinct element.

[14] For further details of these modifications, see Flower’s “Lectures on the Comparative Anatomy of the Organs of Digestion of the Mammalia,” _Medical Times and Gazette_, Feb.-Dec. 1872.

[15] G. Gulliver, _Proc. Zool. Soc._, 1862, p. 91.

[16] The modifications of these bones are fully described by A. Doran, “Morphology of the Mammalian _Ossicula auditus_,” _Trans. Linn. Soc._ ser. 2, vol. i. pp. 371-497, pl. lviii.-lxiv. (1878).

[17] See B. H. Caldwell—“The Embryology of Monotremata and Marsupialia,” _Phil. Trans._ for 1887, p. 463.

[18] _Proc. Acad. Nat. Sci. Philadelphia_, 1881, p. 468.

[19] “_Studien ueber Entwickelungeschichte der Thiere_,” pt. 4, Wiesbaden, 1886.

[20] _Journal of Morphology_, vol. i. p. 373 (1887).

[21] For a full exposition of the present state of knowledge on this subject, see the various memoirs of Sir William Turner, also F. M. Balfour’s _Treatise on Comparative Embryology_, vol. ii. (1881), and J. A. Ryder in _American Naturalist_, vol. xxi. p. 780 (1887).

[22] _Proceedings of the Royal Society of London_, vol. xxviii. p. 395 (1879).

[23] “The Relations between the Theromorphous Reptiles and the Monotreme Mammalia,” _Proceedings of the American Association for the Advancement of Science_, vol. xxxiii. p. 471 (1885).

[24] “On the Phylogenetic Arrangement of the Sauropsida,” _Journal of Morphology_, vol. i. pp. 93-104 (1887).

[25] The names of the groups containing only extinct forms are printed in heavier type than those which contain species still existing.

[26] On this subject see A. Murray, _Geographical Distribution of Mammals_, 1866; and especially A. R. Wallace, _The Geographical Distribution of Animals_, 2 vols., 1876, and _Island Life_, 1881; also A. Heilprin, _The Geographical and Geological Distribution of Animals_, 1887.

[27] _Distribution of Animals._

[28] Generally known, as _Hyomoschus_, but first described as an extinct form under the above name.

[29] The fore limb from S. Africa described as _Theriodesmus_, which appears to be mammalian, and may belong to _Tritylodon_.

[30] The subjects referred to under this heading are mostly described and figured in detail in Owen’s “Monograph of the Fossil Mammalia of the Mesozoic Formations,” _Palæontographical Society’s Publications_, 1871; and in various papers by Marsh, in the _American Journal of Science and Arts_, 1878-89. Important contributions to our knowledge of these forms have also been made by Professors Cope and Osborn, and the reader should especially consult the memoir by the latter writer on the “Structure and Affinities of the Mesozoic Mammals,” published in the _Journal of the Philadelphia Academy_ (1888), vol. ix.

[31] The whole discussion is contained in the following memoirs: (1) H. Falconer, “Description of Two Species of the Fossil Mammalian genus _Plagiaulax_, from Purbeck,” _Quart. Journ. Geol. Soc._ vol. xiv. 1857; (2) R. Owen, art. “Palæontology,” _Encyclopædia Britannica_, 8th ed., 1859; (3) H. Falconer, “On the Disputed affinity of the Mammalian genus _Plagiaulax_,” _Quart. Journ. Geol. Soc._ vol. xviii. 1862; (4) R. Owen, “Monograph of the Fossil Mammalia of the Mesozoic Formation,” _Palæontographical Society_, 1871.

[32] Blumenbach, _Voigts Magazin_, vol. ii. p. 205 (1800).

[33] _Proceedings of the Royal Society of London_, vol. xliii. p. 353 (1888).

[34] _Ibid._ vol. xlvi. p. 126 (1889).

[35] Cuvier, _Tableau Élémentaire d’Hist. Nat._ p. 143 (1798).

[36] Gervais, _Ostéographie des Monotremes_, p. 43 (1877).

[37] For the detailed characters of all the genera and species of Marsupials the reader should consult the British Museum _Catalogue of Marsupialia and Monotremata_, by Oldfield Thomas, 1888.

[38] Except in _Petaurus (Belideus) breviceps_ (Forbes, _Proc. Zool. Soc._ 1881, p. 188).

[39] Including the transitional Austro-Malayan region.

[40] Illiger, _Prod. Syst. Mamm. et Aves_, p. 76 (1811).

[41] Linn. _Syst. Nat._ Ed. 12, vol. i. p. 71 (1766).

[42] Temminck, _Monographies de Mammalogie_, vol. i. p. 60 (1827).

[43] F. Cuvier, _Hist. Nat. des Mammifères_, iv. (1837).

[44] Geoffroy, _Bull. Soc. Philom._ vol. i. p. 106 (1796).

[45] Temminck, _Monographies de Mammalogie_, vol. i. p. 56 (1827).

[46] Thomas, _Ann. Mus. Genov._ sér. 2, vol. iv. p. 503 (1887).

[47] Krefft, _Proc. Zool. Soc._ 1866, p. 434.

[48] Waterhouse, _Proc. Zool. Soc._ 1836, p. 69.

[49] Geoffroy, _Bull. Soc. Philom._ vol. iii. p. 249 (1803).

[50] Grey, in _Grey’s Australia_, vol. ii, p. 401 (1841).

[51] Ogilby, _Proc. Zool. Soc._ 1838, p. 25.

[52] Geoffroy, _Ann. du Muséum_, vol. ii. p. 365 (1803).

[53] Owen, _Phil. Trans._ 1872, p. 257.

[54] Gervais and Verraux, _Proc. Zool. Soc._ 1842, p. 1.

[55] Storr, _Prodromus Meth. Mamm._ p. 33 (1780). Syn. _Phalangista_, Geoffroy, _Bull. Soc. Philom._ vol i. p. 106 (1796).

[56] Lesson, _Dict. Class. d’Hist. Nat._ vol. xiii. p. 333 (1828).

[57] Ogilby, _Proc. Zool. Soc._ 1836, p. 26.

[58] Thomas, _Cat. Marsupials Brit. Mus._ p. 163 (1888).

[59] Gray, _Proc. Zool. Soc._ 1858, p. 109.

[60] Shaw, _Naturalist’s Miscellany_, vol. ii. pl. lx. (1791).

[61] M’Coy, _Ann. Mag. N. H._ (3) xx. p. 287 (1867).

[62] Grey, in _Grey’s Australia_, appendix, vol. ii. p. 407 (1841).

[63] Peters, _Ann. Mus. Genov._ vol. vi. p. 303 (1874).

[64] Desmarest, _Nouv. Dict. d’Hist. Nat._ sér. 2, vol. xxv. p. 405 (1817).

[65] _Cf._ W. A. Forbes, “Anatomy of the Koala,” _Proc. Zool. Soc._ 1881, p. 180.

[66] Blainville, _Bull. Soc. Philom._ 1816, p. 116.

[67] Owen, in _Gervais’s Zool. et Pal. françaises_, 1st ed. pt. i. p. 192 (1849-52).

[68] Ramsay, _Proc. Linn. Soc. N. S. Wales_, vol. i. p. 33 (1876).

[69] De Vis, _Proc. Roy. Soc. Queensland_, ser. 2, vol. iii. p. 8 (1888).

[70] Desmarest, _Nouv. Dict. d’Hist. Nat._ sér. 1, vol. xxiv. _Table Méth._ p. 20 (1804). Syn. _Hypsiprymnus_, Illiger, _Prodromus Syst. Mamm._ p. 79 (1811).

[71] Gray, _Charlesworth’s Mag. Nat. Hist._ vol. i. p. 584 (1837).

[72] Thomas, _Cat. Marsup. Brit. Mus._ p. 114 (1888).

[73] Garrod, _Proc. Zool. Soc._ 1875, p. 59.

[74] Thomas, _Proc. Zool. Soc._ 1886, p. 544.

[75] Schlegel and Müller, _Verh. Nat. Ges. Nederland_, p. 138 (1839-44).

[76] Schlegel and Müller, _Verh. Nat. Ges. Nederland_, p. 130 (1839-44).

[77] Gould, _Monograph of Macropodidæ_, pl. xiii. (1841).

[78] Grey, in _Grey’s Australia_, vol. ii. appendix, p. 402 (1841).

[79] Gray, _Charlesworth’s Mag. Nat. Hist._ vol. i. p. 583 (1837).

[80] Shaw, _Naturalist’s Miscellany_, vol. i. pl. xxxiii. (1790).

[81] For the characters of these species and the under-mentioned distinct genera, see Owen’s _Extinct Mammals of Australia_ (1877), and Lydekker’s _Catalogue of Fossil Mammalia in the British Museum_, pt. v. (1887).

[82] Owen, _Phil. Trans._ 1874, p. 264.

[83] Owen, _op. cit._ p. 788.

[84] Owen, _op. cit._ p. 797.

[85] Owen, in _Mitchell’s Eastern Australia_, 2d ed. vol. ii. p. 362 (1838).

[86] Owen, _Cat. Mamm. and Aves, Mus. R. Coll. Surgeons_, p. 314 (1845).

[87] The characters of the chief groups of the Eutheria here given are, in some measure, a fuller recapitulation of those already detailed in