The Cambridge Natural History Part 47

_Brachyteles_ is a little-known genus, connecting the last with the next genus. The under fur is woolly; the thumb is small or absent. The tail is naked below.

The Spider monkeys, _Ateles_ or Coaitas, have been described as {558} the most typically arboreal of American monkeys. The use of the prehensile tail can frequently be studied in living examples in the Zoological Society's Gardens. With this "fifth hand" the Monkey feels for a place to grasp, and securely twists its tail round, moving it with the greatest ease from point to point. When the tail is being thus used it is carried erect over the head. The fact that this genus possesses no functional thumb is thought to be a.s.sociated with the extreme perfection of its adaptability to an exclusively arboreal life. The hand without a thumb can act as an equally efficient hook for suspending the body; and what is useless in nature tends to disappear. These Monkeys have a wide range, extending from Mexico in the north to Uruguay in the south. There are ten species. The flesh of many Monkeys is eaten not only by natives but by Europeans; but the Spider Monkeys are said to furnish the most sapid food of all.

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FIG. 265.--Spider Monkey. _Ateles ater._ 1/12.

The Howling Monkeys, genus _Mycetes_, have also received the appropriate generic names of _Alouatta_ and _Stentor_. The former of these two names, indeed, is that which should properly be applied to the genus. But _Mycetes_ is perhaps better known. The "howling" is produced by saccular diverticula of the larynx, larger than those of other American Monkeys, such as _Ateles_, where, however, they are also developed. The hyoid bones, too, {559} are enormously enlarged and cavernous, while the jaw--in order to accommodate and protect these various structures--is unusually large and deep. The Howlers are furnished with a fully prehensile tail. The thumb is present. They are described as being the most hideous in aspect of the American Monkeys, and of the lowest intelligence, with which latter characteristic is a.s.sociated a less convoluted brain than in _Ateles_, for example. The noise produced by these Monkeys is audible for miles, and is said not to be due to emulation, _i.e._ not to be comparable to singing or talking, but to serve to intimidate their enemies. The story told of these and other Monkeys with prehensile tails, that they cross rivers by means of a bridge of intertwined Monkeys, is apparently devoid of truth. There are six species, which are Central and South American in range.

The Squirrel Monkeys, genus _Chrysothrix_, are small creatures with a long head, the occiput projecting. Their tail, though long, has no naked area at the extremity and is non-prehensile. It is a remarkable fact that the proportions of the cranium as compared with the face are greater, not only than in other Monkeys, but than in Man himself. The thumb is short, but not so short as in the Spider Monkeys. The cerebral hemispheres are very smooth; but, as already remarked, this is a matter of size, and not of low position in the series. It may appear at first sight that this statement contradicts the one made concerning the Howlers. But the latter are large Monkeys, and therefore ought, so to speak, to have a more complex brain; but they have not. Like so many of the American Monkeys, the Squirrel Monkeys are gregarious, and, in spite of their tails, arboreal. They are largely insect-feeders, and also catch small birds and devour eggs. There are four species, of which _C. sciurea_ is the commonest, and is constantly an inmate of the Zoological Society's Gardens. Humboldt a.s.serted of it that when vexed its eyes filled with tears; but Darwin did not succeed in seeing this very human expression of an emotion.

_Callithrix_ is a genus not far removed from the last, and, like it, occurs both in Central and in South America. It is chiefly to be distinguished from _Chrysothrix_ by the non-extension backwards of the head, and by the more furry character of the tail. The lower jaw is rather deep, as in the Howlers; but there is not, or there has not been discovered, a howling apparatus like {560} that of _Mycetes_. Nevertheless Professor Weldon[432]

has found in a female of _C. gigot_ a patch of ossification on the thyroid cartilage of the larynx which may be an indication of something more in the male. There are eleven species.

_Nyctipithecus_, the Doroucouli Monkeys, is a genus of somewhat Lemurine appearance, caused by their large eyes. But they reminded Bates of an Owl or a Tiger-cat! They have a long, but not prehensile tail. As in the Marmosets, the lower incisors project forwards in a Lemurine fashion. The thumb is very short. A peculiarity of this genus is the twenty-two dorso-lumbar vertebrae. As in _Chrysothrix_, but not as in _Callithrix_, the hemispheres of the brain are smooth. There are five species, of which one occurs so far north as Nicaragua; the rest are Brazilian, extending down to the Argentine.

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FIG. 266.--Red-faced Ouakari. _Brachyurus rubicundus._ 1/5.

The Ouakari Monkeys, _Brachyurus_,[433] are, as the name denotes, short-tailed forms. Two species, _B. rubicundus_ and _B. calvus_, have bright red faces; _B. melanocephalus_ has a black one. There is a small thumb. The brain is fairly convoluted, and is to be specially compared with that of _Cebus_ and _Pithecia_. The {561} species _B. rubicundus_ at any rate has an absolutely as well as a relatively greater length of intestines and caec.u.m than any other American Monkey known.

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FIG. 267.--White-nosed Saki. _Pithecia albinasa._ 1/5. (From _Nature_.)

Not the least remarkable fact about these Ouakari Monkeys is their distribution in South America. We cannot do better than quote the summary given by Messrs. P. L. and W. L. Sclater in their _Geography of Mammals_, which is as follows: "Each of them, as first shown by Bates and afterwards further explained by Forbes, is limited to a comparatively small tract of forest on the banks of the Amazon and its affluents. The Black-headed Ouakari (_B. melanocephalus_) ... is met with only in a tract {562} traversed by the Rio Negro; the Bald-headed Ouakari appears to be confined to the triangle formed by the union of the Amazon with another affluent, the j.a.pura; and the Red Ouakari to the forests on the north bank of the Amazon opposite Olivenca, and lying between the main stream and the River Ica. Each of them evidently takes the place of the others in its particular district. Of this peculiar kind of distribution few instances are known amongst mammals, but many somewhat similar cases have been observed in birds, reptiles, and insects."

The genus _Pithecia_, the Sakis, consists of five species with long bushy tails, which are non-prehensile. They are bearded and have a thumb. Like the last genus, _Pithecia_ does not extend into Central America. The incisors project forwards, and the lower jaw is deep, though the howling apparatus of _Mycetes_ is wanting. The thin, closely-set, and projecting incisors are very suggestive of those of the Lemurs. _Brachyurus_ is much like _Pithecia_ in this respect, and both differ markedly from such a genus as _Cebus_, where the lower incisors are vertical. An anatomical peculiarity of _Pithecia_ is the breadth of the ribs. _P. satanas_ is perhaps the best-known species, but all five have been exhibited at the Zoological Society's Gardens. As its name suggests, _P. satanas_ is entirely black; it shows a curious point of difference from _P.

cheiropotes_ in its way of drinking. The latter species, as its name denotes, uses its hand to drink, while _P. satanas_ puts its mouth to the water. _P. albinasa_ is black with a red patch on the nose, within which again is a small white patch.

GROUP II. _CATARRHINA._

The Catarrhine Apes are divisible into three or perhaps only two families, the Cercopithecidae and the Simiidae, to which must be added the Hominidae.

The Simiidae are sometimes spoken of as the Anthropoid Apes.

FAM. 1. CERCOPITHECIDAE.--Of the Cercopithecidae there are eight genera (perhaps nine) to be recognised, which may be distributed into two sub-families. The first of these two sub-families, that of the CERCOPITHECINAE, has the following characters:--There are cheek pouches in which the animals store food temporarily. {563} The stomach is simple and globular; this corresponds with a mixed diet. The tail is long or short, or practically absent.

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FIG. 268.--Tcheli Monkey. _Macacus tcheliensis._ 1/6. (From _Nature_.)

The most familiar genus is undoubtedly _Macacus_. This includes all the common so-called Macaques, the Bonnet Monkey, the Pig-tailed Monkey, etc.

In this genus we find that the males are larger than the females, and have stronger canine teeth. Ischial callosities are well developed. The genus is purely Asiatic, reaching as far east as j.a.pan, with the exception of the Barbary Ape, _M. inuus_, also known as the Gibraltar Ape. There are altogether some seventeen species.

_Macacus inuus_ is doubtfully indigenous to Gibraltar. It is, however, definitely established there at present, and is carefully fostered. It is a large Ape with no external tail, in which {564} particular it is unique among the members of its genus. At one time its extinction on the "Rock"

was nearly accomplished, but three individuals being known. In 1893 the Governor of Gibraltar informed Mr. Sclater that he had himself counted as many as thirty in one herd. Its depredations seem to have led to the expression of a wish in some quarters that the numbers should be thinned; but feeling on the opposite side appears to be stronger, so that whatever was the actual mode of its introduction on to the "Rock" it will at any rate remain there unmolested for the present.

_M. tcheliensis_ is a species found in the Yung-ling Mountains in North China. It is, with the possible exception of _M. speciosus_, the most northerly form of Monkey. It is interesting on account of the fact that like the Tiger of those regions it has put on an extra coating of fur to enable it to combat with the bitter winters. It is doubtful whether it is more than a variety of the Rhesus Monkey (_M. rhesus_).

_M. nemestrinus_, "the Pig-tailed Macaque," is trained by the natives of the east to climb cocoa-nut palms and to carefully select and throw down only the ripe fruit. Sir Stamford Raffles apparently was the first to report upon this useful intelligence of the animal, and Dr. Charles Hose of Borneo has confirmed him.

The j.a.panese Macaque (_M. speciosus_) is well known from the work of j.a.panese artists. It is the only species of Monkey found in j.a.pan, and goes very far north.

A rather rare form is _M. leoninus_. It has a short tail, and occurs in Burmah. _M. silenus_ is distinguished by a ruff of long light-coloured hair surrounding the face. It is sometimes called the Wanderoo; but this is apparently quite inaccurate, since that term is used by the Ceylonese for a _Semnopithecus_. For those who wish a "pseudo-vernacular" name Dr. Blanford suggests Pennant's name of "Lion-tailed Monkey."

The commonest species of the genus are _M. cynomolgus_, _M. sinicus_, and _M. rhesus_.

The genus _Cercocebus_, including those Monkeys known as Mangabeys, is confined to West Africa. They have always a long tail, quite as long as the body. The upper eyelids are pure white in colour. The ischial callosities are more p.r.o.nounced than in the Macaques. In the Mangabeys also the hairs are not ringed with differently coloured bars, as is the case with both {565} Macaques and _Cercopithecus_, giving to them the greenish hue which characterises so many of the last two genera. There are no laryngeal air sacs as in the Macaques. There are not more than seven species.

The genus _Cercopithecus_ (the Guenons) represents in Africa the Oriental and Palaearctic Macaques; the genus has a long tail. The cheek pouches are larger than in the genus _Macacus_. The ischial callosities are less extensive than in that genus. A tooth character also distinguishes this genus from _Macacus_; the last molar of the lower jaw has, as a very general rule, only four cusps instead of the five which are found in _Macacus_. The supraciliary ridges in the skull are by no means so marked as in the allied genera.

One species, the Talapoin, _C. talapoin_, has been separated into a distinct genus, _Miopithecus_, on account of the fact that the lower molars have only three tubercles instead of the usual four. But if this be done, then _Cercopithecus moloneyi_, which has a lower molar with five tubercles, should also be separated.

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FIG. 269.--Diana Monkey. _Cercopithecus diana._ 1/6.

The genus _Cercopithecus_ is limited to Africa, and its numerous species have often a very limited range. They are frequently rather brightly coloured, with blue and white patches on the face. The Diana Monkey has a pointed white beard. Of the Vervet Monkey (_C. lalandii_) a curious fact was noticed at the Zoological {566} Society's Gardens a year or two back: the young was observed to take both teats of the mother into its mouth at once. Mr. Sclater[434] in a recent list of the group allows forty-seven species, of which thirty-three were examined by himself. Subsequently, however, the list has been reduced to forty by the same authority. One of the rarest species is _C. stairsi_, first described from a skin stripped from a specimen which lived for a short time at the Zoological Gardens.

The genus _Cynocephalus_ (or _Papio_) includes the Baboons; and the scientific name indicates the Dog-like aspect of these animals, due to the projecting snout. _Cynocephalus_ is confined to Africa and Arabia. Several of the species of the genus are well known. The Mandrill, _C. mormon_ (or _maimon_), has blue ridges on the muzzle, the bridge of the nose being red.

The animal lives in herds, and is ferocious and omnivorous. The Chacma Baboon, _C. porcarius_, is the largest of Baboons. It lives in South Africa in large herds. The Arabian Baboon, _C. hamadryas_, is the Sacred Baboon of the Egyptians. The names of two other species, _C. thoth_ and _C. anubis_, serve also to remind us of the ancient Egyptians. There are altogether eleven species of _Cynocephalus_.

_Gelada_ (or _Theropithecus_) is separated as a distinct genus. Though regarded as a Baboon, Garrod has pointed out many points of likeness to _Cercopithecus_.[435] The two species are, like the other Baboons, African.

_Cynopithecus niger_ is a small black Baboon from Celebes. It has swellings on the muzzle as in other Baboons, but differs from them in being a more amiable creature as well as in its smaller size. It has a rudimentary tail, smaller even than the small tail of the typical Baboons. It has, like them, ischial callosities.

In the second sub-family, SEMNOPITHECINAE, the following characters are distinctive:--All the Apes of this group are slender in form, with a long tail. There are no cheek pouches. The stomach is sacculated; it is divided into three portions. This is accompanied by an apparently more exclusively vegetarian diet than characterises other Apes, which mingle with their diet of fruit a large proportion of insects, eggs, etc. {567}

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FIG. 270.--Black Celebesian Ape. _Cynopithecus niger._ 1/5.

The first with which we shall deal is _Colobus_, containing the Monkeys known as Guerezas. These creatures are entirely confined to the African continent, and they are arboreal in habit. It has been attempted to show that their affinities are more with the Platyrrhines than with the group in which they are really to be placed. In favour of regarding them as nearer akin to the American monkeys are only two facts of importance: the first is the practical absence of the thumb, which of course recalls the condition characteristic of _Ateles_; in the second place, the nostrils in their wideness somewhat resemble those of the Platyrrhines. They are slender Monkeys with well-marked callosities. They have a complex sacculated stomach, resembling the large intestine of some other animals; it is not divided into distinct chambers like the stomach of a Ruminant or of a Whale. Correlated apparently with this large stomach is the small development of the cheek pouches. This genus, of which there are about ten species, is characterised by beautiful skins, which are largely collected.

The Arabs have a legend to the effect that one species, when wounded, and seeing its capture and the removal of its skin {568} inevitable, carefully tears the latter, that its captors may not profit by it. The species of this genus are most abundant on the west coast of Africa. It is interesting that one species, _C. kirki_, is limited to the Island of Zanzibar, where, however, it is nearly extinct.

The "Holy Apes," or Langurs, genus _Semnopithecus_, are allied to the last, but they are Asiatic in range. The thumb is better developed, but still shorter than in other Cercopithecidae; the callosities are small, and the cheek pouches are absent. There is a single large laryngeal sac, and the stomach is complex.

This genus is, like the Tiger, often quoted as an example of a race supposed to be characteristically tropical, existing habitually in the coldest climate. A species of _Semnopithecus_ has been observed climbing snow-laden branches at a height of 11,000 feet in the Himalayas. There are some thirty species, which extend as far east as Borneo.

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FIG. 271.--Entellus Monkey or Hanuman. _Semnopithecus entellus._ 1/6.

The name _Semnopithecus_ is derived from the fact that the Hanuman is regarded as sacred by the Hindus. The best-known species of _Semnopithecus_ is this Langur or Hanuman, _S. entellus_. Being regarded as a sacred animal, and with the advantage thus gained, it has become a fell nuisance in gardens and to crops. Though the veneration with which the Hindoos regard these animals will not allow them to slay them, they are exceedingly thankful to a European who will enable them to {569} commit a sin vicariously. This Ape has immense powers of leaping--a s.p.a.ce of 20 to 30 feet can be cleared by them if one side, that from which the leap is taken, be considerably higher than the other. They are useful to the Tiger hunter, as they follow and hoot at this, their deadly enemy. _S. schistaceus_ is a species which lives at great heights, not less than 5000 feet, in the Himalayas.

The genus _Nasalis_ is hardly separable from the genus _Semnopithecus_. It is a Bornean animal, and is distinguished by a comical long nose, which not only suggests, but goes beyond, the aquiline nose of the human species. It is no doubt on this account that the Borneans, unconsciously imitating our habit of comparing "natives" in general to Monkeys, call it by a name which signifies "white man." _Rhinopithecus_ has also a long, but a more definitely upturned nose.

FOSSIL MONKEYS.--Several of the existing genera of Old-World Apes are also known to have existed in past times; in some cases their past distribution indicates a greater range. Thus _Macacus_ is now represented--and that doubtfully--in Europe by the Barbary Ape alone. But from Montpellier have been unearthed the remains of _M. priscus_, from Pliocene beds. The Asiatic _Semnopithecus_ is known to have lived during the Pliocene period; its remains are discovered in France and Italy, as well as in Asia. In addition to these existing forms, a number of totally extinct Old-World genera are known. The rich formation at Pikermi near Athens has produced _Mesopithecus pentelici_; this Monkey has a skull which recalls that of _Semnopithecus_, while the stout limbs are rather Macaque-like. As is the case with many living Catarrhines, the males have stronger canines. The animal had a long tail.