Chapter X: The Monkeys of the New World.76 (1)

THE CEBIDÆ--THE HOWLERS--THE WOOLLY MONKEYS--THE SPIDER MONKEYS--THE SAJOUS.

The Monkeys of the New World--How Distinguished from those of
the Old--Their Division into Families--The First Family, THE
CEBIDÆ, with Prehensile Tails--THE HOWLERS--Appropriateness of
their Name--Where Found--General Description--THE YELLOW-TAILED
HOWLER--Anatomical Peculiarities and Appearance of the Face--Other
Members of the Family--THE BLACK HOWLER--Its Locality--THE
WOOLLY MONKEYS--THE CAPARRO AND BARRIGUDO--First noticed by
Humboldt--Peculiarities of the Skeleton--THE SPIDER MONKEYS--Seen
by Humboldt in the Brazilian Forests--Remarkable Power of the
Tail--Flexibility of the Limbs--Conformation of the Brain--Other
Species--THE COAITA--Curious Stories of them in Captivity--THE
CHAMECK--THE BLACK SPIDER MONKEY--Its Geographical Range--Its
Position in Sleep--THE VARIEGATED SPIDER MONKEY--THE SAJOUS--THE
CAIARÁRA--Observed by Bates on the Amazon--Other Varieties--THE
BROWN SAJOU--THE CAPUCHIN SAJOU--Described by Brehm--Their
Remarkable Dexterity and Cleverness--Diseases of Monkeys.

Not one of the numerous kinds of Monkeys which have been noticed in the former chapters has ever been found in the New World--that is to say, on the American continent. The converse is also true, for not one of those which are about to be noticed, and which inhabit the tropical parts of South and Central America, has been seen in any other part of the world.

The two groups are not only distinct as regards their geographical distribution, but they are also different in many very important points of their construction and habits. It is evident that, although it may be said that the resemblances between the Baboons, Macaques, and Troglodytes, for instance, indicate some kind of relationship, and suggest a community of origin, there is nothing of the sort to be traced between any Old and New World Monkeys. They seem to have started from different sources.

All the Monkeys of the New World have the partition between the nostrils broad, and it separates them widely: they open as it were sideways, and the whole of the lower part of the nose is flat. This peculiarity has given the name to the group, as has been explained in the first chapter, and it is accompanied by some others. Thus, with one exception, the numerous genera of the New World Monkeys have the hinder limbs the longest, and they are wont to go on all-fours, the erect posture being only occasionally adopted by the Spider Monkeys. Their thumbs differ less from the other fingers than do those of the Old World Monkeys, and the toe-thumb is large and movable; no cheek-pouches or callosities are seen in any of them, and only a few have air sacs. It is usual to say that the American Monkeys are known by their prehensile tails, but this is only true in part, for whilst some have this member wonderfully developed and useful, others have it incapable of holding on, whilst a few have barely a tail at all. The teeth are more numerous than in the Apes and Monkeys of the Old World, in one set of New World genera; and they are of the same number in another. In the first instance, there are thirty-six teeth instead of the thirty-two so frequently noticed hitherto, and in the last the thirty-two are differently arranged to those possessed by the Old World kinds. For example, in the prehensile-tailed Howlers, there are thirty-six teeth, or one extra tooth in each jaw and on both sides, over and above the usual thirty-two; and this tooth is a false molar, or one of those between the true grinders and the canine teeth. There are thus three false molars instead of two, as in the Old World kinds, on each side in both jaws.

In the Marmosets, which have only thirty-two teeth, there are only two back grinders in each jaw on each side instead of three, as in the Old World Monkeys, but there are three pre-molars in each jaw on each side. All these distinctions are useful in the classification of these American Monkeys, and therefore they have been divided into two families, one having thirty-six and the other thirty-two teeth, and the first family has again been subdivided into the genera with prehensile tails and those without them. The first to be described are the Cebidæ, and this family contains--first, the genera with thirty-six teeth and with prehensile tails; second, the genera without prehensile tails and the same number of teeth.

THE HOWLERS.[77]

Although articulate speech is denied to the Monkey world, many have very extraordinary voices, the capacity for making a noise being great in them. Thus, the Gorilla has a tremendous voice, and the Gibbons are especially noisy, one of them having been noticed (page 77) to be able to emit something like a series of musical notes. But they are all silent in comparison with the noisiest of all Monkeys--the South American Howlers. The females of this group can make a moderate amount of disturbance, but the males surpass every animal in their prolonged and sustained yelling. Their howlings, commencing often suddenly at the close of day or in the middle of the night, amongst the strange stillness of the great virgin forests, appal the traveller on his first visit. “Nothing,” says Waterton, speaking of the Red Howler, “can sound more dreadful than its nocturnal howlings. While lying in your hammock in those gloomy and immeasurable wilds you hear him howling at intervals from eleven o’clock at night till daybreak. You would suppose that half the wild beasts of the forest were collecting for the work of carnage. Now it is the tremendous roar of the Jaguar as he springs on his prey; now it changes to his deep-toned growlings as he is pressed on all sides by superior force; and now you hear his last dying moan beneath a mortal wound.” Humboldt and Bonpland landed at Cumana, and travelled towards the celebrated cavern of Guacharo, and they saw and heard the Howlers often; and on getting into a cold district their horrible din became worse, and was heard at a distance of two miles. This was near the convent of Caripé, which is more than 4,000 toises (a toise being rather more than our English fathom) above the sea, and where the nights are cold. The animal clearly has earned its appellation of the Howler, and might properly have been called Stentor, as was proposed by a distinguished French zoologist. Stentor was a Greek, whose voice was louder than that of fifty men. But Illiger, probably familiar with the writings of the learned Apuleius--that student of Carthage and Athens who married a rich Roman widow, and was therefore accused of witchcraft, and who wrote the “Golden Ass,” a book singularly applicable to modern society--called the Howler after the word _Mycetias_, an earthquake with a hollow bellowing noise. The word is from μύζω (to moan). An old writer (Margrave) wrote in his Natural History of Brazil, in 1648, that all the Howlers assembled in the morning and evening in the woods, and that one takes his place on a tree high up, and motions to his companions to sit down and listen, and then, after having seen them all seated, commences his discourse, pitched at so high a key that at a distance one would imagine that all the congregation were joining in. But this is not the case; only one orator is allowed to speak at a time, and all the rest wait politely, but not very patiently. When he has had enough howling he motions to the whole, who burst out into a fine chorus for some time. Then, by order, they all cease, and the first recommences, and after having been listened to with due attention the whole depart. What the noise must be sometimes, if they all join in, may be gleaned from the fact that Humboldt saw the trees crammed with them, and believed that more than 2,000 may be found in a square league.

It really does occur that when there is an assemblage of these Monkeys--for instance, of the _Mycetes Caraya_--when the weather is warm and open, they make the forests resound in the morning and evening with their overwhelming voices. The males begin the dreadful concert, in which the females, with their less powerful voices, sometimes join, and which is often continued for several hours. It does not appear that any especial cause induces them to begin their noise, and probably they do it because it pleases them, as the birds do in their prolonged songs. Mr. Darwin suggests very forcibly that the females are pleased or attracted by it, liking (as in higher animals) the loudest and most intolerable of the noise-makers best. Hence one Howler is, of course, always trying to outdo the others. But it is true that some Howlers live in pairs and indulge in their vocation all the same. Wallace, however, states that the females do not join in the noise, and that the howling is made before bad weather, and in the evening.

These Howlers are the largest of the Monkeys of the New World, some being nearly three feet in length, without counting the long prehensile tail; they have movable thumbs on their hands, a hairless space underneath the tip of the wonderful tail, and the howling apparatus in the throat.

They have rather tall heads, with beard and large lower jaws, which, with a thickness about the throat, give the appearance of an unusual swelling being there, the cause of which will be noticed further on. Some have long and others short fur, but generally there is much of it about the head (where it is brushed forwards) and neck. Black and red are favourite colours, and the young of both sexes differ often in their tints from the adults, and so do the males from the females. One kind in particular is decidedly coloured.

THE YELLOW-TAILED HOWLER.[78]

The last half of the tail of this species is of a brilliant golden-fawn colour, and this tint is on the upper parts of the body nearly up to the shoulders; the rest of the tail is light maroon, and what remains of the body is dark maroon, there being a violet tint in the limbs.

Besides its colours this kind presents some points of interest. They live in companies, and when they pass from one tree to another they all play at follow-my-leader exactly. They watch the movements of those which precede them, jump in the same manner, and at the same place, and even place their feet and hands on the same spots on the boughs. They are found in Columbia and New Granada, and in Brazil on the confines of Paraguay.

The limbs of all the Mycetes are long, and whilst there is a good toe-thumb to the foot, the very best of the hand-thumbs is not equal to those of the Monkeys of the Old World. The nails on the fingers and toes are compressed from side to side, as it were, and begin to look like claws.

Ogilby, an admirable observer, noticed years ago that two Howlers did not use their hands so as to take things between the thumb and forefinger, and he ascertained that this thumb was so much on a line with the other fingers that it was not opposable in the ordinary sense of the word, and that it was more like an extra finger than a thumb. This, he noticed, was not the case with the Howlers alone, but that it peculiarised the Monkeys of the New World. The examination of their skeletons shows that the bones of the thumb are on the same plane or level as the fingers, and the whole is brought close to the fingers, as our great toe is to the other toes. Nevertheless, this thumb can move to and from the fingers.

But if the fore-hand so greatly resembles a paw, compensation is made to the animal by the gift of the prehensile tail, which is very muscular, and the under surface is without hair near the end, so that the sensitive surface can touch and feel objects. They can feel, therefore, around them, and also above them, as they move along and lay hold of branches and hanging creepers without looking for them. The delicate sense of feeling depends on the nervous supply; and the power of clasping and holding on upon the bending or flexor muscles. A bony framework supports all these structures, and runs from the last bone of the sacrum to the tip, and consists of many separate vertebral bones placed in a long series. The first few bones which join on to the sacrum, and form the root of the tail, resemble the back-bone pieces, or vertebræ, to a certain extent. Each has a body, and also processes for jointing with the one before and behind, and a spine also. Besides these, there are two curious projections on the lower part of each body, which are called chevron bones, and are V-shaped, and their use is to allow the blood-vessels and nerves to pass along between them without being pressed upon. Towards the end of the tail the vertebræ become long and stout, and are united behind and in front, forming a broad bone, and without the joints, and the chevron bones are reduced to little rounded pieces of bone. Everything tends in this tail to ready, rapid, and forcible motion, and indeed so perfect an organ is it that when one of these Howlers is shot it always hangs to the tree by its tail, even if quite dead, and does not fall down until some hours afterwards, when the strong flexor muscles have relaxed. Therefore, writes a recent author, if fresh food is required, it is best to kill a Lagothrix (see page 171) in the Peruvian valleys, as hung meat soon becomes tainted. The Golden Howler, nevertheless, furnishes the principal animal food to the inhabitants of the banks of some of the rivers entering the Peruvian Amazon. They keep to the low lands and shores of the rivers, and are found moving from place to place in pairs.

(From the _Cyclopædia of Anatomy and Physiology._)]

The head of this and all other Howlers has a large black face, and a high receding forehead; the chin recedes much, and there is a great jowl produced by the large bones of the lower jaw. There is a curious swelling at the back of the orbit; and the part of that cavity for the eye which joins the cheek-bone has a round hole in it, as if it had been made by a gimlet. It has two nose or nasal bones, which remain separate, and the forehead (frontal) bone goes so far back that it joins the side (parietal) bones of the skull in a V-shaped suture, or union, and there is not much back to the brain-case, which is depressed in shape, on the whole. They are vegetarians, and yet have very decided canine teeth, those of the upper jaw being large, and they project downwards much lower than the other teeth; and the large lower jaw has evidently quite as much to do with the howling apparatus as with the teeth, for it opens out behind to admit of the great bone of the tongue moving readily within its boundaries.

This Howler, like all the others, has good lungs, and a windpipe ending, as usual, in the larynx and its thyroid cartilage (see page 22), as in other Monkeys. The bone at the base of the tongue (the hyoid) is attached to this cartilage, as usual, by a membrane, and instead of being a flat curved bone with two projections on each side, called horns, is swollen out into a bag shape, the horns being very small. The bone in other animals is at the base of the tongue, and this is the case in the present instance, although it is so large, the inside of the hollow being able to contain four cubic inches of water. Now, the air from the upper part of the windpipe can get into this cavity, as there is an opening between it and the upper part of the larynx. Hence the same noise is produced as if the animal howled into a resonant shell.

In order to strengthen the voice, the cartilage of the larynx itself is large and strong, and the so-called ventricles of it are enlarged into air sacs, and they unite in front of the “Adam’s apple.” Besides these there are other sacs connected with the gullet. So that the whole of the front and sides of the neck below and between the sides of the lower jaw are complicated by air sacs and resounding chambers. The breast-bone of the Howler differs in certain respects from that of all other Monkeys, for its upper bone (manubrium) is halved, and each half supports the end of the collar-bone and first rib. Possibly the resulting space may have something to do with the air sacs.

The possessor of these curious appendages, whatever Howler it may be, for all the species of the genus have them, is active enough in his woods, but still is a sad-looking animal, much given to crawling listlessly from branch to branch, and becoming melancholy in captivity. They have a surly disposition, are never to be made pets of, and are savage; while at the same time they show none of the lively play which makes the Spider Monkeys and little Sapajous so very amusing. Possibly their howling exhausts much of their nervous energy, and certainly their brains are peculiar. The back, or occipital part of the brain, does not cover the cerebellum, or little brain, which is large in proportion to the rest. The brain is small in comparison with those of the other American Monkeys, due allowance being made for the greater size of the Howler; and its surface markings or convolutions are few and simple.

There is much less brain-matter packed up in folds, or convolutions, than in most Monkeys, and some of the most important are wanting (the angular and external perpendicular), and it has a shrunken and contracted look. Everything shows a low condition of intelligence and mental power. The absence of so much brain-matter behind, so unusual amongst the Monkeys, has suggested to those who believe in phrenology that the bump of philo-progenitiveness was absolutely deficient in this species. But in spite of this, we find that the Howlers are kind to each other, and bring up their solitary little ones, teaching and feeding them with just the same amount of affection that all the other New World kinds display. So the love of offspring is not deficient; nevertheless, it may be assumed that the sameness of habits and the slight requirements of their lives render a more elaborate brain unnecessary.

Finally this and all the Howlers have the stomach a little disposed to be arranged as more than one single sac, and in this there is just the hint of the condition in the Semnopitheci of the Old World.

THE BLACK HOWLER.[79]

These Monkeys are called the Monos by the natives of Guatemala, and certainly deserve some other name than Howlers. Howling is a moderate noise in comparison with the loud, widely-heard yell which they can produce. The effect of these noises when produced by four or five animals trying their voices one against the other in the quiet forest is most remarkable and unpleasant. Salvin thus writes:--“The wonderful cry whence Mycetes gets its trivial name of Howling Monkey is certainly most striking, and I have sometimes endeavoured to ascertain how far this cry may be heard. It has taken me an hour or more to thread the forest undergrowth from the time the cry first struck my ear to where, guided by the cry above, I stood under the tree where the animals were. It would certainly not be over-estimating the distance to say two miles. When the sound came over the Lake of Yzabal unhindered by trees, a league would be more like the distance at which the Monos’ cry could be heard.”

The Monos are abundant throughout the forests of the eastern part of Guatemala, but are unknown in the forest-clad regions which stretch toward the Pacific Ocean. They are particularly plentiful in the unbroken forest country which occupies the northern part of Vera Paz, for seldom an hour passes without the weird outcry falling on the ear of the traveller even when at the height of 6,000 feet. At this height in a cold and damp region, where the forest trees are of the largest growth, these Howlers congregate in the upper branches of the highest trees. Living in small companies of five or six, they crawl sluggishly along the boughs when disturbed. It was from such a locality that those specimens of this species were found which are now in the British Museum. The animals afford a dark and not very nice meat, which is readily eaten by the Indians. The young as well as the females are of the same dense black colour as the old males, but the hair is shorter and not so glossy. All have the hair of the front part of the head long and soft, and inclined forward over the forehead nearly to the eyes. There are ten species of Howlers, and they are found in the forests covering the country from East Guatemala to Paraguay.

THE WOOLLY MONKEYS.[80]

Humboldt, in one of his geographical excursions amongst the great streams which feed the Orinoco, went far up towards their sources. Going once into an Indian cabin in those remote regions he saw a large Monkey, of a kind which he had never seen before. He named it, after the words of the natives, “The Caparro,” and from its having a peculiar furry skin which reminded him of the familiar hare-skin of home, he termed it Lagotriche, from λαγώς (a hare), and θρίξ, τριχός (hair, or fur), and thus arose the genus about to be described.

Humboldt’s new Monkey had a prehensile tail which was longer than the body, and underneath, close to the tip, there was a naked and sensitive spot of some length. It had a round and large head, a naked black face, but no beard. There were, however, smellers or long hairs around the mouth. It had long limbs and a shortish body, whose fur was long and sable-grey in colour. A good temper and a quiet disposition appeared to characterise this Monkey, and the natives said it was found in troops, and that it often stood upon its hind legs.

They have thumbs, as well shaped as those of any American Monkey, on the fore hands, as well as on the hinder extremities. They were deficient, however, in the howling apparatus, and therefore they differ from the Mycetes, and as their thumbs were noticed to be large, they differ from the next group of Monkeys, or the Spider Monkeys.

A careful examination of the skeleton shows that the outside differences are accompanied by inside ones, especially in the skeleton.

Thus, there are fourteen rib-bearing back-bones, or vertebræ, and this increase of number over the ordinary thirteen is interesting, because it makes the animal approach those lower than the Primates; then it has four loin vertebræ, and three are in the sacrum bone. There is a curious growth of the second vertebra of the neck or the axis, for its spine is trifid, and has three projections for the attachment of muscles. Finally, the long tail is very elaborate in its bony part, and seven of its bones near the root have so great a resemblance to the back-bones higher up in the body, that they have a canal like that which in the others protects the spinal marrow, which, however, does not reach further down than the lower loins. Then five of them have good strong spines, and all have the chevron or V-shaped bones underneath well grown.

This tail is quite as useful to the Lagothrix as it is to the Howlers and to the Spider Monkeys about to be considered, and they feel with, and swing and hold by it, to perfection.

The Caparro is about two feet two inches in length without the tail, and has been subsequently to its description by Humboldt called _Lagothrix Humboldtii_, or Humboldt’s Lagothrix.

THE BARRIGUDO.[81]

Bates says of this Monkey, that it is, with the rest of those found in the district of the Upper Amazon, arboreal and diurnal in its habits, and that it lives in troops, travelling from tree to tree, the mothers with the children on their backs; leading, in fact, a life similar to that of some Indians, and like them occasionally plundering the plantations which lie near their line of march. The Barrigudo is the “big-bellied Monkey” of the Portuguese colonists, and they are very bulky animals. They have the head clothed with grey, and they live with the Caparro mentioned above, in the same forests, and lead the same kind of life. One measured twenty-six inches in length, and the tail six, and it was the largest Monkey he saw in America, with the exception of a Black Howler, who was twenty-eight inches in length. The skin of the face of a Barrigudo is black and wrinkled, the forehead is low, and the eyebrows project; and, in short, the features resemble in a striking manner those of an old negro. It is not an active animal in the forests, and lives exclusively on fruits, but is much persecuted by the Indians on account of the excellence of its flesh as food. From information given to Mr. Bates he calculated that one troop of these Indians numbering about 200, destroyed 1,200 Monkeys a year for food. Consequently they are diminishing in numbers, and are not found on the Lower Amazon at all. Its manners in captivity are grave, and its temper is mild and confiding. Owing to these traits the Barrigudo is much sought after as a pet; but it is not hardy, and seldom survives a journey down the river.

There are five species of the Woolly Monkeys, and they are found in the valley of the Upper Amazon and along the slopes of the Andes to Venezuela and Bolivia (Wallace).

THE SPIDER MONKEYS--THE THUMBLESS MONKEYS OF AMERICA.[82]

Many early travellers recorded that during their wanderings by the sides of the rivers of the northern part of South America, and in the Isthmus of Panama, small troops of dark-coloured Monkeys could be seen rushing along amongst the trees, swinging under the branches, and feeding upon berries. Sometimes they would stop on the lower branches of the trees and look at the intruders; but usually they scampered off, swinging with their front limbs and clasping with the hinder, having their stout and long tail ready for emergencies. Their length of limb, slender bodies, long hair, and their long tail, by which they suspend themselves, and their extremely variable movements, soon gave them the name of Spider Monkeys amongst those interested in their habits, although, of course, the natives had some names of their own for them.

Humboldt saw them in the great virgin forests of Brazil, hanging in curious clusters, clasping each other by means of their limbs and tails, and all being suspended by the tail of one strong fellow. He was, as everybody must be, greatly impressed with their clever use of their tails, for he observed them being used as a fifth member, and with all the dexterity of hands. The natives will have it that they fish with their tails, but this is of course untrue, and they do not carry anything to their mouths with them. They are wonderful swingers and claspers, and they are exquisitely sensitive at the tip and for some inches underneath it, and they are stout where they join the body, exceedingly muscular, and in some kinds there are long hairs on them, especially near the end.

These Monkeys have small heads, long necks, and exceedingly long arms and legs; some are covered with a soft fur, and in others it is harsh, and the hairs are long and rigid; and all have the thumbs of the hands either absent or just visible as slight projections. The feet are long and have well-shaped toe-thumbs. Their head is round, and the muzzle only projects slightly, so that there is something human in their appearance, especially when their large eyes are open; and the hair in some kinds is brushed forwards on the cheeks and brows so as to resemble whiskers and front hair. There is something in their shape, without the tail, which reminds one of the Gibbons, those long-armed Apes of the East, and the fore-hands resemble those of the Colobi of Africa (page 100); but the Spider Monkeys have not the power of jumping possessed by these, and their hind legs, useful as they are when amidst the great trailing orchids and the climbers of the American tropics, are feeble members when on the ground. Then the Monkey walks on the outside edge of the feet, and on the inside edge of the hand, with its tail feeling here and there for anything to catch hold of. Often they are very sedate and slow in their movements, like the Semnopitheci of India, and they indulge in a series of climbings from bough to bough, swinging from one to the other, and holding on now and then and assisting in the movement with the tail. They are as gentle in their manners as those just mentioned, and are full of play with each other.

Their teeth resemble those of the Howlers, but the eye teeth, or canines, are smaller, and the crushing teeth, or molars, are rounder.

From the defective thumbs, all these Monkeys as a group or genus have been termed “imperfect-handed,” and therefore two Greek words which convey these terms ἀτελής (imperfect), and χείρ (the hand), have been conjoined in the word Atelochirus, of which Ateles is used as an abbreviation.

But on examining the hands carefully, and noticing the deep parts as well as the outside, it was found that they could be ranged into two sub-groups. In one there is no external appearance of a thumb, and in the other there is a stunted projection, but in both the member is not quite deficient so far as its bones are concerned. In the first group the metacarpal bone (the bone which is in man covered by the ball of the thumb, and which extends from the wrist to the first joint) is just seen, but it does not project; and in the second group there is one phalanx or thumb-bone on the metacarpal, and this sticks out and is covered with skin so as to resemble a hard pimple. In one kind this little thumb has no nail, and in another there is one on it.

It is curious that some of the woolly-haired kinds of Ateles should have no thumbs and others their rudiments; and that this should be the case in the long and harsh-haired kinds also. There are many kinds of Ateles, and there is consequently some difficulty in recognising them as species and many attempts have been made to classify them, so that they might be readily distinguished. Those with short and thick thumbs have been called Brachyteles, and those without them Ateles; those with woolly fur have been termed Eriodes, but all are now included in the genus Ateles.

Everybody is interested in seeing the curious sprawling swinging of the Ateles in the Zoological Gardens, and also in noticing the curious way in which some can place their hand right over the head nearly on to the opposite shoulder, and brush the hair with it forwards, and especially because both kinds of movement refer to the great length of the fore-limbs. On the contrary, although they can maintain the erect posture for a short time, they seem feeble about the hind limbs, which are shorter than the others. Their heel-bones are evidently short, so that leaping is never well done.

They are fruit and vegetable eaters, and enjoy eggs, and a nut occasionally, but they have no cheek-pouches. They have, however, an air-pouch, or sac, in front of the throat, but none of the noise-making gifts of the Howlers, and this sac enters the windpipe differently to those of the Monkeys of the Old World, and this is very curious. It opens into the windpipe below the cartilage which forms the “Adam’s apple” in man, and not above and between it and the tongue. Below this cartilage, which is called the thyroid cartilage, there is another attached to it by which it joins on to the rings of the windpipe. The opening is between this lower cartilage, the cricoid,[83] and the top ring of the windpipe.

Their stomach is single, and the large intestine, as they are vegetarians, is large, and its termination the “cæcum” also, but it has no little worm-like appendage as in the Gibbons. No especial points have been noted in the muscular system, except the very curious fact that, although the bones of the thumb are so rudimentary, the muscles are all there except the one which principally bends it forward.

As the activity of the Spider Monkey is marvellous, as they swing on and catch hold of boughs with great skill and energy, and as they display much intelligence, their brains ought to be well developed. Doubtless there is a great deal of movement in these long-limbed creatures which takes place like the walking of man, _i.e._, without direct thought, for we move our leg muscles, and all those which assist them in the act of walking, without a constant direction of the will. Just as man’s walking is thus said to be done automatically, so much of the swinging and progression of the Ateles is produced without direct exertion of the will. But it is evident that the Spider Monkey judges his distance, and very often considers whether such and such a bough will bear his weight, and uses exactly sufficient muscular exertion for what he requires.

Moreover, there is a graceful co-ordination or mutual action of the muscles of the limbs, body, and tail to a common end in most of its movements which is evidently done by will. The movements of the tail are perfectly wonderful, and, indeed, so perfectly does it hold on, although the animal cannot see what this long slender organ is doing, that most children think there is an eye at the end of it. Directly the Spider Monkey rises on its hind legs, up goes the tail straight behind its back, and curves a little at the tip downwards: the delicate hairs stick out and feel the slightest touch or passage of air; and the least touch induces the last few joints to clasp hold. The animal will walk along and catch hold of things with its tail at every other step or so, and will change its hold in exact proportion to its rate of progression. All these movements necessitate clasping, unclasping, twisting, and a regular succession of efforts, and are not likely to be carried out except by an animal with a well-developed nervous system. Hence it has been a matter of some interest to compare the brain of Ateles with those of other Monkeys, and even with that of man.

Even in this Monkey, which is low in the scale on account of its having badly-developed thumbs, the structures of the brain greatly resemble those of the Monkeys of the Old World. The nerves are large in proportion to the substance of the brain, and the brain proper is narrow in front and hollowed out beneath, where it rests on the orbits. But these proofs of a low kind of intelligence and of great muscular power are accompanied by structures which mimic or sketch out those of the human brain in an extraordinary manner. The cerebellum, or little brain, is large, as it is the organ which has much to do with regulating and co-ordinating the movements of the muscles, but it is quite covered by the back part, or posterior lobes, of the brain. Inside the brain the cavities called the ventricles may be seen, and they are made on the human plan, for the cavity on each side (lateral ventricle) has a front part, a back part, and a deep one, and on its lower surface, or floor, certain roundings, which are called by odd names, such as the hippocampus minor and the hippocampus major. These are visible in the brain of Ateles as they are in man. Now, it is very remarkable, allowing for the difference in the size of the brain of most other Monkeys and of man, that the Spider Monkey should have larger posterior lobes to its brain than they have. Moreover, this unusual size produces a greater length of the back part (or horn, or cornu) of the lateral ventricle in Ateles. The difference, however, between the packing of the nervous substance of the brain in man and in the Spider Monkey is vast, for in this last there are few convolutions, but the principal are happily said by Huxley to sketch out the position of the most important in the human brain. The projection of the back part of the brain of the Spider Monkeys over the cerebellum is at least one-tenth of an inch. Hence there is much nervous matter in the back part of the brain, and this compensates for the narrowing and diminution of nervous matter in the front. Are the nerves, then, which give the Spider Monkey its wonderful power of activity and complicated movement, situated in the back part of the head? At present physiologists have not satisfactorily shown what are the offices of these back or occipital lobes of the brain; the rounded floor of the cavity in the brain, which goes by the absurd name of hippocampus, because it is curved like a “sea horse,” and which is well seen in Ateles, has much to do with the sensation of touch, and the nervous matter at the sides of the brain appears to be connected with the nerves of the muscles of the limbs. The Ateles lead a life of very great sameness in their forests, and their perceptions and intelligence are never greatly stimulated, hence the fore part of the brain is small.

THE COAITA.[84]

This is the Monkey of which an extraordinary story is told by Acosta. It belonged to the Governor of Carthagena, and was regularly sent to the tavern for wine. They who sent him put an empty pot in one hand, and the money into the other, whereupon he went “spidering,” as Broderip terms it, to the tavern, where they could by no means get his money from him till they had filled his pot with wine. As the ganymede of the Governor came back with his charge, certain idle children would occasionally meet him in the street, and cast stones at him, whereupon he would put down his pot, and cast stones at them, till he had assured his way; then would he return to carry home the pot. And what is more, although he was a good bibber of wine, yet would he never touch it till leave was given to him. It is about as true as the account of the habits of the genus given by a distinguished French author. He says that they live in greater or smaller troops in the forests; their food consists of insects, and they also eat little fishes, mollusks (shellfish), and other animal substances. When they are a little way from the coast they sometimes come down to the beach by the sea-side and collect such things as oysters, and they get at the inside by breaking the shells between stones. Most of the species live far away from such luxuries, and one and all are vegetarians, as a rule, and eat an insect or suck an egg or two as the exception.

The Coaita, or Quata, is large for an Ateles, and is covered with long, coarse hair, of a glossy black colour, the under part at the groin being without any. The hair of the head is directed forwards, and conceals the ears, which have no lobe, and the face is of a reddish flesh-colour. It is an intelligent animal, and shows much curiosity when anything new is seen in its vicinity. All the agility of the genus is to be witnessed in its climbing and swinging from tree to tree; and it has no thumbs. They live in Surinam and in the Brazils. Bates, when living on the Lower Amazon, saw much of this Monkey, or Coaita, as he properly terms it. He describes it as a large black Monkey, covered with coarse hair, and having the prominent parts of the face of a tawny, flesh-coloured hue. Moreover, he found that the natives esteemed its flesh very much, and the military commandant of the place used to send out a hunter every week to shoot one for his table. “One day,” writes this author, “I went out on a Coaita hunt, borrowing a negro slave of a friend to show me the way. On the road I was much amused by the conversation of my companion. He was a tall, handsome negro, about forty years of age, with a staid, courteous demeanour, and a deliberate manner of speaking. He told me he was a native of Congo, and the son of a great chief, or king. He narrated the events of a great battle between his father’s and some other tribe, in which he was taken prisoner, and sold to the Portuguese slave-dealers. When in the deepest part of a ravine we heard a rustling sound in the trees overhead, and Manuel soon pointed out a Coaita to me. There was something human-like in its appearance, as the lean, dark, shaggy creature moved deliberately amongst the branches, at a great height. I fired, but only, unfortunately, wounded it in the belly. It fell with a crash headlong about twenty or thirty feet, and then caught a branch with its tail, and remained suspended in mid air. Before I could reload it recovered itself, and scrambled nimbly to the topmost branches, out of the reach of a fowling-piece, and we could perceive the poor thing apparently probing the wound with its fingers.” He states that “Coaitas are more frequently kept in a tame state than any other Monkey. The Indians are fond of them as pets, and the women often suckle them when young at their breasts! They become attached to their masters, and will sometimes follow them to a considerable distance. I once saw a ridiculously tame Coaita. It was an old female, and had accompanied its owner--a trader on the river--on all his voyages. By way of giving me a specimen of its intelligence and feeling, its master set to and rated it soundly, calling it scamp, heathen, thief, and so forth, all through the vocabulary of Portuguese vituperation. The poor Monkey, seated on the ground, seemed to be in sore trouble at this display of anger. It began by looking earnestly at him, then it whined, and lastly rocked its body to and fro with emotion, crying piteously, and passing its long, gaunt arms continually over its forehead, for this was its habit when excited, and the front of the head was worn quite bald in consequence. At last her master altered his tone--‘It’s all a lie, my old woman, you’re an angel, a flower, a good, affectionate old creature,’ and so forth. Immediately the poor Monkey ceased its wailing, and soon after came over to where the man sat.” The disposition of the Coaita is mild in the extreme. It has none of the painful restless vivacity of the Cebus, and no trace of the surly, untamable temper of the Howlers. Bates says it is an arrant thief, and that it shows considerable cunning in pilfering small articles of clothing, which it conceals in its sleeping-place. The natives of the Upper Amazon procure the Coaita when full grown by shooting it with the blow-pipe and poisoned darts, and restoring life by putting a little salt (the antidote to the poison with which the darts are tipped) in its mouth. The animals thus caught become tame forthwith. Two females were once kept at the Jardin des Plantes, in Paris, and Geoffroy St. Hilaire says they rarely quitted each other, remaining most part of the time in close embrace, folding their tails round each other’s bodies; they took their meals together, and never squabbled over their favourite fruit.

The same traveller when once very hard up for food was obliged to kill a white-whiskered Coaita, and cook it. He writes:--“I thought the meat the best flavoured I had ever tasted. It resembled beef, but had a richer and sweeter taste. We smoke-dried the joints, and the last one was an arm with the clenched fist. This I used with great frugality, hanging it between meals on a nail in the cabin, and nothing but the hardest necessity could have driven me to an act so closely resembling cannibalism.”

THE CHAMECK, OR TSCHAKMECK.[85]

An old author, Von Sack, in his voyage to Guinea, gives the following account of the manners of this Spider Monkey:--“It is of a very docile disposition, and capable of being quite domesticated. I have seen a pair of them at a gentleman’s house at Paramaribo, which were left quite at liberty. When the female negroes were employed at their needlework, they used to come and sit amongst them and play with pieces of paper, and afterwards go and gambol amongst the trees, but never went over to the neighbouring gardens. They well knew the hour of dinner of their master, when they would come to the gallery, look in at the windows, though without attempting to enter into the room, being aware that this was a liberty which was not allowed them; they therefore patiently waited for their dinner outside.”

The Latin name of this species refers to its having hardly five fingers. It has four and a short stump of a thumb, visible and useless, but consisting of two bones, the usual muscles, and the skin covering. It is larger than the Coaita, and is black, and covered with long hair, but the face is brown. The tail is considerably longer than the body.

THE BLACK SPIDER MONKEY.

This Spider Monkey is more interesting for its geographical range and favourite localities than for anything else. It lives in Central America, north of Panama, and is common in the neighbourhood of the volcano called Orizaba, in the state of Vera Cruz. It lives in companies in the deep barrancas, up to an elevation of two thousand feet above the sea, and in the State of Oaxaca it roams in the forests up the country to a height of four thousand feet, being the same elevation to which the Tapir often reaches in its roaming. It is a black Ateles, with very long hair, which spreads out in all directions, but there is grey-white on the inside of the limbs, and underneath. It has no thumbs on the hands.

The position which the Ateles take in resting is often very curious. The great Apes of the Old World can lie on their backs like a man, and the Monkeys with callosities sit on them, and, drawing up the knees, let the head fall on to them, or on to the breast, bringing the arms forward when they sleep. But the want of callosities, and of the peculiar flatness of back which characterises the Anthropomorpha, prevents the American Monkeys from adopting either of these positions. Many lie on their sides, and others huddle up in parties, but the Ateles often lie across two or three rope-like horizontal stems, with the face looking downwards, a turn being taken by the tail round the support to insure safety. The length of the back has something to do with this, and of course with their extraordinary agility. The dorsal region of the back-bone, or that which bears ribs, is as long in comparison with the other (neck and loin) regions as in any Monkey; indeed, the maximum of length is attained. There are either thirteen or fourteen back-bone pieces (vertebræ), which have ribs attached to them. The lower vertebræ are four or five in number, and the tail is at its maximum of length in relation to that of the body, its pieces (caudal vertebræ) being very complicated near its root. There, eight pieces (vertebræ) are so like those of the back that they have spines, cross processes, of course without ribs, jointing processes, and a similar nervous canal to those which are higher up in the body. The spinal marrow does not go down it, however. Underneath them are the V-shaped or chevron bones. The end bones are short and thick.

THE VARIEGATED SPIDER MONKEY.[86]

These Monkeys appear to go in small parties, passing through the forests at a rapid pace, feeding on different kinds of berries. The berries which Mr. Bartlett found in their stomachs resembled a gooseberry with a large stone inside. Owing to their great length of limb and tail, and to their muscular vigour, these Spider Monkeys travel far and wide. They are found on both sides of the Peruvian Amazon (or Marañon), and on both sides of the Huallaga. They are also common on the Rio Tigri, and range along the lower spurs of the Andes, across Ecuador and Columbia, over the head waters of the Rio Napa, Rio Japura, and Rio Negro, where it was first discovered. They have also been found in Venezuela. Bartlett endeavoured to hunt them on the Rio Tigri, a small tributary that runs into the Amazon about four miles above the town of Nanta, on the north-western shores of the Peruvian Amazon, but was prevented by the fever and ague of the climate, and the fears of the Indians. Going into the mountains up the Marañon River, he heard from the Indians of the presence of a long-armed Ape--called in their language Maciosuppeh--at the distance of three days’ journey. He engaged three Indians, started by way of a forest footpath that had been opened by a Catholic priest, to the town of Moyahamba, as part of his penitence. He writes:--“At the end of three days I reached the highest point of the mountains; here we came across a number of the Monkeys in question--about eight or nine. I shot the male that is now in the British Museum, and my Indians brought down another with a poison-dart. Having obtained two of them I was satisfied that I had found a new species. While, however, I was busily engaged preparing the first specimen, my Indians had quietly placed the other on the fire; and, to my great horror and disgust, they had singed the hair off, and thus spoiled the specimen. Of course I was obliged to keep the peace, for they had not tasted meat for some days, and the Monkey proved a very dainty dish.”

THE HOODED SPIDER MONKEY.[87]

Probably one of the most extraordinary-looking creatures in the world is _Ateles cucullatus_ (Gray). This very spidery-looking Monkey has a very curious head of hair, which looks as if it sadly required cutting, for it comes over the forehead, and forms a regular hood, which expands over the eyebrows. Everywhere the fur is long and flaccid, and of a blackish silvery-grey colour. The face is reddish, the cheeks and lower jaw being nearly bare of hair; the skin, however, is of a black shade. The skin around the orbits and upon the nose is bare, and of a brownish flesh-colour. The body is about fourteen inches, and the tail twenty-seven inches in length. The tail is stout near the body, and becomes very slim towards the end, the greater part of it, especially the under surface, being extremely hairy. The length of the hind feet, the long scraggy limbs, the spare, long body, and its great agility, give the Monkey a most extraordinary appearance. Probably it comes from the northern coast of Columbia.

There are many species of Ateles, and they range on the Pacific side of Guatemala, on the west side of the Andes, and in the forests watered by the great rivers.

THE SAJOUS, OR CAPUCHINS.[88]