Part 19

Now that we have passed in review the whole of the Anthropoid species inhabiting the New World, a short account of the regions to which they are confined will be of some interest. The most northern limit of Monkeys is, as mentioned above, the State of San-Louis Potosi, about the latitude of 23° North. Their most southern limit attains to nearly 25° of South latitude. They are now confined to the Mexican and Brazilian sub-regions of what has been defined as the Neotropical Region, by Dr. A. R. Wallace, in his great work, "The Geographical Distribution of Animals." The Mexican sub-region belongs to the Neotropical Region, one of those six great areas into which the globe has been divided off by Dr. Sclater on the basis of the geographical distribution of the animals that now inhabit it--the final product of the slowly-changing features of the earth's surface, and of the form, structure, and habits of its animal and vegetable life.

The Mexican sub-region forms the northern part of the {247}Region, and, to condense Mr. Wallace's account of it, it is of comparatively small extent; but the whole of its area is mountainous, being, in fact, a continuation of the great range of the Rocky Mountains. It varies in elevation above the sea from 6,000 to 18,000 feet. "With the exception of the elevated plateaus of Mexico and Guatemala, and the extremity of the peninsula of Yucatan, the whole of Central America is clothed with forests; and as its surface is much broken up into hill and valley, and the volcanic soil of a large portion of it is very fertile, it is altogether well adapted to support a varied fauna, as it does a most luxuriant vegetation." In this region only species of Spider-Monkeys (_Ateles_), of Howlers (_Alouatta_), of Capuchins (_Cebus_), of Night-Monkeys (_Nyctipithecus_), and of Squirrel-Monkeys (_Chrysothrix_) are found. The Spider-Monkeys and the Howlers alone extend so far North as Mexico, and the Night-Monkeys reach to Nicaragua, while the Squirrel-Monkeys and Capuchins have penetrated no further than to Costa Rica.

The Brazilian Sub-region includes all the open plains and pasture lands, surrounded by, or intimately associated with, the forests. Its central mass consists of the great forest plain of the Amazons, from the north-east coast of Brazil to high up in the Andes on the west, a stretch of more than 2,000 miles; and from the mouth of the Orinoko to near La Paz in the Bolivian Andes, a distance of 1,900 miles, of continuous forest in both directions. Within this area are some open "campos" or patches of pasture lands, along several of the tributaries of the Amazon, and Llanos--open flat plains generally flooded in the wet season--on the northern bank of the Orinoko. Unbroken forest also covers the country from Panama southwards by the Magdalena Valley along the western aspect of the {248}Andes to Guayaquil. There is a very arid tract on the northeast coast of Brazil; but south of Cape San Roque the coast forests extend to 30° south latitude, "clothing all the valleys and hill-sides as far inland as the higher mountain ranges, and even penetrating up the great valleys far into the interior. To the south-west the forest country reappears in Paraguay, and extends in patches and partly wooded country till it almost reaches the southern extension of the Amazonian forests. The interior of Brazil is thus in the position of a great island plateau, rising out of, and surrounded by, a lowland region of ever-verdant forests." Of its Anthropoid life the Woolly Monkeys (_Lagothrix_), the Sakis (_Pithecia_), and the Uakaris (_Brachyurus_) are confined to its Amazonian forests. The Woolly Spider-Monkeys (_Brachyteles_) keep to the wooded coast-regions of South-east Brazil, while the Titis (_Callithrix_) do not range out of the tropics of South America. The Howlers (_Alouatta_), the Spider-Monkeys (_Ateles_), and the Capuchins (_Cebus_) roam nearly over the whole region--the first and last ranging from Costa Rica to Paraguay as well. The Spider-Monkeys indeed extend over to the west side of the Equatorial Andes, and in Guatemala across to the Pacific coast. No species of Monkey, however, is known to inhabit the western side of the Andes, to the south of the Gulf of Guayaquil.

THE BABOONS, GUEREZAS AND LANGURS. FAMILY CERCOPITHECIDÆ.

With the following account of the numerous species of the genera of this family, we come to consider the first section of the Old World, or Catarrhine[14] Monkeys. These are {249}distinguished from their New World cousins, described in the previous pages, by many important and obvious characters. The partition dividing the nostrils is narrow, instead of broad, and the openings of the nostrils themselves are directed downwards and outwards. Certain genera possess also sacs formed by distensible folds of the skin in the cheeks. These "cheek-pouches" serve as a storing-place by the side of the jaws, for food which they cannot masticate at the moment. When this store is disposed of, the folds of skin come together again and give no indication of the presence of the pouch, which, moreover, when full does not interfere with the mastication of other food in the mouth, or with the utterance of the animal's usual cries.

The hind-limbs are never shorter than the fore-; they may be equal in length, but they are generally somewhat longer, the animal being more or less quadrupedal, or very partially erect in gait. Their thumb is not invariably present, but when it is, it is always opposable to its fellow digits. The great-toe is never rudimentary, and is never, as it is in Man, the longest, but is the shortest digit of the foot, and it is capable of free motion to and from the others. All of the digits possess nails. The length of the foot among this group approximates more to the proportions of the foot in Man. The hairs on the arms and fore-arms are directed downwards from the shoulder to the wrist.

The tail in this family varies very much; it may be long or short, or even externally absent, but it is never prehensile. All the species, however, possess "callosities," or hard fleshy pads--often of large size--on the buttocks or seat, which, like the naked skin of the face, are usually brilliantly coloured and often of large size. The perineal region and organs are at certain periods, especially in the females, subject to great turgescence and brilliant coloration.

{250}Besides these external characters, we find, on examining their bony structure, much variation in the skull. Some have a rounded forehead, the ascending portion of the lower jaw being high, broad, and flat, with a large facial angle; in others, we have great production of the upper jaw (the horizontal part of the lower jaw being greater than the ascending portion), and a low facial angle. The cerebral portion of the skull is long and flattened, and the palate long and narrow. The dental formula is I2/2, C1/1, P2/2, M3/3 = 32, that of the milk-teeth I2/2, C1/1, M (the forerunners of the permanent _pre-molars_) 2/2 = 20, exactly the same as in a Man. The outer lower incisors are equal to, or sometimes smaller than, the inner pair. The permanent canines--which are long and sharp--come in before, or with the posterior molars of both jaws. Between them and the incisors above, and between the canine and the anterior pre-molar below, occurs a gap (or diastema). The anterior upper pre-molar has its outer cusp modified and sharpened; the anterior lower pre-molar has the anterior margin of its crown so shaped as to work "as a scissors'-blade against the posterior edge of the upper canines." (_Henley._) The crowns of the molar teeth are long from before backwards, and their fore and hind cusps are united by transverse ridges, a third being present in the same genera, on the posterior lower five-cusped molar.

The nasal bones are often ossified together to form one bone. The surface of the skull is in general oval and smooth, but in some of the Baboons there appear strong ridges over the eyes (hiding the forehead) and along the top of the head, being stronger, when present, in the male than in the female. The external orifice to the ear has a considerable bony tube, or meatus, a distinguishing character which is absent in the New {251}World Monkeys; their tympanic (or ear) cavity being close to the outer wall of the skull. The line of junction (or suture) between the upper jaw-bones, the pre-maxillary and the maxillary, remains unclosed until long after the permanent teeth have come in. Sometimes it remains unclosed throughout life. The foramen for the passage of the spinal-cord, and the condyles for the articulation of the skull with the neck, lie far back.

In the spinal column there are nineteen dorsal and lumbar vertebræ together. The number of caudal vertebræ varies greatly; in some there are as many as thirty-one, in others only three. The posterior ends of the ischiatic bones of the pelvis are rough, flattened, and broad, for the attachment of the fleshy callosities mentioned above.

The bones of the thigh and leg (_femur_ and _tibia_) together, are longer than those of the arm and fore-arm (_humerus_ and _radius_) together. The bones of the thumb are modified more for support and progression than for the actions of a true hand; by these modifications the movements of rotation (pronation and supination) are much restricted.

The ankle (_tarsus_) does not exceed one third of the length of the foot.

The stomach is simple, or but very slightly sacculated, in those genera which possess cheek-pouches; but is tripartite--the middle compartment being sacculated--in those that have not store-pockets in their mouths, "a groove with raised edges leading from the gullet-entrance to this middle compartment." The intestine has a cæcum, or blind diverticulum. "When laryngeal air-sacs are developed, they are formed by a single sac, with a median aperture--immediately beneath the epiglottis. This median air-sac is very large, extending down {252}over the front of the neck, and sending [in some genera] processes into the _axillæ_" or arm-pits. (_Huxley._)

The main brain (or cerebrum) covers the cerebellum in all the members of the _Cercopithecidæ_; and in them the principal convolutions and fissures found in the human brain are more or less developed.

The family _Cercopithecidæ_ includes all the Old World Monkeys except the Anthropoid or true Apes, and Man, these latter constituting the two remaining families of the _Anthropoidea_, namely _Simiidæ_ and _Hominidæ_. The _Cercopithecidæ_ have been again divided into two Sub-families, the _Cercopithecinæ_ and the _Semnopithecinæ_. The first contains the Baboons (_Cynocephalus_), the Gelada Baboons (_Theropithecus_), the Mangabeys (_Cercocebus_) and the Guenons (_Cercopithecus_), all of which inhabit the African continent; and likewise the Black Apes (_Cynopithecus_) from Celebes, and the Macaques (_Macacus_), which are almost exclusively confined to the Asiatic continent. In the second Sub-family are included the Nosed-Monkeys (_Nasalis_) of Borneo; the Langurs (_Semnopithecus_) of India, Malaizia, and the Sunda Islands; and the Guerezas (_Colobus_) of Africa.

THE BABOONS, MANGABEYS, AND MACAQUES. SUB-FAMILY CERCOPITHECINÆ.

This Sub-family is characterised by the presence, in all its members, of cheek-pouches, and a simple stomach. The tail is variable in length, being long or externally invisible. The callosities on the ischiatic bones are large; in many species they become very turgescent at certain seasons, the enlargement extending sometimes to the tail. The hues of the skin on and round the face also become more vivid periodically. {253}Many of the species of this Sub-family are arboreal; some, however, are found only in barren rocky regions; others in low jungle in the neighbourhood of villages, water-tanks, and cultivated patches. Fruits and insects form their principal diet.

THE BABOONS. GENUS PAPIO.

_Papio_, Erxleb., Syst. Regne Anim., p. 15 (1777).

_Cynocephalus_, Lacép., Mem. de l'Inst. iii., p. 490 (1801). Type, _P. sphinx_ (Geoffr.).

The members of this genus may easily be recognised by their very Dog-like face, their muzzle being greatly elongated and truncated at the end, with the nostrils set in the truncated termination. Their eyes are directed downwards along the visage. In form and massiveness of body and in length of tail they vary very much. Their fore- and hind-limbs are nearly equal in length, and consequently they progress on all fours, with the palms of the hands and the soles of the feet flat to the ground. Their "fore-paws" are, however, very efficient _hands_, which some species use very dexterously in turning over stones in their search for food. Their feet are long. Their hair is grizzled or ringed with various colours.

The facial region of the skull is more developed in this genus relatively to the flattened brain-case, than in other Monkeys. In several of the species longitudinal osseous ridges are developed on the bones of the upper jaws, especially in the adult males, adding to the hideousness of the countenance of these animals. The neck is elongated. The _radius_ is longer than the _humerus_ (or arm-bone), and the elbow projection of the _ulna_ (of the fore-arm), named the _olecranon_ process, is prolonged upwards beyond what occurs in Man. The thumb, though relatively shorter than in Man, is much {254}longer proportionately than in other Monkeys, reaching to the middle of the first joint of the forefinger.

Both halves of the liver are much sub-divided.

Gestation lasts seven months, and the young are suckled for six months.

The Baboons are the lowest of the Catarrhine or Old World Monkeys. Most of them are large, ferocious, dangerous, and gregarious animals, and when disturbed or alarmed they give utterance to screams, barks, and guttural murmurs.

Both Dr. Emil Holub and Sir Richard Burton have spoken of the ferocity of the Baboons. "The South African farmers," says the first-named naturalist, "complain of these animals as a great and perpetual nuisance." They were always on the look-out, and no sooner was a field or a garden left unguarded than they would be down at once, breaking through the hedges and devouring the crops. They were likewise very destructive amongst the Sheep. If a shepherd happened to leave his post for ever so short a time, or even to fall asleep, the Baboons, who had been watching their chance from the heights, would be down upon the flock in the valley, and, seizing the Lambs and ripping up their stomachs with their teeth, would feast upon the milk they contained, then leaving the poor mangled victim writhing on the ground. Then they would lose no time in repeating the terrible operation upon another. "About the middle of the morning," says Dr. Holub, "we started eastwards in the hope of catching the herd at their drinking-place.... When we had advanced some distance along the hill we found ourselves approaching the pool ... and could distinctly hear the hoarse barking of the Baboons. Looking across to the opposite side, about 300 yards away, we caught sight of a herd of seven, only four of them full-grown; {255}they seemed to pause and scan us carefully before they decamped to a glen on the right. With all speed we followed them.... As one of our party had only small shot, and the other nothing but a stick, I insisted upon their remaining close at my side, knowing that a full-grown Baboon, when infuriated, is as dangerous a foe as a Leopard.... Behind one of the embankments we took our position. Only a few minutes had elapsed when we could distinctly recognise them as a herd of Baboons. The boy said he was quite sure that they were on their way to the water; but to our surprise they did not make any further advance. A quarter of an hour passed--half an hour--still no symptom of their approach. All at once, as if they had started from the earth by magic, at the open end of the pond, not sixty yards from our place of ambush, stood two huge males.... Being anxious to watch the movements of the animals I refrained from firing, and determined to see what would follow next. Both Baboons sprang towards the water, and leaning down, drank till they were satisfied; then, having gravely stretched themselves, they stalked away solemnly on all fours in the direction of the herd. There was little doubt, therefore, that they had been sent forward to reconnoitre; for as soon as they got back, the entire herd put itself in motion, and made its way towards the pond. There were mothers taking care of their little ones; there were the half-grown animals, the boys and girls of the company; but there did not seem to be more than three or four full-grown males. At first only one Baboon at a time came to the water's edge, and having taken its draught retired to the rest; but when about ten of them had thus ventured separately, they began to come in small groups, leaving the others rolling and jumping on the sand.... It was not {256}long before two males--the same, I had no doubt, which we had noticed before--came and squatted themselves one on each side of the little creek.... Crack went my rifle. But instead of either of them dropping, the two Baboons started up; by a mutual instinct they both clutched their noses, gave a ringing bark and scampered off. The whole herd took the alarm, and joining in the shrieking clamour were soon lost to sight."

On another occasion Dr. Holub and his servant had a _rencontre_ with a herd of Baboons. He writes:--"We caught sight of them in one of the glens. They were on the further side, and being anxious to obtain a specimen of their skulls, I fired and killed one Baboon; but unfortunately for me, the creature fell into the river. At my second shot I wounded two more. This induced the right wing of the herd to retreat; but the main body kept their ground, and the left flank, moreover, assumed the aggressive, and commenced pelting us so vigorously with stones, that, remembering that I had only one cartridge, I considered it far more prudent to withdraw than to run the risk of a hand-to-hand encounter." On a still further occasion the same well-known traveller says: "I was turning to leave the ravine when some stones came pattering down the rocks in my direction. I soon became aware that the stones were being designedly aimed at me; and, looking up, I saw a herd of Baboons."

"The Nyanyi or Cynocephalus," writes Sir Richard Burton in his "Lake Regions of Central Africa," "in the jungles of Usukuma attains the size of a Greyhound, and, according to the natives, there are three varieties of colour--red, black and yellow. They are the terror of the neighbouring districts; women never dare to approach their haunts; they set the {257}Leopard at defiance, and when in a large body, they do not, it is said, fear the Lion."

"Baboons often show their passion," as Mr. Darwin has related, "and threaten their enemies in a very odd manner, namely, by opening their mouths widely, as in the act of yawning. Mr. Bartlett has often seen two Baboons, when first placed in the same compartment, sitting opposite to each other, and then alternately opening their mouths; and this action seems frequently to end in a real yawn. Mr. Bartlett believes that both animals wish to show to each other that they are provided with a formidable set of teeth, as is undoubtedly the case. As I could hardly credit the reality of this yawning gesture, Mr. Bartlett insulted an old Baboon and put him into a violent passion; and he almost immediately thus acted.... Baboons likewise show their anger, as was observed by Brehm with those which he kept alive in Abyssinia, in another manner, namely, by striking the ground with one hand, 'like an angry man striking the table with his fist.' I have seen this movement with the Baboons in the Zoological Gardens; but sometimes the action seems rather to represent the searching for a stone or other object in their beds of straw.... With several species of Baboons, the ridge of the forehead projects much over the eyes, and is studded with a few long hairs, representing our eyebrows. These animals are always looking about them, and in order to look upwards they raise their eyebrows. They have thus, as it would appear, acquired the habit of frequently moving the latter. However this may be, many kinds of Monkeys, especially the Baboons, when angered, or in any way excited, rapidly and incessantly move their eyebrows up and down, as well as the hairy skin of their foreheads."

{258}Baboons are confined to the African continent and to Arabia, to the region, indeed, termed Ethiopian, as defined by Sclater and Wallace. They live chiefly on the ground, especially in rocky and barren hills, and less frequently among trees, for which their equally long front and hind limbs are not so well adapted. Mr. H. H. Johnson, C.B., now H.M. Commissioner in Nyasa-land, found, however, on his Kilimanjaro Expedition, that Baboons were singularly abundant in the big trees at Taveita, on the rise to that mountain. Their food consists of fruits and Lizards, but principally of insects, which they search for under stones, turning these over with their hands. They are, indeed, nearly omnivorous, as the reader will have gathered from Dr. Holub's observations.

I. THE MANDRILL. PAPIO MAIMON.

_Simia maimon_, Linn., Syst. Nat., p. 35 (1766).

_Simia mormon_, Altstr., Acta. Noem., p. 144, pl. 3 (1766).

_Papio maimon_, Erxl., Syst. Regne Anim., p. 17 (1777); Schl., Mus. Pays Bas, vii., p. 130 (1876).

_Cynocephalus mormon_, Fr. Cuvier, Hist. Nat. Mammif., pp. 143, 146, pls. 52, 53 (1807).

_Papio mormon_, Geoffr., Ann. Mus., xix., p. 104 (1812).

_Mormon maimon_, Gray, Cat. Monkeys, Brit. Mus., p. 36 (1870).

CHARACTERS.--MALE.--Body massive and strong; trunk declining backwards; head disproportionately large; muzzle much elongated and protruding, with large longitudinal rugose swellings along each side when full grown; mouth large, and with very animal-like lips; brows strongly projecting over the base of the nose and the small, approximated, deep-set eyes; {259}ears black, naked, and pointed; under-jaw heavy; tail carried erect, very short, two inches long, and naked beneath; limbs short and powerful; the Dog-like nose shorter than the upper lip; nostrils large. Hair rising from the ridge on the lower edge of the brow to a crest on the top of the head, descending into a mane on the back of the head and neck; hair of the body bristly; chin bearded; whiskers proceeding from over the cheek-bones and from under the outer corner of the eyes, long, and directed from the face; the very large callosities, parts of the rump in their neighbourhood, and the inside of the thighs naked. Hands and feet naked.

Skull very massive, having numerous strong muscular crests; the jaws and teeth very powerful, especially the canines, which are huge; the forehead flat and the brain-case small, and further reduced by the great projection backward of the orbits. The cheek-bones enormously swollen along the side of the nose; in the neck a large air-sac. The back-bone has to some extent the peculiar double curve characteristic of the human vertebral column but in the conformation of certain of their vertebræ a similarity to the lower quadrupeds, especially to the Carnivora, is seen in the Mandrill, in accordance with their quadrupedal mode of progression. The metacarpal bones, except that of the thumb, are all of the same length, while in the Man-like Apes they are unequal. The thumb is much restricted in its motions on account of the disposition of certain of the muscles of the hand. The pectoral and pelvic muscles are strongly developed.