Modern naturalists, having become acquainted with many of these species closely resembling each other in some important particulars, have arranged them all under the term Cercopithecus from κέρκος (a tail), and πίθηκος (an ape). The grimaces and odd gestures of these Monkeys have given to them the name of Guenons, and this term is now used accordingly.
At first sight they resemble the Colobi, inasmuch as they have long bodies, long hind legs, and long tails, but the fore limbs are short in the Guenons, and the tail, which is as long or longer than the body, is stout and not slender. Moreover, they have well-made and exceedingly useful cheek-pouches, besides the callosities behind. The face of the Guenons is long, and rounded, and the eyes are somewhat prominent. On examining the inside of one of these particularly African species the stomach is found to be single, and not to resemble that of the genera last described, and on looking at the lower jaw it will be found that the last crushing teeth on each side have only four points, or cusps, and not five, as in Semnopitheci. The wearing of the first premolar tooth next to the lower dog tooth, and behind it, resembles somewhat that noticed before, and which will be described in treating of the Inui, or Macaques, in the next chapter. The hands and feet are well grown, and the thumbs are long and useful.
So that the distinctive peculiarity, or what is called the diagnosis of the group, or genus Cercopithecus is—Monkeys with long hind and short fore limbs, and with long tails, cheek-pouches, single stomachs, and callosities, there being only four cusps on the last lower molar teeth.
DIANA MONKEY.
Many of the Guenons are often seen in menageries and zoological gardens, or as the more or less unwilling companions of organ-grinders; and their trick of crowding everything into their mouth, and allowing it to distend the cheeks, is sure to be noticed. The quantity of nuts which can be stored away is enough for a good meal; and hence these Monkeys are not only good purveyors for themselves, but great robbers of the riches of cultivators. In the wild state they assemble in troops in the forest, for they are essentially tree dwellers, and make raids on all sides of their favourite home, moving with such rapidity under the shadow of leaves and boughs that they are rarely seen by men. In their own little tract of forest they are very noisy and restless; they chase away in a body all intruding Monkeys, and whilst the more aged spend their time in more or less restless movement, in occasional family jars, and in picking the insects from their young and from each other, the juvenile part of the troop are full of play, mischief, and wanton aggression upon the quietude of their elders. A Snake may appear, and there is a terrible noise made, and a general rush off out of danger, the little ones clinging to the fur of the mother, and being carried off safely in spite of her bounds and jumps from tree to tree. Or a Leopard may make a spring, and not always fruitlessly, and great is the surrounding howling and grimacing at it. The hatred of Snakes is carried into their captivity; and Mr. Darwin having read Brehm’s account of the instinctive fear which his Monkeys had of Serpents, and also of their great curiosity regarding snake-like things and their doings, took a stuffed Snake to the Monkey-house of the Zoological Gardens. The excitement which was produced, he writes, was one of the most curious spectacles ever beheld. Three species of Cercopithecus were the most alarmed. They darted about their cages, and uttered sharp cries of danger, which were understood by the other Monkeys. A few young Monkeys and an old Anubis Baboon alone took no notice of the Snake. He then placed the stuffed specimen on the ground in one of the larger compartments. After a time all the Monkeys collected round it in a large circle, and staring intently, presented a most ludicrous appearance. They became extremely nervous, so that when a wooden ball with which they were familiar as a plaything was accidentally moved in the straw under which it was partly hidden, they all instantly started away. These monkeys behaved very differently when a fish, a mouse, and some other new objects were placed in the cage; for though at first frightened they soon approached, handled and examined them. He then placed a living Snake in a paper bag, with the mouth closed loosely, in one of the larger compartments. One of the Monkeys immediately approached, cautiously opened the bag a little, peeped in, and instantly dashed away. Then he witnessed what Brehm has described, for Monkey after Monkey with head raised high, and turned on one side, could not resist taking momentary peeps into the upright bag at the dreadful creature lying at the bottom.
It would appear as if Monkeys had some notion of zoological affinities, for those kept by Brehm exhibited a strange though mistaken instinctive dread of innocent Lizards and Frogs.
FACE OF THE DIANA MONKEY.
Birds of prey attack them, and not always with a successful result; and there is a story of a little Guenon being darted at by an Eagle, who swooped down and struck it, but it did not get off, for a rush was made against the bird by several of the active elders, and they not only held it, but nearly plucked off all its feathers, so that when it got away it remembered for ever after the treatment it received. The Guenons are very choleric, and the expression of the face and of the mouth, and the shrill sounds which are emitted when they are angered, would probably be accompanied by extremely bad language were they men; but their rage is soon over, and some mutual tail-pulling and biting are the worst part of it. There is a curious defiant look about the eyes of some, with or without extreme restlessness of them; they seem to be the very embodiment of cunning and sharpness, and this look is really very peculiar to the group. By way of additional force of expression, those which are very fond of fighting with their teeth have the power of drawing back their ears like angry Dogs; and this is done by the action of a muscle which springs from the ear-bone behind the ear, and is attached to it behind. There is just a rudiment of this muscle in man. Usually very good-tempered when young, like all the Quadrumana, they grow cross, savage, and uncertain in temper when old; there are some exceptions to this, but, on the other hand, so savage do some of them become, that breaking or removing their great upper canine teeth appears to be the only way of making them behave at all properly. The loss of these fine weapons of offence has a most humiliating effect on the most insolent and petulant of them. Many are very pretty, and are as elaborately coloured as the Douc, that prince of beautiful Semnopitheci; and this leads to their destruction, for every now and then, besides the native desire to have some fine Monkey skins, European ladies desire Monkey muffs, and many an irascible chatterer out of the woods of Western Africa has its skin paraded by the fashion. Bright red, green, fawn, yellow, and white colours are constantly mixed up with black shades, and every tint of grey is clotted here and there. The hair is longer in some parts than in others, especially about the cheeks and chin; one has a white spot on its nose, another has white moustaches, and a third a white band across the forehead. And these tints, and the disproportion of the long hairs, have served to identify the different kinds.