In general the American monkeys are distinguished by a much milder disposition than those of the eastern hemisphere, and retain at an advanced age the playful manners of their youth. They are commonly more easy to tame, and learn many little tricks which are taught with much greater difficulty to their restless Asiatic or African cousins. Their weakness, their short canine teeth, their good temper, render them harmless play-fellows, and thus they are generally preferred in Europe to the Old World monkeys, though they are not so lively, and constantly have a more or less dejected mien, as if they still regretted the primitive freedom of the forest.
The American monkeys may be conveniently divided into two large groups; with or without a prehensile tail. To the first great subdivision belong the Howling Monkeys or Aluates (Mycetes), the Spider Monkeys (Ateles), the Sajous, and several other intermediate genera.
The Aluates are chiefly remarkable for their stentorian powers, which no other animal can equal or approach. When the nocturnal howl of the Large Red Howling Monkey (Mycetes ursinus) bursts forth from the woods, you would suppose that all the 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 terrible and 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. Some naturalists have supposed that these awful sounds can only proceed from a number of the red monkeys howling in concert, but one of them alone is equal to the task. In dark and cloudy weather, and just before a squall of rain, the Aluate often howls in the day-time; and on advancing cautiously to the high and tufted tree where he is sitting, one may then have a good opportunity of seeing the large lump in his throat, the sounding-board which gives such volume to his voice, move up and down as he exerts his stentorian lungs.
HOWLING MONKEY.
The howling monkeys are the most robust of the American simiæ, and in spite of their long tail have a certain analogy with the urans, whom they may be said to represent in the New World. Their various species range from Paraguay to Honduras, while the Ateles or Spider Monkeys, thus named from their long slender limbs and sprawling movements, extend over the whole surface of tropical America. The marimonda (Ateles Belzebub) is even found on the eastern slopes of the Andes at a height of 10,000 feet above the level of the sea, an elevation attained by him alone of all the quadrumanous tribes. Like the African Colobi, the spider monkeys have no thumb on their fore-hands; their voice is a soft and flute-like whistling, resembling the piping of a bird. It is said that when a mother burthened with her young hesitates to take too wide a leap, paterfamilias seizes the branch she intends to reach, and swings himself to and fro with it, until his companion is able to attain it by a spring.
The second group of American monkeys, consisting of those with a non-prehensile tail, comprises the Sakis, the Saïmiris, the Ouistitis, &c.
The Sakis, or Fox-tailed Monkeys, are distinguished by their bushy tail, which, however, in some species, is very short. They usually live in the outskirts of forests, in small societies of ten or twelve. Upon the slightest provocation, they display a morose and savage temper, and, like the howling-monkeys, utter loud cries before sunrise and after sunset.
The elegant ease of their movements, their soft fur, the large size of their brilliant eyes, and their little round face, entitle the Saïmiris to be called the most graceful of monkeys. On speaking to them for some time, they listen with great attention, and soon lay their tiny hand upon the speaker’s mouth, as if to catch the words as they pass through his lips. They recognise the objects represented in an engraving even when not coloured, and endeavour to seize the pictured fruits or insects. The latter, and particularly spiders, which they catch most dexterously with their lips or hands, seem to be their favourite food. The weak little creatures are very fond of being carried about by larger monkeys, and cling fast to their back. At first the animal to which they thus attach themselves endeavours to get rid of its burden, but finding it impossible, it soon becomes reconciled to its fate, and after a short time an intimate affection arises between them, so that when the saïmiri is busy chasing insects, his friend, before leaving the spot, first gives him notice by a gentle cry.
The habits of the Nyctopitheci, or nocturnal monkeys, bear a great resemblance to those of the bats or flying foxes. The shy and quiet little animals sleep by day, concealed in the dense thickets of the forest. Their eye and motions are completely feline. Those which Von Martius observed in his collection, crept by day into a corner of the cage, but after sunset their agility made up for their diurnal torpor.