They are small in size, and more like squirrels than true monkeys in their manner of climbing.The nails, except those of the hind thumbs, are long and claw-shaped like those of squirrels, and the thumbs of the fore extremities, or hands, are not opposable to the other fingers.I do not mean to imply that they have a near relationship to squirrels, which belong to the Rodents, an inferior order of mammals; their resemblance to those animals is merely a superficial one.They have two molar teeth less in each jaw than the Cebidae, the other family of American monkeys; they agree with them, however, in the sideway position of the nostrils, a character which distinguishes both from all the monkeys of the old world.The body is long and slender, clothed with soft hairs, and the tail, which is nearly twice the length of the trunk, is not prehensile.The hind limbs are much larger in volume than the anterior pair.The Midas ursulus is never seen in large flocks; three or four is the greatest number observed together.It seems to be less afraid of the neighbourhood of man than any other monkey.I sometimes saw it in the woods which border the suburban streets, and once I espied two individuals in a thicket behind the English consul's house at Nazareth.Its mode of progression along the main boughs of the lofty trees is like that of the squirrel; it does not ascend to the slender branches, or take those wonderful flying leaps which the Cebidae do, whose prehensile tails and flexible hands fit them for such headlong travelling.It confines itself to the larger boughs and trunks of trees, the long nails being of great assistance to the creature, enabling it to cling securely to the bark, and it is often seen passing rapidly around the perpendicular cylindrical trunks.It is a quick, restless, timid little creature, and has a great share of curiosity, for when a person passes by under the trees along which a flock is running, they always stop for a few moments to have a stare at the intruder.
In Para, Midas ursulus is often seen in a tame state in the houses of the inhabitants.When full grown it is about nine inches long, independently of the tail, which measures fifteen inches.The fur is thick, and black in colour, with the exception of a reddish-brown streak down the middle of the back.When first taken, or when kept tied up, it is very timid and irritable.It will not allow itself to be approached, but keeps retreating backwards when any one attempts to coax it.It is always in a querulous humour, uttering a twittering, complaining noise; its dark, watchful eyes are expressive of distrust, and observant of every movement which takes place near it.When treated kindly, however, as it generally is in the houses of the natives, it becomes very tame and familiar.I once saw one as playful as a kitten, running about the house after the negro children, who fondled it to their hearts' content.It acted somewhat differently towards strangers, and seemed not to like them to sit in the hammock which was slung in the room, leaping up, trying to bite, and otherwise annoying them.It is generally fed sweet fruits, such as the banana; but it is also fond of insects, especially soft-bodied spiders and grasshoppers, which it will snap up with eagerness when within reach.The expression of countenance in these small monkeys is intelligent and pleasing.
This is partly owing to the open facial angle, which is given as one of 60; but the quick movements of the head, and the way they have of inclining it to one side when their curiosity is excited, contribute very much to give them a knowing expression.
On the Upper Amazons I once saw a tame individual of the Midas leoninus, a species first described by Humboldt, which was still more playful and intelligent than the one just described.This rare and beautiful little monkey is only seven inches in length, exclusive of the tail.It is named leoninus on account of the long brown mane which depends from the neck, and which gives it very much the appearance of a diminutive lion.In the house where it was kept, it was familiar with everyone; its greatest pleasure seeming to be to climb about the bodies of different persons who entered.The first time I went in, it ran across the room straightway to the chair on which I had sat down, and climbed up to my shoulder; having arrived there, it turned round and looked into my face, showing its little teeth and chattering, as though it would say, "Well, and how do you do?" It showed more affection towards its master than towards strangers, and would climb up to his head a dozen times in the course of an hour, making a great show every time of searching there for certain animalcula.
Isidore Geoffroy St.Hilaire relates of a species of this genus, that it distinguished between different objects depicted on an engraving.M.Audouin showed it the portraits of a cat and a wasp; at these it became much terrified; whereas, at the sight of a figure of a grasshopper or beetle, it precipitated itself on the picture, as if to seize the objects there represented.
