served that the different explosions of voice have each its own meaning, whenever it is designed to establish concert of action between individuals. The cercopitheci, the most graceful and sprightly monkeys of Africa, live together in more or less numerous groups. Having for their usual dwelling-places the branches of trees, they descend to the ground with great misgiving, and only in order to go foraging. On an expedition the band of cercopitheci march under the command of a chief, who is always an old male experienced in the ways of men and animals. At first the troop advance cautiously, passing along the highest branches of the trees. Now and then the chief climbs into one of the loftiest tree-tops and peers into space. If all is well, he makes announcement accordingly in guttural tones, and the troop show that they are reassured; if the chief suspects or perceives danger, he utters a peculiar cry, which is understood by all, and the troop retreat in confusion. The marauders, having reached the edge of the forest, descend to the ground. Then begins a hideous massacre of sorgho and maize. The sajous, those pretty little South American monkeys kept in every menagerie, also show the resources of the inarticulate voice as a means of communication among animals. One day the naturalist Rengger, while wandering along the border of a forest, observed a family of these monkeys whose conduct interested him. One individual, having parted company with the rest, had found an orange-tree loaded with ripe fruit. Without going to the trouble of turning about, he uttered a series of short cries, and made for the tree with the speed of an arrow. The others understood all, and in an instant were assembled amid the branches of the tree, enjoying the savory fruit. If man had no articulate speech, he would have no difficulty in constructing a language by the aid of sounds or cries diversified by intonation, intensity, and resonance, and variously combined. Such a language no doubt could never equal the languages of Homer, of Dante, of Shakespeare, and of Bossuet, but it would answer all the essential needs of life. By supposing such an imaginary though realizable mode of communication, we may form an idea of the more or less limited language of animals.
In mammals the sounds of the voice differ considerably with respect to volume, timbre, and pitch; these differences we can in some measure account for by peculiarities in the conformation of the larynx. In horned animals the vocal cords are lax, but little prominent, never coming near to one another, nor vibrating with much force. The sounds they produce are grave, as in the lowing of cattle. The rodents, as hares, rabbits, squirrels, and mice, whose vocal cords are thin, emit acute cries. Some species, belonging to different mammalian groups, have air-pouches opening into the larynx which produce extraordinary resonance. Some monkeys are distinguished for the enormous development of these pouches, and their voice is very loud. The howling monkeys, also called stentors, which inhabit the deepest
