The shriek, or scream, can be heard half a mile, and at close range it is literally ear-splitting. Usually it is accompanied by violent stamping or pounding with the feet upon the floor. It may signify rage, or nothing more than the joy of living, and of having a place in which to yell. It is this cry that is uncannily human-like in sound, and when heard for the first time it seems to register anguish. In its Bornean jungle home, the orang-utan is nearly as silent as the grave. Never save once did I hear one utter a vocal sound. That was a deep bass roar emitted by an old male that I disturbed while he was sleeping on the comfortable nest of green branches that he had built for himself. Concerning the chimpanzee, the late Mr. Richard L. Garner testified as follows: "Not only does the chimpanzee often break the silence of the forest when all other voices are hushed, but he frequently answers the sounds of other animals, as if in mockery or defiance. ... Although diurnal in habit, the chimpanzees often make the night reverberate with the sounds of their terrific screaming, which I have known them to continue at times for more than an hour, with scarcely a moment's pause,--not one voice but many, and within the area of a square mile or so I have distinguished as many as seven alternating adult male voices. "The gorilla is more silent and stoical than the chimpanzee, but he is far from being mute. He appears to be devoid of all risibility, but he is often very noisy. Although diurnal in habit, he talks less frequently during the day than at night, but his silence is a natural consequence of his stealth and cunning. There are times, however, when he ignores all danger of betraying his whereabouts or his movements, and gives vent to a deluge of speech. At night his screams and shouts are terrific." The gibbons (including the siamang) have tremendous voices, with numerous variations, and they love to use them. My acquaintance with them began in Borneo, in the dense and dark coastal forest that there forms their home. I remember their cries as vividly as if I had heard them again this morning. While feeding, or quietly enjoying the morning sun, the gray gibbon (_Hylobates concolor_) emits in leisurely succession a low staccato, whistle-like cry, like "Hoot! Hoot! Hoot!" which one can easily counterfeit by whistling. This is varied by another whistle cry of three notes, thus: "Who-ee-hoo! Who-ee-hoo!" also to be duplicated by whistling. In hunting for specimens of that gibbon, for American museums, I could rarely locate a troop save by the tree- top talk of its members.