That many animals have a kind of language is nowadays admitted to be a truism, but this is more evident among mammals and birds, and, reviewing the classes of the former, we find a more or less defined ascending complexity and increased number of varying sounds as we pass from the lower forms--kangaroos and moles--to the higher herb-and-flesh-eaters, and particularly monkeys. Squeaks and grunts constitute the vocabulary, if we dignify it by that name, of the mammals. The sloths, those curious animals whose entire life is spent clinging to the underside of branches, on whose leaves they feed, may be said almost to be voiceless, so seldom do they give utterance to the nameless wail which constitutes their only utterance. Even when being torn to pieces by an enemy, they offer no resistance and emit no sound, but fold their claws around their body and submit to the inevitable as silently and as stoically as did ever an ancient Spartan. Great fear of death will often cause an animal to utter sounds which are different from those produced under any other conditions. When an elephant is angry or excited, his trumpeting is terribly loud and shrill; but when a mother elephant is "talking" to her child, while the same sonorous, metallic quality is present, yet it is wonderfully softened and modulated. A horse is a good example of what the fear of death will do. The ordinary neigh of a horse is very familiar, but in battle when mortally wounded, or having lost its master and being terribly frightened, a horse will scream, and those who have heard it, say it is more awful than the cries of pain of a human being. Deer and elk often astonish one by the peculiar sounds which they produce. An elk can bellow loudly, especially when fighting; but when members of a herd call to each other, or when surprised by some unusual appearance, they whistle--a sudden, sharp whistle, like the tin mouthpieces with revolving discs, which were at one time so much in evidence. The growl of a bear differs greatly under varying circumstances. There is the playful growl, uttered when two individuals are wrestling, and the terrible "sound"--no word expresses it--to which a bear, cornered and driven to the last extremity, gives utterance--fear, hate, dread, and awful passion mingled and expressed in sound. One can realise the fearful terror which this inspires only when one has, as I have, stood up to a mad bear, repelling charge after charge, with only an iron pike between one's self and those powerful fangs and claws. The long-drawn moan of a polar bear on a frosty night is another phase; this, too, is expressive, but only of those wonderful Arctic scenes where night and day are as one to this great seal-hunter.