The Nile produces the hippopotamus, another wild beast, of a still greater size. It has the cloven hoof of the ox; the back, the mane, and the neighing of the horse; and the turned-up snout, the tail, and the hooked teeth of the wild boar, but is not so dangerous. The hide is impenetrable, except when it has been soaked with water; and it is used for making shields and helmets. This animal lays waste the standing corn, and determines beforehand what part it shall ravage on the following day; it is said also, that it enters the field backwards, to prevent any ambush being laid for it on its return. [Illustration: HIPPOPOTAMUS, OR ZEEKOE.—_Hippopotamus Amphibius._] Marcus Scaurus was the first to exhibit this animal at Rome, together with five crocodiles, at the games which he gave in his ædileship, in a piece of water which had been temporarily prepared for the purpose. The hippopotamus has even been our instructor in one of the operations of medicine. When the animal has become too bulky by continued overfeeding, it goes down to the banks of the river, and examines the reeds which have been newly cut; as soon as it has found a stump that is very sharp, it presses its body against it, and so wounds one of the veins in the thigh; and, by the flow of blood thus produced, the body, which would otherwise have fallen into a morbid state, is relieved; after which, it covers up the wound with mud. CHAPTER XIII. PROGNOSTICS OF DANGER DERIVED FROM ANIMALS. Nature has bestowed upon many animals the faculty of observing the heavens, and of presaging the winds, rains, and tempests, each in its own peculiar way. It would be an endless labor to enumerate them all; just as much as it would be to point out the relation of each to man. For, in fact, they warn us of danger, not only by their fibres and their entrails, to which a large portion of mankind attach the greatest faith, but by other kinds of warnings as well. When a building is about to fall down, all the mice desert it, and the spiders with their webs are the first to drop. Divination from birds has been made a science among the Romans, and the college of its priests is looked upon as peculiarly sacred. In Thrace, when all parts are covered with ice, the foxes are consulted, an animal which, in other respects, is baneful from its craftiness. It has been observed, that this animal applies its ear to the ice, for the purpose of testing its thickness; and the inhabitants will never cross frozen rivers and lakes until the foxes have passed over them and returned. [Illustration: COMMON MOUSE.—_Mus Músculus_ (White, Brown and Pied Varieties).]