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 not so dangerous.[1769] The hide is impenetrable, except when it has been soaked with water; and it is used for making shields and helmets.[1770] 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. CHAP. 40. (26.)—WHO FIRST EXHIBITED THE HIPPOPOTAMUS AND THE CROCODILE AT ROME. M. Scaurus was the first who exhibited this animal at Rome, together with five crocodiles, at the games which he gave in his ædileship, in a piece of water[1771] which had been temporarily prepared for the purpose. The hippopotamus has even been our instructor in one of the operations of medicine.[1772] When the animal has become too bulky by continued over-feeding, 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. CHAP. 41. (27.)—THE MEDICINAL REMEDIES WHICH HAVE BEEN BORROWED FROM ANIMALS.[1773]