There are, however, four species of rhinoceros--two black, or of a dark colour; and two of a whitish hue. The black is supposed to be of a wilder and more morose disposition than the white. It has a peculiar upper lip, which is capable of extension, and is extremely pliable, so that it can move it from side to side, and twist it round a stick. It in this way collects its food, and carries it to its mouth, making use of it somewhat as an elephant does his trunk. The black species are very fierce, and probably, next to the buffalo, are the most dangerous beasts in Southern Africa to encounter; for the lion gives notice of his approach by his roar, and can easily be driven off, while even the elephant is less pertinacious in assailing an enemy. Senhor Silva said he had heard of rhinoceroses with three horns, but he had never seen them, and rather doubted their existence. One species known as the cobaba has a front horn frequently upwards of four feet in length, pointing slightly forward from the snout, at an angle of 45 degrees. It can easily be conceived how fearful is a charge from an animal with such a weapon, active and determined as it is. Although the rhinoceros sees but badly, it has a peculiarly acute sense of hearing and smell. It winds an enemy at a great distance; but the hunter may approach to leeward of it within a few paces, if he walks with care, without being discovered, though at the same time any noise will instantly arouse it. Ugly as the rhinoceros is, the female is a very affectionate mother, and guards her young with the tenderest care. The calf also clings to its dam; and Senhor Silva told us that he had seen a calf watching by the side of the carcass two days after the mother had been killed. Until aroused, the rhinoceros looks the most stupid and inoffensive of animals; but woe betide the unwary traveller who offends him! If on horseback, he will have to scamper for his life; if on foot, his only chance of safety is to climb a tree, or hide on the opposite side of the thick trunk of one. A lion will never attack a rhinoceros, and slinks out of his way if he meets one. Even the elephant avoids an encounter, if he can, with so formidable an opponent, who, careless of the blows of his trunk or the thrusts of his tusks, will charge him with his sharp horn, and pierce him to the heart.