The sagacity of the elephant has been the theme of many stories, which have also celebrated its affection, gratitude, its sensibility to kindness, its revengeful memory of affronts, and its treacherous disposition, given to sudden bursts of rage. White elephants, of which so much is said, are not a separate species, but albinos. We have now seen the greatest of the ungulates. With him in a menagerie we often find the tapir, remarkable for its long nose, and as being one of the oldest species of living mammals, therefore of an ancient dignity of family to which the king-crab, hatteria, opossum, and beaver may make their best bows. The hippopotamus is a hoofed animal, next in size to the elephant. It is a hideous and dirty-looking animal, but one that in a menagerie or garden moves our compassion, for it is by its nature an amphibious creature, born to live in the rivers, and to spend the most of its time diving or swimming, or standing neck deep in water; and nothing can be more wretched than its appearance as it chews dry hay, and panting waits for a keeper to throw a few pailfuls of water over its fevered skin. The hippopotamus is a tusk-wearer like the elephant, and while the ivory of its tusks is not quite so good as that furnished by the elephant, it is yet in great demand. The hide is also used in the manufacture of boots, trunks, and many instruments. The rhinoceros is another big specimen of the ungulates, with a bare, smooth hide. It is an aquatic animal, wearing a single horn on the front of its snout. In its native home, this horn serves to root up river-plants, on which it feeds; it is also the weapon of war. Given in its natural haunts to spending hours in rolling in the mud or wading in water, the rhinoceros suffers severely in confinement. Usually of a mild, quiet temper, it seems sometimes filled with homesickness and despair, and with loud moans dashes its head against the walls of its prison as if wishing to end its miseries by breaking its skull. No hoofed animal is better known, whether dead or alive, than the pig. The pig is the direct descendant of the wild boar, and owes the various changes in its appearance and conformation to ages of domestication. The wild boar is an animal with long legs, long bristles, lean body, a long snout, and a pair of big tusks formed by the elongation of two canine teeth on each side of the mouth. The two canine teeth on the lower jaw are much larger and stronger than those on the upper. The boar has fiery little eyes, a fierce and active disposition, and great courage.