BABIRUSA, the wild swine of Celebes and Buru (Babirusa al f urus). The skin is nearly naked, and very rough and rugged. The peculiarity of this genus is the development of the canines, or tusks, of the male. These teeth are ever-growing, long, slen der and curved, and without enamel. Those of the upper jaw are directed upwards from their bases, so that they never enter the mouth, but pierce the skin of the face; they curve backwards, downwards, and finally often forwards again, almost or quite touching the forehead. Wallace remarks that "it is difficult to understand what can be the use of these horn-like teeth. It is conceivable that these tusks were once useful, and were then worn down as fast as they grew, but that changed conditions of life have rendered them unnecessary, and they now develop into a monstrous form. . . . In old animals they reach an enormous size, and are generally broken off as if by fighting." See SWINE;