The other peculiar animal among the ungulates, which demanded a sub-order all for itself, is the elephant. Of this creature there are but two species now living, the Indian and the African elephants. They are classed by themselves on account of the proboscis or trunk, which no other animal possesses, and which a little boy described as a “big be-front tail, so that the elephant could walk backwards or forwards all the same.” But this is a most unhappy description of an elephant. The African elephant is the larger species, being sometimes eleven feet high. Its ears are much larger than those of the Asiatic species, are differently set, and there are also differences in the structure of the head and teeth. The tusks of the elephant are two large curved, bony appendages, projecting from the mouth on either side of the trunk. What are they? Why, _teeth_ to be sure! Teeth? Yes; they are the two incisors such as I told you the beavers have, but the odd thing about these teeth is, that, beginning to grow in the second year of the elephant’s life, they keep on growing as long as he lives. Of course they are soon too long to be kept within the shelter of the mouth, and so they project and grow and grow, until sometimes they become so enormous as to weigh from one hundred and fifty to two hundred pounds each. But these are exceptions; from thirty to eighty pounds is a more usual weight. Sometimes the tusks turn upward; sometimes they grow almost straight, or with a downward inclination. Besides these huge incisors the elephant has six molars or grinding teeth on each side of each jaw. As these molars are its only teeth useful in eating, we see at once that the food of an elephant must be grass, hay, grain, and fruit. The tusks of the elephant are almost entirely the purest of ivory, and as they are our main source of this valuable material, thousands of elephants are slaughtered to secure the tusks. As the elephant has the fewest young of any known animal, the race of elephants cannot keep up with the rapid destruction produced by the ivory hunters, and there is great danger that it will become extinct. In Africa elephants are not tamed and trained, but in India for many hundred years they have been kept as beasts of burden, as war animals, and as ornaments to the state of kings. The most notable characteristic of the elephant is its proboscis. What is that? As the tusks are two overgrown teeth, so the proboscis is an overgrown nose and upper lip. The nose and upper lip of the elephant are prolonged into a tube, often six feet long, tapering almost to a point. At the extreme end of this organ the nostrils are situated, and elephants often swim entirely under water, by simply carrying the end of the proboscis above the surface. The proboscis is composed chiefly of muscles, four thousand of them we are told, together with many nerves. Thus it is exceedingly strong, flexible, and very sensitive, and an injury to it gives the animal intense pain.