The Elephants belong to the Pachydermatous order, in which they constitute a family readily distinguishable from the other enormous beasts which form part of it, the Hippopotamus and the Rhinoceros, by a combination of characters of the most remarkable description. To the immense size and clumsy figure of the two last named animals, which indeed they commonly surpass in both those particulars, they add the following distinctive zoological characters. Their teeth consist of two formidable tusks, which, occupying the place of the incisors of the upper jaw, project forwards in a nearly horizontal direction, generally with a slight curvature upwards; and of one or occasionally two cheek teeth of considerable magnitude on each side of each jaw, formed of vertical layers of bony matter surrounded by enamel, and connected together by a third substance called cortical. These latter are not, as in almost all the other Mammalia, renewed for one only time and at a certain age by the growth of others to supply their places from the cavity of the jaw beneath them; but, on the contrary, are pushed forwards by the advance of those which are destined to replace them from behind, and are renewed, according to the statement of Mr. Corse, no less than eight times at different periods of the animal’s existence. On each successive change the number of laminæ of which they are composed is increased, the earliest not offering more than four, while the later ones frequently exceed twenty; and it is in consequence of the new teeth generally making their appearance for some time prior to the total failure of their predecessors that their number occasionally appears to be double its proper and more usual amount. The tusks on the contrary admit but of a single displacement and renewal; the first or milk pair seldom exceeding two inches in length, and falling out between the first and second year. The permanent ones which succeed are much larger and more powerful in the adult male than in the female, and not unfrequently project as much as two feet. They are well known as furnishing one of the most beautiful and ornamental productions which the animal kingdom affords, as well as a valuable article of commerce, in the pure and polished ivory of which they are formed. They have been known to weigh as much as one hundred and fifty pounds, but their usual average is from fifty to seventy.