Page:Natural History (1848).djvu/214

204 The Order before us, which is very extensive in genera and species, consists of animals, all of which may be characterized as of small, and, for the most part, of diminutive size. They may be readily known by the incisor teeth, which, two in number in each jaw, project from the very extremity of the jaw, in a forward curve: they are strong, compressed, and armed only on the

SKULL OF PORCUPINE.

front side with enamel; which being more durable than the bony matter of the rest, always maintains a sharp chisel-like edge to the teeth. They have no roots, but are deeply inserted in their sockets; and springing from a pulpy germ, are