Many of the Gnawing Quadrupeds have their hind limbs much larger than the front ones, so that they leap rather than walk, giving them the appearance of the Kangaroo and others belonging to the Marsupial family. The animals of the Rodent order feed mainly on seeds, fruit, leaves, grasses and occasionally on roots and bark. Some of them, however, such as the Rat, are omnivorous, and will even eat flesh. A great number of the Rodents have their bodies covered with fine, soft and prettily-colored hair. For instance, the small Grey Squirrel and the Chinchilla both furnish furs of value; and the coats of the Beaver and the Rabbit are used in some of our manufactures. The Rodents are not usually divided into very distinct families, as their natural characteristics are not clearly marked. In the family of Rats and Mice a large number may be grouped. These form the Mus species, from the Latin, Mus, meaning Mouse or Rat. The most of the members of this family are too well known to require more than mere mention. This family includes besides what are known as the Rats and Mice proper, the Field Rats and Mice, the Dormice, Ondatras, Musquash or Musk Rats, Lemmings, Hamster Rats and Jerboa Rats. Grouped with the Chinchillas we find the Lagotis, the Viscacha, and the Ctenomys. Then come the Porcupine family, the family of Ground Hogs, Guinea Pigs and the Agoutis. The Beavers and the extensive Squirrel family are then followed by the Marmots and Woodchucks, the Prairie Dogs, and the large family of Hares and Rabbits. THE BEAVERS. [Illustration: BEAVERS.] These animals, which are celebrated all over the world for their industrious habits and their intelligence, do not possess a very pleasing appearance. The thick-set shape of the large head, small eyes, cloven upper lip which shows its powerful incisors, the long and wide tail, flattened like a spatula and covered with scales—combine to give the animal an awkward appearance. The hind feet are larger than the fore, and are fully webbed. The Common Beaver is an aquatic animal; the structure of its feet and tail enables it to swim with perfect facility. As these animals live principally upon the bark of trees and other hard substances, their front teeth are excessively strong, and by their assistance they are enabled to cut down trees of considerable size, to be used in the construction of the curious edifices for the erection of which they have been long celebrated. Their mode of building, as adopted by the Beaver of America, is described by Hearne with great exactness.