The Agouti (_Dasyprocta Agouti_) is another South American Rodent, about one-third the size of the Paca; he swims, but does not dive. He has sometimes been named "the rabbit of the South American continent," but differs from it in many essential points, and really belongs to the _Cavidæ_, or guinea-pig tribe. He possesses the voracious appetite of the hog, and devours indiscriminately everything that comes in his way. He conveys his food to his mouth with his fore-paws, like a squirrel, and as he has long hind legs, runs, or rather leaps, with considerable swiftness. He is hunted very perseveringly on account of the devastation he causes among the sugar-canes. There is a larger species called the _Mara_, or Pampas Hare (_Dasyprocta Patachonica_), which will wander for miles away from its home. Among the most interesting Rodents of the New World must be classed the Vizcacha and the Chinchilla, whose furs are so highly valued. The Vizcacha, or Bizcacha (_Calomys bizcacha_), somewhat resembles a rabbit, but his teeth are larger, and he has a long tail. He lives, it is said, on roots, and never wanders far from his burrow. His flesh, when cooked, is very white and savoury. The Chinchilla (_C. lanigera_) inhabits the cold mountain-valleys, where his close, fine gray fur is an invaluable protection. He is a pretty animal, much like the rabbit, but with a squirrel's tail; of a mild and sociable disposition; and living with his kind on the most amicable terms. Nor must the Beaver be forgotten, the most industrial animal of the Rodentia, which has wholly disappeared from Europe, and is yearly growing scarcer in America. The Beaver (_Castor fiber_) is specially recognizable by his broad horizontally-flattened tail, which is of a nearly oval form, but slightly convex on its upper surface, and covered with scales. His hind feet are webbed, and together with the tail, which acts as a rudder, propel him through the water with ease and swiftness. His length, exclusive of his tail, which measures one foot, is about three feet; colour, a deep chestnut; hair, very fine, glossy, and smooth. The incisor teeth are large, and so hard, that the North American Indians used them in fabricating their horn-tipped spears and cutting bone, until iron tools were introduced from Europe. The sagacity with which he constructs his habitation has long been a theme of eulogy, and has furnished moralists with many an apt image and pregnant illustration. Water is the necessity of his life. It is indispensably necessary that the stream near which the animal lives should never run dry; and to prevent so dire a misfortune, he is gifted with an instinct which teaches him to keep the water at or about the same mark, by building a dam across the channel. In order to comprehend the art with which this dam is constructed, we must watch the beaver at his patient toil.[137]