The _Cavies_ appear to represent the hare family in the tropical parts of America. It is true that these last differ from hares in many particulars; but they have also many points of resemblance, and they may be grouped together in a very natural manner. They live much in the same manner; they are swift and inoffensive as the hares; but, instead of being clothed in soft wool, which would be altogether unsuitable to the climate in which they dwell, the cavies have a covering of hair so fine and thin as to convey to the touch a feeling of coolness rather than warmth. Some of the cavies are among the largest animals of the Rodent Family; for instance, the great Capivara, which is equal in size to an ordinary pig. This species is not a swift runner upon land; but it is semi-aquatic in its habits, and can swim and dive like an otter, its feet being webbed or palmated. It herds in troops of from five or ten to fifty in number, and is found upon the banks of all the great South American rivers, where it has for its chief enemy the fierce jaguar. The Guinea Pig is one of the family of cavies. This beautiful little animal is too well-known to require description. It may be remarked, however, that the name Guinea Pig is altogether a mistake, since the creature is found wild only in South America, and is _not_ a native of Guinea in Africa. Very likely it was originally brought from Guiana, and this has led to the misnomer. There are several species of Guinea pig in South America, differing from one another in size, shape, and colour. Besides the large Capivara and the little Guinea Pig, there are several intermediate kinds. These are known as the True Cavies, and are usually called Agoutis, or Acouchis. The agoutis are about the size of the common hare, and run almost as swiftly. For their food they prefer nuts to herbage, which is natural enough in a region where the latter is scanty and the former exists in plenty; and in eating they "squat" upright on their haunches, and convey the food to their mouth after the manner of squirrels. The agouti, like the hare, frequently rolls over when descending a hill at full speed--a habit, or rather an accident, due to the same cause in both animals, namely, the great length of the hind legs. When angry, the agouti stamps with the fore-feet, grunts like a young pig, and erects the bristly hair upon its crupper after the manner of porcupines. There are many species of agouti throughout tropical America and the West India Islands, and the range of the genus extends as far south as the plains of Patagonia.