South America also produces a family of rodents not unlike small pigs, but nearer to the mouse-deer in general appearance; they are called AGUTIS. Mainly forest animals, but living also in the plains, they feed on grass, leaves, and plants of all kinds; they are very swift in their movements, and have much the habits of the small South African bucks. The fur is long, olive- or chestnut-coloured, and thick.
The PACAS are allied to the agutis, but are stouter; they live either in burrows made by themselves, or in holes in the banks of rivers, or in old tree-roots. The pacas are spotted and rather ornamentally marked; they are found from Ecuador to Brazil and Paraguay.
The DINOMYS, a spotted rodent known by one example from Peru, has been thought to form a link between the pacas and the cavies, of which the guinea-pig is the most familiar and the aquatic capybara the largest. The original of our guinea-pig is believed to be the RESTLESS CAVY, a small rodent common on the plains of La Plata. It is dark blackish, with yellowish-grey and white hairs of the domesticated species; and it is suggested that the original of the present name was "Guiana pig." This cavy lives in thickets rather than in forests or plains.
The PATAGONIAN CAVY is a larger form, about twice the size of our hare. It burrows in the ground, and has a grey coat, with yellowish markings on the sides. It has been acclimatised successfully in France and England. The flesh is like that of the rabbit.
[Illustration: _Photo by York & Son_] [_Notting Hill._
This photograph, which represents young animals, shows in great perfection the linear arrangement of the stripes.]
The CAPYBARA is the largest of all rodents. This species is, in fact, a gigantic water-guinea-pig. It is found in all the great rivers of South America, from the Orinoco to the La Plata. It swims as well as a water-rat, though it is as large as a small pig. It feeds on reeds, water-plants, and grass. A capital photograph of this animal appears on page 146.
[Illustration: _Photo by Scholastic Photo. Co._] [_Parson's Green._
This large species of cavy has been acclimatised successfully both in England and in France.]
The last two families of the Rodents have a small pair of rudimentary incisor teeth behind the large ones in the upper jaw. The PIKAS, or CALLING-HARES, resemble the marmot tribe in general appearance. Their heads are short, their ears rounded, and, being tailless, they still less resemble the common hare; but their dentition marks them as allied. One species, about 9 inches long, is found in Siberia; and another, only 7 inches long, in the Rocky Mountains. The former has a habit of cutting grass and storing it in small stacks outside its hole for winter use; the Rocky Mountain species carries its hay into its burrows.