( Originally Published 1936 )
This is a small family, including a few South American rodents, with four toes on the front feet and three on the hind feet, and having rudimental or short tails. The ears are large, and the claws broad and hoof-like.
Guinea Pig (Cavia cobaya)
There are several species of Cavia found in South America, but none in Africa, and therefore the English name of the domesticated animal is misleading. It measures about seven inches or rather more in length, and is parti-coloured, being white, black, and reddish, in varying proportions, differing from the wild species (C. aperea) from which it is supposed to be derived, a somewhat similar animal, but olive-brown in colour. See Plate 18, Fig. 91. The Guinea Pig is extensively reared in Europe, both as a pet and for scientific experiments. It feeds on roots, grass, and so on, and the wild species dig burrows in the ground.
Capibara (Hydrochcerus Capybara)
The Capibara, found only in South America, is the largest of all rodents. It is a very bulky, clumsy, and stupid animal, covered with coarse light-brown hair, having toes that end in hoofs, rather than claws, and a short and insignificant tail. The ears and eyes are small, the head broad, and the muzzle enormously thick and heavy. See Plate 19, Fig. 93. The Capibara is practically semi-aquatic, spending most of its time on the borders of streams, and its chief enemy is the jaguar, with whom it is a favourite article of food.
Another interesting South American form of rodent is the Agouti (Dasyprocta agouti), somewhat smaller than the capibara, and having a more sharply-pointed muzzle. There are many varieties, all distinguished by brilliant colouring, some being bright chestnut-red on the hindquarters. The form is much more delicate than that of the preceding animal, but like it, the Agouti has somewhat hoof-like claws and a short tail. It also is fond of water, and runs along the banks of streams in large herds.
Still another species, somewhat resembling the agouti, but having shorter legs, is the Paca (Coelogenys paca) . The colour of the fur is a deep brown, curiously spotted with white. A more southern form is known as the Patagonian Cavy (Dolichotis patachonica), a singular-looking animal, with long ears and long hind legs, like a hare, or rabbit. The fur is greyish, darker on the hindquarters, which are crossed with a white stripe.