The Capybaras frequent the borders of the lakes and rivers, with which all this part of the South American continent abounds, and, according to Mr. Darwin, they used to frequent the islands in the mouth of the La Plata, where the water is quite salt. In this part of America they are called “Carpinchos.” They never wander far from the water-side, and show a marked preference for the larger rivers, among the reeds and other plants fringing which they take up their abode. In populous districts they seem to pass the day in concealment, coming forth in search of food only at morning and evening, but where they are less in danger of pursuit they come out freely in the day-time. Seen from a little distance when walking they have much the appearance of Pigs, but they lose this when they sit, like the other Cavies, on their haunches. When danger threatens they emit a short, sharp bark, and immediately plunge into the water, where they swim about with little more than the nostrils above the surface; but under pressing circumstances they can dive and swim for a considerable distance under water. When swimming, the female is said to take her young ones on her back. About Maldonado Mr. Darwin observed that the Capybaras were usually to be seen only three or four together, but they are more numerous and go in larger companies more in the interior of the country. They constitute the ordinary food of the Jaguar, and are also eaten by the Indians, although their flesh is said not to be very good. The female produces five or six young at a birth, but has only one litter in the year. The young follow their mother about at a very early age.
SUB-ORDER II.—DOUBLE-TOOTHED RODENTS.
With the Cavies concludes the long series of simple-toothed Rodents, and some of them, as we have seen, present no small resemblance to the Hares and Rabbits which constitute the greater part of the second great group into which we have divided the order. The chief peculiarity of this section, as has been already stated, consists in the presence in the upper jaw of a pair of minute incisor teeth, placed immediately behind the large effective incisors; and in the newly-born animal the number of these teeth is even greater, there being six incisors in the upper jaw, two of which fall out at an early period. Though the number of species included in this section is very considerable (about fifty, according to Mr. Wallace’s estimate), it includes only two families, and each of these contains only a single genus. We will commence with that which includes the best-known forms, the Hares and Rabbits.
CAPYBARA.
FAMILY XVII.—LEPORIDÆ (HARES AND RABBITS).
The general appearance of these animals hardly needs to be described, and we may, therefore, indicate merely the structural peculiarities which serve to define the family. These consist in the presence of six rootless molars on each side in the upper, and five in the lower jaw (see figure on p. 82), each molar being divided into lobes by transverse folds of enamel; in the compressed form of the skull and the presence of wing-like post-orbital processes of the frontal bones; in the imperfect condition of the clavicles; the greater development of the hind limbs; and the presence of a short, bushy, upturned tail. The ears are long; the inner surface of the cheeks is more or less clothed with short hairs; the fore-limbs have five, and the hind-limbs only four toes; and the soles of the feet are hairy throughout. In all these characters, however they may differ in some respects, all the true Hares and Rabbits agree. The representatives of this family occur in nearly all parts of the world, but chiefly in the northern hemisphere, and the few species which pass down within the tropics are generally found only in mountainous regions. In the north they reach the Arctic regions in both continents. In the Old World a few species are scattered over India and Further India, and four or five occur in Africa, but chiefly in the southern part of the continent. In North America the species are numerous, and some of them range southward into Central America; but South America has only a single species, which occurs in the mountains of Brazil and upon the Andes.
As the whole of the family consists of animals to which in common parlance the names of Hares and Rabbits are given, we may take as examples of it the Hares and Rabbits which are so abundant in Great Britain, the other species agreeing generally with one or other of them in character and habits.
They may all be characterised as animals destitute of any means of defence against their enemies, except the rapidity of their movements, and as exceedingly shy and timid. Their general colour is a mixture of grey and brown, sometimes quite tawny, sometimes almost pure grey, and, as Mr. Bell remarks, “The admirable wisdom which has assigned such colours to a group of defenceless animals which conceal themselves amidst the brown sombre vegetation of woods and heaths, will appear more striking when it is recollected that certain species inhabiting the snowy regions of the north become wholly white in winter. All the members of the genus,” he adds, “are remarkable for their timidity, and their whole structure is such as at once to announce to them the presence of danger, and to enable them to escape from it. The eyes and ears are so formed and situate as to become instantly cognisant of even distant warnings of peril, and the limbs are admirably adapted for the most rapid flight.”