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 Jaguar to America, and so forth. The entire expanse of country which is inhabited by an animal is called its area of distribution. Such areas are larger or smaller. The Lion ranges over the whole of Africa, a small part of India, and some neighbouring countries; on the other hand, the Insectivore Solenodon is limited to Cuba and Hayti, a separate species to each. Among other groups of animals are instances of an even more restricted range. There are humming-birds confined to the slopes of a single mountain, and fishes limited in their range to a single small lake.

A species may be found everywhere within the area of its distribution, or it may be confined to a number of limited tracts within that area. In this case it is usual to speak of "stations." In such cases the species in question is generally suited to some particular kind of environment. Thus the Otter and other aquatic mammals will only be found where there is water; and intervening tracts of waterless country will contain no Otters. Goats and Chamois live only upon mountains; the intervening plains are destitute of them. This discontinuity of distribution within the area is very general. But a discontinuity of area is also seen—not so commonly however; and, indeed, when it does occur, it is a matter of a genus and not of a species. Thus the Tapir is found in the East Indies on the one hand and in South and Central America on the other, being absent in the intermediate tracts.

It is clear that tracts of country eminently suitable for the housing of a particular mammal do not always possess that kind, or even an allied form. Africa, for example, possesses no arboreal Anteaters; there are no Anteaters at all (of the order Edentata) in Australia, though there are plenty of ants for them to feed upon, and tropical conditions of climate prevail. But as in these cases the inference may be denied on the grounds that no experiments exist to prove or to disprove the assertion, the matter may be better emphasised by such cases as the introduction of the Rabbit into Australia, and various mammals, such as Goats, into oceanic islands. The plague caused by the former is a matter of notoriety. But although climate and conditions and animal inhabitants do not march accurately together, there is certainly some connexion between temperature and the range of animals. Mr. Lydekker writes on this point as follows: "The llama-like animals, respectively known as vicunas and guanacos, are met with in