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Show 88 DISTRIBUTION OF [Ch. VI. • 1 'd to be common to the southern extremities of amma s sa1 America and Africa * • . The mt· gra tw' n of quadrupeds from one. part. of the globe to h b I·ves one of our ablest writers, IS prevented by the ot er, o se . uncongem· a1 cl 1' ma t es and the branches of the ocean· whtch m· tersect con t'm en t s. ''Hence by a reference to. the geogra. - h p . 1 't f untries we may divide the earth mto a ccrtam ICa Sl e 0 CO ' b f lnum er 'ons fitted to become the abodes of particular o reg . . f animals and we shall find, on mqmry, that each groups o ' . . of these provinces, thus conJecturally marked out, IS actually iuhabited by a distinct nation of quadrupeds t ." Where the continents of the old and new world approximate to each other towards the north, the narrow straits which separate them are frozen over in winter, and the dis .. tance is further lessened by intervening islands. Thus a passage from one continent to another becomes practicable to such quadrupeds as are fitted to endure the intense cold of the arctic circle. Accordingly, the whole arctic region has become one of the provinces of the animal kingdom, and contains many species common to both the great continents. But the tern .. perate regions of America, which are separated by a wide extent of ocean from those of Europe and Asia, contain each a distinct nation of indigenous quadrupeds. There are three groups of tropical mammalia belonging severally to America, Africa, and continental India, each inhabiting lands separated from each other by the ocean. In Peru and Chili, says Humboldt, the region of the grasses, which is at an elevation of from twelve thousand three hun· dred to fifteen thousand four hundred feet, is inhabited by crowds of lama, gu::maco, and alpaca. These quadrupeds, which here represent the genus camel of the ancient continent, "' Buffon, vol. v.-On the Virginian Opossum. t Prichard's Phys. Hist. of Mankind, vol. i. p. 54. In some of the preliminary chapters will be found a sketch of the leading facts illustrative of the geographical distribution of animals, drawn up with the author's usual clearness and ability. Ch. VI.] MAMMIFEROUS QUADRUPEDS. 89 have not extended themselves either to Brazil or Mexico, because, during their journey, they must necessarily have descended into regions that were too hot for them*· New Holland is well known to contain a most singular and characteristic assemblage of mammiferous animals, consisting of more than forty species of the marsupial family, of which no congeners even occur elsewhere, with the exception of a few American opossums. This exclusive occupation of the A ustralian continent by the kangaroos and other tribes of pouched animals, although it has justly excited great attention, is a fact, nevertheless, in strict accordance with the general laws of the distribution of species ; since, in other parts of the globe, we :find peculiarities of form, structure, and habit, in birds, reptiles, insects, or plants, confined entirely to one hemisphere, or one continent, and sometimes to much narrower limits. 'l~he southern region of Africa, where that continent extends into the temperate zone, constitutes another separate zoological province, surrounded as it is on three sides by the ocean, and cut off from the countries of milder climate, in the northern hemisphere, by the intervening t-orrid zone. In many instances, this region contains the same genera which are found in temperate climates to the northward of the line; but then the southern are different from the northern species. 'l~hus in the south we find the quagga and the zebra: in the north, the horse, the ass, and the jiggetai of Asia. The south of Africa is spread out into :fine level plains from the tropic to the Cape; in this region, says Pennant, besides the horse genus, of which· five species have been found, there are also peculiar species of rhinoceros, the hog, and the hyrax, among pachydermatous races ; and amongst the ruminating, the giraffe, th.e Cape buffalo, and a variety of remarkable antelopes, as the springbok, the oryx, the gnou, the leucophoe, the pygarga, and several others t· • Description of the Equatorial Region !I. t. Pennant's Hist. of Quadrupeds, cited bY' Prichard, Phys. Hist. of Mankin~l vol.1. p. 66. |