Imágenes de páginas
PDF
EPUB

locality, but seem to be alike descendants of a group of extinct Camel-like ancestors formerly found in North America. The two species of Camelus now living are the One-humped Camel (C dromedarius) and the Two-humped or Bactrian Camel (C. bactrianus) both of which are now best known in a domestic state. Indeed the original home of the One-humped Camel has not yet been certainly ascertained, although it is usually supposed to have been Arabia, where wild Camels are said to have existed about the commencement of the present epoch. We may therefore, perhaps, class the Arabian Camel as an Ethiopian type. But the true home of the Bactrian or Two-humped Camel is certainly the great deserts of Central Asia, where specimens of the wild species have been obtained both by Russian and English explorers. We may therefore place the Bactrian Camel as a Palfearctic animal.

The two wild species of Lama—the Huanaco and Vicuna,—are found only in the temperate portions of the Neotropical Region; from one or both of these are descended the Lamas and Alpacas of domesticity. The Lamas may consequently be classed as an indigenous form of the Neotropical Region.

Section XIII.—Distribution Of Swine-like
Ungulates

At the end of the great Ungulate series we come to the Swine or Swine-like mammals, of which the existing forms are usually assigned to four separate families, the Hippopotamuses, Wart-Hogs, true Swine, and Peccaries. Most of these forms, except the Swine, have in these days a very limited distribution, but in former days the whole series was connected, in locality as in form, by hosts of ancestors now extinct.

The Hippopotamidm, or Hippopotamuses, formerly widely-spread over the whole world, have now only two surviving species, the larger Hippopotamus amphibiv^, which is met with in nearly all the great African lakes and rivers, and the smaller Liberian Hippopotamus (H. liberiensis) which has hitherto been found only in one of the rivers of Liberia. As regards the existing creation, therefore, this peculiar form of Ungulates must be regarded as strictly Ethiopian.

The second family of Swine-like Ungulates—the Warthogs (Phacochceridm)—is also entirely confined to Africa, where two species are widely distributed from Upper Nubia, throughout Eastern Africa, down to the Cape Colony.

The true Suidm, or Swine, to which the Wart-hogs are indeed closely allied, embrace three genera—Sus, Potamochcerus and Babirussa. The typical Swine (Sus) are found in the southern part of the Palaearctic and the Oriental Regions, extending from Southern Europe, through Western Asia into India and the islands of the Indian Archipelago. It is difficult in many cases to ascertain what are the real wild species of this group, the domestic forms having varied much under domestication for many ages and having been carried by man all over the world. It is probable that the Swine of New Guinea—the so-called Sus papuensis—and those of other Eastern islands may be descendants of domestic or semi-domestic animals.

In the Ethiopian Region the place of Sus is taken by the River-hog (Potamochoerus), with a slightly different dentition. Two or perhaps three distinct species of this genus have been generally recognized, but the recent researches of Dr. Forsyth Major (c/. P. Z. S. 1897, p. 359) tend to show that we are by no means yet well acquainted with the species of this difficult group. The third genus of Suidm, the Babirussa, remarkable for the peculiar shape of its four tusks, exists only in the far-away island of Celebes and (perhaps introduced) in the adjacent island of Bouru. It must, therefore, be attributed to the Oriental Region, to which, we believe, we have now definitely shown (see above, p. 146) that Celebes must be referred.

The fourth and last family of Swine-like Ungulates contains only the Peccaries (Dicotyles) of the New World. The two species belonging to this genus range from Texas and the Southern United States down to Patagonia; and must be regarded as purely Neotropical in their geographical classification, although one of the species—the Collared Peccary—undoubtedly intrudes slightly within the boundaries of the Nearctic Region.

Section XIV.—Summary And Deductions

Table of the genera of the Order Ungulata with the numbers of species belonging to the great Zoological Regions.

[graphic][table]
[merged small][table]
« AnteriorContinuar »