Page:Encyclopædia Britannica, Ninth Edition, v. 7.djvu/288

270 270 DISTKIBUTION [ANIMAL. being two genera of snakes and four of lizards not found in any other region. All reptiles diminish rapidly as we go north, and cease before we reach the Arctic circle. The common viper reaches 67 N. lat. in Scandinavia, the northern limit of reptiles in the region. Amphibia are much more patient of cold, the common frog ranging to the extreme north of Europe. There are no less than 16 peculiar genera of Amphibia, 8 of the tailed and 8 of the tailless group, the most remarkable being the Proteus, found only in subterranean lakes in Caruiola and Carinthia. Of fresh- water fishes about 20 genera are wholly confined to the region, of which the perches (Percidce) have 3 genera ; the salmons and trout (Salmonidoe) 3 genera ; the carp (Cyprinid-ce) 13 genera; with a peculiar genus and family (Gomephorus) found in Lake Baikal, and another (Tellia) belonging to the CyprinodontidcE, in the Atlas Mountains. Insects are so extensive a class that the barest enumera tion of their most remarkable forms would be out of place in such a sketch as this. We can only mention that, although butterflies are not very numerous, yet no less than 15 genera are peculiar to the region. Beetles, how ever, abound, and the most characteristic Palasarctic group is undoubtedly the Garabidce, or predaceous ground-beetles, which are more predominant here than in any other region, and are also of larger average size a most unusual cir cumstance in the insects of a temperate as compared with those of tropical regions. Land shells are tolerably numerous both in species and in dividuals, but are of small size and little beauty as com pared with those of wanner countries. Very few of the genera are peculiar. The total number of the generic forms of Vertebrata peculiar to the Pakearctic region is, as nearly as can be estimated, 138, a very large number when we consider the general severity of the winter, and the circumstance that along its whole southern margin this region is bounded by tropical lands with no absolute barrier against intermi- gration. The amount of peculiarity may be even better estimated by the fact that, out of a total of 274 genera of Mammalia and birds inhabiting the region, 87, or somewhat less &quot;than one-third, are confined to it. This mode of esti mating the zoological character of a region by genera, gives a far truer idea than any enumeration of peculiar species, because the former imply more radical and important differences than the latter. Subdivisions of the Palcearctic Region. The general zoological characters here given apply with considerable uniformity to the whole of the Paloearctic region, the similarities being of course greater where climate and physical conditions generally correspond. Thus, even between such remote islands as Great Britain and Yesso (North Japan) there is a wonderful similarity in the general forms of life, many of our most familiar birds and insects reappearing at the other extremity of the region under identical or but slightly modified forms. Owing perhaps to the great climatal changes tho north temperate zone has undergone in recent geological times, and the vast amount of migration thereby produced, as well as to the absence of any continuous barriers, it is very difficult to mark out with accuracy the ?oological subdivisions of this region. Certain broad divisions, depending partly on climate, partly on physical features, and partly on geographical proximity to other regions, may, however, be indicated. Europe, north of the Pyrenees, Alps, Balkans, and Caucasus, may perhaps be considered as the most typical portion of the Paltearctic region, possessing most of its characteristic features in their full de velopment. It may be termed the European sub-region. South of this comes the Mediterranean sub-region, including South Europe and North Africa, which wonderfully resemble each other in all their chief forms of animal life, although some few purely African species are found south of the Mediterranean. This sub-region in cludes also Asia Minor and Persia, with Syria and Northern Arabia. It is chiefly characterized by a number of desert forms, such as gazelles, civets, jerboas, quails, desert-larks, and numerous lizards ; and by a number of species which cannot endure the colder climate of the north, as porcupines, monkeys, ichneumons, and a host of peculiar groups of insects. To this region belong the Atlantic islands from the Azores to the Canaries, the animal pro ductions of all of them being closely related to those of South Europe or North Africa. It is a curious fact that the remotest of these islands, the Azores, offer less peculiarity in their birds and insects than Madeira and the Canaries, which are so much nearer the continent ; but this is sufficiently explained by the greater pre valence of storms and gales in the more northern latitude of the Azores, and helps to prove that aerial currents are the chief means by which these two classes of animals are dispersed. For a discus sion of this interesting subject and its bearing on the theories of distribution and development, see Wallace, Geographical Distribu tion of Animals, vol. i. p. 206. The northern part of Asia differs very little in the main features of its zoology from the corresponding parts of Europe, but as we ap proach the northern slopes of the great plateau of Central Asia many peculiar forms occur, as wild horse, pikas (Layomys], starlings of the genus fodoccs, and many others. The great desert plateaus of Thibet and Mongolia form another subdivision, with many peculiar forms. Here are found the yak, some peculiar antelopes, with wild sheep and goats, and several peculiar rodents ; and among birds many peculiar forms of grouse, partridges, and pheasants. Another well-marked division is formed by the temperate portion of Eastern Asia, comprising Japan, Manchuria, Northern and Cen tral China, with parts of East Thibet and the higher portions of the Himalayas as far west as Nepaiil. This is a fertile and luxuri ant district which receives several tropical forms of life from the adjoining Oriental region. It is rich in Insectivora and in ducr, the deer-like musk being confined to it ; it has a peculiar form of wild-dog (Nydcrcutcs), and even several peculiar species of tho monkey tribe. It is also pre-eminently the home of the pheasant tribe, such magnificent birds as the golden, silver, and lleeve s pheasants being peculiar to it. It has also a number of showy jays, finches, tits, and warblers ; and its insects present a number of fine tropical-looking species. The Manchurian sub-region has thus a very beautiful and varied fauna, but the intermingling of Oriental types, and the uncertainty of its southern boundary, render it less characteristically Palasarctic than the European sub-regions. II. The Ethiopian Region. This region is much less extensive than the last, but being almost wholly tropical it presents a richer and more varied assemblage of animals. Its southern extremity, although really extra-tropical, is yet so warm and so little subject to extremes of temperature that the growth of vegetation and the corresponding develop ment of animal life are scarcely diminished, and the same may be said of the elevated interior of the continent. As Madagascar is quite isolated and its productions very pecu liar, it will be best first to sketch the main features of African zoology, which are tolerably well marked and homogeneous. The African continent is pre-eminently the country of large Mammalia. It possesses an abundance of elephants, rhinoceroses of several species, giraffes (now peculiar to it), gorillas and baboons the largest of the ape tribe, a host of large and remarkable antelopes, the huge hippopotamus, several species of zebras, wild buffaloes, several remarkable forms of swine, and an abundance of lions, leopards, and hyosnas, forming together an assemblage of large and highly organized animals such as occur nowhere else upon the globe. There are also many smaller, but very remark able forms. There are 7 peculiar genera of apes, 3 of lemurs, 5 of Insectivora, 12 of Vivcrridce, the remarkable Proteles forming a distinct family allied to hyaenas and weasels, 2 of Canidce, 2 of Mustelidce, 2 of Suidce, 1 of Tragididce, 12 of Bovidce (antelopes), 18 of various families of llodents, and the curious aardvark (Orycteropus), form ing a distinct family of Edentata. In birds Africa is not so peculiar, yet it has many remarkable groups. Such are the plantain-eaters (Muso- phagidce), the colics (Cdiidee), the secretary-birds (Ser- pentariidte), the ground horn-bills, and the guinea-fowl, all of which are peculiar. It abounds also in peculiar fly catchers, shrikes, sun-birds, weaver-birds, starlings, larks, barbets, grouse, and hawks, more than half the genera of land-birds being peculiar, and, if we include those of Madagascar, nearly two-thirds, Reptiles abound, there being three peculiar families of snakes and one of lizards ; and there is one peculiar family