There was a great causes of this change were of two kinds. geographical and physical revolution effected by the elevation of the Himalayas and the Thibetan plateau, and, probably at the same time, the northward extension of the great Siberian plains. This alone would produce an enormous change of climate in all the extra-tropical part of Asia, and inevitably lead to a segregation of the old fauna into tropical and temperate, and a modification of the latter so as to enable it to support a climate far more severe than it had previously known. But it is almost certain that, concurrently with this, there was a change going on of a cosmical nature, leading to an alteration of the climate of the northern hemisphere from equable to extreme, and culminating in that period of excessive cold which drove the last remnants of the old sub-tropical fauna beyond the limits of the Palæarctic region. From that time, the Oriental and the Ethiopian regions alone contained the descendants of many of the most remarkable types which had previously flourished over all Europe and Asia; but the early history of these two regions, and the peculiar equatorial types developed in each, sufficiently separate them, as we have already shown. The Malayan sub-region is that in which characteristic, Oriental types are now best developed, and where the fundamental contrast of the Oriental, as compared with the Ethiopian and Palearctic regions, is most distinctly visible. TABLES OF DISTRIBUTION. In constructing these tables, showing the distribution of various classes of animals in the Oriental region, the following sources of information have been chiefly relied on, in addition to the general treatises, monographs, catalogues, &c., used for the compilation of the Fourth Part of this work. Mammalia.-Jerdon's Indian Mammalia; Kelaart's Fauna of Ceylon; Horsfield and Moore's Catalogue of the East India Museum; Swinhoe's Catalogue of Chinese Mammalia; S. Müller's Zoology of the Indian Archipelago; Dr. J. E. Gray's list of Mammalia of the Malay Archipelago (Voyage of Samarang); and papers by Anderson, Blyth, Cantor, Gray, Peters, Swinhoe, &c. Birds.-Jerdon's Birds of India; Horsfield and Moore's Catalogue; Holdsworth's list of Ceylon Birds; Schlegel's Catalogue of the Leyden Museum; Swinhoe on the Birds of China, Formosa, and Hainan; Salvadori on the Birds of Borneo; Lord Walden on the Birds of the Philippine Islands; and papers by Blyth, Blanford, Elwes, Elliot, Stoliczka, Sclater, Sharpe, Swinhoe, Verreaux, and Lord Walden. Reptiles.-Günther's Reptiles of British India; papers by same author, and by Dr. Stoliczka. |