186 THE GEOGRAPHY OF MAMMALS 



Alps and the continuing mountain ranges that form the 

 backbone of the continent; secondly, the Mediterranean 

 Sub-region, which consists of the remainder of Europe, 

 Northern Africa, and Western Asia as far as the borders 

 of the Oriental Region ; thirdly, the Siberian Sub-region, 

 which includes not only the country from which it takes 

 its name, but also the whole of the desert region of Central 

 Asia, and reaches as far south as the Himalayas ; fourth 

 and last, the Manchurian Sub-region, containing the 

 greater part of China proper and Manchuria together 

 with Japan. 



These Sub-regions, however, do not appear to represent 

 the true faunal divisions of the Palsearctic Sub-region 

 quite adequately. In the first place, there seems to be 

 a fairly continuous and unchanging fauna extending from 

 the west of Europe all across Siberia and embracing the 

 northern island (at any rate) of Japan. This wide area 

 is still, to a great extent, covered with forest, and was, no 

 doubt, mainly so beset until within comparatively recent 

 times. 



Again, Wallace's arrangement divides between two Sub- 

 regions the vast extent of desert country that reaches 

 from the Sahara through Egypt, Arabia, Persia, and 

 Turkestan to Mongolia, which also appears to contain a 

 fairly homogeneous fauna. Wallace's Manchurian Sub- 

 region, on the other hand, seems to be well established, 

 and to be the most distinctive of all his Sub-regions, but 

 as it only embraces a part of Manchuria, we prefer to call 

 it the Chinese Sub-region. 



We may, therefore, distinguish three Sub-regions in the 

 Palsearctic Region as follows : — 



1. The Europasian Sub-region, containing Europe, the 



