CHAPTER X. 



THE PAL^ ARCTIC REGION. 



Tins region is of immense extent, comprising all the temperate 

 portions of the great eastern continents. It thus extends from 

 the Azores and Canary Islands on the west to Japan on the 

 east, a distance not far short of half the circumference of the 

 globe. Yet so great is the zoological unity of this vast tract, 

 that the majority of the genera of animals in countries so far 

 removed as Great Britain and Northern Japan are identical. 

 Throughout its northern half the animal productions of the 

 Pakearctic region are very uniform, except that the vast elevated 

 desert-regions of Central Asia possess some characteristic forms ; 

 but in its southern portion, we find a warm district at each ex- 

 tremity with somewhat contrasted features. On the west we have 

 the rich and luxuriant Mediterranean sub-region, possessing many 

 peculiar forms of life, as well as a few which are more especially 

 characteristic of the Ethiopian region. On the east we have the 

 fertile plains of Northern China and the rich and varied islands 

 of Japan, possessing a very distinct set of peculiar forms, with 

 others belonging to the Oriental region, into which this part of 

 the Palaearctic region merges gradually as we approach the 

 Tropic of Cancer. Thus, the countries roughly indicated by the 

 names — Northern Europe, the Mediterranean district, Central 

 and Northern Asia, and China with Japan — have each well- 

 marked minor characteristics which entitle them to the rank of 

 sub-regions. Their boundaries are often indefinable ; and those 

 here adopted have been fixed upon to some extent by considera- 



