THE FAUNA OF BRITAIN. 97 



we shall see, the Irish Stoat, Horse, and Reindeer 

 probably came by a different route from that taken 

 by the English representatives of the same species. 



Very few of the lower animals of Siberian origin 

 have reached the British Islands. Most of those 

 which were formerly thought to be Siberian are either 

 of East European or of Central and South Asiatic 

 origin, though they probably joined the Siberian 

 migration on their way to England. The Arctic 

 migration brought a greater variety of species to 

 this country than the Siberian, but neither the one 

 nor the other has contributed more than a small per- 

 centage to the British fauna. The bulk of that fauna 

 is derived from the various European centres of dis- 

 persal, and especially from Central and Southern Asia. 



Those animals which have their home in the latter 

 area, I have named Orientals, though it must be re- 

 membered that they need not necessarily have come 

 from what is known among zoologists as the " Oriental 

 Region." The terms " Oriental animals " and " Ori- 

 ental migration " are used here in a wider sense, and 

 include even those species which reached Central and 

 Northern Europe from South-Eastern Europe. It is 

 astonishing, what a vast number of both vertebrate 

 and invertebrate animals can be traced back to this 

 Oriental migration. Great tracts of Europe were 

 repeatedly submerged beneath the sea during Tertiary 

 times, and on their re-appearance were formed into 

 green fields and pastures new for the rich Asiatic 

 fauna, which was ever ready to flood the neighbouring 



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