THE FAUNA OF BRITAIN. Ill 



and Ireland, and thence the famous deficiencies of 

 the sister isle, as, for instance, its freedom from 

 reptiles" (p. 10). He is also of opinion, that the 

 separation between England and the Continent took 

 plade at a later date than that between England 

 and Ireland. 



According to Dr. A. R.Wallace (p. 338), we possessed 

 just before and during the Glacial period "a fauna 

 almost or quite identical with that of adjacent parts 

 of the Continent, and equally rich in species." But 

 the submersion, he thinks, which is supposed to have 

 occurred during the latter part of the Glacial period, 

 destroyed the greater part of the life of our country. 

 When England again became continental, continues 

 Dr. Wallace, this fauna was succeeded by an assem- 

 blage of animals from Central Europe. " But sufficient 

 time does not seem to have elapsed for the migra- 

 tion to have been completed before subsidence again 

 occurred, cutting off the further influx of purely 

 terrestrial animals, and leaving us without the number 

 of species which our favourable climate and varied 

 surface entitle us to." The comparative zoological 

 poverty of Ireland he attributes to the fact that " the 

 depth of the Irish Sea being somewhat greater than 

 that of the German Ocean, the connecting land 

 would there probably be of small extent and of less 

 duration, thus offering an additional barrier to 

 migration." 



Dr. Wallace's explanation of the origin of the 

 British fauna is disappointing after Forbes's careful 



