THE ARCTIC FAUNA. I&3 



climate, such as might have been produced by the 

 proximity of a cold sea on one side and of a warm 

 one at the other, than by invokirg an arctic climate 

 with enormous glaciers. Most of the living animals 

 and plants would have been exterminated under the 

 latter conditions. Palaeontological evidence in Great 

 Britain clearly indicates that southern species migrated 

 first to these islands, that Arctic species were then 

 driven south from their native lands, probably owing 

 to insufficient food-supply and climatic changes in 

 the north, that finally eastern species invaded the 

 country all this without the annual temperature 

 of Europe being apparently much affected. For we 

 find in the British pleistocene deposits and Mr. 

 Lydekker draws particular attention to this remark- 

 able fact a curious intermingling of southern and 

 northern mammals, which undoubtedly lived side by 

 side. Everybody knows that northern and Arctic 

 species can live perfectly well in a temperate climate, 

 but that it is almost impossible to acclimatise 

 southern animals in an Arctic or even temperate 

 one. We have in this circumstance almost a proof, 

 therefore, that the climate cannot have been very cold. 

 Though a cold sea bathed the shores of Eastern 

 England, and even eventually invaded a portion of 

 Northern England, the warm ocean on the west 

 must have effectually prevented any great lowering 

 of temperature. 



At the time when the North European Sea flooded 

 a portion of England, Scandinavia was still connected 



