1 82 HISTORY OF THE EUROPEAN FAUNA. 



with the Atlantic Ocean across the north of England 

 (Fig. 6, p. 126), the junction between the former 

 and the Ponto-Caspian having meanwhile become 

 dry land (Fig. 13, p. 170). A fresh current, now 

 flowing westward, was set up in the North Euro- 

 pean Ocean, which accounts for the fact just cited 

 that the erratics in the upper continental boulder- 

 clay have travelled in a different direction from 

 those in the lower. The boulder-clay laid down by 

 the sea on the midland and northern counties of 

 England, just as was the case with the similar deposit 

 on the Continent, is generally accredited to the 

 action of land-ice. It is by most geologists looked 

 upon as the ground-moraine, partly of the huge 

 Scandinavian glacier which is supposed to have 

 impinged upon the English coast, partly of local 

 British glaciers. 



But renewed geological investigations on this point 

 throw doubts upon these theories. Thus Mr. Harmer 

 remarks in a recent contribution to glacial literature 

 (p. 775), that "it is difficult to see how the Baltic 

 glacier could have reached East Anglia, though ice- 

 floes with Scandinavian boulders might easily have 

 done so, while had the Norwegian ice filled the North 

 Sea and overflowed the county of Norfolk, some evi- 

 dence of its presence ought to be found in the glacial 

 beds of Holland." 



All the phenomena of distribution of the British 

 fauna and flora are, as we have seen, much more easily 

 explained by the supposition of a damp, temperate 



