520 PREHISTORIC EUROPE. 



epoch must have sufficed to destroy such a flora as it now pos- 

 sesses. And the same must have been the case with Greenland. 

 Indeed I do not see how it is possible to resist the conclusion 

 that the floras of all those high latitudes must have been intro- 

 duced since the close of the' Glacial Period. And as the plants 

 could only have migrated over a land-surface, we are compelled 

 to infer that in postglacial times the Fseroe Islands, Iceland, 

 Greenland, and Spitzbergen also, must have been united to the 

 European continent. 



It is hard to tell what amount of elevation would suffice to 

 bring about such an union at present. The soundings in the 

 Arctic Ocean are few and widely separated. We know that a 

 trough, which in places exceeds 500 fathoms in depth, lies 

 between the Outer Hebrides and the Fseroe Islands. But at 

 one place this deep hollow appears to contract to a width of not 

 more than thirty miles, and it is quite possible that an elevation 

 of less than 500 fathoms might produce a land-surface so nearly 

 continuous as to permit of immigration by wind and ocean- 

 currents, and by birds. An elevation of apparently less than 

 400 fathoms would join the Fseroe Islands to Iceland, and the 

 Danish Straits between Iceland and Greenland might perhaps 

 be bridged with a similar or even a less amount. The sea 

 between Norway and Spitzbergen appears to be comparatively 

 shallow, not exceeding 200 fathoms or thereabout. In these 

 speculations, however, we must remember that it is perfectly 

 possible that the depression which brought about the isolation 

 of the regions in question may have been unequal — some regions 

 sinking deeper than others. Even at the present day similar 

 earth -movements are believed to be going on within the very 

 area under review. Thus, while the shores of the Danish 

 settlements in Greenland are slowly sinking, a part of the 

 Swedish coast is supposed to be gradually rising. Again, in 

 Scotland the presence of raised -beaches on the coasts of the 

 mainland proves a recent gain of land, while the complete 

 absence in the Outer Hebrides, the Shetlands, and the Fseroe 

 Islands, of any such deposits shows that those regions have 



