DISTRIBUTION IN ARCTIC REGIONS. 199 



present, Scandinavian flora might be carried by the 

 Gulf Stream to Greenland. 



Ocean currents will not, of course, explain the 

 migration of land animals, but floating ice may. 

 During part of the postglacial period, when the 

 volume of warm water passing along the Scandi- 

 navian shores was much less than at present, the sea 

 would doubtless be frozen during winter. The result 

 would likely be that some of the animals which might 

 happen to get on the ice in spring, or in the early 

 summer, when it broke up, would become entrapped 

 and carried away on the floating rafts. The same 

 system of currents which carried the flora to the shores 

 of Iceland and the Faroe Islands would also carry to 

 the same place many of the floating rafts. Most animals 

 would survive for a week or two without food, and 

 certainly none would perish on an ice-raft for want of 

 fresh water. In addition, some of the animals might 

 cross over to the Faroes during winter before the ice 

 broke up. To some animals, an ice-bridge would be 

 nearly as suitable as a land connection. 



In order that those places should have become 

 possessed of a flora and fauna, it was by no means 

 necessary that there should have been a continuous 

 transference of plants and animals from Scandinavia. 

 All that was necessary was simply the introduction of 

 a few members of each species ; and this could hardly 

 fail to have incidentally taken place during the course 

 of a few centuries by the agencies which I have been 

 detailing. 



If a land connection, demanding an elevation of 

 some 2000 or 3000 feet, be necessary in order to re- 

 furnish those places with a flora and fauna after a 

 period of glaciation, then we must assume that there 

 were prior elevations to that extent, or else assume 



