ARCTIC INTERGLACIAL PERIODS. 195 



constantly driven by the ocean -currents along the 

 coasts." * 



This testimony is the more valuable as it is given 

 by an experienced geologist so much opposed to the 

 theoiy of interglacial periods. A more special and 

 thorough search of those beds might probably reveal 

 further indications of intero-lacial ao-e. 



Was Greenland free from Ice during any of the 

 Interglacial Periods? — There is nothing whatever 

 improbable in the supposition that, during some of 

 the earlier interglacial periods, when the eccentricity 

 was about a maximum, the ice might have completely 

 disappeared from Greenland, and the country become 

 covered with vegetation. 



Mr. Wallace thinks that the existence at present of 

 an ice-sheet on Greenland is to be explained only by 

 the fact that cold currents from the polar area flow 

 down both sides of that continent. He further thinks 

 that could these two Arctic currents be diverted from 

 Greenland, " that country would become free from ice, 

 and might even be completely forest-clad and habit- 

 able." t 



I am inclined to aoree with Mr. Wallace in thinking 

 that the withdrawal of the two cold currents in ques- 

 tion would effectually remove the ice. We know that 

 Greenland is at present buried under ice, as has been 

 shown on former occasions, simply because there 

 happens to be about two inches more of ice annually 

 formed than is actually melted. It certainly would 

 not require any very great change in the present 

 physical and climatic conditions of things to melt two 



* "On Former Climate of Polar Regions," " Geol. Mag.," Nov., 



1875, p. 531. See also "Geology of Spitzbergen," "Geol. Mag.," 



1876, p. 267. 



f "Island Life," p. 149. 



