244 PBOtfESSOR JAMES GE1KIE, LL.D., D.C.L., F.K.S., ETC., ON 



movement hypothesis explain this remarkable succession of 

 climatic changes? Their views as to the cause of glacial 

 conditions we have considered. If we can believe that the 

 glacial phenomena were due to elevation of the land, then 

 we need have no difficulty in understanding how glacial 

 conditions would disappear when the continents again 

 subsided to a lower level. Not only did North America and 

 Europe lose all their early glacial elevation, but by a lucky 

 coincidence the Isthmus of Panama re-appeared, and the 

 Gulf-stream resumed its beneficent course into the North 

 Atlantic. This we are to suppose was the cause of the inter- 

 glacial epoch. But I would point out that the geographical 

 conditions which are thus inferred to have brought about 

 the disappearance of the glacial climate, and to have ushered 

 in the interglacial epoch are precisely those that now obtain 

 — and, nevertheless, we are not yet in the enjoyment of a 

 climate like that of interglacial times. The strangely 

 equable conditions that permitted the development of the 

 remarkable Pleistocene flora and fauna are not experienced 

 in the Europe of our day. And what about the second 

 glacial epoch ? Are we to suppose that once more the lands 

 were greatly uplifted, and that convenient Isthmus of 

 Panama again depressed ? Did the Alps, the Pyrenees, 

 and the Plateau of Central France — in all of which we have 

 distinct evidence of at least two glacial epochs — did these 

 heights, one may ask, rise up to bring about their earlier 

 glaeiation, sink down again to induce interglacial conditions, 

 and once more become uplifted at the succeeding cold epoch, 

 to subside eventually in order to cause a final retreat of 

 their glaciers'? 



But the climatic changes to be accounted for were in all 

 probability more numerous and complex than those just 

 referred to. Competent observers have adduced unmistake- 

 able evidence of three epochs of glaeiation in the alpine 

 lands of Europe. And we are not without distinct hints 

 that similar changes have taken place in Northern and North- 

 Western Europe. Nor in this connection can we ignore the 

 evidence of several interglacial episodes which Mr. Cham- 

 berlin and others have detected in the glaciated tracts of 

 North America. Even this is not all, for the upholders of 

 the earth-movement hypothesis have still further to account 

 for the climatic oscillations of postglacial times. If it be 

 hard enough to allow the possibility of one great movement 

 of elevation having affected so enormous an area of our 



