THE GLACIAL PERIOD AND THE EAETH-MOVEMENT HYPOTHESIS. 245 



hemisphere, if we find it extremely difficult to believe either 

 that one such wide-spread movement, or that a multitude of 

 local movements, each more or less independent of the other, 

 could have lifted the glaciated regions successively within 

 reach of the snow-line — we shall yet find it impossible to 

 admit that such remarkable upheavals could be repeated 

 again and again. 



We seem driven to conclude, therefore, that the earth- 

 movement hypothesis fails to explain the phenomena of 

 Pleistocene times. One cannot deny, indeed, that glaciation 

 might be induced locally by elevation of the land. It is 

 quite conceivable that mountains now below the limits of 

 perennial snow might come to be ridged up to such an 

 extent as to be capable of sustaining snow-fields and glaciers. 

 And such local movements may possibly have happened here 

 and there during the long-continued Pleistocene period. 

 But the glacial phenomena of that period are on much too 

 grand a scale, and far too widely distributed to be accounted 

 for in that way. And if the occurrence of even one glacial 

 epoch cannot be thus explained, we may leave the supporters 

 of the earth-movement hypothesis to show us what light is 

 thrown by their urim and thummim on the origin of suc- 

 ceeding interglacial and glacial climates. 



While we have no evidence of wide-spread elevation having 

 coincided with glacial conditions, proofs of subsidence are 

 almost everywhere associated with the glacial phenomena of 

 the maritime districts of North America and Europe. Raised 

 beaches and marine deposits are traced on the coasts of 

 North America, from an elevation of 50 feet or so in Southern 

 New England up to 75-100 ft. near Boston ; of 200 ft. or 

 thereabout in Maine ; of 520 ft. at Montreal ; of 1,500 ft. in 

 Labrador; and of 1,000-2,000 ft. in Arctic regions. None of 

 the raised beaches of glacial age met with in Europe reaches 

 such an elevation as these last — the highest being met with 

 in Norway at 580 ft. or thereabout. Marine shells occur in 

 the glacial series of Scotland at a height of 500 ft., but the 

 highest raised beach of the period does not exceed 100 ft. in 

 elevation. It is doubtful if all those indications of submer- 

 gence can be assigned to one and the same stage of the 

 glacial period. So far as regards Scotland they certainly 

 belong to separate stages. Thus the shell-beds at 500 ft. are 

 of interglacial age — theyrestupon and are covered by boulder- 

 clay, while the 100 ft. beach pertains to the close of the last 

 glacial epoch. But putting such considerations aside, it 



