230 PREHISTORIC EUROPE. 



quartz, and more and more rounded, and accumulated in a 

 stratum at the bottom of the bed, or constituting the whole 

 of it." x 



The glacial phenomena of Europe are, in short, reproduced 

 in North America. Similarly it is well known that in Asia the 

 valleys of the Himalaya formerly supported enormous glaciers, 

 and that traces of ice-action occur in China in regions which 

 are certainly very far from being glacial now. All this, as I 

 have said, points to some widely-acting cause, a conclusion in 

 which geologists are now pretty well agreed. But while I 

 reject the view that the Glacial Period of Europe, or of any 

 portion of Europe, was directly induced by an elevation of the 

 land, I do not doubt that here and there the intensity of glacia- 

 tion may have been locally influenced in some measure by 

 changes in the relative level of land and sea. 



Hitherto we have confined our attention to phenomena 

 which are more or less directly due to the action of frost, of 

 snow, and glaciers. "We must now glance for a little at the 

 general character of those aqueous deposits which we have 

 every reason to believe were accumulated upon certain areas in 

 the low grounds of Europe contemporaneously with the erratics, 

 moraines, and angular cUhris of other districts. And among 

 these must be included those angular gravels in the southern 

 districts of England, which have been described and explained 

 by Mr. Darwin. The fact that perennial snow and ice were so 

 widely distributed over the northern latitudes of our continent, 

 and that so many of the hilly regions, even in the extreme 

 south, supported large glaciers, sufficiently proves that during 

 the Glacial Period the winter must have been severe, but it 

 also indicates the prevalence of great humidity. There must 

 have been excessive evaporation, and a more copious distribu- 

 tion of moisture, over the length and breadth of our continent 



i Mr. Kerr's explanation of these superficial phenomena, it will he observed, 

 does not differ greatly from that adopted by Prof. Eamsay and myself to account 

 for the origin of the Gibraltar breccias. "When our paper was written we did not 

 know of Mr. Kerr's investigations in this matter, otherwise we should have made 

 special reference to them. 





