290 THE ICE AGE IN CANADA. 



were covered with a mer-de-glace, moving to the southward 

 and outward to the sea. This great ice-mantle not only 

 removed stones and clay to immense distances, and 

 glaciated and striated the whole surface, but it cut out 

 lake basins and fiords, ground over the tops of the highest 

 hills, and accounted for everything otherwise difficult in 

 the superficial contour of the land. It was even trans- 

 ferred to Brazil, and employed to excavate the valley of 

 the Amazon. But this was its last feat, and it has 

 recently melted away under the warmth of discussion 

 until it is now but a shadow of its former self. I may 

 mention a few of the facts which have contributed to 

 this result. It has been found that the glacial boulder- 

 clays are in many cases marine. Cirques and other 

 alpine valleys, once supposed to be the work of glaciers, 

 are now known to have been produced by aqueous denu- 

 dation. Great lakes, like those of America, supposed to be 

 inexplicable except by glacier erosion, have been found to 

 admit of being otherwise accounted for. The transport 

 of boulders and direction of striation have been found to 

 conflict with the theory of continental glaciation, or to 

 require too extravagant suppositions to account for them 

 in that way. Greenland, at one time supposed to be an 

 analogue of the imaginary ice-clad continent, has proved 

 to be an exceptional case which could not apply to the 

 interior of a wide continental area. The relation of 

 Greenland to Baffin's Bay and Davis straits is indeed 

 similar to that which may have obtained between the 

 Laurentide hills and the submerged valley of the St. 

 Lawrence, or to that of the Cordillera range to seas lying 

 west and east of it. The conditions of modern Greenland, 

 in short, at that time spread southward over the high 

 ridges exposed to the vapour-laden atmosphere of the 



