290 THK ICK A(JK IN CANADA. 



were covered with a nier-ih'-f/fmr, moving' to the sontliwurd 

 and outward to the sea. This t^'reat ice-mantle not oidy 

 removed stones and chiy to immense distances, and 

 ;;laciated and striated tiie whole snrface, hut it cut out 

 lake basins and fiords, ^'ruund over the tops of the hi<,'hest 

 liills, and accounted for every thiiif,' otherwise didicult in 

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

 ferred to IJrazil, and employed to excavate the valley of 

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

 recently melted away under the warmth of discussion 

 until it is now hut a shadcnv of its former self. I may 

 mention a few of the facts which have contributed to 

 this result. It has been found that the ^dacial boulder- 

 days 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 acpieous denu- 

 dation, (treat lakes, like those of America, supjxised to bo 

 inexplicable except ))y glacier erosion, have been found to 

 admit of Ijeing 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 J^avis straits is indeed 

 shnilar to that which may have obtained between the 

 Laurentide hills and the su emerged 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 



