20 THE ICE AGE IN CANADA. 



matter of gratification to me to find, in connection with 

 this, that researches in other regions are rapidly tending 

 to overthrow extreme views on the subject, and to restore 

 this department of geological dynamics more nearly to 

 the domain of ordinary existing causes. Whymper, 

 Bonney, and other Alpine explorers, have ably supported 

 in England the conclusion which, after a visit to Switzer- 

 land in 1865, I ventured to affirm here, that the erosive 

 power of glaciers is very inconsiderable. Mr. Milne 

 Home, Mr. Mclntosh, and others, have combated the 

 prevalent notions of a general glacier in England and 

 Scotland. Mr. James Geikie, a leading advocate of land 

 glaciers, has been compelled to admit that marine beds 

 are interstratified with the true boulder clay of Scotland, 

 and consequently to demand a succession of elevations 

 and depressions in order to give any colour to the theory 

 of a general glacier. The idea of glacier action as means 

 of accounting for the drifts of Central Europe and of 

 Brazil seems to be generally abandoned. Lastly, in a 

 recent number of the "American Journal of Science," Prof. 

 Dana has admitted the necessity, in order to account for 

 land glaciation of the hills of New England [by a conti- 

 nental glacier], of supposing a mountain range or table 

 land of at least 6,000 feet in height, to have existed 

 between the St. Lawrence and Hudson's Bay, while in 

 addition to the imaginary N. W. <fc S. E. glacier, flowing 

 from this immense and improbable mass, there must have 

 been a transverse glacier running beneath it up the valley 

 of the St. Lawrence. Such demands amount, in my 

 judgment, to a virtual abandonment of the theory of other 

 than large local glaciers in America in the pleistocene 

 period. Thus there are cheering indications that the 

 world-enveloping glacier, which has so long spread its 



