16 THE ICE AGE IN CANADA. 



to represent the supposed previous ice-clad state of the 

 land, except the scratches on the rock-surfaces, whicli 

 must have been caused by the same agency which 

 deposited the boulder-clay.* 



" 5. The peat deposits with fir-roots, found below the 

 boulder-clay in Cape Breton, the remains of plants and 

 land-snails in the marine clays of the Ottawa, and the 

 shells of the St. Lawrence clays and sands, show that the 

 sea at the period in question had nearly the temperature 

 of the present arctic currents of our coasts, and that the 

 land was not covered with ice, but supported a vegetation 

 similar to that of Labrador and the north shore of the St. 

 Lawrence at present. This evidence refers not to the 

 later period of the mammoth and mastodon, when the 

 re-elevation was perhaps nearly complete, but to the 

 earlier period contemporaneous with, or immediately fol- 

 lowing, the supposed glacier -period. In my former 

 papers on the Pleistocene of the St. Lawrence, I have 

 shown that the change of climate involved is not greater 

 than that which may have been due to the subsidence of 

 land, and to the change of course of the equatorial and 

 arctic currents, actually proved by the deposits them- 

 selves. 



"These objections might be pursued to much greater 

 length ; but enough has been said to show that there are 

 in the case of north-eastern America, strong reasons 

 against the existence of any such period of extreme 

 glaciation as supposed by many geologists ; and that if we 

 can otherwise explain the rock striation and polishing, 

 and the formation of fiords and lake-basins, the strong 



* This was intended to apply to the valley of the St. Lawrence, not 

 to the mountainous regions having local glaciers. 



