The Glacial Theory, 



149 



the north. Thus> while the shells, which are now found in lat. 65° 

 to 70° on the coasts of Iceland and Greenland, where the mean 

 temperature is several degrees below zero (32° F.), lived in lat. 55° 

 to 60° on the coasts of Scotland and of England, where the mean 

 temperature at present is -)- 8° (46° .4 F.) ; the species of the coasts 

 of England and of the British Channel which now live in lat. 50° 

 to 55°, lived in Sicily in lat. 35° to 40° ; or, in other words, when 

 the climate of Greenland extended its frosts beyond Scotland, when 

 the mean temperature of the British Islands, in a place of being 

 above + 8° (46° .4 F) cent., scarcely reached zero, the present cli- 

 mate of England, and of the north of Germany, prevailed in those 

 parts of Europe which are now the warmest, and where the mean 

 temperature exceeds + 16° (60° .8 F). 



I shall afterwards publish the details of these observations, when 

 they embrace a basis sufficiently complete to form an intimately con- 

 nected whole ; it is sufficient, for my purpose at present, to have 

 indicated the principal results of these researches, which confirm the 

 opinion of the former existence of a climate much more rigorous 

 than that which now exists in Europe, by proofs independent of 

 those derived from the traces of ancient glaciers. Now, a climate so 

 different, could not have existed without exercising a marked influ- 

 ence on organic life ; and it is thus that the Arctic faunas, in our 

 temperate regions, confirm as fully the existence of ancient glaciers, 

 as the presence of these same glaciers explains the existence of 

 northern animals ; and, nevertheless, the facts which establish the 

 presence of the one, have nothing in common with the facts which 

 prove the presence of the other.* 



Parallel Terraces, — These have been observed by nume- 

 rous geologists particularly in the vallies of the north of 

 Scotland, the Eldon hills. The example of Glen Roy and 

 Glenspean, are taken by M. Agassiz, as best calculated 

 to explain other similar phenomena. 



The first, or the least elevated of these three terraces, is 972 

 English feet above the level of the sea ; and, as it is horizontal, its 



» Edinb. New Phil. Journ. No. 66, p. 226 ^ 



