Glaciers in Scotland in Ancient Times, 37 



globe depends, in a great degree, on the distribution of sea 

 and land. The east side of all extensive continents in the 

 extra-tropical regions, has a warmer summer and a colder 

 winter than the western. The extremes of heat and cold, 

 for instance, are incomparably greater in Lower Canada than 

 in the Oregon territory, though they are both in the same la- 

 titude. Now, if North America at one time extended much 

 farther eastward — if, for instance, it occupied all the portion 

 of the Atlantic between Newfoundland and Britain — in that 

 case, it is certain that Britain would have had the inhospi- 

 table climate of Labrador, or even one still more severe, like 

 that of Greenland. There are various facts which point to 

 the state of things here put hypothetically. Thus, the fresh- 

 water strata of the Wealden group of rocks, from their ex- 

 tensive range and great thickness, imply that a river as largo 

 as the Mississippi had its estuary in England, and such a 

 river could not exist unless a tract of land 1000 or 2000 miles 

 in breadth, in connection with the British Isles, had occupied 

 the eastern part of the Atlantic. — (See LyelVs Elements^ i., 

 p. 431.) Again, the same able geologist found evidence in 

 the carboniferous rocks of North America, that the coarser 

 materials composing them came from land lying to the east- 

 ward, and now covered by the Atlantic. — {Travels in North 

 America, i., p. 86.) Finally, Professor Edward Forbes, in a 

 most interesting memoir recently published, has shewn, from 

 the relationship between the Fauna and Flora of the British 

 Isles and of North America, that either the one has derived 

 a certain portion of its animals and plants from the other, or 

 that both have derived them from land now sunk in the in- 

 tervening ocean. — {Memoirs of the Geological Survey of Great 

 Britain, vol. i., p. 336-402.) 



