THE ANCIENT ARCTIC FLORA 303 



tale more plainly than do the mountains of Scotland 

 and Wales, with their scored thinks, pohshed surfaces, 

 and perched boulders, of the icy streams with which 

 their valleys were lately filled." 



There is little doubt that some members of the 

 floras of Europe and North America, both of the 

 plains and the mountiiins, date back to a period prior 

 to the Ice Age. The history of both these floras 

 begins in the jNIiocene period. 



We now turn to the explanation of the origin of 

 the Alpine flora of Europe, which is most generally 

 accepted, and examine how far it will explain the 

 present geographical distribution of Alpine plants, 

 and the historical fcicts as a])Ove outlined. This 

 theory was elaborated many years ago by Forbes, 

 Charles Darwin, Sir Joseph Hooker, Asa Gray, and 

 others. Briefly, it is as follows : — It is believed that 

 in Miocene and Pliocene times a flora existed in 

 Europe and North America, which was essentially 

 similar in both these regions. The Alps no doubt 

 also then possessed their Alpine flora. In the Far 

 North, however, there was another flora, which we 

 may speak of as the ancient Arctic flora. This, 

 then, was the state of affairs prior to the Ice Age. 



With the setting in of ghicial conditions at the 

 Pole, these floras were driven, each in their turn, 

 further and further southward. The ancient Arctic 

 flora retreated before the growing ice cap of the Arctic 

 regions, and migrated into North America (Canada, 

 and the United States) and into Eui'ope. The 



