52 HISTORY OF THE EUROPEAN FAUNA. 



European flora much more systematically, and our 

 knowledge of the origin of that flora has been greatly 

 increased within the last twenty years, chiefly by 

 the researches of Professor Engler. More recently, 

 detailed studies have been made in Scandinavia by 

 Professor Blytt, in the Alps by Dr. Christ and Mr. 

 Ball, in Germany by Professor Drude, Dr. Schulz, 

 and many others. Dr. Schulz (p. i) is of opinion 

 that the great majority of the European plants have 

 either migrated to or have originated in our conti- 

 nent since the beginning of the Pliocene epoch, and 

 that the original home of the immigrants must be 

 looked for in Asia and in Arctic America. From the 

 latter an almost uninterrupted migration must have 

 taken place during the greater part of Tertiary times 

 up to the commencement of the Pliocene epoch, partly 

 over a direct land-connection with Europe by way of 

 Greenland, Iceland, and the Faroes, and also vid 

 Spitsbergen, Franz Josef Land and Novaya Zemlya, 

 and partly by an indirect one across the Behring 

 Straits between Alaska and Kamtchatka. 



A good deal of work still requires to be done before 

 zoologists have acquired the same intimacy with the 

 European fauna as botanists have with the flora. 

 However, the view that our animals all come from 

 Asia, as was long ago believed, has been abandoned 

 for some time. The first to bring under the notice 

 of naturalists the hypothesis, that there must have 

 been two distinct migrations of northern animals to 

 Central Europe one from the north, and another 



