306 



HISTORY OF THE EUROPEAN FAUNA. 



tanian centre was never a very active one compared 

 with, for instance, the Oriental is indicated by many 

 distributional facts. It is difficult to understand, 

 however, why the Oriental species, on the whole, 

 have migrated so far west, while few Lusitanians have 

 gone very far east. This seems to have been noted 



FlG. 21. The Irish Spurge {Euphorbia hiberna] in its native habitat 

 in the south of Ireland. (From a photograph by Robert Welch.) 



particularly in the case of the flora. Mr. Bonnet drew 

 attention to the fact that in Tunis there are none of the 

 absolutely characteristic plants of Morocco and Spain, 

 while the Oriental flora is represented by a good 

 many species. Lusitanian species have spread chiefly 

 southward into North Africa, and northward into 

 France, the British Islands, and even Scandinavia. 



