AFFINITIES OF THE FLORA 297 



The question, however, is naturally bound up with 

 the greater problem of the origin of the Alpine Hura 

 of Switzerland, and its relation to the vegetation on 

 the north and south of the Alps. To this question 

 we wnll now turn. Before we attempt to summarise 

 the theories which have l)een advanced, we may first 

 set out the facts which such theories should explain. 



The Affinities of the Swiss Alpine Flora. 



The mountain ranges of Central Europe form an 

 incomplete chain, stretching roughly west and east, 

 beginning with the Pyrenees, then the Swiss and 

 Austrian Alps, and finally the Carpathians. The 

 widest gaps in the chain are between the Pyrenees 

 and the Swiss Alps, and between the Austrian Alps 

 and the Carpathians. The Alpine floras of these 

 mountain regions are essentially similar, many species 

 being common to them all. Although, in the Swiss 

 Alpine region, there is probably no species which 

 is not found elsewhere, there are, on the other hand, 

 many plants in the Austrian Alps and the other 

 ranges, which do not occur in Switzerland. At the 

 same time, there is a distinct unity in type and marked 

 relationship between the floras of all these Alpine 

 chains. 



Further, many Swiss Alpine species occur so far 

 afield as the mountains of Central Asia, such as the 

 Himalayas and the Altai. The Edelweiss (p. 15), 

 for instance, is found in the Pyrenees, the Swiss 

 Alps, the Tyrol, the Carpathians, and the Himalayas. 



