342 HISTORY OF THE EUROPEAN FAUNA. 



tains and Northern Persia. Turning to Afghanistan, 

 our author mentions' (p. 121) a few Alpine plants as 

 occurring in that country, and likewise in the 

 Caucasus and the Himalayas. He considers it 

 probable that the route of migration of some glacial 

 plants from the east to the west, and vice versa, lay 

 across the Afghan mountains. Many of our Alpine 

 plants occur in the Siberian mountains, but in the Altai' 

 and Eastern Siberia generally a considerable number 

 of these are by no means confined to the mountains 

 (p. 125). They are also met with in the lower regions, 

 and the rare Alpine Edelweiss (Leontopodium alpinuvi} 

 frequently covers wide tracts in the plain, and is 

 passed by almost unnoticed by the Siberian botanist. 

 Special attention is drawn by Professor Engler to 

 the fact (p. 130) that several of the Siberian plants 

 inhabit the Alps and the Caucasus, but are not 

 found in Scandinavia. And from this he deduces the 

 conclusion that part of the Siberian flora migrated 

 in a south-westerly direction towards the Caucasus 

 and the mountains of the Mediterranean area, exactly 

 in the manner indicated in respect to the fauna of the 

 Alps. We learned that the migration to the Alps 

 from Central and perhaps also parts of Northern 

 Asia took a south-westerly course first, and was 

 then followed by one in an easterly direction. I 

 called the former the Oriental migration and the 

 latter the Siberian. Later on Professor Engler 

 states (p. 142) that the main mass of the Siberian 

 forms of plants certainly wandered westward to 



