338 HISTORY OF THE EUROPEAN FAUNA. 



Asia to Kamtchatka and the Russian convict island 

 of Saghalien in the Pacific. Besides the Common 

 Hazel Grouse, two other species are known, one from 

 Eastern Russia and the other from China. 



Having now shortly reviewed the whole grouse 

 family, we have seen that, although some species 

 live within the Polar Circle, the majority are 

 more or less confined to the more temperate 

 or rather the less arctic parts of the Northern 

 Hemisphere. They are quite absent from Southern 

 Asia and even the southern parts of North America, 

 and almost so from the Mediterranean basin. The 

 whole range of the family is therefore suggestive of 

 a northern origin, and this view agrees perfectly with 

 all the details of distribution. The centre of dis- 

 tribution lies in Northern Asia, or in Arctic North 

 America. From there the great genus Lagopus 

 spread east and west, reaching Europe by these 

 vastly divergent routes at a time when the physical 

 geography was very different from what it is to- 

 day. Several of the species common to the Alps 

 and Scandinavia have migrated from Siberia direct 

 to Eastern Europe. But we can now imagine how 

 from a similar centre in Asia perhaps at a rather 

 more remote time a species spread eastward across 

 North America and Greenland to Scandinavia, and 

 westward along the mountain ranges of the Tian 

 Shan and the mountains of Asia Minor to Greece, 

 and finally to the Alps. We should then have the 

 same species in the Alps and in Scandinavia, not far 



