INTERNAL MIGRATIONS. 139 



and Northern Europe up to the Arctic Circle. A 

 few individuals, however, ascend the mountains of 

 South Europe to breed in the pine region. The 

 Wheatear (Scuncola oenanthc) has a very similar 

 range, but extending much further north ; a few 

 individuals ascend the highest mountains of South 

 Europe to breed in the pine and birch regions. 

 The Whinchat [Pratincola rubetra) breeds sparingly 

 on the mountains of South Europe. The Black- 

 throated Ouzel {Menda at?igu/ans) breeds in Central 

 Siberia, and winters in Baluchistan, India, and West 

 Turkestan ; but many individuals ascend the Hima- 

 layas and the mountains of Turkestan to the pine 

 region, where they breed. 



We also find that in many sedentary species 

 ranging, say from sub-tropical to north temperate 

 regions, the individuals in the extreme southern and 

 warmest limits of the range ascend mountains to 

 breed, where they find similar climatal conditions 

 as those individuals dwelling in the more northern 

 and cooler portions. Hence, one section of the 

 species is resident, the other portion has acquired 

 migratory habits, although the journey is vertical 

 instead of latitudinal. The Hedge Accentor 

 {Accentor modidaris) is one of the most familiar 

 instances occurring to me. This species is prac- 

 tically sedentary, except in the extreme northern 

 portions of its range (although even here it is said 

 in some places to be resident), which extends 

 throughout Europe south of lat. 70° in the west, 

 and lat. 64° in the east. Everywhere in the extreme 



