210 ORIGIN OF BUTTERFLIES 



statements are true to a large extent as regards the 

 species of Cyaniris. There is a single form on 

 each continent which extends across its entire width, 

 but is not found in the high north. As in Heodes 

 also, its immediate relatives are found in greater 

 abundance in the Old World than in the New ; 

 but on the other hand the development of varietal 

 forms within the species is so greatly in excess in 

 America that we must conclude it probable that 

 its life on this continent has been longer than on 

 the Old. 



There remain only those species which occur 

 within our district, but which belong more properly 

 to high boreal regions. Among these we have 

 first a species of Oeneis (Oeneis jutta, the Arctic 

 Satyr), which is unquestionably identical on the 

 two continents. Its distribution on this continent 

 is probably much more extensive than known, as 

 it has been found at widely distributed localities. 

 The genus to which it belongs is a characteristi- 

 cally alpine and arctic group, and is so widely 

 developed on both continents that here again it is 

 extremely difficult to decide as to the probability 

 of its origin. Often living close beside the ice, it 

 has undoubtedly been a companion of the terminal 

 moraine throughout the ages. One indication 



