216 BUTTERFLIES 



and mammals we have geographical races distinctly rec- 1 

 ognized instead of separate species. 



While the study of butterflies has by no means received ; 

 the degree of attention which has been given the birds and 

 mammals, it is already evident that a similar condition pre- i 

 vails with reference to many species. As the size of col- j 

 lections has increased and more careful studies have been j 

 made of the various forms from different regions it has been 

 found in numerous cases that they intergraded to so great j 

 an extent that it is impossible to distinguish many species 

 which were formerly considered entirely distinct. One of 

 the most striking examples of this is found in the case of • 

 our common Wood-nymph, which is sometimes called the i 

 Blue-eyed Grayling. The form which is one of our most i 

 abundant butterflies in southern New England and many 

 of the Eastern states was described as Satyrus alope by the ! 

 French naturalist Fabricius, who also described another 

 species from the Southern states as Satyrus pegala, and a 

 form found in northern Canada was described by the ] 

 English entomologist Kirby as Satyrus nephele. Various ] 

 other forms from isolated regions have been given specific ' 

 names by other authorities. (See plate, page 81.) \ 



During recent years many collectors have gathered these ; 

 butterflies from all parts of North America and many \ 

 specimens have been grouped together in the more im- 

 portant collections. When this occurred it became easy | 

 to see that this is essentially a variable species which \ 

 under varying climatic conditions has assumed slightly j 

 different forms, so that we have a good illustration of 

 well-developed geographical races. The more important ! 

 of these are indicated in the synopsis of the Meadow- \ 

 browns on page 227. i 



