It may be remarked in passing that the genus Argynnis is 

 very difficult, and the writer has been in the habit of compar- 

 ing it to the genus Salix, the willows, among flowers. Botan- 

 ists know how the willows seem to run together, and how hard 

 it is to discriminate the species. The same thing is true of 

 tkis great genus of butterflies with which we are now dealing. 

 It is particularly true of the species which occur in the region 

 of the Rocky Mountains, of which the writer has probably the 

 largest collection in existence, including all of the types of the 

 late William H. Edwards. The test of breeding has not been 

 fully applied as yet to all of these forms, and it is doubtful 

 whether some of them are more than varieties or local races. 

 There is here a field of inquiry which should tempt some young, 

 ardent, and careful student. The day for more thorough 

 work is at hand, and I hope some reader of these pages may 

 be converted to the task. Entomological study should become 

 more intensive, as well as extensive. The fathers of the science 

 have paved the way and laid foundations; it remains for the 

 rising generation to complete the work which the fathers have 

 begun. 



PL. XIII 



.. - 



77 



