So KANSAS UNIVERSITY QUARTERLY. 



membrane and of producing color effects. The function of giving 

 off scent is confined to scales whose peculiar structure allows them to 

 be readily identified and considered apart.* The specialization of 

 scales for strengthening organs and for color-producing organs follows 

 the same general line, so that a confusing complexity, brought about 

 by specialization for two needs tending to similar structural results, 

 confronts the student. 



Finally it has been sufficiently shown that the specialization of 

 scales may come about very quickly. On a moth showing the most 

 generalized of scales there may exist scales of considerable special- 

 ization. And on but very few moths is there anything like a covering 

 wholly composed of generalized scales. A considerable degree of 

 specialization is attained by the scales, among even the more gener- 

 alized Lepidoptera, so that the covering of a wing must be looked at 

 as a whole, and an averagj condition, as it were, determined, rather 

 than its being possible to learn much from a few scales taken at 

 haphazard from the wing. 



Thus it is that recognition characters calculated to be easily avail- 

 able to the systematist will not often present themselves in the wing- 

 covering of the Lepidoptera, while nevertheless the scales may afford 

 indications of real value regarding the phylogenetic relationships of 

 various forms. 



The Lepidoptera. 



Wings bearing a covering of fine, fixed hairs (from .005 mm. 

 to .03 mm. in length) in addition to the covering of spe- 

 cialized scales Suborder Jugate. 



Scales pigmented and showing a coarse and a fine 



striation Family Hepialidaa. 



Scales transparent, with uniform striation 



Family Micropterygidae. 



Wings not bearing a covering of fine, fixed hairs in addition to 



the covering of generalized or specialized scales 



Suborder Frenat^. 



THE JUCAT^E.t 



The Jugatee are distinguished from the Frenata;, according to the 

 wing-covering, by the presence in the Jugate and its absence in the 

 Frenatee of a covering of fine, fixed hairs (the hairs never more than 

 .03 mm. long) on the upper and under surfaces of the fore and hind- 



*In comiectionwitli the oceiirrence of imdroconla the form and airangement of contig- 

 uous scales may be considerably affected in order to conceal or enclose the scent-scales. 

 But such exceptional conditions are usually immlstakably apparent as exceptions to the 

 general condition of scale-development on the wing. 



tFor an account of the establishing of suborder Jugats see p. 60. 



