April iS()5.] 



psr( HE. 



223 



approximate cqu;ilit\ with the others. 

 Examples of Eli.'' in whicli the border 

 spots of primary are not pretty uniform 

 in size and siiape. and those in which 

 the mid-wing spot is not at least mod- 

 erately well developed, are exceptional. 

 The most informal in this series of Ells 

 have the spots more neatly regular tlian 

 in the most formal MeacJii in the lot. 

 Those JMeadii with the spots largest 

 are not nearer to Elis on that account, 

 but rather show stronger contrast, as 

 the diverse system of maculation in the 

 two species is therebv rendered more 

 obvious. 



An occasional Mead/i. having the 

 spots on primary border more symmet- 

 rical than is usual, closely risembles 

 some Hecla, so that in a large sci'ies of 

 both a small percentage of the Meadii 

 migiit prove difficult to part from a 

 few of the Hccla by this test solely. 

 In a large majority of cases, however, 

 the two females differ widely in char- 

 acter of dark border of hind-wing; iS 

 out of 23 of these Meadii have a prac- 

 tically solid black hind-wing border, 

 and 3 of these 5 Hecla have a most 

 distinctly maculated border with the 

 yellow spots large and conspicuous. 

 Meadii with hind-wing border partly 

 maculated, and Hccla w ith maculation 

 of hind-wing border partly obscured, 

 might not readily separate on this 

 character alone. It follows then, that 

 among the small number not distin- 

 guishable by characters of fore-wing 

 border, one individual in many may 

 also fall in the small proportion with 

 hind-wing border of ambiguous char- 



acter : that is to say, a percentage of a 

 percentage occurs wherein the macu- 

 lation of dark border of both primary 

 and secondary is liable to prove too 

 approximate or too obscure to rely 

 upon in determining the position of the 

 individual. Even these rare instances 

 of close approximation should not 

 defeat a student familiar with the tyvo 

 species. Other specialties of pattern 

 are in some degree indicative, and it 

 rarely indeed occurs that all significant 

 distinctions lapse in a single individual. 

 There remains also that indefinite but 

 obvious fact known as " the general 

 appearance," which furnishes an expe- 

 rienced obsei-yer with the most reliable 

 and satisfactory guide in distinguishing 

 one species from another. 



In a general view of the three species, 

 the most obvious fact is that Hecla 

 male is distinct from the respective 

 males of Meadii and Eli.^. Also, 

 properly representative material makes 

 conspicuously- evident the divergence 

 of the female of Elis from the females 

 of Hecla and Meadii. The close 

 approximation occurs between Hecla 

 and Meadii in the female, between 

 Elis and Meadii in the male. This 

 complex of relationship is perhaps 

 partly capable of explanation. Hecla 

 may safely be considered the oldest of 

 the three species, and Elis the 

 youngest. In Colias the law of the 

 agency of sex in race progress appears 

 to be that the male is the conservative 

 and the female the progressive sex. 

 Accordingly, in the alliance under con- 

 sideration, Hccla being the oldest 



