GENERAL FEATURES 21 



species, is, nevertheless, widely different in ornamentation from 

 the t_ypical specific form of its parents. Such a freak or 

 sport is, I believe, of the female sex, although itself prac- 

 tically sexless, or at any rate, infertile; and as its race is not con- 

 tinued, it is scarcely entitled to a place in the list of names, be- 

 cause, so far as known, there never was, and never will be, another 

 like it. Yet it is usually accorded a place in the catalogues, with a 

 status about on a par with a variety. 



It is apparent that the female sex is more liable to be found mas- 

 querading under the guise of aberration than the male ; male aber- 

 rations are practically unknown. Therefore an unknown or 

 strange female specimen should not be readily accepted as a spe- 

 cies, but rather it should be held in abeyance till the affair 

 clears up. 



Some species are especially given to aberration : for instance, 

 Mclitcca Hoffmanni has many aberrations, someof which havebeen 

 named and others have not, and some of them are far, far away 

 from the type, as Mirabilis. in this volume. Another species which 

 is given to aberration is Lyccriia Acmon, several eccentric forms 

 of which have been noted, and some of them named ; e. g., Mcli- 

 moiia, a maleless variety. 



§ 12. Se.\sonal Forms. 



Often, and probably, usually, the early appearing imagines are 

 darker in markings than the later ones. The reason for this is a 

 matter of speculation. Perhaps it is the colder nights which 

 ordinarily prevail in the early spring, though it seems to me that 

 this factor would have but slight influence, if any at all. And 

 there are contradictory circumstances ; as, for one, the early or 

 cold weather forms of Colias Eurythcme are paler than those 

 forms which appear in the warmer months of summer, so that the 

 term "seasonal forms" should be taken with some caution, until 

 the matter is followed out to its conclusion, or proved up by breed- 

 ing or by experiment. 



§ 13. Hybrids. 



By "hybrids" is meant that race of butterflies that would pre- 

 sumably result from the pairing of butterflies of different species. 

 Not very much has ever been written upon this subject, and that 

 little is based altogether upon speculation, no facts bearing upon 

 the subject having ever been printed, that I know of. the discus- 



