GENERAL FEATURES 23 



the dimorphic female is white ; in Argynnis she is black; with this 

 provision noted that where the black female is found, there is no 

 normal-colored female at all. Whether there ever was a normal- 

 colored female in these cases, no one knows. I believe, however, 

 that at one time the normal-colored female existed, and that she 

 has disappeared, just as at the present time the normal female of 

 Colias is being replaced by the albino, so that in a few decades, 

 a yellow-colored female will be difficult to find, if the present rate 

 of change shall be kept up. 



In Colias, at any rate, if one can build upon twenty-five years' 

 observation, the orange-yellow female will shortly be difficult to 

 find, or will have been entirely supplanted by the white, so that, 

 like Argynnis Nokomis, Nitocris, and Leto, there will be no nor- 

 mal yellow female Colia.s at all. 



§ 15. Albinism. 



This term is applied to the dimorphic, or secondary, white 

 females, as of Colias, many examples of which are illustrated here- 

 with. But one example of a white or albino male is recorded, 

 that one being the male of Philodice, from Western New York, 

 taken in the summer of 1891, and noted by the veteran butterfly 

 captain, W. H. Edwards. Philodice is considered to be the East- 

 ern form or representative of our Western Eurytheme. No other 

 white male or albino has ever been noticed anywhere, and but for 

 the faith that the name of such a man as W. H. Edwards com- 

 pels, I should disbelieve the statement of the existence of a male 

 albino. 



§ 16. Bisexual. 



Is a term applied to such butterflies as have on the right-hand 

 the wings of one sex, and on the left-hand the wings of the 

 other sex. This variation appears to occur occasionally, every- 

 where. The only specimen ever taken by me was a Lyccena Pi- 

 asus, and which is figured on Plate XXX, in this book. I have 

 also heard of a Lyccena Sonorenisis so marked, also taken in 

 Southern California. Examples of bisexuals are illustrated in 

 Edwards's Butterflies of North America. 



Bisexual individuals appear to be infertile, like the hybrids and 

 other mules ; it is not known whether they are of one sex or of 

 the other, or neither. No fact is known, upon which a theory may 

 be based, except the single one, that such butterflies are occasion- 



