IN COLORING AND STRUCTURE. 183 



at last we found him, united, alas ! to another 

 wife ; a case quite like that of the swallow-tails 

 just described ; so now we christen this twin- 

 wived species the Mormon. 



These cases might be multiplied, but we will 

 turn rather to the albinic side. As far as I am 

 aware, albinic antigeny occurs only in one group, 

 the red-horns or yellow butterflies (Fugacia) ; but 

 it appears there in several genera. In ]N"ew Eng- 

 land it is conspicuous, and must have been ob- 

 served by at least every entomologist, in our com- 

 mon Clouded Sulphur [see Figs. 102, 103]. Here 

 all the females differ to a certain extent from the 

 males ; principally in having the marginal black 

 band, which is sharply defined on its inner side 

 in the male, ill-defined and broken by spots of 

 the ground color in the female ; the yellow, too, 

 is invariably somewhat paler and duller than the 

 clear canary of the male ; this is complete anti- 

 geny. But there is also partial antigeny, for 

 an albinic form occurs in which the yellow is al- 

 together replaced by a dead dull white with a 

 greenish tinge. It is a curious fact that these 

 pale females never appear in the early spring 

 brood, and increase in proportion as the season 

 advances. This is in harmonious contrast with 

 the occurrence of a melanic male in the spring 

 brood of the azure butterfly ; when we consider 

 that albinism is a northern, melanism a southern 



