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THE AMERICAN NATURALIST [Vol. XL V 



taken, about 50 per cent, of the females are white. These 

 regions are Lava, Sullivan Co., N. Y., reported by Mr. 

 Geo. Franck, and Alstead, N. H., on the authority of Mr. 

 W. L. W. Field, who has seen only one white male, how- 

 ever, during several seasons of field work in that region. 



Scudder makes the statement that "In the north this 

 rarely, almost never, occurs in the lirst brood of the sea- 

 son, and is found much more abundantly in the latest 

 than in the middle brood, the numbers increasing as the 

 season advances." If this statement is true, it has an 

 important bearing on the inheritance of the white char- 

 acter, 2 for he means, of course, that the proportions of 

 the white females to yellow in the spring broods is less 

 than in the later broods. My observations at Hanover in 

 1909, and those of my collaborator Mr. P. W. Whiting in 

 Cambridge, Mass., in 1910, do not bear this out, for we 

 found the white females in both places quite as common 

 in the spring brood as in those of summer or autumn. 

 Edwards likewise states that in the south the white form 

 is not infrequent in the spring brood. The probable rea- 

 son for Scudder's observation is that the population of 

 the spring brood in the long run may be relatively small, 

 because many of the hibernating caterpillars perish. 

 The chances of finding white females in the field in the 

 spring after a severe winter may therefore be less than 

 during the flight of the more abundant summer broods 

 that have not been affected by disastrous winter weather. 



One of the most interesting observations that I have 

 made during the past two seasons was the discovery of 

 a wild female Colias philodice of the spring brood closely 

 resembling Colias nastes of Labrador (Fig. 4), with a 

 greenish-yellow field overspread with brownish scales, 

 giving a grayish effect. In the margin brown replaces 

 black. This form of female is not common, and I have 

 seen it nowhere described. It was captured at Hanover, 

 N. II., on June 10, 1909, and produced a brood of 34 

 butterflies (Fig. 5) of which 19 are males, all of which 

 are yellow, 10 are yellow females, 5 are white females. 

 The yellow and white colors of these offspring are of an 



