No. 533] INHERITANCE IN COLIAS PIIILODICE 



which species a most complicated polymorphism occurs, 

 probably represents a stage in evolution beyond the yel- 

 low, as does also the black of the melanic male mutant of 

 ( 'olias pliilodice. 



The view that the color and color pattern of the male 

 butterfly diverge more widely from the typical colora- 

 tion of the group to which the species belongs, than those 

 of the female, though advocated by Darwin, 1871, was 

 strenuously opposed by Scudder ('89, Vol. 1, p. 531), 

 who cites the white female of Colias pliilodice as evi- 

 dence to support his position. The case of Argynnis 

 diana, in which the dark blue female differs much more 

 widely from the usual tawny color of the fritillaries 

 than does the male, certainly points strongly to Scudder 's 

 view, but it may well be that no one rule applies to all 

 genera of butterflies, though there are in butterflies and 

 in birds few if any exceptions to the law that the plumage 

 of the male is more brilliantly colored and more highly 

 differentiated than that of the female. 



4. Inheritance in Papilio memnon 

 Jacobson's observations on the Javan butterfly Papilio 

 memnon, in which there are three varieties of female, 

 and the discussion of them by de Meijere, 1910, show 

 that, as in Colias, the dominant form among the females 

 is the one most unlike the male, viz., the brownish, tailed 

 Achates; the form that is recessive in the female, as in 

 Colias also, is the one most like the male, viz., the dark 

 tailless Laocoon. The intermediate variety, Agenor, is 

 heterozygous, epistatic to Laocoon but hypostatic to 

 Achates. In the male the dark color, recessive in the 

 female, is completely dominant. 



Inspection of Jacobson's results leads one to believe 

 that two, or probably three, pairs of unit characters are 

 involved, and that not all of the individuals recognized as 

 Achates or as Agenor are of the same gametic consti- 

 tution. The remarkable fact brought out by Jacobson 

 is that, in the various combinations made, only two of the 

 three varieties of female were obtained in any one brood. 

 As a working hypothesis, I regard the dominant female 



