44 



THE AMEBIC AN NATURALIST [Vol. L 



tribution of color are well established this further argu- 

 ment is superfluous. 



In 1906 Toyama described a gynandromorph that arose 

 when two races of silkworm moths were crossed. From 

 an analysis of the genetic evidence I pointed out that in 

 this case the male parts of the gynandromorph must have 

 been paternal and the hybrid parts maternal (dominant). 

 If the same conditions prevail here as in the bee, viz., one 

 nucleus producing a male and two producing a female, 2 the 

 case is in harmony with my hypothesis and not with that 

 of Boveri. But the evidence for my view is not as strong 

 as that Boveri 's is now for the bee; yet it may be true, 

 nevertheless, that in both of these ways gynandromorphs 

 may arise. A third mode of origin has been shown, from 

 the genetic evidence, to apply to Drosophila, viz., disloca- 

 tion during ontogeny of the two sex chromosomes. In fact 

 we should expect that gynandromorphs would arise in in- 

 sects whenever certain nuclei come to contain two sex 

 chromosomes and others only one. The means by which 

 this segregation takes place may differ under different 

 conditions. 



Goldschmidt has recently explained the remarkable 

 gynandromorphs that he obtains in crosses between Ly- 

 mantria dispar and L. japonica in still a different way, 

 one that involves the relative potencies of the sex factors 

 in the different races. 



LITERATURE CITED 



Boveri, Th. 1888. fiber partielle Befruchtung. Sitz.-Ber. d. Ges. f. 



Morph. u. Phys., Miinch., IV. 

 Boveri, Th. 1915. fiber die Entstehung der Eugsterschen Zwitterbienen. 



Arch. f. Entw. Organismen, XLI. 

 Cuenot, L. 1909. Comp. Send. Soc. Biol LXVI 

 Donhoff. 1860a. Ein Bienenzwitter. Bienenseitung . 



2 Whether one is justified in applying to the case of the moth the 

 hypothesis for the bee may be seriously questioned because in the case of 

 the moth the male is assumed to be the result of one sex chromosome (s) in 

 moThone " ^h ^ number of autosomes, while in the female 



evidence has no sex- determining influence) in conjunction with the diploid 

 number ot autosomes is assumed to stand for the female soma. 



