244 



THE THEORY OF THE GENE 



series. In one series the females are finally all changed 

 over into males ; in the other series the males are changed 

 over into females. The former change is spoken of as 

 female intersexuality ; the latter, as male intersexuality. 

 Without attempting to review the long series of experi- 

 ments from which the evidence has come, Goldschmidt 's 

 theoretical deductions may be stated as briefly as possible. 



Fig. 140. 



a, Male and b, female of Lymantria dispar; c and d two inter- 

 sexes. (After Goldschmidt.) 



The formula he uses for the male is MM and for the 

 female Mm ; in other words, the WZ-ZZ formula. In addi- 

 tion, however, Goldschmidt adds another set of sex-de- 

 termining factors that at first he called FF, which stand, 

 in a way, for femaleness. The male factors are supposed 

 to segregate, as do Mendelian factors in general, but the 

 FF factors do not segregate and are transmitted only 

 through the egg. They were supposed to reside in the 

 cytoplasm, although Goldschmidt has later shown an in- 

 clination to locate them in the W-chromosome. 



