44 



THE ORIGIN OF GYNANDROMORPHS. 



Description. — The left side of the thorax of the gynandromorph was male, 

 with a sex-comb and a shorter wing. Both eyes were red and female. The 

 abdomen and genitalia were female. The body-color was wild-type through- 

 out. Sections showed ovaries on both sides. 



Explanation. — An egg containing the lethal 6 X chromosome was fertilized 

 by a wild-type X sperm. Either one of the X chromosomes being eliminated 

 would account for the result. If the paternal X were eliminated the male 

 parts would be lethal 6, and hence it is more probable that the maternal X 

 was eliminated. 



/. 



I, 



or 



No. 1808. July 7, 1915. C. B. Bridges. Text-figure 27 (diagram). 



Parentage. — The mother was pure for the second-chromosome recessives 

 purple, curved, and speck. The father was heterozygous for the dominant 

 star (eyes). No sex-linked mutant characters were present. 



Text-figure 25. 



Text-figure 26. 



Text-figure 27. 



Text-figure 28. 



Description. — The gynandromorph was female throughout, except for the 

 abdomen, which had male coloration on the left side and was twisted to the 

 left. A perfect penis was present. The eyes were star. The male parts 

 could not have shown the recessive second-chromosome characters, even 

 had they been present. No testes or ovaries were found, but there was a 

 genital tube with pointed cells like abnormal spermatozoa. 



