THE ORIGIN OF GYNANDBOMORPHS. 37 



Description. The right side of the gynandromorph was male, with a 

 white eye (with a fleck of red in it) and a sex-comb. The right wing was 

 smaller. The genitalia were mainly male, but also with some female parts. 



Testes were found in sections of the abdomen, with plenty of sperm. 



Explanation. An egg containing the white X was fertilized by a sable- 

 bearing X sperm. A paternal sperm suffered elimination, leaving the white- 

 bearing X to produce the male side. The female side is wild-type, since one 

 X has the normal allelomorph for white (viz, red eye), and the other X the 

 normal allelomorph for sable (viz, wild-type body-color). 



w w 



No. 1373. February 22, 1915. C. B. Bridges. Text-figure 16 (diagram). 



Parentage. One of the X chromosomes of the mother carried the genes 

 for eosin and for vermilion, and the other X the genes for sable body-color 

 and forked bristle. The X chromosome of the father carried the dominant 

 gene for bar. 



Description. The left side of the gynandromorph was male throughout, 

 being of smaller size in head, thorax, abdomen, wing, bristles, and legs, and 

 having a sex-comb. The right eye was o in-vermilion in color and not- 

 bar. The coloration of the abdomen was male on the left side at the tip, 

 and the genitalia were very largely male. The right side was female, with 

 a red-bar eye. The abdomen was sectioned and found to contain a pair of 

 poorly developed ovaries. 



Explanation. An egg containing the X chromosome with genes for eosin 

 and for vermilion was fertilized by the bar-bearing X sperm. Elimination of 

 a paternal X chromosome left the eosin-vennilion-bearing X to produce the 

 male side, while the female side contained the dominant allelomorphs for these 

 two genes, as well as the dominant gene for bar eye in the female XX complex. 



w e v w v 



B 



No. D. From Lethal 2 Stock. May 1, 1915. E. M. Wallace. 

 Text-figure 17 (diagram). 



Parentage. The wild-type mother carried lethal 2 in one X and the genes 

 for bifid and tan in the other. The stock was maintained by repeating in 

 each generation the cross of wild-type lethal-bearing females to their bifid- 

 tan brothers. 



Description. The gynandromorph was completely bilateral, the left side 

 being male and the right female. The left side showed tan body-color through- 

 out and had a bifid wing. The left side showed all the size, coloration, and 

 other secondary sexual characters of the male. The genitalia were male. 

 Sections showed that two rudimentary ovaries were present. 



Explanation. A non-cross-over egg containing the genes for lethal 2 was 

 fertilized by an X sperm with the genes for bifid and tan. Elimination of 



