THE ORIGIN OF GYNANDROMORPHS. 



43 



No. 922. December 16, 1914. C. B. Bridges. Text- 

 figure 24 (diagram). 



Parentage. One of the X chromosomes of the 

 mother contained the genes for eosin and for vermil- 

 ion, the other X the gene for forked. The X chromo- 

 some of the male carried the genes for white and for 

 bar. 



Description. The fly was female throughout (with- 

 out sex-combs) and possessed white-eosin heterozy- 

 gous-bar eyes, except that the tip of the abdomen 

 on the left side was banded like a male. Below there 

 was a normal penis and male armature. In sec- 

 tions an ovary was found on one side, nothing on 

 the other, 



Explanation. An egg containing the X chromo- 

 some with the genes for eosin and for vermilion was 

 fertilized by the X-bearing sperm with the genes for 

 white and for bar. Elimination of either X chro- 

 mosome would account for the male parts at the tip 

 of the abdomen. 



w e 



TEXT-FIGURE 24. 



or 



w 



B 



w 



No. 925. December 18, 1914. C. B. Bridges. Text-figure 25 (diagram). 



Parentage. The mother was club, carrying in one X the sex-linked gene 

 club, and in the other X lethal 2 which is a deficiency for club. The X sperm 

 of the father carried the genes for eosin and for miniature. 



Description. The only male part was the right eye, which was eosin (male 

 type) in color, except for a fleck of red (female). The fly was fertile as a 

 female when mated to a wild male and produced: No. 1117; wild type females, 

 101; eosin miniature males, 55; miniature male, 1; eosin males, 9. 



Explanation. An egg with an X bearing the gene for lethal 2 was fertilized 

 by an X sperm with the genes for eosin and miniature. Elimination took 

 place in one of the maternal chromosomes, leaving the paternal X with eosin 

 and miniature to form the male parts, viz, the right side of the head (in part). 

 The rest of the mosaic was female; hence both wings were wild-type. 



Cl 



m 



w e 



m 



No. 1010. December 20, 1914. C. B. Bridges. Text-figure 26 (diagram). 



Parentage. One X chromosome of the mother carried the genes for yellow 

 and for white, and the other X the gene for lethal 6. The X chromosome of 

 the father carried only wild-type genes. 



