36 



THE ORIGIN OF GYNANDROMORPHS. 



eosin color. The right male eye was much lighter than the female left eye, 

 as is the rule with eosin even when diluted. 



Explanation. Both egg and sperm carried the genes for eosin and cream. 

 Elimination of the paternal or of the maternal X occurred. Presumably the 

 autosome carrying the cream gene behaved normally as in all known cases, 

 but this case is not diagnostic, since the fly was homozygous for cream. 



Mf W e 



w e 



TEXT-FIGURE 14. 



TEXT-FIGURE 15. 



TEXT-FIGURE 16. 



No. 1-5. A. M. Brown. April 9, 1914. Plate 2, Figure 4 (colored drawing). 



Parentage. The grandmother was homozygous for vermilion and hetero- 

 zygous for a lethal. The grandfather was eosin-miniature. A gynandro- 

 morph was produced by one of their wild-type daughters which had been 

 out-crossed to an eosin-miniature male. 



Description. The right side was male throughout with an eosin (male 

 color) eye and miniature wing. A sex-comb was present on the right foreleg. 

 The left side was entirely female, with red eyes and a long wing. 



Explanation. A non-cross-over egg containing the wild-type X was fertil- 

 ized by an X sperm with genes for eosin and for miniature. Elimination of 

 one of the maternal X's left the male parts eosin-miniature. 



w" 

 No. 195. 



m 



April 27, 1914. C. B. Bridges. Text-figure 15 (drawing). 



Parentage. One X chromosome of the mother carried the gene for white 

 eye-color and the other X the genes for eosin and for lethal 4. 

 chromosome of the father carried the gene for sable. 



The X 



