THE ORIGIN OF GYNANDROMORPHS. 



39 



the abdomen had male coloration on both sides and the genitalia were largely 

 male. The right eye was eosin of the male type. The left side was mostly 

 female with a red eye and a large notched wing. The gonads a.s seen through 

 the body-wall seemed to be both ovaries. 



Explanation. — A notch-bearing egg was fertilized by an eosin sperm. 

 Elimination of the maternal notch X occurred. 



N 



w' 



w 



Text-figure 20. 



No. F. January, 1916. T. H. Morgan. Text-figure 20 (diagram). 



Parentage. — The parentage of gynandromorph F is unrecorded, though it 

 is probable that it was found in a wild stock. 



Description. — The fly was a completely bilateral gynandromorph having 

 on the right side a sex-comb, shorter wing, shorter bristles, and smaller parts 

 in head, thorax, and abdomen. The coloration of the abdomen was male 

 at the tip on the right side, but female in the remainder. The genitalia were 

 entirely female. The abdomen contained a fully developed pair of ovaries 

 and she produced many offspring which were all wild-type. 



Explanation. — Elimination of one X occurred in a normal female zygote; 

 whether this X was maternal or paternal is indeterminable. 



