40 



THE ORIGIN OF GYNANDROMORPHS. 



No. 380. March 28, 1916. A. Weinstein. No diagram. 



Parentage. — The mother carried the genes for ruby and forked in one X 

 and the genes for eosin and sable in the other X. The father was eosin-bar. 



Description. — The gynandro- 

 morph was about half and half, 

 the left side being mainly male 

 and the right female. The left 

 side of the head and thorax and 

 the left wing were smaller and 

 the left foreleg bore a partly 

 double sex-comb. The left eye 

 was eosin bar of the male type. 

 The genitalia were double pos- 

 teriorly; there was a penis with 

 claspers and anterior to the 

 right of this an ovipositor and 

 female-type anal prominences. 

 The abdomen was female in 

 coloration, except at the tip on 

 the left side, which showed the 

 male banding. The right eye 

 was red and of the broad hetero- 

 zygous bar female type. 



Explanation. — A ruby forked 

 X egg was fertilized by an eosin 

 bar X sperm. Elimination of 

 the maternal ruby forked X oc- 

 curred. 



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Text-figure 21. 



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B 



No. SS01122AAA7344512 Selection Experiment. January 18, 1917. 

 T. H. Morgan, Plate 4, Figure 1 (diagram). 



Parentage. — The mother was notch, having therefore one X chromosome 

 with the dominant gene for notch; the other X carried the recessives eosin 

 and ruby. The father was likewise eosin ruby. 



Description. — The gynandromorph was male on the right side, except for 

 spots of red (female) in the eosin ruby eye of that side. The coloration of 

 the abdomen was male throughout. The genitalia were mainly male, but 

 showed female parts. The left side was mainly female, having a red eye and 

 a notch wing of slight type. No gonads were found in the sections examined, 

 but it is probable that there were very rudimentary ovaries. 



Explanation. — An egg bearing the gene for notch was fertilized by an 

 X sperm with the genes for eosin and for ruby. Elimination of a maternal 

 X chromosome left the male parts to be determined by the paternal eosin 

 ruby X. 



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n 



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