THE ORIGIN OF GYNANDROMORPHS. 



51 



Gynandromorphs Roughly "Fore-and-Aft." 

 No. II 139. January 12, 1914. C. B. Bridges. Text-figure 37 (diagram). 



Parentage. — The mother was black (second chromosome), but carried only 

 wild-type genes in her X chromosomes. The father was a bar not-])Iack male. 



Descriptions. — The fly was heterozygous bar in both eyes and female through- 

 out, except for the external genitalia, which were male (penis), and the 

 coloration of abdomen. Sections showed that a pair of ovaries was present. 



Explanations. — An egg with a wild-type X was fertilized by the X sperm 

 with the gene for bar. Since the male parts did not involve the eye, it can 

 not be determined whether they arose from cells carrying the bar (paternal) 

 or the wild-tj^e (maternal) X. The fly did not show black in the male parts, 

 but since the male region was so small and also normally dark-colored, this 

 case could not be accepted as proving that the elimination did not aff"ect the 

 autosomes, as is proved in several later cases, especially devised for that purpose. 



or 



B B 



No. 1813. July 5, 1915. C. B. Bridges. Text-figure 38 (diagram). 



Parentage. — One X chromosome of mother carried the genes for forked and 

 for cleft (wing); the other X only wild-type genes. The father was forked. 



Descriptions. — The head, thorax, wings, and legs were female. The ab- 

 domen had the male coloration and a normal penis. The (poor) sections 



Text-figure 38. 



Text-figure 39. 



Text-figure 40. 



showed that at least one ovary was present. The wings were not cleft and 

 the male parts showed no forked spines. 



Explanations.— The egg contained the wild-type X and was fertilizec by the 

 X sperm carrying forked. The paternal X was eliminated, leaving the male 

 parts wild-type. e 



