52 THE ORIGIN OF GYNANDROMORPHS. 



No. 2204. October 5, 1914. C. B. Bridges. Text-figure 39 (diagram). 



Parentage. — One X of the mother carried the gene for eosin, the other the 

 genes for vermihon and forked. The father was bar. 



Description. — The gynandromorph was of the "fore-and-aft" type. The 

 abdomen was of the male shape, with male coloration on the left side and 

 partially male on the right. There was a normal penis. The eyes were 

 heterozygous bar (female) and the head, thorax, legs, and wing were female. 

 Sections showed that email ovaries were present. 



Explanations. — Since the male parts were not forked, the egg probably 

 carried the eosin X. The X sperm carried bar. The eyes were female and 

 there is no criterion as to which X was eliminated. An alternative explana- 

 tion assumes a vermihon forked X in the egg, and subsequent elimination of 

 this same X to give the not-forked male parts. 



No. X. August 1916. A. Weinstein. Text-figure 40 (drawings of wings) . 



Parentage. — The mother had the genes for eosin, ruby, and forked in one 

 X and for fused in the other. The father was probably eosin ruby forked. 



Description. — The gynandromorph was largely male anteriorly and female 

 posteriorly. The head was entirely male, with eosin ruby eyes. There 

 were sex-combs on both forelegs, which means that the ventral part of the 

 thorax was male. The left dorsal part was also male, having a small wing 

 which was fused. The right dorsal part was female with a large wild-type 

 wing. The abdomen and genitalia were female. 



Explanations. — The egg carried a cross-over eosin ruby fused X and the 

 sperm an eosin ruby forked X. Elimination of the paternal X occurred. 



W rb fu W rb fu 



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No. 4614. January 22, 1918. A. H. Sturtevant. Text-figure 41 (diagram). 



Parentage. — One X of the mother carried the genes for eosin, vermilion, 

 and forked; the other X carried only wild-type genes. One of the third- 

 chromosomes carried the recessive genes for sepia, spineless, kidney, sooty, 

 and rough; the other was wild-type. The father was a bar male from stock. 



Description. — Except for the wings, the gynandromorph is divided antero- 

 posteriorly. The right wing was slightly larger than the left and may have 

 been female. The other wing and the remainder of the thorax was male. 

 There were sex-combs on both forelegs. The head was entirely male, with 

 eosin-vermilion eyes and forked bristles. The thorax and legs had also forked 

 bristles. The abdomen was female, both in banding and in shape. The 

 genitalia were female, but slightly abnormal. Tested as a female she proved 

 sterile. None of the third-chromosome recessives showed in any part, either 

 male or female, of the gynandromorphs. 



Explanations. — An egg containing the non-cross-over eosin vermilion forked 

 X was fertilized by an X sperm carrying bar. The paternal X was eliminated, 

 producing the anterior male parts. The absence of the recessive third-chromo- 

 some characters in the male parts proves that the elimination of the X was 

 independent of the third chromosome. 



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I I I I t I 



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