THE ORIGIN OF GYNANDROMORPHS. 



25 



right side being male, with sex-comb, smaller eye, wing, etc., and the 

 right side of the abdomen with male coloration. The genitalia were 

 half-and-half also. The interesting feature was that throughout the 

 female left side the bristles were weak and irregular and the bands 

 "faint, " while the male right side was entirely wild-type in appearance. 



Another striking case appeared (on March 23, 1916) among the 

 offspring of a pair, the female of which was heterozygous for the sex- 

 limited character (" side-abnormal") and the father was pure for it. 

 The character "side-abnormal" is sex-linked in inheritance and sex- 

 limited in appearance, being seen only in females. In this mutant 

 the bands of the abdomen of the female are "abnormal" at the sides, 

 i. e., while the mid-dorsal part of the band is normal the ends of the 

 band where they come 

 around the side are cut 

 away irregularly to 

 ragged points and the 

 color is etched with 

 white splotches in the 

 dark. The ventral 

 plates are much 

 smaller and are irreg- 

 ularly rounded. In 

 the male all parts are 

 as in the wild flies. 

 This gynandromorph 

 (3806) showed a nor- 

 mal male right half 

 of the abdomen and 

 a female left half, with 

 all the characteristics 

 of the side-abnormal 

 character. The ven- 

 tral plates were full 

 and normal in the 

 male parts and small 



and irregular in the female parts. Other evidences of maleness were 

 present — a sex-comb on the right foreleg and a smaller right wing. 



Elsewhere in the text we have described several other cases involv- 

 ing characters both sex-linked and sex-hmited. Thus in gynandro- 

 morph 7530, page 46, the male eye on the right showed marked devel- 

 opment of the character facet, as in the normal facet male, while the 

 female left eye, also facet, could hardly be told from wild-type, as is 

 usual in facet females. All gj^nandromorphs involving eosin eye-color 

 show the Ught type of eosin in the male eyes and the dark t>T)e in the 

 female eyes. 



Text-figure 6. 



