50 



THE ORIGIN OF GYNANDROMORPHS. 



Explanations. — An egg containing the rudimentary fused X was fertilized 

 by the vermiHon forked sperm. A paternal vermilion forked X was elim- 

 inated, leaving the other rudimentary fused X to produce the male side, 

 while the female side contains both original X's, namely, rudimentary fused 

 and vermilion forked, and is accordingly wild-type. 



A 



/. 



V f 



No. 3272. February 10, 1916. C. B. Bridges. Text-figures 36 and 36a 



(drawings). 



Parentage. — One X chromosome of the mother carried the genes for sable, 

 garnet and also "sable-duplication" at zero. The other X carried the genes 

 for eosin and for miniature. The father was eosin-miniature. 



Descriptions. — The entire abdomen was apparently male in shape, banding, 

 and genitalia, though it is not known whether testes or ovaries were present. 

 The right side of the thorax was smaller in size and bore smaller bristles and 



Text-figuhe 36o. 



Text-figure 36. 



Text-figure 37. 



a smaller (male-type) miniature wing. All right legs were male and both fore- 

 legs bore sex-combs. The right eye (see drawing) had a streak of male 

 tissue ("light" eosin color) running forward completely through. Above and 

 below this streak the tissue was female ("dark" eosin color) There is one 

 other curious feature — the left foreleg as well as the right bore a sex- comb. 

 The head, except the male streak, the right side of the thorax with its miniature 

 wing, and the two rear legs were female 



Explanations — An egg bearing the eosin miniature non-cross-over X was 

 fertilized by the X sperm carrying eosin and miniature Elimination of one 

 of these X's (either maternal or paternal) was followed by shifting of cleavage 

 nuclei or by shifting of the anlage in the formation of the pupa. 



