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THE AMEBIC AN NATURALIST [Vol. XLIX 



as a result of competition, for, as Morgan and Tice have 

 shown, such males tend to disappear if too many other 

 larvaB are present. 



Lastly sixty-eight more rudimentary females from stock 

 were tested with bar males. They gave twenty-four long 

 bar (heterozygous) females, two rudimentary round males 

 and one mosaic that will be described below. In one bottle 

 there had been twenty-seven rudimentary females and an 

 examination of their food showed over forty eggs present. 

 Since the eggs are not easily found I estimate that prob- 

 ably a hundred eggs were present. Out of these eggs 

 sixteen females and one male developed (included in the 

 total given above). It appears then that many of the 

 eggs laid by the rudimentary females do not develop. 



The condition of the ovaries of the eight surviving rudi- 

 mentary females showed that seven were full sized and 

 contained mature eggs. The mosaic that appeared in one 

 of the last crosses (Fig. 2) is interesting in several ways. 

 Genetically it is a female, externally it is a male in ap- 

 pearance, in reality it is a male in part and a female in 

 part although the egg must have been fertilized by a 

 female-producing sperm. On the right side of the body 

 the eye is heterozygous for bar, there is no sex comb on 

 the fore leg, the spines on the thorax are long, and the 

 wing is large. On the left side the eye is pure bar, there 

 is a sex comb on the foreleg, the spines on the thorax 

 are short, and the wing is small. The difference in size 

 of the two wings, and of the spines, is a characteristic 

 difference between the male and female, connected with a 

 difference in body size. The abdomen is pigmented above 

 as in the male, and below there is a normal penis. 



Despite the apparently normal male copulatory organs, 

 the mosaic, when placed with mature, unmated females, 

 paid not the slightest attention to them, although it was 

 quite active. Of course its organs of perception were 

 female on one side of the anterior end, although male on 

 the other side. What physiological complex this might 

 give, is, of course, problematical. The mosaic died by 



