THE GENETICS OF HABROBRACON JUGLANDIS ASHMEAD 



that normal males are X and Y with equal fre- 

 quency. 



The feminized structures just mentioned do 

 not appear on all mosaics, for in many the line 

 of mosaicism does not pass through the genital- 

 ia. It has also been found, however, that these 

 structures do not always occur in mosaics even 

 when the line does bisect the body (Fig. 15). 

 These facts have led to the supposition that in 

 Habrobracon there are several kinds of males, 

 genetically distinct for sex-determining fac- 

 tors but phenotypically similar. When tissues 

 differing in sex-determining factors adjoin in 

 a haploid mosaic male, one influences the other, 

 and traits characteristic of diploid tissue are 

 the result. 



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