GYNANDROMORPHS IN HABROBRACON. 113 



found in vial b (May 15, 1923). Sternites were similar to those 

 of a normal male. The head was of normal male type with 

 twenty-seven joints in left antenna, twenty-six in right. Internal 

 organs were in every way typical for the male. No tests of 

 responses were made. 



DISCUSSION. 



Impaternate Females. 



If in parthenogenesis both oocyte divisions occur without 

 subsequent nuclear fusion but with somatic doubling, or if the 

 first oocyte division is entirely reductional and the second is 

 suppressed, homozygous individuals are to be expected. 



Impaternate females of Habrobracon juglandis, however, may 

 be heterozygous. Thus freak 257, homozygous for D n , and, 

 like freaks 276 and 259, for o, was at the same time heterozygous 

 for Ww clearly demonstrating that the first maturation division 

 must have been equational for one locus at least. Had it been 

 reductional for Ww one of the derivatives of the first polar body 

 must have returned to fertilize the female pronucleus in order to 

 produce Ww. In that case, however, we would have Oo and 

 Dndn95 unless for them the first oocyte division had been equa- 

 tional. 



Either one of two theories are tenable. For all three loci 

 the first division may be equational, a derivative of the first 

 polar body effecting fertilization or the first division may be 

 equational for some loci, reductional for others, diploidism being 

 effected by suppression of the second oocyte division. 



Mosaic Males. 



Since mosaic-eyed male freak 185 had a virgin mother, he 

 arose from an unfertilized egg. Since mosaic-eyed male freak 

 264 had no sisters, he presumably also arose from an unfertilized 

 egg. As regards the other three males with mosaic eyes orange 

 parts of freaks 65 and 256 and black parts of freak 154 as well 

 as defective r 4 veins of freak 65 must have been of maternal 

 origin. 



As regards method of origin of these males it is assumed that 

 cleavage of the second oocyte produced a haploid mosaic (haploid 

 mosaic arrenotoky). It is clear that reduction must have 



