ORIGINS OF GYNANDROMORPHS 



Fig. 24.--Diagram showing the modes of origin of gynandromorphs in different 

 insects directly observed in the egg or inferred from the genetic character of the 

 two sides of the body which are of opposite sex. In Bombyx (after Goldschmidt 

 and Katsuki, 193 1) two sperm may fertilize the two dissimilar products of the 

 second meiotic division in the XY female. In Habrobracon (after Whiting, 1943) 

 a sperm may fertilize one of the products of the second meiotic division to give 

 a diploid temale side, a haploid and parthcnogenetic male side being derived from 

 the other product. More rarely a second sperm may cleave side by side with the 

 fertilized egg. In Drosophila one of the two X's in a fertilized female egg may be 

 lost at the first cleavage division to give an XO side which is morphologically 

 male (after Morgan, Bridges and Sturtevant, 1925). More rarely two sperms, 

 one X- and the other Y-bearing, may fertilize the two first products of cleavage 

 to give a perfect gynandromorph. Thus all the different irregularities occur which 

 will give workable results in each organism. 



LkmcnU of Gaieties 



113 



II 



