444 ANNA R. WHITING. 



nine biparental males carrying w were tested by crossing to ww 

 females, some of them several times, no daughters were obtained 

 among the 1,733 sons, all wrinkled like their mothers. 



DAUGHTERS OF BIPARENTAL MALES. 



Of the two exceptional biparental males mentioned above one 

 occurred in a mating of ivory defective female by orange defec- 

 tive male. He had orange eyes and defective wings as would be 

 expected. His mate was of the same genetic constitution as his 

 mother. In the first culture bottle appeared 2 orange females, i 

 with abnormal abdomen which died within the cocoon, the other 

 sterile. In the fourth bottle was found an ivory defective female. 

 She was fairly fertile. In the first culture bottle she laid over 

 thirty eggs, one of which hatched into an ivory female. In the 

 second bottle there was likewise a high mortality of eggs but 9 

 ivory males and 5 ivory females ultimately emerged. Her daugh- 

 ter from bottle a gave 49 males, another which lived but a short 

 time gave 10 males. There are three possible explanations for the 

 appearance of this ivory female. Her mother may not have been 

 virgin when mated. This is improbable since great care was ex- 

 ercised in this matter and many more ivory females would be ex- 

 pected early in the life of the mother if she had mated with an 

 ivory brother. The female may have been produced from an un- 

 fertilized egg, a phenomenon which has occurred but rarely in 

 Habrobracon, or the male may have produced a spermatozoon not 

 carrying the chromosome containing the o factor. 



The comparatively late appearance of this female serves as an 

 argument for the second explanation since daughters of biparental 

 males usually appear in the first or second culture bottles. On 

 the other hand the high mortality of her eggs might indicate that 

 she is the daughter of the biparental male since the few females 

 obtained from unfertilized eggs have proved highly fertile. 



The second exceptional case was found early in the work by 

 P. W. Whiting. It has not been previously discussed in detail. 

 A male of type stock I was crossed with female of orange defec- 

 tive stock 3. 118 orange sons showed defect typical of stock 3. 

 Black daughters were 15 normal, I defective; black sons were 3 

 normal, I defective, the defective among the black being due to 



