Determination of Sex in Hydatina senta 



19 



These three experiments, including Tables X to XX, clearly dem- 

 onstrate that food has no influence in determining whether a 

 female shall produce male or female off^spring. 



TABLE XV 



Record of the sex character of the eggs laid 

 by 49 sisters, 19 of which were without food for 

 the first 11 to 41 hours after hatching and 30 

 weie abundantly supplied with food from the 

 moment they hatched. 



Temperature 14° to 15° C- 



TABLE XVI 



Record of the sex character of the eggs laid 

 by 35 sisters, 16 of which were without food for 

 the first 20 to 64 hours after hatching and 19 

 were abundantly supplied with food from the 

 moment they hatched. 



Temperature 14° to 15° C. 



VII MALE AND FEMALE STRAINS 



Punnett says: "My experiments have led me to the conclusion 

 that among the rotifers I used were certainly three different types 

 of thelytokous (female-laying) females, viz: 



A Females producing a high percentage of arrenotokous 

 (male-laying) females. 



B Females producing a low percentage of arrenotokous 

 females. 



C Purely thelytokous females producing no arrenotokous 

 females" (p. 226). 



