Determination of Sex /« Hydatina senta 



17 



hatching each daughter-female was kept in this water without 

 food from 6 to 71 hours. 



Of 109 daughter-females from the same mother as the above, 

 62 were well supplied with food from the moment they hatched. 



Tables X to XIII give the detailed results and Table XIV gives 

 the summary. The mother-individuals of Tables X and XII 



TABLE XII 



Record of the sex character of the eggs laid 

 by 53 sisters, 31 of which were without food for 

 the first II to 59 hours after hatching and 22 

 were abundantly supplied with food from the 

 moment they hatched. 



Temperature 20 to 22° C. 



Sister- Starved from 

 individ- time of hatch- 

 uals j ing 



Character of eggs 

 produced 



TABLE XIII 



Record of the sex character of the eggs laid 

 by 46 sisters, 5 of which were without food for 

 the first 50 to 71 hours after hatching and 41 

 were abundantly supplied with food from the 

 moment they hatched. 



Temperature 20° to 22° C. 



were sisters. The ii sisters-individuals of Table XI were 

 starved in filtered boiled spring water placed in sterilized test tubes 

 with cotton stoppers. 



The percentage of male-laying females among all the starved 

 daughter-females is sUghtly lower than that of those which were 

 fed. 



