CONTROL OF SEX BY FOOD IN ROTIFERS 



265 



ducers to male-producers. The mother of the female-producing 

 or male-producing daughters is the individual influenced by the 

 diet. If the mother is fed the colorless diet all of her daughters 



Fig. 1 Hydatina sonta. A, female; B, male; C, parthenogenetic egg which 

 develops into a female; D, smaller parthogenetic egg which develops into a male; 

 E, fertilized egg, which is often called resting or winter egg, and always develops 

 into a female. This egg if unfertilized would have formed a small parthenoge- 

 netic egg which would have developed into a male. 



will produce females but if the diet of the mother is changed 

 from the colorless flagellates to the green flagellates she will 

 begin soon to produce daughters which will produce males. 



