LIFE CYCLE OF HYDATINA SENTA 



139 



TABI-E 32 



Showing the number of male- and fetnale-producers in the progeny of three sister 

 individuals of Hydatina senta, one line being bred in spring water, the other two 

 in creatin solutions of different strengths. 



*Remainder of family not recorded. 



eggs then hatched. Table 33 presents the details of the experi- 

 ments. 



In both of these tables the same result appears, that is, a lower 

 percentage of male-producers in the creatin solution than in 

 spring water, and a lower percentage in the stronger solution than 

 in the weaker. The differences are as great as were those of the 

 beef extract, and are too marked to leave any doubt regarding the 

 influence of creatin. 



