MALE-PRODUCTION IN HYDATINA 



129 



The effect of the sugar sohition, as shown in table 1, was to 

 reduce the number of male-producers. But the amount of 

 reduction was less than was expected on the theory that osmotic 

 pressure was responsible for that reduction. It was less than 

 the effects of certain ammonium salts whose effects should have 

 been, theoretically, less than those of the sugar. 



TABLE 1 



Two lines of the rotifer Hydatina senta derived from sisters, one line reared in dis- 

 tilled water, the other in a ~| solution of cane sugar. The number of male-pro- 

 ducing (cf 9 ) and female-producing (9 ?) females is recorded for each line. 

 The cane sugar reduces the number of male-producers 



THE JOURXAL OF EXPERIMENTAL ZOOLOGY, VOL. 21, NO. 1 



