134 



A. FEANKLIN SHULL 



TABLE 28 



Showing number of male- and female--producers in the -progeny of four sister indi- 

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

 three respectively in solutions of ammonium chloride, ammonium carbonate, 

 and ammonium nitrate. 



*Remainder of family not recorded. 



Experiment XXVII. Ammonium hydroxid. On July 6, 1910, 

 a female from the same pure line as those of the preceding experi- 

 ment was placed in a solution of ammonium hydroxid, made by 

 diluting strong NH4OH to 5000 times its volume with Great Bear 

 spring water. Its progeny for thirteen generations were bred in 

 the same solution. The strength of the original hydroxid was not 

 known. Table 29 shows this line, and a control in Great Bear 

 spring water. 



