i88 



Life Cycle of Hydatina Senta 



[Dec. 



TABLE II. 



Shozving tlic numher of male- and female-producers in the progeny of iwo 

 sister individuals of Hydatina senta, one line being hred in spring water, the other 

 in a Solution of beef extract. A and B are separate experiments. 



Experiment 29. The preceding experiment was repeated, but 

 this time two strengths of the extract were used, one a 0.04 per cent., 

 the other a 0.05 per cent. Solution. Both lines are represented in 

 Table 12. The results of these repetitions agree closely with those 

 of the first experiment, showing even a smaller percentage of male- 

 producers in the stronger Solution of the extract. There can scarcely 

 be any doubt that beef extract tends to reduce the proportion of 



