1 82 



LOUISE H. GREGORY. 



These results when considered alone are too few to allow 

 any definite conclusions to be drawn, but when they are con- 

 sidered in the light of the preceding experiments with potassium 

 phosphate and previous ones with beef-flour they indicate the 

 same variations in the response of the protoplasm at different 

 ages. 



B. THE EFFECTS OF DAILY STIMULATION WITH DI-POTASSIUM 

 AND DI-SODIUM PHOSPHATE. 



i . Experiments with Potassium Phosphate. 



Initial experiments were conducted with series 133 at a period 

 of early maturity in the iO-}.th generation in order to determine the 

 most favorable amount of KoHPCX to be added to the normal 

 medium. Five series of five lines each were kept for ten days in 

 a medium consisting of normal hay-flour mixture to which 

 potassium phosphate in different densities was added. The 

 results showed that the individuals kept in a medium to which 

 had been added daily N/$ooo KoHPCh gave the highest division 

 rate averaging 5 divisions per line more than that of the control 

 series. This strength of solution therefore was used in all of the 

 experiments with potassium phosphate. Table III. shows the 

 results of these experiments. 



TABLE III. 



EFFECTS OF POTASSIUM PHOSPHATE ADDED Daily TO NORMAL MEDIUM. 



