i8o 



LOUISE H. GREGORY. 



transferred to the normal medium. Table I. shows the results 

 of these experiments, giving the age at the time of the experiment 

 and the amount of variation from the control series of the 

 number of divisions per line for the ten days. 



TABLE I. 



EFFECTS OF AN INITIAL DOSE OF DI-POTASSIUM PHOSPHATE ON PROTOPLASM OF 



VARYING AGES. 



In the first four experiments where the age of the protoplasm 

 varied from the i6th to the 23d generation the treatment with 

 the salt caused a lowered rate of division varying from one to 

 three divisions per line less than that of the control series. The 

 next ten experiments with lines whose age varied from the 57th 

 to the 2Q8th generation gave results which showed in six cases an 

 increase in the division rate and in four a slight decrease. In no 

 case was the change or variation from the control series very 

 marked. In the last two experiments there was no stimulation 

 of the vitality. The old lines were slightly depressed. Thus as 

 in the experiments with the beef-flour medium, the young series 

 are depressed by the potassium phosphate, the older lines too 

 show a slower rate, while the intermediate individuals may be 

 slightly stimulated by the treatment. 



