8 4 



MARY H. CHAMBERS. 



TABLE II. 



POTATO (BOILED). Daily Division Average For Six Day Periods. 



It will be observed that when the potato extract was boiled 

 the average rate of division was about the same for the weaker 

 and stronger solutions. 



A similar experiment was carried on at the same time with 

 yeast. Two and three drops each of the whole and ground yeast 

 were used. 



TABLE III. 



YEAST (WHOLE). Daily Division Average For Six Day Periods. 



As this table shows, the individuals in the solution containing 

 whole yeast divided more rapidly than the control. 



TABLE IV. 



YEAST (GROUND). Daily Division Average For Six Day Periods. 



In this case a decided increase in the rate of division is shown 

 when ground yeast is added to the diet. 



A second set of experiments was made upon four races of 

 Paramecia as follows: Race A had been in spring water in the 



