1G8 



RUTH L. PHILLIPS 



TABLE 7c 

 Summarizing the data contained in table 7 a and h, for the time from January 12, 1921, 



to March 7, 1921 



below that for those in the hay infusion. That this depression 

 was not due to the changed medium is shown by the significance 

 factor for A'C, the only mixture in which the depression ap- 

 peared to be at all marked. 



When the data for the two observation periods are combined, 

 it is seen that on the whole this change in medium was without 

 significant effect. In general it may be said that changes in 

 medium which were tried had no appreciable effect over a con- 

 siderable time. The only result of change in medium of any 

 importance was that of a slight transitory stimulation of the 

 metabolism in animals changed to the moneywort infusion. 



Jf. Change in medium accompanied by change in food. In order 

 to determine whether a change in medium would produce an 

 effect upon the metabolism of Paramecium if the food was 

 changed at the same time, animals were washed and placed in 

 0.1 per cent standard timothy hay infusion and in 0.1 per cent 

 moneywort infusion with the bacteria J, K, L and the mixtures 

 JK, JL, KL, and JKL as food. The culture C was used as con- 

 trol. It was found that the animals in the moneywort infusion 

 did not show any significant increase in rate of metabolism, but 

 the duration of life in the moneywort was in most cases slightly 

 longer. In the hay infusion none of the animals fed with the 



