External Factors and Size 



151 



of the later work of Paine, which was just discussed, 

 one would like to know the mean time elapsed before 

 the recorded results were obtained; the investigators 

 merely state that "at least 15 minutes" elapsed before 

 measurements were begun. 



Almost identical with the results of Drabble are the 



50 



o400 



O-: 



c 



q; 



E 



B 200 

 o 



> 



>■* 

 *o 

 o 



CQ100 





0.2 0.4 06 08 



Molar concentration ofNaCI 



10 



Figure 52. Effect of various concentrations of sodium chloride upon the 

 mean volume of Saccharomyces cereviseae. The yeasts were placed in each 

 solution directly from a sugar medium where the mean volume was 402 

 cubic micra. From 16 to 31 different individuals were measured for each 

 point. (Data of Drabble, Drabble, and Scott, '07). 



changes of volume in yeast which may be derived from 

 data that Rubner ('24) obtained by an entirely differ- 

 ent method. He placed samples of a uniform stock of 

 yeast into various concentrations of sodium chloride, 

 and measured the ratio of water to nitrogen at the end 

 of 24 hours. When calculated as relative body vol- 

 umes, the data fall along the curve of figure 52. This 

 fact makes it probable that the yeast cells measured by 



