98 



LORANDE LOSS WOODRUFF. 



The copper sulphate experiments on the Stylonychia culture 

 were carried on for only ten days, but increased susceptibly to 

 copper sulphate is shown by the alcoholized lines (cf. Fig. 7). 



The division rate of the three Paramecium cultures and the three 

 Stylonychia cultures subjected to copper sulphate shows distincly 

 that the organisms which have been treated with alcohol are less 

 resistant to copper sulphate. 



\T. General Considerations. 

 The aim of this paper has been to set forth merely the facts 

 which the experiments have revealed. Several possible causes 



47 4» 49 50 51 52 



Fig. 5. Paramecium. Culture 1^ (hay infusion + alcohol) = ■ line; 



culture I ' (hay infusion + alcohol + CuSOJ = line. X = po'^t at which 



the culture subjected to copper sulphate died out. 



of the phenomena observed may be suggested, but it will be of 

 more value to reserve a general discussion of these until more 

 data from experiments are at hand. 



Calkins and Lieb, as already mentioned, found that alcohol in 

 medium doses, c. g., one part of alcohol in 2,500 parts of culture 

 medium, acted as a continued stimulus to the division rate of 

 Paramecium. The results of my experiments obtained up to the 

 present time fail to show such a marked uniformity of effect from 

 alcohol treatment, as a depression of the rate of division, followed 

 by fluctuations above and below the control, was the result in 

 Paramecium P and in all the succeeding cultures of both 

 species, after an initial stimulation of the division rate of a longer 



