462 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Time hr. 



No. of Paramaecia ... 59 

 No. of Divisions .... 



Mortality 



Mean Result 



Expt. No. 29, Dec. 7, 1901. 



Hanging-drop preparations of Paramaecia in 0.02 m., and 0.01 m., 

 potassic chloride medium, also containing 20 per cent of strong, fer- 

 mented hay infusion. Medium of control experiment consisted of similar 

 20 per cent hay infusion only. 



A number of experiments were made to ascertain the effect of chloro- 

 form upon the rate of division in Paramaecia. The general result of 

 this was to accelerate division when the reagent was present in the 

 proportion of 5 per cent of a saturated aqueous solution. A concen- 

 tration of 10 per cent had a retarding influence. I shall give but one 

 experiment. 



Expt. No. 22, Nov. 22, 1901. 



A sufficient volume of a saturated solution of chloroform in tap-water 

 was added to fermented hay infusion (bacterial food) to make the mix- 

 ture contain 5 percent of the strong hay infusion. The control consisted 

 of this diluted 5 per cent hay infusion only. All necessary dilutions 

 were made with tap-water. 



