PETERS. — METABOLISM AND DIVISION IN PROTOZOA. 461 



previously determined that a fraction of a minute longer than this was 

 sufficiently injurious to stop locomotion. 



0.167 m. NaCl, 1 min. Control. 



Time hr. 24 hr. hr. 24 hr. 



No. of Paramaecia ... 39 135 55 205 



No. of Divisions .... 96 150 



Mortality 



Mean Result 3.46 3.73 



On account of their motion the animals were too numerous to be 

 counted alive, and they were therefore killed before counting. 



Expt. No. 21, Nov. 21, 1901. 



Purpose and method the same as in the preceding experiment. Para- 

 maecia. 



0.167 m. NaCl, 1 min. Control. 



Time hr. 30 hr. hr. 30 hr. 



No. of Paramaecia ... 37 49 40 64 



No. of Divisions .... 13 24 



Mortality 1 



Mean Result 1.32 1.60 



Expt. No. 10, Oct. 30, 1901. 



Hanging-drop preparations 0.01 m. potassic chloride continuously 

 applied in hay infusion. Paramaecia. 



0.01 m. KCl. Control. 



Time da. 1 da. da. 1 da. 



No. of Paramaecia .... 99 103 87 91 



No. of Divisions 4 4 



Mortality 



Mean Result 1.04 1.04 



Expt. No. 19, Nov. 18, 1901. 



Hanging-drop preparations of Paramaecia in hay infusion containing 

 0.01 67 m. potassic chloride. 



