206 



BIOLOGY OF THE PROTOZOA 



different conditions of organization. Series 111 and 112, for 

 example, were 279 and 263 generations old at the beginning of the 

 ex])eriment, the single individual isolated daily in a drop of medium 

 di^■ided 60 times in sixty days. Series 120 and 121 were 12 and 10 

 generations old, and each solitary individual divided 86 and 107 

 times in the same sixtv davs. 



raOLEPTUS MOBILIS — DIVISION RATE. 



Experiment Jrom September 24 to November 10, 1924. 



