Abstract
The relation of cell growth to population growth in bacteria-free cultures of T. geleii was examined. Cell growth proceeds independently after the onset of the stationary period of population growth. The ratio of fissions occurring to the population concentration has been determined and described. The normal Oo2 of exponential and stationary phase ciliates in phosphate buffer and in proteose peptone was detd. There is a significant difference in the respiratory rates of organisms from the 2 phases.