362 



RESPIRATORY METABOLISM 



above 25° C. With these same materials in COa-free alkaHne media 

 below 25° C, O, consumption was independent of Oo tension. The 

 effect of Oo tension apparently varied with pH, COg tension, salt con- 



Table 4: Measurements of Protozoan Respiration 



Not Q02 but mm^ O2 per hour per mm^ 



tent, and temperature. Since O, consumption of the yellow pigment of 

 respiration (see below) varies with Oo tension, it would not be sur- 

 prising to find a similar relationship in organisms with this mechanism. 

 However, this is not always the case (Schlayer, 1936). Clarification of 



