Physiology 479 



by Trypanosojna rhodesiense decreases as pH of the medium falls, and 

 both changes can be prevented by buffering the medium (64). Accelerat- 

 ing effects of carbohydrates on growth of Tetrahymena pyriformis are 

 marked below pH 7.0, but are insignificant in alkaline media (114). The 

 effect of plant auxins on growth of Euglena gracilis varies with pH of 

 the medium and stimulation is greatest at pH 5.6 (118). The rate of 

 locomotion in Amoeba proteus is related to pH of the medium (208, 

 449), and pseudopodial activity in ingestion of food may be influenced 

 likewise. Also, the rate at which food vacuoles are formed in Colpidium 

 increases from pH 4.5 to 6.0, and then decreases to zero at pH 8.0 (399). 

 For Protozoa in general growth in pure cultures has been reported 



TABLE 8. 8. GROWTH-pH RELATIONSHIPS OF VARIOUS 

 PROTOZOA IN PURE CULTURES 



Species pH Range Optimum 



MASTIGOPHORA 



Astasia klebsii, peptone (82) 



Chilomonas Paramecium, peptone (324) 



C. Paramecium, peptone, acetate (324) 



C. Paramecium, heteroautotrophy (453) 



Chlorogonium elongatum, peptone (324) 



C. elongatum, heteroautotrophy (453) 



C. euchlorum, peptone (324) 



C. euchlorum, heteroautotrophy (453) 



Euglena anabaena, peptone (172) 



E. deses, peptone (172) 



E. gracilis, peptone (2) 



E. gracilis, peptone (104) 



E. gracilis, peptone (237) 



E. gracilis var. bacillaris (331) 



E. klebsii, peptone (105) 



E. mutabilis, peptone (84) 



E. piscijormis, peptone (105) 



E. stellata, peptone (105) 



E. viridis, inorganic (508) 



Polytoma uvella (453), heteroautotrophy 



Polytomella caeca (346), peptone 



Trichomonas vaginalis (254) 



SARCODINA 



Alayorella palestinensis (472) 6.4-7.2 6.8 



CILIATEA 



Colpidium campylum (272) — 5.4 



Glaucoma scintillans (272) — 5.6-6.8 



Paramecium bursaria (328) 4.9-8.0 6.8 



Tetrahymena pyriformis E (113) 4.5-8.5 5.5; 7.4 



T. pyriformis GY-] (252) 4.9-9.5 5.1-6.0 



T. Pyriformis GP (252) 4.0-8.9 4.8-5.3 



T. Pyriformis U {\\A) . 4.5-8.5 5.5; 7.4 



r. pyriformis W (272) — 5.6-8.0 



Tetrahymena vorax (272) — 6.2-7.6 



