56 Phylum Protozoa 



MEDIA FOR SARCODINA 



Acanthamoeba castellanii has been grown by Cailleau ( 1933) in a liver 

 extract-serum medium sterilized by filtration, and later (1933a) in a 

 peptone medium of the following composition: peanut peptone (Vaillant), 

 3.0'; ; sodium chloride, 0.4% ; magnesium sulphate, 0.001% ; monopotas- 

 sium phosphate, 0.001%. Other peptones found to be satisfactory were: 

 pancreatic stomach peptone, pancreatic peptone of spleen, and peptic 

 peptone of "delipo'ide" liver, all three being Vaillant preparations. With 

 peptone in a concentration of 3.0%, growth of Acanthamoeba was ob- 

 tained through successive transfers, while low concentrations of peptone 

 were found to be unsatisfactory, as reported previously by Lwoff ( 1932 ) . 



GROWTH OF PROTOZOA ON KILLED MICRO-ORGANISMS 



The growth of several species of amoebae on killed bacteria was re- 

 ported by Tsujitani (1898) and Oehler (1916, 1924, 1924a). Re- 

 views of early and later investigations are to be found in papers by 

 Wulker (1911) and Sandon (1932), respectively. Among the ciliates, 

 Colpoda steiniiwas grown by Oehler ( 19 19) on killed bacteria and yeasts; 

 Glaucoma scintillans, on dead bacteria by E. and M. Chatton (1923); 

 Paramecium caudatum, on dead yeasts and bacteria by Glaser and Coria 

 (1933); and Glaucoma ficaria by Johnson (1936a) on dead bacteria, 

 yeasts, and flagellates. Negative results have been obtained by a number 

 of other workers. The literature has been reviewed by Sandon (1932) 

 and Johnson (1936a). 



GROWTH OF PROTOZOA ON SINGLE SPECIES 

 OF MICRO-ORGANISMS 



The maintenance of pure-line cultures of Protozoa on single species of 

 living bacteria, yeasts, or other micro-organisms has been accom- 

 plished by a number of investigators, particularly Oehler (1919, 1924, 

 1924a). More recent investigations include those of Geise and Taylor 

 (1935), Loefer (1936), and Johnson (1936a). The literature has been 

 reviewed by Sandon (1932) and Johnson (1936a). Such methods are 

 much more reliable than the use of the common "infusion" cultures and, 

 while they do not offer the precision of the bacteria-free technique, the 

 procedures are relatively simple and are often worth while in view of 

 the good results obtained. 



GROWTH IN RELATION TO pH AND OTHER FACTORS 



The observations of a number of workers have shown that the pH of 

 the medium is an important factor influencing the success or failure 

 of bacteria-free cultures of Protozoa. The findings of Dusi (1930a), 

 Jahn (1931), Elliott (1933), Dusi (1933, i933a), Hall (1933), Loefer 



