108 Phylum Protozoa 



1934c The pure culture of Paramecium. Science 79:413- 



1936. The precise control of growth in a pure culture of a ciliate, 



Glaucoma pyriformis. Biol. Bull. 71:426. 

 Lwoff, A. 1923. Sur la nutrition des Infusoires. C. R. Acad. Sci. 176:928. 



1932. Recherches biochimiques sur la nutrition des Protozoaires. Paris, 



Masson et Cie. 

 Penn, A. B. K. 1935. Factors which control encystment in Pleurotricha lanceolata. 



Arch. f. Protist. 84:101. 

 Peters, R. A. 1920. Nutrition of the Protozoa: the growth of Paramecium in 

 sterile culture medium. J. Physiol. 53: ioS - 



1929. Observation upon the oxygen consumption of Colpidium colpoda. 



Ibid. 68:1. 



Phelps, A. 1934. Studies on the nutrition of Paramecium. Arch. j. Protist. 82 : 134. 

 Pringsheim, E. G. 1915. Die Kultur von Paramecium bursaria. Biol. Zentralbl. 



35:375- 

 Taylor, C. V., Thomas, J. O., and Brown, M. G. 1933 • Studies on Protozoa, 

 IV; Lethal effects of X-radiation of a sterile culture medium for Colpidium 

 campylum. Physiol. Zool. 6:467. 



CULTIVATION OF COLPIDIUM CAMPYLUM* 



T. M. Sonneborn, Johns Hopkins University 



USE a basic fluid of spring water in which rye grains, in the concentra- 

 tion of 1.5 gms. per 100 cc, have been boiled for 10 minutes. The 

 fluid is filtered while hot and allowed to stand 1 day exposed to the air. 

 Good mass cultures can be obtained within a day or so by placing 200 cc. 

 of ripe fluid in a finger bowl and inoculating with 10 to 15 cc. of an old 

 culture of C. campylum. Such cultures should be renewed every 2 to 6 

 days. 



Isolation cultures under bacteriologically controlled conditions may 

 readily be carried by the following method: Distribute the standard 

 rye infusion as soon as filtered into test tubes, plug with cotton, auto- 

 clave, and store till needed. When ready for use, open tube in a flame 

 and inoculate by means of sterile platinum needle with pure cultures of 

 the bacterium, Achromobacter candicans, grown on beef-agar slants. 

 Using glassware (petri dishes, Columbia dishes, pipettes, etc.) previously 

 baked in an oven at 150 C. for an hour, the one-bacterium rye fluid is 

 pipetted into Columbia dishes inside of petri dishes and into these dishes 

 sterilized Colpidia are introduced by means of a sterile fine pipette. 



Isolation cultures carried with less refined technique, may be main- 

 tained by using depression slides containing one drop of one-day-old 

 ripened rye infusion. These should be started with one Colpidium to 

 each drop of culture, and should be renewed daily by transferring one 

 Colpidium to a fresh drop on a fresh slide. A favorable temperature is 



22°-23°C. 



* Condensed by the author from Biol. Bull. 63:187, 1932. 



