COLLECTION, CULTIVATION, OBSERVATION 715 



Freshwater ciliates. — They are easily cultivated in a weak infusion 

 of hay, bread, cracker, lettuce leaf, etc. The battery jars containing 

 the infusions should be left standing uncovered for a few days to al- 

 low a rich bacterial growth in them. Seed them with material such 

 as submerged leaves or surface scum containing the ciliates. If de- 

 sired, culture may be started with a single individual in a watch 

 glass. For bacteria-free cultures, various culture media have been 

 used by recent investigators. For example, Glaser and Coria (1933) 

 cultured Paramecium caudatum bacteria-free in a medium composed 

 of Lily liver extract, killed yeast and rabbit kidney, for a period of 

 six months. Kidder (1941) used the following basic medium for bac- 

 teria-free culture of Glaucoma and Colpidium: 10 grams of Brewers 

 yeast and 1000 cc. of Pyrex distilled water are brought to a boil and 

 filtered, through cotton and then through Schleicher and Schiill No. 

 595 filter paper. After adding 20 grams of Difco proteose peptone, 

 the whole is autoclaved at 15 pounds pressure for 20 minutes. 



B. Parasitic Protozoa 



Intestinal flagellates of man. — There are numerous media which 

 have been used successfully by several investigators. 



(a) Ovo-mucoid medium (Hogue, 1921). White of two eggs are 

 broken in a sterile flask with beads. Add 200 cc. of 0.7 % NaCl solu- 

 tion and cook the whole for 30 minutes over a boiling water bath, 

 shaking the mixture constantly. Filter through a coarse cheese cloth 

 and through cotton-wool with the aid of a suction pump. Put 6 cc. of 

 the filtrate in each test tube. Autoclave the tubes for 20 minutes un- 

 der 15 pounds pressure. After cooling, a small amount of fresh faecal 

 material containing the flagellates is introduced into the tubes. Incu- 

 bate at 37°C. 



(b) Sodium chloride sheep serum water (Hogue, 1922). Composed 

 of 100 cc. of sterile 0.95% NaCl and 10-15 cc. of sterile sheep serum 

 water (dilution 1:3). 15 cc. to each tube. Trichomonas hominis, T. 

 elongata, and Retortamonas intestinalis grow well. 



Trichomonas vaginalis. — Bland et al. (1932) used the following me- 



