APPENDIX 413 



large numbers of a single species, individuals are taken out by 

 means of a finely drawn pipette and transferred to a suitable 

 ripe culture medium which contains proper food material. 



Aside from the successful cultures of blood-inhabiting Pro- 

 tozoa, the so-called protozoan cultures are by no means "pure" 

 cultures in the bacteriological sense, even if only one species of 

 Protozoa is present, since bacteria and other Protophyta are 

 invariably present abundantly in them. 



Some of the more commonly used culture media will here be 

 mentioned. 



Cultivation of Free-living Forms 

 Euglena, Phacus, and other holophytic Mastigophora. — These 

 flagellates usually do not live long in ordinary collection jars, 

 but rich cultures of them may be obtained in Zumstein's 

 medium, which is made up as follows: 



Peptone 0.5 to 1 gm. 



Grape sugar 0.4 to 0.5 gm. 



Citric acid 0.2 to 0.4 gm. 



Magnesium sulphate 0.2 gm. 



Potassium phosphate 0.05 gm. 



Ammonium nitrate to 0.05 gm. 



Distilled water 100 c.c. 



Goniiim, Eudorina, and other Phytomonadida. — Several au- 

 thors have obtained excellent results with one of the following 

 media: 



Knop's solution : Magnesium sulphate 0.25 gm. 



Calcium nitrate 1.0 gm. 



Potassium phosphate 0.25 gm. 



Potassium chloride 0.12 gm. 



Iron chloride Trace 



Distilled water 1000 c.c. 



Benecke's solution : Ammonium nitrate 0.3 gm. 



Calcium chloride 0.15 gm. 



Potassium phosphate 0.15 gm. 



Magnesium sulphate 0.15 gm. 



Iron chloride One drop 



Distilled water 1500 c.c. 



