60 Phylum Protozoa 



Actinosphaerium eichhorni. To each ioo cc. of pond water add 4 grains 

 of wheat, some Chilomonas and, if available, any other small Protozoa. 

 Inoculate with Actinosphaerium. Culture in a flat, shallow dish. Con- 

 siderable search of small, permanent ponds may be necessary before 

 Actinosphaerium are found, but by repeated inoculation of a number of 

 rich mixed cultures with each sample taken, one should soon discover 

 them. 



Arcella vulgaris. Both wheat and hay infusions are good, but a mix- 

 ture is best. To 100 cc. of pond water add 2 grains of wheat and % 

 gram of hay. Inoculate with Chilomonas if available, although Arcella 

 will grow by feeding merely on the decomposing infusion. After two or 

 three days add Arcella which may be found on the bottom of many old 

 cultures or in the bottom ooze from any shallow pond. Isolate them from 

 the ooze and other Protozoa with a fine pipette [see p. 43] and place 

 them in a watch glass with a drop of water. See that there are no other 

 Protozoa nor worm eggs present that might develop and feed on the 

 Arcella. Then place them in the culture in a shallow dish. 



Euplotes patella. To a liter of water add 5 grams of timothy hay, 

 10 halves of yellow split peas, and 10 grains of wheat. Heat to boiling 

 point and set aside until the next day. Inoculate with Chilomonas which 

 serves as food. In a few days these will be abundant and the culture is 

 ready for the Euplotes. When kept in such medium, Euplotes will multi- 

 ply to incredible numbers. 



Blepharisma sp. Follow directions given for Euplotes patella but 

 dilute medium with equal parts of pond water before adding Blepharisma. 



Spirostomum ambiguum and 5. teres. Putrid cultures are best. Rich 

 wheat and hay infusions give excellent results. To each 100 cc. of water 

 add 5 grains of wheat and 5 or 10 2-inch lengths of timothy hay stalks. 

 Inoculate with Chilomonas for food and after a day or two add the 

 Spirostomum. If available, bed the bottom of the dish with old, thor- 

 oughly washed sphagnum moss. They should multiply to such numbers 

 as to make large white blotches on the moss. 



Stentor coeruleus. Fill a battery jar % to % full of a culture of Para- 

 mecium prepared as follows: One liter of lake water is brought to a 

 boil and a handful of timothy hay added; as soon as all the hay has been 

 submerged in the boiling water the heat is turned off and, on the follow- 

 ing day, the infusion is diluted with an equal portion of lake water and 

 inoculated with the Paramecia. In a week or so the Paramecia are suffi- 

 ciently abundant. Then add a gram or two of timothy hay and inoculate 

 with Stentor. If kept near a window but not in direct sunlight, the 

 Stentor should become very abundant. With occasional (every 2 or 3 

 weeks) additions of small amounts of raw, dry hay, rich cultures will 

 last for months. 



