Amoebidae 71 



not be used. Distilled water is very good. Boil a little hay and add the 

 hay (not water) to distilled water in several short stender dishes (2% 

 to 4 in. diam.), or finger bowls. Inoculate the cultures with Euglena, 

 diatoms, and other algae, small colorless flagellates, or some small ciliates 

 like Colpidium [see p. 107]. When these cultures are going well 

 inoculate with material containing plenty of good-sized Amoebae. If the 

 food organism is an alga the Amoeba culture must have diffuse light. 

 If ciliates are the food organism darkness will be suitable but not neces- 

 sary. When such cultures are once established add dry or boiled hay 

 at intervals of a few days to a few weeks and add distilled water to 

 make up for evaporation. Reinoculate cultures if they do not show 

 numbers of good Amoebae. 



The following method of culturing large Amoebae has proved very 

 successful. Thoroughly wash and rinse finger bowls and fill % full of 

 distilled water. Add 6 or 8 grains of rolled wheat, rolled oats, or rice. 

 Rice is best. Label, cover, and mark level of water on label. Inoculate 

 at once with Amoebae from a good culture, taking material from the 

 bottom of the dish and examining it to ascertain that Amoebae are 

 actually being taken. At intervals of a week or two fill cultures up to 

 mark, using distilled water. After culture is well established add a few 

 kernels of rice or flakes of wheat or oats occasionally. Removal of a 

 part of the water from time to time and the addition of fresh distilled 

 water stimulates reproduction. 



Euglena. Euglena thrives best in water having considerable organic 

 material. For this reason good cultures may be made in manure solu- 

 tions. Horse or cow manure is boiled in spring water or distilled water. 

 These solutions should be made and allowed to stand 36 to 48 hours 

 and then inoculated with Euglena. Old hay cultures if left in diffuse 

 light almost invariably end in being almost pure cultures of Euglena. 

 In collecting Euglena in nature seek it in barnyard pools, or pasture 

 pools which receive considerable organic material. It may often be 

 found among the algae of ponds even though no green scum is found on 

 the surface. Any green scum on the surface of a pond, or green slime 

 on decaying vegetation in ponds or streams, is almost certain to have 

 large numbers of euglenoid forms in it. 



Besides hay and manure solutions, rice in water yields good cultures. 

 In using rice, boil 7 or 8 grains in a pint of distilled water or old water 

 from a tank, put in a broad dish and allow to stand until a bacterial 

 scum has formed. Then inoculate. Euglena cultures come on slowly, 

 and must be started 4 to 8 weeks before they are needed for study. In 

 old cultures Euglenae usually encyst on the surface of the dish, and they 

 may be kept many months in the encysted condition. Covered cultures 

 may be good for months and since they may be revived after encystment 



