52 ! RESEARCH IN PROTOZOOLOGY 



Balantidium coli, an intestinal ciliate of the pig, guinea pig, and 

 man. His method has been tried on cattle ciliates in this laboratory 

 with no success, but it is not improbable that some modification of 

 it would be successful. If certain experiments in vivo mean any- 

 thing, it appears that chlorophyll and perhaps cellulose materials 

 will be essential to a successful culture medium. 



Possible methods of obtaining pure line cultures of infusoria 

 in vivo should be considered. This means that, since all ruminants 

 are infected with protozoa, it will be necessary to disinfect them 

 of protozoa for the experiment. The goat is a very convenient 

 laboratory animal to use. The method of disinfecting its rumen 

 and reticulum, as worked out by Becker (1929), is as follows: 



1. The animal is given no food for at least seventy-two hours. 

 Water should be given ad libitum. 



2. A small rubber stomach tube (as a horse catheter) is inserted 

 into the rumen. This is accomplished by holding the goat's jaws 

 apart by a short piece of wood (two inches square) with a hole 

 bored in the middle through which the tube is run down the 

 esophagus into the stomach. One must put his ear to the free end 

 of the tube to listen for sounds of regular breathing. If these are 

 heard the tube is in the lungs and must be withdrawn and in- 

 serted again. 



3. A glass funnel is inserted into the free end of the tube. Then 

 fifty cubic centimeters of two per cent copper sulphate in a pint 

 of distilled water is transferred to the rumen through the funnel 

 and tube. The goat can be put on his back and rolled so that the 

 copper sulphate solution will become well mixed with the rumen 

 contents. The animal does not yet receive any feed. 



4. A second administration of the copper sulphate solution 

 follows twenty-four hours after the first. Roll the goat on his 

 back again. 



5. Six hours later some oats, hay, or paper may be fed. Little 

 will be eaten for a day or two. In another three days the goat will 

 again be eating normally. 



The animal should be kept isolated from other ruminants. He 

 should not be permitted to drink out of a pail from which other 

 ruminants have drunk. No hay or feed which has been "messed 

 over" by other ruminants should be fed to it. With ordinary pre- 

 cautions the animals may be kept azoic. 



A single protozoon might be isolated from infected material 



