CHAPTER XIV 

 INTESTINAL FLAGELLATES OF RATS 



By 



D. H. Wenrich 



It is the purpose of this chapter to call attention to some of 

 the known facts and some of the problems in relation to the 

 intestinal flagellates of rats. 



METHODS 



I. Obtaining fresh material 



A. Feces. Few flagellates are to be found in fully formed fecal 

 pellets, except the cysts of Chilomastix, Hexamitus and Giardia, 

 and these cysts are not numerous as a rule. When rats are handled, 

 defecation is often stimulated so that soft feces become available. 

 Soft feces may contain the trophozoites of flagellates which can 

 be identified, but trichomonads from feces are usually not in good 

 condition for study. 



Laxatives and purgatives may be used. Hegner (1923a) fed 

 sunflower seeds to bring down the flagellates and Kessel (1923) 

 fed stale bread soaked in a saturated aqueous solution of mag- 

 nesium sulphate as a purgative. 



B. Material from the cecum and small intestine is usually ob- 

 tained by killing the host, opening the abdominal cavity and re- 

 moving the contents of the cecum and small intestine after making 

 incisions in these organs. Killing with ether leaves the muscles 

 of the rat in a relaxed condition and is preferable to killing with 

 chloroform. Ratcliffe (1928) removed material from the cecum 

 of rats under ether anesthesia. 



2. Examining fresh material 



A. Examination of living flagellates. Any of the following may 

 be used for diluting cecal and intestinal contents for the study of 

 living flagellates : physiological salt solution. Ringer's solution, 

 Locke's solution and a solution made by adding 0.5 of a gram of 

 sodium chloride and 0.5 of a gram of sodium citrate to 100 

 cubic centimeters of water. Any of these solutions is more satis- 

 factory if diluted to about two-thirds the usual strength. 



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