AMEB.E IN NORMAL INTESTINAL CONTENTS. 371 



probable. Amebae have been encountered in peritonitic 

 exudates, and hepatic abscesses are frequently quite super- 

 ficial and preferably in the right lobe. Dissemination through 

 the lymph-channels appears improbable by reason of the 

 numerous lymph-glands interposed. 



Finally, some observers consider hepatic abscesses as not 

 always the sequel of dysentery, but both diseases as due 

 to a common cause, and of which one may at times pre- 

 cede the other, and vice versa. If primary amebic ab- 

 scesses of the liver actually occur, and are, perhaps, fol- 

 lowed subsequently by dysentery, migration of the amebae 

 through the biliary passages would naturally have to be 

 assumed under such conditions. 



Amebae in Normal Intestinal Contents. In the stools 

 of healthy persons there occur, usually in small number, 

 and sometimes in rather considerable number, amebae 

 that are indistinguishable microscopically from those that 

 give rise to dysentery. Thus, amoeba coli (Kruse and 

 Pasquale) or amoeba intestini vulgaris (Quincke and Roos) 

 is not pathogenic for animals (cats), whereas the amoeba 

 dysenteriae causes dysentery in animals. Whether this 

 difference in virulence is permanent, or whether the two 

 amebae are identical, the one merely having lost its viru- 

 lence temporarily, or the other having acquired virulence 

 temporarily, can not be decided at present in the absence 

 of a method of culture. Quincke observed as the causa- 

 tive agent in a case of rather mild dysentery of autoch- 

 thonous origin in Kiel an ameba closely resembling that 

 of dysentery, but equally nonpathogenic for cats as the 

 intestinal ameba. He places this amoeba coli mitis between 

 the amoeba intestini vulgaris and the ameba of dysentery 

 (amoeba coli (Losch)). (See Fig. 83.) Such transitions 

 render it probable that the virulence of the amebae is no 

 more constant than is that of the bacteria. 



Examination of the Stools for Amebae. In examining 

 the stools for amebae the most important requirement is 

 that the stools should be quite fresh and be examined as 

 soon as possible after evacuation. It is best to receive the 

 stool in a vessel previously heated (in water at a tempera- 

 ture of 40 C. 104 F.). If the stool is thin, a drop is 

 simply placed beneath the cover-glass ; when blood-tinged 

 flocculi of mucus are present, these are examined. If the 

 stool is mushy, a dilution with a warm solution of sodium 



