COMPARATIVE STUDY OF AMCEB^. 267 



from the Manila water supply (Plate I, figs. 1 and 2). For reasons 

 already stated no attempt has been made to identify these species with 

 species named in the literature; it is sufficient for our present purpose, 

 as in the case of the water amoebse, to determine the genus to which they 

 belong. All 5 species cultivated from both non-dysenteric and dysenteric 

 stools possess the characters of the genus Amceba Ehrenberg described in 

 the previous section (Compare figs. 1 to 3 with figs. 4 to 10). 



AMCEBA FOUND MICROSCOPICALLY IN THE INTESTINAL TRACT OF MAN. 



This part of the investigation has included a microscopic study of the 

 living amoebse in the fresh stools from 143 cases of amoebiasis without 

 symptoms of dysenterj-, from 28 cases of amoebic dysentery, and in the 

 pus of 2 cases of amcebic liver-abscess; of fixed and stained preparations 

 from 21 cases of amoebiasis without symptoms of dysentery and from 

 16 cases of amoebic dsentery; and in sections of the intestine in 1 case 

 of amoebic dysentery, and of the liver in 2 cases of amoebic liver-abscess. 

 I am indebted to Dr. E. E. Stitt of the United States Naval Hospital, 

 Canacao, Cavite, for a section of one of the cases of amoebic liver-abscess 

 and to Dr. V. L. Andrews of the College of Medicine and Surgery, Uni- 

 versity of the Philippines, for sections of the other case of amoebic liver- 

 abscess and sections of the intestine from a case of amoebic dysentery. 



The stools have been studied fresh in ordinary cover-glass and slide prepara- 

 tions. Stained preparations of the faeces and of the pus from liver abscesses have 

 been made by spreading thin smears on cover-glasses, floating them "wet" on the 

 surface of Zenker's fluid for 5 minutes, washing in water until the fixing fluid 

 is removed, staining 5 minutes in aqueous alum hsematoxylin, washing in distilled 

 water, dehydrating in dift'erent grades of alcohol, clearing in oil origanum, and 

 mounting in xylol balsam. I have found Zenker's fluid preferable to Schaudinn's 

 alcohol-corrosive-sublimate mixture as a fixative for amoebae. Aqueous alum 

 hematoxylin has proved a more precise stain for the chromatin of amoebae than 

 iron hematoxylin or any other stain that I have tried. The sections from one 

 case of amoebic live-abscess were stained with iron hematoxylin, and from the 

 other case of liver abscess and frona the dysenteric intestine with hematoxylin 

 and eosin. 



One type of amoeboid organism has been found exclusively in all of 

 this material (Plate IV, figs. 9 to 13 and Plate V, figs. 13 to 16). This 

 differs from the Amceba type found in the Manila water supply and culti- 

 vable from the intestinal tract of man in certain fundamental morpho- 

 Icgical and biological characters. The trophozoite has the nucleus situated 

 excentrically instead of centrally in the resting organism; the chromatin 

 is arranged peripherally instead of centrally in the nucleus; there is no 

 contractile vacuole ; reproduction by sporulation does not occur ; and 

 multiplication does not take place on ordinary artificial media. The 

 cyst contains 4 or 8 nuclei instead of a single nucleus; a reproductive 

 process takes place in the cyst; and encystment occurs only in the body 



