PROTOZOA IN THE DIGESTIVE TRACT 9 



not follow this opinion, since the structures of the resting 

 nuclei in Endamoeba, Entamoeba, lodamoeba, Endoli- 

 max, and Dientamoeba, are distinctly different from one 

 another. Unless all five genera are combined under one, 

 these genera should be considered as distinctive. There- 

 fore, the generic name. Entamoeba, is retained here. 



1. Entamoeba histolytica Schaudiiin 1903 



Synonym: Endmnoeha histolytica (Schaudinn) 



This is the pathogenic amoeba of man and commonly 

 referred to as the "dysentery amoeba." The amoeba lives 

 in the lumen and tissues of the colon wall, producing a 

 typical ulceration and, in case of acute infection, it brings 

 about dysentery, although in chronic infection there may 

 not be any svmptoms at all. It frequently enters the liver 

 by way of portal veins, and produces abscess in it. Other 

 internal organs, such as the lung, brain, etc., have also 

 been known to be invaded by this amoeba. The tropho- 

 zoites are found in dvsenteric or diarrhoeic faeces, and 

 cysts usually in formed faeces. 



Trophozoites 



1. Living specimens. When seen in freshly obtained 

 dysenteric or diarrhoeic faeces, the trophozoite (Fig. 1, l) 

 is a typical amoeboid organism with the well differentiated 

 cytoplasm. When undergoing progressive movements, it 

 changes its body form little by forming a single pseudo- 

 podium as broad as the body itself. Others may be seen 

 changing their body forms continuously by actively form- 

 ing lobose pseudopodia in an eruptive manner in which 

 the hyaline ectoplasm plays a leading part, followed by 



