OF THE INTESTINAL TRACT. 181 



ing with Entamceba tetragena in dysenteric patients 

 returning from the Philippine Islands, and during 

 the last winter while demonstrating these parasites 

 to the class at the Army Medical School, my atten- 

 tion was called to amoebae in one of the specimens 

 which answered to the description of this species. 

 The amoebae in this instance were obtained from a 

 discharged soldier who had contracted dysentery in 

 the Philippine Islands and who had suffered from 

 many recurrences. This observation taken in con- 

 junction with my previous records upon a similar 

 amoeba observed in soldiers returning from the Philip- 

 pines and in natives of the Philippine Islands con- 

 vinces me that Entamceba tetragena is a not infre- 

 quent cause of dysentery in those Islands. I have 

 also found this species in material sent me by Captain 

 Siler of the Medical Corps, U. S. Army, from cases 

 of dysentery originating in Illinois. 



Much of the confusion and difficulty regarding the 

 differentiation of Entamceba coli and Entamceba his- 

 tolytica has undoubtedly been due to the presence in 

 many cases of this third species which possesses mor- 

 phological features common to both of the other 

 species. Thus, while Entamceba Mstolytica possesses: 

 an ill defined nucleus and does not form cysts as 

 does Entamceba coli,, yet in certain cases of dysentery 

 amoebae may be observed in which there is a well de- 



