90 HUMAN INTESTINAL PROTOZOA IN THE NEAR EAST 



cercomonas, except that it possesses three instead of one anterior 

 flagellum. Hence the name tricercomonas which we suggest. In 

 the fresh condition the flagellate is very active, but some time after 

 leaving the intestines the movements are less violent and the details 

 can be studied. No definite cytostome could be distinguished, 

 though bacilli and cocci are ingested. The body changes its shape 

 very readily, and is to a certain extent amoeboid. The body of 

 the flagellate measures 4 to 8 microns in length. The flagella 

 are longer than the body. Sometimes the body of the flagellate is 

 deformed, in that one or two curious pseudopodia or pedunculated 

 processes project from the surface. 



In one case the flagellate which was present in large numbers 

 was associated with a small oval cyst 6 to 8 microns long by 

 about half this in breadth. No structure could be seen in the 

 unstained specimens, but in stained films the cysts were found to 

 contain one, two, or four nuclei of a type resembling the nuclei of 

 the stained flagellates. It seems very probable that they represent 

 the encysted stage of the flagellate (Plate III, figs. 5 to 8).* In 

 stained films the flagellate is found to have a nucleus like that of 

 cercomonas, with a central karyosome and a nuclear membrane 

 which is drawn out at one spot into a cone-like elevation, from the 

 summit of which the flagella take origin. In stained films forms 

 with two nuclei, probably dividing forms, can be found. As 

 mentioned above the flagellate has been seen in about a dozen cases. 

 Unlike Waskia intestinalis, which persisted in the stool for long 

 periods, the Tricercomonas intestinalis was present only for a day or 

 two at a time. In one case only was it present for as long as nine 

 days, when it disappeared not to be found again. The cases were 

 under observation in hospital and the stools were examined every 

 day. There is no evidence whatever to suggest that the flagellate 

 is in any way pathogenic. On account of its resemblance to cerco- 

 monas and its possession of three anterior flagella we suggest the 

 name Tricercomonas intestinalis. 



(22) Entamwba nana, n. sp. 

 (Plate I, figs. 10 to 23).* 



The small amoeba which, on account of its small size, we 

 describe under the above name has turned out to be one of the 

 commonest protozoa in the human intestine in Egypt, rivalling in 

 some groups examined even E. coli in its frequency. The cysts 



* See inset between pages 148 and 149. 



