PART II. CHARACTERS AND DIAGNOSIS 95 



The cysts of E .coli vary in size from 13 to well over 30 microns. 

 These cysts may contain chromidial bodies. 



E. coli is not always to be found in the stools of persons who 

 are known to be infected. There is no evidence that E. coli is 

 even pathogenic. 



(7) Lamblia intestinalis reproduces by a process of longitudinal 

 division in the unencysted state. The flagellate may vary very 

 much in size. Judging by the presence or absence of encysted or 

 free forms of lamblia in the stool, the infection runs a very irregular 

 course. The flagellates may be absent from the stool for compara- 

 tively long periods. Of all the flagellates of the human intestine 

 lamblia has the greatest claim to pathogenicity. 



(8) Tetramitus mesnili occurs in the stool in the free and 

 encysted stages and one or both of these may be present at one 

 time. Tetramitus infections, like those of lamblia, run a very 

 irregular course. 



(9) The commonest form of human trichomonas in Egypt is 

 that with four anterior flagella (tetratrichomonas). The three 

 (trichomonas) and five (pentatrichomonas) flagellar forms also 

 occur. An axostyle is always present. A trichomonas of the 

 mouth in pyorrhoea occurs and appears to be distinct from the 

 intestinal form. Trichomonas infections may persist for long 

 periods, during which the flagellates cannot always be detected 

 in the stool. There is little evidence of the pathogenicity of 

 trichomonas. 



(10) A case of coccidium (isospora) infection was followed for 

 some time. Ernetin appeared to cure the infection. 



(11) Iodine cysts (I-cysts) were commonly found and their 

 likeness to cysts of E. histolytica was sometimes very close. 



(12) Blastocystis infections were very common and the largest 

 infections and the largest forms were found in cases of diarrhoea or 

 dysentery. 



(13) Two new human intestinal flagellates (Waskia intestinalis 

 and Tricercomonas intestinalis) and a new amoeba (Entamoeba nana) 

 are described. 



