118 



PROTOZOAN PARASITISM 



small and sluggish. The encloplasm is granular, the 

 nucleus within it usually not visible. 



The cysts, measuring about 8 to 10 microns in 

 length, are usually elongated or ovoid and one side of 

 the rim may be less convex than the other. Seen 

 fresh they are hyaline bodies without very definite 



Fig. 20. — Endolimax nana. 



Drawings of specimens stained by iron-haematoxylon. A, tro- 

 phozoite. X 3500. B, C and D, cysts with one, two and four nuclei. 

 X 1500. 



wall, and the nuclei are invisible. Iodine prepara- 

 tions of fresh cysts may show the nuclei but not as 

 clearly as in some other cysts. 



For satisfactory study and identification of E. 

 nana, it is virtually necessary to have well differ- 

 entiated iron-haematoxylon preparations. In such 



