PROTOZOA IN THE DIGESTIVE TRACT 29 



10(1) Troplio/oitc in tlu' material aroiiiul Icclli 



K)ilmnoeha (^iuf^ivaVis (p. 19-21) 



B. Tlic c\sts ill fresh and stained smears 

 Of the six known human amoebae, Entamoeba gingivalis and Dien- 

 tamoeba fragilis have not yet been seen in eneysted condition 

 1(2) Mature cysts uninucleate and of various shapes; nucleus 

 with a large endosome often attaclied to membrane; cyto- 

 plasm witli a large glvcogen body lodamoeba butschlii (p. 21-24) 



2(1) Mature cysts with more than one nucleus 3 



3(4) Mature cyst with 8 nuclei; body spherical or o\al, about 

 10-30J.I in diameter; chromatoid bodies if present fila- 

 mentous, acicular, or irregular with sharply pointed ends 



Entamoeba coll (p. 15-19) 



4(3) Mature cvst with 4 nuclei 5 



5(6) Mature cyst spherical, about 5-20|ii in diameter; chromatoid 

 bodies numerous, rod-shaped with rounded ends; nuclei 

 composed of a small central endosome and peripheral 



chromatin granules Entamoeba lu.stolytica (p. 9-14) 



6(5) Mature cyst often ovoidal, small, about 5-121.1 in diameter; 

 chromatoid body rarely found; nuclei with a large angu- 

 lar endosome variable in position . . .Endolimux nana (p. 24-26) 



