COPROZOIC PROTOZOA IN THE FAECES 63 



1. Hartinannella hyalina ( Danjifeard 1900) 



Trophozoites. It is an actively amoeboid organism with 

 flattened pseudopodia (Fig. 14, i), and is 5-20m in diameter. 

 The cytoplasm is well difl^erentiated. The endoplasm con- 

 tains a contractile vacuole and bacteria taken in as food. 

 When stained, the nucleus, .3-4n in diameter, ])ecomes 

 \ isible. It is composed of a distinct membrane, a large 

 endosome, and chromatin granules distributed in the nu- 

 cleoplasm. 



Cysts. Spherical; 10-15m in diameter (Fig. 14, 2). The 

 inner cyst wall is thin, but the outer one is thick, brownish, 

 and much wrinkled. The cvst wall has no pores. It contains 

 a single nucleus. 



2. Dimastigamoeba gruberi (Schardinger 1899) 



This amoeba has both amoeboid and flagellate stages 

 (diphasic). It is ordinarily seen in amoeboid form, but 

 when the medium becomes more fluid, it changes into 

 flauellate form, Cvsts also occur. 



Trophozoites. 1. Amoeboid stage. The active amoeba 

 (Fig. 14, ^^) forms a few broad lobopodia which are com- 

 posed mostlv of ectoplasm. In the endoplasm of a living 

 amoeba can be seen a vesicular nucleus with a large endo- 

 some, a contractile vacuole, and bacteria taken in as food. 

 The amoeba measures about 10-20n in length. When 

 stained, the nucleus (about 3-4m in diameter) shows a 

 central endosome and scattered chromatin granules be- 

 tween it and the membrane. 



2. Flagellate stage. When distilled water is added to 

 the medium in which amoeboid forms occur, the latter 

 become flagellated (Fig. 14, ^). The body is ovoid to pyri- 



