18 MANUAL OF HUMAN PROTOZOA 



the largest diameter. It is refractile and could be readily 

 detected under a low power objective, although species 

 identification is of course not possible under it. The cyst 

 contents are granulated and often contain a large homo- 

 geneous body particularly in uni- or bi-nucleate forms. It 

 stains reddish brown with Lugol's solution and is con- 

 sidered as a glycogen body. The nuclei are faintly visible. 

 In uni- or bi-nucleate cysts, the nucleus may be seen as a 

 ring pushed against the glycogen body. In older cysts 

 with four or eight nuclei, not all of them may be seen. 

 In addition, colorless needle-like bodies (chromatoid bodies 

 in stained smears) may be present. 



When the cysts are treated with Lugol's solution, the 

 nuclei become plainly visible, and the glycogen body 

 stains reddish brown, while the filamentous bodies remain 

 unstained. 



2. Stained specimens. The cyst wall is not recognizable. 

 The cytoplasm is finely reticulated, and in young cysts 

 with one or two nuclei, there may be present a large well- 

 defined vacuole in which glycogen body occurs. This 

 vacuole may be very large in some cysts so that the cyto- 

 plasm forms a narrow ring enclosing the nucleus (Fig. 2, 8). 

 The chromatoid bodies are less abundant as compared 

 with those of E. histolytica, and when present they are 

 filamentous or irregularly shaped fragments with sharply 

 pointed extremities (Fig. 2, 9). There are usually 1, 2, 4, or 

 8 nuclei, as in each of the second and third division, the 

 nuclei divide simultaneously. Sometimes because of ir- 

 regular divisions cysts containing 3, 5, or 7 nuclei of un- 

 equal sizes may be seen. Very rarely cysts with more than 

 eight nuclei may also be seen. All these cysts are more or 



