20 MANUAL OF HUMAN PROTOZOA 



teristically pale greenish and mostly rounded, each being 

 enclosed in a food vacuole. They are probably the nuclei 

 of leucocytes, pus cells, or other degenerating host cells 

 found outside the gum tissues. Erythrocytes have however 

 not been observed in this amoeba. Bacteria are also found 

 in food vacuoles. The amoeba measures 8-30^ in diameter, 



i$4^' .A 



'1 







4 5^7 



Fig. 3. Entamoeba gingivalis. X 1150. (original) 

 1, 2. Living trophozoites. 

 3-7. Stained amoebae. 



but the most commonly seen individuals are 10-20|j in 

 diameter. 



2. Stained specimens. The amoeba (Fig. 3, 3-7) appears 

 more rounded and somewhat contracted than in life, the 

 majority having withdrawn their pseudopodia at the time 

 of fixation. The cytoplasm shows a little differentiation into 

 the ectoplasm and endoplasm. The whole is finely granu- 

 lated or vacuolated and food vacuoles are very conspicu- 



