32 MANUAL OF HUMAN PROTOZOA 



intestine. It is widely distributed, but of comparatively 

 rare occurrence. Fluid faeces contain both the active 

 trophozoites and cysts, while formed faeces cysts only. 



Trophozoites 



1. Living specimens. The flagellate (Fig. 7, 1-3) is highly 

 plastic, and therefore polymorphic. It is 4-9|j long by 3-4n 



f 



I « 



'^ 



::©' 



J 6 7 8 



Fig, 7. Retortamonas intestinaUs. X 1150 

 1-3. Living trophozoites. 

 4, 5. Stained trophozoites. 



6. A fresh cyst. 



7, 8. Stained cysts. 



(1-4, modified after Wenyon and O'Connor; 5, after Dobell 

 and O'Connor; 7, modified after Jepps; 6, 8, original.) 



broad. It undergoes continued jerky movements. The body 

 is often pyriform or ovoid. The anterior end is broadly 

 rounded, and the posterior end is either attenuated or 

 rounded. The body length is usually about twice (or 

 sometimes three times) the body width. Near the anterior 

 end, there is seen a clear area which is the cytostome. The 

 cytoplasm is granulated or slightly reticulated. There are 



