Chapter 6 



Coprozoic protozoa and objects present 

 in the faeces 



Coprozoic protozoa 



NUMEROUS free-living protozoa which inhabit waters 

 containing abundance of organic matter or decompos- 

 ing organic matter, mav sometimes be found in stale faeces. 

 These have been collectively called coprozoic protozoa. 

 With food or water, the cysts of these protozoa may enter 

 the human mouth and pass through the intestine un- 

 harmed. In the old faeces, they exc\'st and the trophozoites 

 may develop in a larger number. Furthermore, the tropho- 

 zoites or cysts of certain free-living protozoa which live in 

 fresh, brackish, or salt water, may be introduced into the 

 faeces after it has been voided and if conditions are favor- 

 able, numerous trophozoites may appear in it. The copro- 

 zoic protozoa are, of course, not seen in the trophic stage in 

 freshly voided faeces, but develop in old specimens. There- 

 fore, if old faeces contains actively moving protozoa which 

 were not present in the specimen when examined fresh, 

 they are most certainly coprozoic and not parasitic proto- 

 zoa. But when the faecal material is not examined fresh, 

 and examined a few to several days later, one cannot tell 

 without careful examination if the protozoan observed is 

 parasitic or coprozoic. 



Coprozoic protozoa belong to all of the three major 

 groups, Sarcodina, Flagellata, and Ciliata. Here a few 

 forms will be mentioned. 



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