66 ENTOZOA FOUND IN MAN. 



The parts of the intestinal canal in which these 

 entozoa live are as follows : — In the small intestines 

 are found the vibrio, the cercomonas hommis, the 

 tsenia soHum, the bothriocephalus latus, the taenia 

 nana, the distomum heterophyes, the anchylostomum 

 duodenale, the ascaris lumbricoides, and the ascaris 

 alata ; the tricocephalus dispar mhabits the caecum, 

 and the paramecium coli and oxyuris vermicularis 

 infest the large intestines. 



No entozoa are found, excepting as an accidental 

 circumstance, in that part of the ahmentary tube 

 which extends from the mouth to the pylorus. 



Hydatids and the distomum hepaticum, which 

 have wandered from their usual habitat, have also 

 been met with in the mtestiues. 



Chapter IV. 

 INTESTINAL PEOTOZOA. 



Protozoa, or infusoria, of different species, are deve- 

 loped in vegetable and animal substances which are 

 undergomg putrefaction. It might be supposed that 

 those which exist in the matters which are still con- 

 tained within the intestines are developed in that 

 situation as a result of putrefaction, but there is an 

 important distinction between the infusorial worms 

 which are developed in a free state, and those wliich 

 are, properly speaking, intestinal protozoa. Those 

 which exist in the fsecal matter, prior to its e vacua- 



