122 



INTESTINAL FLAGELLATES AND C1LIATES 



have established themselves in the membranes high up in the 

 intestine they are said to disappear after this treatment. As 

 with other intestinal Protozoa infection occurs through polluted 

 food or water. 



Enteromonas hominis. - - This minute spherical or nearly 

 spherical organism, 5 to 6 /x in diameter, was first described by 

 Fonseca in Brazil. It possesses two equal anterior flagella, and 

 a larger trailing flagellum; the nucleus is situated anteriorly as in 

 Chilomastix. It is probable that Tricercomonas and Diplocerco- 

 monas, described as distinct human parasites, are really identical 

 with Enteromonas. 



Chilomastix (or Macrostoma) mesnili. A parasite which 

 closely resembles Trichomonas in many respects is Chilomastix 



FIG. 32. Chilomastix (or Macrostoma) mesnili; A, adult parasite (n., nucleus; 

 cyt., cytostome, 4th fl., fourth flagellum) ; B, end view of adult parasite, showing 

 cytostome with flagellum in it; C, degenerating form, resembling an ameba; D, 

 cyst, showing nucleus and cytostome. X 2000. (After Wenyon.) 



mesnili (Fig. 32). It is smaller than the former, averaging about 

 eight or ten n (^innr of an inch) in length. It has three slender 

 anterior flagella like Trichomonas but has no conspicuous undulat- 

 ing membrane. It has a large and conspicuous slit or cytostome 

 along one side which corresponds to the very small mouth cavity 

 of Trichomonas. Within the cytostome is a fourth inconspicu- 

 ous flagellum which seems to be attached to a small undulating 

 membrane. The posterior end of the body is drawn out into a 

 long point. As in Trichomonas the nucleus lies just behind the 

 origin of the flagella. The rest of the body contains numerous 

 vacuoles filled with bacteria, the latter apparently serving as the 

 staple article of diet. 



