INTESTINAL FLAGELLATES OF MAN 33 



Cysts (Plate IV, Fig. 7): These are oval bodies 10 to 

 15 microns long and 7 to 9 microns wide. Two or four nuclei 

 are present, usually at one end, and two longitudinal curved 

 axostyles extend down the center of the cyst. Two rod- 

 shaped parabasal bodies and a variable number of loops 

 which probably represent the cytostomal fibrils are also 

 embedded in the cytoplasm. 



b. Trichomonas hominis (Plate IV, Fig. 4). Motile stage: 

 This is a pear-shaped organism measuring from 10 to 15 

 microns long and 3 to 4 microns wide. An axostyle is 

 situated near the center of the body and projects beyond 

 the posterior end. Along one side is an undulating mem- 

 brane terminating at the posterior end in a flagellum. Three 

 other flagella extend out from the anterior end. The cyto- 

 plasm is vacuolated. Within it, near the anterior end are 

 a nucleus containing scattered chromatin granules and a 

 parabasal rod. Reproduction is by binary fission. No 

 cysts have yet been identified with certainty. Specimens 

 of T. augusta, which resemble the species found in man, are 

 abundant in the intestine of the frog. 



c. Chilomastix (Tetramitus) mesnili (Plate IV, Fig. 2). 

 Motile stage: This may also be described as a pear-shaped 

 organism, rounded anteriorly and pointed posteriorly. It 

 varies considerably in size ranging from 7 to 8 microns in 

 length. Three flagella extend out freely from the anterior 

 end, and a fourth flagellum lies within the cytostome. The 

 cytostome is about one-half the length of the body. A large 

 spherical or oval nucleus lies near the anterior end. 



Cysts (Plate IV, Fig. 3) : These are usually pyriform but 

 often spherical and measure 6 to 9 microns in diameter. A 

 single nucleus is present containing a chromatin granule 

 near the center and chromatin masses on the membrane. 

 Extending across the cyst are the remains of the cytostome 

 characteristic of this species. 



