654 



FAMILY: TRICHOMONADID.E 



Kessel (1925) has seen the flagellate in pus from an amoebic abscess of the 

 liver. 



T. liominis infections may be very persistent. In Egypt, the writer 

 and O'Connor studied a case in which the flagellates were present during 

 an observation of sixty-two days. Cases are on record, however, in which 

 they are known to have been present for many years. 



« 



m 





\^ 



■m m 



1 1 \ 



^Jte 



Fig. 267. — Section of Human Large Intestine, showing Invasion of the Wall 

 BY Trichomonas liominis (x ca. 1,000). (After Wenyon, 1920.) 



The flagellates pass through gaps in the lining cells of the intestinal glands into the surrounding 



connective tissue. 



VARIETIES OF TRICHOMONAS HOMINIS.^As already pointed out, 

 T. hoininis usually possesses four flagella. In any infection it will be seen 

 that the great majority of the flagellates have a definite number of flagella, 

 so that it seems clear that for any particular form the number is constant. 

 It is known, however, that in certain cases the majority of flagellates have 

 five flagella, and in other cases three (Figs. 26, 266, 289). Some observers 

 have given special generic names, according to the number of flagella. 

 Thus, the four-flagellate type has been called Tetratrichomonas by Parisi 

 (1910), the five-flagellate type PentatricJiomonas by Mesnil (1914) and 



