TRICHOMONAS 



119 



pair.i}.(?). 



part of the large intestine and coecum, often multiplying in 

 prodigious numbers. Trichomonas also lives in the vagina and 

 in the urinary tract, being quite often found in vaginal discharges, 

 especially in cases of leucorrhea. It has been commonly beheved 

 that the vaginal parasite, which is larger than that of the intestine, 

 is a distinct species, and it has been given the name T. vaginalis, 

 but there is reason for believing that it is identical with the 

 intestinal parasite. Other intestinal parasites are sometimes 

 found in the urinary tract. This or a closely allied species is also 

 occasionally found in the mouth, 

 about the tartar of the teeth. Ac- 

 cording to Goodey the mouth form 

 differs from the intestinal form to 

 a sufficient extent to warrant its 

 being given a distinct name, at least 

 provisionally, and he proposes the 

 name Trichomonas [Tetratrichomo- 

 nas) huccalis. 



Trichomonas intestinalis (Fig. 30) 

 is a pear-shaped flagellate averaging 

 about eight to 15 yit (jtjVtt to y^Vir of 

 an inch) in length, the size being in- 

 versely proportional to the rapidity 

 of multiplication. It has three vig- 

 orously moving flagella arising from 

 the blunt anterior end and a fourth 

 wavy one which turns backward and 

 is attached to the side of the body by 

 an undulating membrane. Along the 

 line of attachment of the undulating 

 membrane to the body is a structure which takes a deep stain, 

 called the chromatic basal rod and believed by some workers to 

 be a modified parabasal body. Arising near the anterior end and 

 running through the body is a sort of supporting rod called the 

 " axostyle," which, according to Kofoid and Swezy, is also used 

 as an organ of locomotion. At the anterior end at one side of 

 the point where the flagella originate is a slight depression or 

 " cytostome " which serves as a mouth. The small round 

 nucleus lies in the body just behind the origin of the flagella. 

 Other forms of the parasite with four or five anterior flagella 



Fig. 30. Trichomonas intestinalis; 



n., nucleus; cyt., cytostome; axo., 



axostyle; par. b., parabasal body (?) ; 



und. m., undulating membrane. 



X 2400. (After Wenyon.) 



