CHAPTER LVI 



CLASS II MASTIGOPHORA (DIESING) 

 SUB-CLASS FLAGELLATA (COHN EMEND. BtJTSCHLI) 



ORDER I POLYMASTIGINA (Blochmann) 



These are flagellates, possessing three to eight flagella. 



GENUS 1. Trichomonas (Donne, 1837). These have pyroform 



(pear-shaped) bodies, rounded in front and tapering to a point behind, 



provided with three long flagella, often matted together at the anterior 



end. An internal supporting structure, known as the axial filament or 



axostyle, is present. There is an undulat- 

 ing membrane bordered by a trailing 

 flagellum that begins anteriorly and runs 

 obliquely backwards. 



Trichomonas vaginalis (Donne). The 

 organism is fifteen to twenty-five microns 

 long and seven to twelve wide; it is pro- 

 vided with three flagella and an undulat- 

 ing membrane. It is found in the vaginal 

 secretion only when it is acid, and in three 

 instances it has been transmitted to the 

 male. 



Trichomonas intestinalis (B. Leuckard, 

 1879). This parasite is practically indis- 

 tinguishable from Trichomonas vaginalis. 

 It occurs in the small intestine and appears 

 in the stools during diarrheal attacks, but 

 is probably non-pathogenic. It is readily 

 found in the intestine and colon of mice and 

 guinea-pigs. In fresh specimens (protected 

 with a cover glass and vaseline) it is ac- 

 tively motile, but the undulating membrane is difficult to detect until 

 the movement has slowed down. 



738 



FIG. 166. TRICHOMONAS IN- 

 TESTINALIS. (After 

 Brumpt, " Precis de Para- 

 sitologie," 1914 ed.) 



