TRICHOMONAS VAGINALIS 



53 



of the body. The cuticle is very thin and the body substance finely 

 granular. At the anterior extremity there are three some say four ! 

 flagella of equal length which are frequently united together, at least 

 at the base, and are easily detached. 



There is an undulating membrane (fig. 16) 

 which runs spirally across the body, arising 

 from the place of insertion of the flagella, and 

 terminating at the base of the caudal process. 

 A cytostome seldom is recognizable in fresh 

 specimens, but is apparently present. The 

 nucleus is vesicular, elliptical and situated near 

 the anterior extremity. 2 



Multiplication takes place by division 

 (Marchand). Encysted forms are almost un- 

 known. 



Trichomonas vaginalis lives in the vaginal mucus of 

 women of various ages, not in normal mucus, but in 

 mucus of acid reaction. It is found in menstruating 

 females as well as in females who have passed the 

 menopause. It occurs in pregnant and non-pregnant 

 women, even in very young girls, provided always that 

 they have a vaginal catarrh with acid reaction of the 

 secretion. Should the acid reaction change, as, for 

 instance, during menstruation, the parasites disappear, 

 as they do likewise on injection of any alkaline fluid into 

 the vagina. A low temperature (below + 15 C.) is also 

 fatal to the parasites. These flagellates can pass from 

 the vagina through the urethra into the bladder, and 

 produce severe catarrh, and are not easily removed. 



T. vaginalis appeared to be a parasite specific to the female organs 

 and not transmissible to man. However, several observations have 

 since been made that confirm the occurrence of this species in the 

 urethra of the male. The infection apparently takes place through 

 coitus when changes are present in the urethral mucous membrane. 

 At any rate, three cases observed point to this circumstance. 



Attempts at experimental transmission to rabbits, guinea-pigs and 

 dogs failed (Blochmann, Dock). So far, the manner in which women 

 become infected is unknown. 



FIG. 1 6. Trichomonas 

 vaginalis, Donne. X 2,000 

 approx. (After Ktinstler.) 

 Four flagella are repre- 

 sented, but usually only 

 three are present. 



1 To explain this discrepancy it is stated that the border of the undulating membrane can be 

 detached in the form of an independent flagellum. But Parisi (1910) places such quanriflagellate 

 forms in the sub-genus Tetratrichomonas , Arch. f. Protistenk., xix, p. 232. 



- According to Marchand, the nucleus is connected with a line, which becomes visible on 

 addition of acetic acid, terminates at the posterior extremity, and does not correspond to the 

 line of insertion of the undulating membrane. This formation probably is the same as the 

 axostylein Trichomonas batrachorum, Perty. Blochmann (1884) also mentions two longitudinal 

 rows of granules, which commence at the same place as the nucleus and converge posteriorly. 



