44 



THE ANIMAL PARASITES OF MAN 



recognisable. Nucleus vesicular, elongated, situated at the anterior 



extremity. 1 



Propagation takes place by division (Marchand) ; encysted forms 



are unknown. 



Trichomonas vaginalis lives in the vaginal 

 mucus of women of various ages ; not in 

 normal mucus, but in mucus of acid reac- 

 tion. It is found in menstruating females 

 as well as in females that have passed the 

 menopause ; it is found in pregnant and non- 



P re g nant WOmen > 6Ven in V6r y y OUn S g Ms > 



provided always that they have a vaginal 

 catarrh with acid reaction of the secretion. Should the acid re- 

 action 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. 



Trichomonas vaginalis appeared to be a 

 parasite specific to the female organs and 

 not transmissible to man. Recently, how- 

 ever, several observations have 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 ; in any case the three cases observed 

 point to this circumstance. 2 



Experimental transmission to rabbits, guinea- 

 pigs and dogs failed (Blochmann, Dock). So 

 far the manner in which women become in- 

 fected is unknown. 



FIG. g. Trichomonas 

 vaginalis, D., high mag- 

 nification. (After 

 Kiinstler.) 



2. Trichomonas intestinalis, R. Lkt. 



Now several authors believe that a second 

 trichomonade inhabiting man, Trichomonas intes- 



1 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 one known as the " quill " in Trichomonas batrachorum, 

 Perty. Blochmann also mentions two longitudinal rows of granules, which commence 

 at the same plane as the nucleus and converge towards the back. 



- Donne, A. Rech. sur la nature du mucus, Paris, 1837 '> Scanzoni, F. W., Beitr. 

 z. Gbrtskde., 1855, ii.. p. 131 ; Scanzoni, F. W., and A. Kolliker, " Quelq. rem. sur le 



