386 



PROTOZOOLOGY 



he became infected by an intestinal Trichomonas of a monkey 

 (Macacas nemestrinus) by swallowing "a rich two-day culture" plus 

 bacteria which were mixed with 10 cc. of sterilized milk on an empty 

 stomach. The presence of Trichomonas in his stools was established 

 on the 6th day by culture and on the 13th day by microscopical 

 examination after taking in the cultures. The infection which lasted 

 for about four and a half years, did not cause any ill effects upon 



Fig. 164. Diagrams showing the species of Trichomonas which live 

 in man, X2500 (modified after Wenrich). a, Trichomonas hominis; b, T. 

 tenax; c. T. vaginalis. 



him. The organism is killed after five minutes' exposure to N/20 

 HC1 at 37°C, but at 15-22°C, is able to survive, though in small 

 numbers, up to 15 minutes after exposure to the acid (Bishop, 1930). 

 This flagellate is widely distributed and of common occurrence, es- 

 pecially in tropical and subtropical regions. 



T. tenax (Miiller) (T. elongata Steinberg; T. buccalis Goodey) 

 (Fig. 164, b). Similar to the last mentioned species; commensal in the 

 tartar and gum of human mouth. Nomenclature (Dobell, 1939). 



T. vaginalis Donne (Fig. 164, c). Broadly pyriform; 10-30/x by 

 10-20/x; cytoplasm contains many granules and bacteria; cytostome 

 inconspicuous; nutrition parasitic and holozoic; parasitic in human 

 reproductive organ. Although the organism does not enter the vagi- 

 nal tissues, many observers believe it to be responsible for certain 

 diseases of the vagina. Trussell and Johnson (1945) maintain that it 



