TRICHOMONAS INTESTINALIS 



55 



between T. vaginalis, Donne, and T. intestinalis, LeuckaU, disappeared. On the 

 other hand, it is worthy of note that the smaller size, the more pear-shaped form, and 

 the longer flagella differentiate T. intestinalis (= T. hominis] from T. vaginalis.* 



The easily deformed pear-shaped body has three free flagella 

 anteriorly, and an undulating membrane with its flagellar borde~ 

 terminating in a short free flagellum posteriorly (figs. 

 17, 18). The undulating membrane may coil itself 

 spirally round the body. A supporting rod or axo- 

 style projects as a posterior spine. It appears to 

 begin near the nucleus and blepharoplast, which are 

 situated near the more rounded, anterior end of the 

 body. There may be a chromatoid basal supporting 

 line along the body for the undulating membrane. 

 Rows of chromatoid granules are sometimes situated 

 along one side of the axostyle. A cytostome may 

 sometimes be seen. In mice, Wenyon (1907) found 

 these parasites to vary in length from 3 p to 20 //,. 

 They occur in the caecum and intestine of mice, 

 where their internal structure seems more obvious 

 than in man. The flagellates divide by longitudinal 

 fission. 



T. intestinalis, R. Leuckart, appears to be capable 

 of settling in all parts of the human intestine in which 

 the contents have an alkaline reaction. Trichomonads showing anterior 

 have been cited as occurring in the oral cavity by 

 Steinberg, Zunker, Rappin and Prowazek ; in the iorly, 

 oesophagus by Cohnheim, and in the stomach by 

 Strube, Cohnheim, Zabel, Hensen and Rosenfeld. x 2,500. Original. 

 The normal situation seems to be the small intestine. 

 The parasites then appear in the dejecta, especially in various intestine 

 diseases the course of which is connected with an increased peristalsis. 

 They are also found in healthy persons, from whom they are obtained 

 after the administration of laxatives. They have been regarded by some 

 workers as commensals, which, however, have the power of accelerating 



1 For the present the following should be regarded as synonymous : Protoryxomyccs 

 copriv arius , Cunningham (Quart. Journ. Micr. Sci. [2] 1880, xxi, p. 234), (Zeitschr. f. Biol., 

 1882, viii, p. 251). Monocercomonas hominis , Grassi, 1882. Cimcenomonas hominis^ Grassi. 

 1882. Trichomonas hominis, Grassi, 1888. Cercomonas coli hominis , May (Deutschts 

 Archiv. f. klin. med., 1891, xlix, p. 51). Monocercomonas hominis, Epstein (Prag. mcd. 

 Wochenschr. 1893, Nos. 38-40). Trichomonas confusa, Stiles (Zool. Anz., 1902, xxv, p. 689), 

 Trichomonas elongata, Trichomonas elliptica, Cohnheim (Deutsche med. Wochenschr., 1903 

 xxix, Nos. 12-14). Trichomonas elongata, Trichomonas caudata, Trichomonas flagellata, 

 Steinberg (Kiewer Zeitschr. f. neuere Medicin, 1862). Trichomonas pulmonalis, A. Schmidt, 

 (Munch, med. Wochenschr., 1895, No - 5 1 ), and St. Artault (Arch, de parasit. 1898, i, 

 p. 279). 



FiG. 18. Tri- 



undulating 



