352 MASTIGOPHORA AND PROTOMONADINA 



II. With undulating membrane: — 



1. Three anterior fiagella- — ^(8) Trichomonas Donne, 



1837- 



2. Four anterior fiagella— (9) T etratrichomonas Parisi, 

 . 1910. 



3. Five anterior fiagella- — (no) Pentatrichomonas Chat- 



terjee, 1915. 



Of these genera, Trichomonas, Tetratrichomonas, and Pentatri- 

 chomonas concern us. 



Genus Trichomonas Donne, 1837. 



Definition.- — ^Trichomonadinse with a cytostome, an undulating 

 membrane, and three anterior fiagella. 



Remarks. — In his work ' Recherches microscopiques sur la nature 

 du mucus,' Donne (1837) described and figured an organism which 

 he found in innumerable quantities in vaginal mucus. 



He considered that it possessed a single fiagellum which at times 

 Was bifurcated distally, a series of three to five cilia with very rapid 

 rotatory movement, and that at times it was 

 elongated posteriorly into a tail. The name Was 

 first spelt Tricomonas, but afterwards altered to 

 Trichomonas. 



Dujardin (1841) described T. limacis from 

 Limax agrestis in much the same terms, and so 

 did Perty (1852) with regard to T. batrachorum, 

 though he depicted the axostyle, but Stein's 

 figures of Perty 's organism show clearly the three 

 anterior fiagella, the undulating membrane, the 

 posterior free fiagellum, the axostyle, the nucleus, 

 and the cytostome, and in this way was laid the 

 foundations upon which the main features of the 

 genus were placed. 



Returning now to the type T. vaginalis, this 

 was restudied in 1884 by Blochmann, who illus- 

 FiG. 78. — Tetra- trated the three anterior fiagella, the undulating 

 trichomonas gal- membrane, the axostyle, and the nucleus, but in 

 i'^Roi^RTsoN ^^^^ y^^^ Kiinstler produced a much better 



1912). (x 2,000 illustration showing four anterior fiagella taking 

 Diameters.) their origin from a blepharoplast from which the 

 undulating membrane also arose, while this shows 

 a trace of a parabasal. The nucleus is also represented, while the 

 axostyle shows exceedingly clearly. He also saw the cytostome. 

 Bensen (1910) figured two blepharoplasts, one of which is connected 

 with the nucleus by means of a rhizoplast, and he also gave an 

 illustration of a cyst. Thus the type species T. vaginalis was 

 brought into line with the results of researches upon the species 

 found in animals, of which a number have been carefully described 

 and drawn by Dobell, Alexeieff, Martin and Robertson, Kuczynski, 

 and by Kofoid and Swezy. 



