336 MASTIGOPHORA AND PROTOMONADINA 



Morphology. — 0. hominis is a round or pear-shaped parasite 

 averaging from 8 to lo m in diameter, with a long flagellum projecting 



from the more pointed end. 

 There is no undulating mem- 

 brane. The nucleus is small, 

 indistinct, and usually situated 

 near the flagellar extremity. 



Life-History. — Reproduction is 

 by binary fission, and Perroncito 

 and Piocardi have described en- 

 cystment. 



Habitat. — According to our 

 experience at autopsies, the 

 parasite may live not only in 

 the small intestine, as generally 

 stated, but also in some cases in 

 the large intestine. Oicomonas 

 is readily killed, as observed by 

 Castellani and Willey, by a solu- 

 tion of methylene blue (i in 3,000). 



Oicomonas vaginalis Castellani and Chalmers, 1909. 



Synonym.- — Cercomonas vaginalis Castellani and Chalmers, 1909. 



This is a pear-shaped or rounded parasite, measuring 5 to 12 in 

 its maximum diameter, and provided with one flagellum, a small 

 nucleus, and food vacuoles, but without a pulsating vacuole. It is 

 not uncommon in the vagina of native women in Ceylon. 



Oicomonas perryi Castellani, 1907. 

 Synonym. — Cercomonas ferryi Castellani, 1907. 



Found by Castellani in Ceylon in monkeys {Macacus pileatus and Semno- 

 pithecus priamus) suffering from diarrhoea. It is morphologically extremely 

 similar to O. hominis, being roundish or pear-shaped, 8 to 12 in diameter. 

 There is one flagellum originating from the pointed end. The nucleus is 

 situated near the flagellar end. Reproduction seems to be by binary fission, 

 but cysts can be seen. 



Other Species. — O. anatis Davaine, in the alimentary canal of ducks; 

 O. oanis Gruby and Delafond, in dogs; O. gallinarum Davaine, in fowls. 



Bodonidse Biitschli, 1884, emendavit Dofiein, 1901. 



Definition. — ^Monozoa, free living or parasitic, with one anterior 

 and one posterior (or trailing) flagellum, with or without a kineto- 

 nucleus and an undulating membrane. 



Nomenclature. — In part, at all events, this family represent the 

 Heteromitidae of Saville Kent, as Heteromita Dujardin, 1841, is in 

 part Bodo and in part Cercomonas. 



Type genus. — Bodo Stein, 1878. 



Classification. — ^The following is a poor attempt to differentiate 

 the genera of the Bodonid?e known to us 

 A. With an undulating membrane: — 



1. Kinetonucleus well marked — Trypanoplasrna. 

 II. Kinetonucleus poorly marked — Trypanophis. 



Fig. 68. — Oicomonas hominis 

 (Davaine) . 



1-3, and 5, Flagellate forms; 

 4, encysted form. 



