OICOMONAS 



335 



This sarcode thread was the only point of distinction from the 

 genus which Saville Kent called Monas, but which Stein in 1878 

 had improved, so that it came to be defined as possessing two anterior 

 fiagella, one long and one short, while the posterior end was capable 

 of forming a filiform pseudopodium. In view of this, and as the 

 filiform pseudopodium is not an essential character, Oicomonas 

 came to be looked upon as including forms with a single anteriorly 

 directed flagellum, and as such requires investigation by modern 

 cytological methods. In this genus must come all those organisms 

 which resemble Form B of Davaine's Cercomonas hominis, as this 

 is not a Cercomonas, and they must include Monas pyophila 

 Blanchard. 



With regard to the flagellate called Monas lens Miiller, 1786, and 

 reported as being present in man, it is not a Monas, but was classified 

 by Saville Kent as a Heteromita . It may be a Bodo or a Prowazekia. 



Type Species. — Oicomonas mutabilis Saville Kent, 1880, found in 

 vegetable infusions. 



The more important parasitic species which concern us are: — 



Oicomonas pyophila R. Blanchard, 1895, 



Oicomonas hominis Davaine, 1854, 



Oicomonas vaginalis Castellani and Chalmers, 1909, 



and these may be differentiated as follows:- — ■ 



A. With thick cuticle — Pyophila. 



B. Without thick cuticle, in human intestine — Hominis. 



C. Without thick cuticle, in vaginal mucus — Vaginalis. 



Oicomonas pyophila R. Blanchard, 1895. 



Synonym.— Mow^jjs pyophila R. Blanchard, 1895. 



Definition. — Oicomonas with a thick cuticle. 



Historical.^ — -Grimm found this flagellate in the sputum and pus 

 of a pulmonary and of a hepatic abscess occurring in a Japanese 

 woman living in Sappho. The organism requires reinvestigation 

 by modern methods.' 



Morphology. — The flagellate measures 30-60 microns in length 

 and is heart-shaped, being enclosed in a thick cuticle which extends 

 into the cytoplasm, dividing it into three parts, and is continued 

 along the flagellum for a considerable distance. At its tip the flagel- 

 lum is free. 



Life-History. — Nothing is known as to this. 



Oicomonas hominis (Davaine, 1854), emendavit Castellani and 

 Chalmers, 1918. 



Synonyms. — Cercomonas hominis Davaine, 1854, pro parte — ■ 

 i.e., Form B. 

 Definition.— Oicomonas with a thin cuticle. 



History.— In 1854 Davaine described two forms, A and B, under 

 the heading Cercomonas hominis. Form A is Chilomastix mesnili, 

 while Form B is Oicomonas hominis. 



