Cercomonas vaginalis (Castellani and Chalmers, 1909) was found in the vagina of native women in Ceylon.

Other species of Cercomonas have, at various times, been recorded from man. However, the parasitic species of the genus Cercomonas require further investigation.

According to Janowski (1896–7), typical Cercomonads have also been observed in the intestine of man by Escherich, also by Cahen, Massiutin, Fenoglio, Councilman and Lafleur, Dock, Kruse and Pasquale, Zunker, Quincke and Roos, and others. However, it is an open question whether the Flagellata observed by Roos in one of his cases belonged to Davaine’s species, the size showing some deviation (14 µ to 16 µ). In his, as in many other cases, doubts have been raised as to whether the flagellates found in the stools had actually lived in the intestine, or had subsequently appeared in the fæces: for this a surprisingly short time only is necessary. Salomon also appears to have observed Cercomonads (Berl. klin. Wochenschr., 1899, No. 46).

As with T. intestinalis so with C. hominis, it appears that the parasite settles not only in the intestine but also in the air-passages. This is demonstrated by the statements of Kannenberg and Streng of the occurrence of Monads and Cercomonads in the sputum and putrid expectoration in gangrene of the lungs, which no doubt apply to C. hominis (cf. also Artault). Possibly also the Flagellata observed in the pleural exudation by Litten and Roos may be included here; this is the more probable in Roos’s case as the process ensued in the pleura after the breaking through of a vomica.

Perroncito and Piccardi have described encysted stages of Cercomonads.

Fig. 23.—Monas pyo­phila, R. Blanch. (After Grimm.)

Monas pyophila, R. Blanch., 1895.

R. Blanchard thus designates a Flagellate that Grimm found in the sputum, as well as in the pus of a pulmonary and hepatic abscess, in the case of a Japanese woman living in Sapporo. The parasites resemble large spermatozoa (fig. 23). The body, 30 µ to 60 µ, has the shape of a heart or a myrtle leaf, and is surrounded by a thick cuticle which is supposed to extend into the interior of the body, dividing it into three parts. A long appendix at the rounded pole is covered for the greater part of its length by the cuticle; the extremity, however, is free and resembles a flagellum. The parasites were very active, frequently changed their shape, and were able to retract the long appendix within the body, which then assumed a round form.