GENUS: ENTEROMONAS 



307 



flagellate described by him (1919) as Enteromonas Bengalensis is possibly 

 the same organism, though some of the figures suggest Embadomonas 

 intestinalis. Leger, M. (1918a), described a similar form from man in 

 Guiana, and regarded it as E. hominis. These various accounts agree 

 in describing E. hominis as a flagellate with rounded body, three flagella, 

 and no cytostome. Yakimoft" (1925) gave the name Enteromonas fonsecai 

 to a form in the guinea-pig. 



There seems to be considerable doubt as to the accuracy of the descrip- 

 tions of the genus Enteromonas. Dobell and O'Connor (1921) suggest that 

 the various observers were actually dealing with Tricercotnonas intestinalis, 

 and that the fourth posterior flagellum had been overlooked (Fig. 261). It 

 appears, however, that another and more probable explanation can be 

 found. As described by the writer (19106), Chilomastix mesnili may occur 

 as a small spherical flagellate with three anterior flagella (Fig. 256, 7, 8). 

 In these forms the cytostomal groove 

 and its enclosed flagellum may be 

 difficult to detect or quite invisible, so 

 that flagellates appear to have the 

 structure ascribed to Enteromonas 

 hominis. This mistake appears to 

 have been made by Chalmers and 

 Pekkola, for the writer has been able 

 to examine their original films. There 

 can be no doubt that their E. hominis 

 is merely a small rounded form of 

 C. mesnili. Though they state that 



the latter flagellate was never found in association with E. hominis, the 

 writer has found typical forms in the films. In their description of C. mesnili, 

 these observers (1918) draw attention to the small round forms with ob- 

 scured cytostomal groove, but it did not occur to them that their E. hominis, 

 previously described, might be the same forms. It is not improbable that 

 Fonseca and other observers were also describing as Enteromonas the small 

 forms of C. mesnili. If this be so, then the name Enteromonas becomes a 

 synonym of Chilomastix. Fonseca (1918) described as E. intestinalis of the 

 rabbit a flagellate which was said to have the same structure as his E. hominis 

 of man. This form, as well as the human one, was seen by da Cunha and 

 Pacheco (1923), who also saw another in the viscacha in Brazil. If the 

 human form is a Chilomastix, it is not improbable that the rabbit one is 

 also, as it is liable to infection with a species of Chilomastix. Lynch (1922a) 

 has, however, obtained from the guinea-pig a culture of a flagellate having 

 the structure ascribed to Enteromonas. It apparently showed no tendency 

 to develop into Chilomastix, with which the guinea-pig may also be infected, 



Fig. 146. — Enieromonafi hominis {x ca 

 2,000). (After Fonseca, 1910.) 



