The Morphology and Cultivation of Embadomonas cuniculi n. sp.

Abstract

The genus Embadomonas was founded by Mackinnon (1911) to include two species of flagellates (E. agilis and E. alexeieff) obtained from tricopterous larvae. According to Mackinnon (1915), to this genus belong small slipper-shaped flagellates, characterized by a very large cytostome bordered by prominent lips, which are more or less siderophilous, and two flagella not so long as the body, one acting as an organ of locomotion, and the other lying in the cytostome; the spherical nucleus is placed at the anterior end of the body; the two basal granules from which rise the flagella, lie at the anterior border of the cytostome. There is a definite periplast, which prevents deformation of the body. The anterior part of the body shows a well marked torsion. The cysts are relatively small, and are ovoid in form. Since then other species have been discovered. Wenyon and O'Connor (1917) described E. intestinalis from man; da Fonseca (1920), E. wenyoni (Waskia) from the monkey Cebus caraya. Faust and Wassell (1921) described E. sinensis from man but from the figures of Faust (1922) there is some likelihood that they were dealing with a flagellate of another genus, since the posteriorly directed flagellum is not shown emerging from the cytostome or lying within it for any of its length as is the case in other species belonging to this genus. In some respects the new species, described since the founding of the genus by Mackinnon, do not conform with the original generic description, but there is general agreement with respect to the presence of two flagella, one of which is directed anteriorly and the other, posteriorly, the latter lying either wholly within the cytostome or for only the proximal portion of its length. In some forms this flagellum is shorter and thicker than the anterior flagellum. We do not accept the statement of da Fonseca (1920) that flagellates of the genus Embadomonas possess an undulating membrane in the cytostome for none of the observers who have studied various species of this genus has recorded such a finding and moreover his description of the genus Waskia is definitely synonymous with Embadomonas as given by Mackinnon except for the description of double forms which, however, are doubtless division forms.