Observations upon Embadomonas intestinalis in Culture

Abstract

1. Embadomonas intestinalis has been cultivated on an inspissated horse-serum slope covered with Ringer egg-white or with inactivated horse-serum diluted 1:10 in 0·5 NaCl solution, at 17–20° C. as well as at 37° C.2. Attempts to infect tadpoles of Bufo vulgaris, bred free from Protozoa, with E. intestinalis have failed.3. In the division of E. intestinalis there is duplication of the basal granules and flagella with the formation of a centrodesmose between one granule of each pair. The cytostome disappears and new ones are formed when nuclear division is complete. No spindle fibres are formed but the nucleus becomes spindle-shaped and discrete chromatin granules are present.4. Double individuals occur but they do not represent a stage in normal division. Long observation failed to reveal division of such individuals.5. Cysts of E. intestinalis have been found in cultures at all temperatures studied. The nuclear membrane and peripheral chromatin is elongated and stains intensely, and the two basal granules are prominent. A siderophilic mass in the centre probably represents the karyosome. There is no evidence that division occurs in the cyst.