Observations on Blastocystis hominis

Abstract

In 1908 intestinal parasites of man were described by Bohne and Prowazek. The authors considered them to be cysts of Trichomonas hominis. The parasites consist of a highly refractile spherical body, staining yellow or yellowish brown with iodine and pale grey or black with iron haematoxylin; this sphere is surrounded by a narrow plasmatic layer, containing the nuclei. Bensen (1910) gave a detailed description of these bodies, with stages of autogamy, and considered them also to be cysts of Trichomonas. Prowazek (1911) did not subsequently change his opinion regarding the systematic position of these bodies and James (1914) confirmed Prowazek's views by stating that cats infected with the same bodies showed Trichomonas in their stools.