[Blastocystis hominis: morphological study using optical and electron microscopy].

Blastocystis hominis is a member of the phylum Protozoa as described by Zierdt et al. Despite the complexity of its yet not well defined biological cycle, Blastocystis was found to possess all the structures characterizing protozoans. The physiochemical and biological growth conditions are those of many protozoans. The high degree of cell differentiation is probably due to the existence of two reproduction modes.