ELECTRON-MICROSCOPIC STUDIES ON PROTOZOA

I. FINE STRUCTURE OF ENTAMOEBA HISTOLYTICA

Abstract

Electron-microscopic observations on Entamoeba histolytica were made. Morphological details on the trophozoites, precesses of encystations and degeneration are investigated.
1) Trophozoite has a definite outer membrane. The nuclear membrane is consisted of two layers having minute perforations.
2) The chromatine granules lining the nuclear membrane are made of a substance of a high electron-density.
3) No structural differences were observed by the electron-microscopic observation between the endo and ectoprasm except the former contains vacuoles and ingested inclusions.
4) The encystation takes the following process : rounding off of the cell, decrease in number and then disappearance of vacuoles, production of glycogen vocuoles, then the chromatoid bodies and finally the cyst-membrane.
5) The degeneration process of the trophozoite is as follows: rounding oft' of the cell, disappearance of vaculoes and inclusions in the cytoplasm, vacuolization of the cytoplasm and nucleoplasm, decrease in number and increase in size of the chromatine granules, rupture of the outer membrane and flowing out of the cytoplasm.
6) Mitochondoria, endoplasmic reticulum (in a narrow sense) and Golgi's apparatus were not found in Entamoeba histolytica.