Functional Cytology of Entamoeba histolytica

Abstract

A study was made of a clone culture derived from Dobell''s strain of E. histolytica. Observations were made of the func-tional cytology of living, active and unstained amoebae. using apochrornatic lens systems. Engulfed food was attacked and digested by "digestive spherules" which are derived from the nucleus. These spherules absorb the food and migrate out into the cytoplasm where they are recognized as granules or vacuoles. Here, they fragment or coalesce, depending upon the redox potential. During the precystic stage when the amoeba is in a much reduced state, they coalesce to form the chromatoids. On oxidation, excretion bodies form irf the vacuoles. These and fecal vacuoles are eliminated to the out-side. Locomotion in E. histolytica is fundamentally the same as for other amoebae. The osmotic activities of vacuoles and of the nucleus are about the same or only slightly higher than the outside medium. Staining with vital dyes was unsuccessful since most vital dyes bleach at a redox potential above that in which the amoebae normally live.