Comparison of Water Diffusion and Water Filtration Across Cell Surfaces.

Abstract

Summary. Diffusion and filtration constants for water were measured on the plasma membranes of the ovarian eggs of Rana temporaria and Danio rerio, on the body cavity eggs of Rana and Xenopus laevis, on the shed, but not developing eggs of Danio rerio, on the unfertilized and fertilized eggs of Salmo irideus and on the amoeba Chaos chaos. The filtration constant was always higher than the diffusion constant except in the trout egg where no permeability was demonstrated. The two constants varied in the same direction but far from proportionally. It is suggested that the results give information about the structure of the membranes studied.