Developmental Mechanics of Fucaceous Algae XIV

Plasmolysis Pattern in Coccophora Eggs.

Abstract

As a result of plasmolysis experiments in eggs of Coccophora Langsdorfii, the
following was revealed. (1) The permeability of the egg protoplasm to NaCl and to
saccharose decreases after occurrence of the fertilization. (2) plasmolysis is liable to
occur at the pointed end, i.e. the rhizoid pole, after the egg was transformed to an
ovate form by the morphogenetic movement. (3) After occurrence of the first nuclear
division, the plasmolysis occurs along the equatorial zone as well as at the rhizoid
pole, though the form of the egg is identical with the former stage. This indicates
that a certain change in the physical properties of the cytoplasm is taking place locally
in that zone. (4) At an early stage after the first segmentation, the wall of segmentation
is not firmly connected with the wall of the mother cell, so that it can be
separated from the latter with contraction of the protoplasm upon plasmolysis.