Developmental Mechanics of Fucaceous Algae XIX

Negation to the Presence of Polar Cyto-skeletal Systems in the Endoplasm of Coccophora Eggs

Abstract

Eggs of Coccophora Langsdorfii were centrifuged respectively before fertilization and after determination of the morphological polarity towards various directions at 400 to 25, 000 times gravity. As a result, the following was revealed. (1) The limit of centrifugal force necessary for stratification of the endoplasmic elements lay between 2, 200 and 2, 700 times gravity regardless of the developmental stage. (2) No difference was perceived in the velocity of stratification among directions, basal, apical and lateral, towards which the egg was centrifuged. The velocities of redistribution of the stratified elements also could not be distinguished with directions in which they were centrifuged. (3) From these facts, it is not considered that there is a polar cyto-skeletal system in the endoplasm of fucoid eggs.