The Rate of the Protoplasmic Flow in the Myxomycete Plasmodium. I

Abstract

The present work concerns a quantitative-descriptive study of the protoplasmic flow in the slime mold, Physarum polycephalum, in terms of its rate. The measurement was done at a straight capillary of protoplasm under normal state.
First is determined by aid of a cinematographic technique the velocity distribution of protoplasm at a time in an optical section of the streaming channel. It looks apparently like a parabola, but its apex is too flattened to be taken as a perfect parabola. This behavior of protoplasm is very similar to the case in which an anomalous liquid is made to move through a capillary tube by a difference in pressure.
Next are mentioned two techniques permitting the successive measurement of the rapidly changing velocity of the protoplasmic flow. They are the “running belt” method and “shadow imprinting” method. By means of the latter technique, a grain-like pattern consisting of numerous brighter and darker lines is obtained automatically representing the shadow of the protoplasmic streaming.