Motive Force Responsible for the Protoplasmic Streaming
It is a relatively simple matter to express the protoplasmic streaming by means of the speed of flow. But the rate of the streaming is a function not only of the force behind the streaming, but also of the viscosity of protoplasm, which is likely to change in accordance with internal and external conditions. Consequently even if we recognize the change in speed of flow under some external influence, we cannot determine just how far the change is due to the increase or decrease of the motive force and how much of it is due to changes in viscosity (cf. HEILBRUNN 1952, p. 366). In case of a plasmodium the ever-changing width of the channel (diameter of the capillary) along which endoplasm streams is another factor which exerts an influence on the streaming rate. Physiological studies on protoplasmic streaming, which have hitherto taken almost exclusively the speed of flow as a criterion of the activity, seem to have been hampered in their progress at this point. If we want to go still closer to the causes in our understanding of the phenomenon, it becomes essential to overcome the technical difficulties in measuring the motive force of the streaming.
KeywordsVersus Versus Versus Wave Form Motive Force Slime Mould Centrifugal Acceleration
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