Reversible Changes in Living Protoplasm.

Abstract

It has been shown 1 that when a cell of Nitella is cut a wave of some sort, which we may for convenience call a death wave, passes rapidly along the cell and that at each spot it reaches a characteristic death process is brought about. In dilute solutions (e. g. 0.001 M KCl) this consists of a sudden change whereby the protoplasm becomes more negative after which its potential difference approaches zero.

These alterations are irreversible but similar changes of a reversible character may occur spontaneously or may be induced by a variety of reagents (both organic, and inorganic). After the removal of the reagents the changes often cease at once or after some minutes. Very often these changes are rhythmical and appear to travel along the cell, sometimes at a high rate of speed.

During the past 5 years a large number of such cases have been recorded photographically by means of the technique previously described. 2 These are being studied with a view to correlating all the phenomena since, to arrive at a theory of living matter, it is necessary to have accurate observations of its fluctuations under normal conditions. It would seem that such alterations might be due to changes in the permeability of the surface or in resistance elsewhere. Such changes in the surface might be essentially structural (e. g., due to the temporary formation of openings in certain layers) or chemical in nature.