The Action of Pressure and of Electricity
One of the essential characteristics of living protoplasm is its ability to respond to sudden changes of environment—that is to say, to stimulation. This is especially evident for those types of protoplasm which are capable of making an easily observable response. Strangely enough, very diverse kinds of stimulating agents may produce—and typically do produce—the same sort of a response in a given type of protoplasm. The basic reason for this amazing fact will be considered in another section of this treatise. Suffice here to say that the outer cortex of the cell apparently initiates the response mechanism, at least toward most stimuli. There is considerable evidence to show that sudden heat, sudden cold, sharp uneven pressure, ultraviolet radiation, electric shocks, as well as certain types of chemical treatment, all cause a release of calcium from the cortex, and that this calcium on entering the cell interior causes a sharp increase in protoplasmic viscosity.
KeywordsElectric Current Electric Shock Bean Plant Outer Cortex Observable Response
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