FACTORS RENDERING THE PLASMOLYTIC METHOD INAPPLICABLE IN THE ESTIMATION OF OSMOTIC VALUES OF PLANT CELLS

Abstract

The relationship between conc. of plasmo-lyticum and time required for plasmolysis is considered from a theoretical standpoint and the conclusion reached that a considerable time is necessary before equilibrium is attained between a cell and a surrounding fluid of only slightly greater or slightly less osmotic strength. Experimental conc. time plasmolysis curves for 7 spp. of plants are presented and compared with the ideal curve. When mechanical injury and the pathological actions of fluids from ruptured cells are eliminated and when temp. and light are those of normal laboratory conditions, plasmolysis is a slow process and limiting plasmolysis is so much deferred that secondary changes must be expected to have occurred in the cells such as would render invalid the interpretation of plasmolysis data as any measure of the osmotic value of the contents of plant cells.