Conductivity as a Measure of the Permeability

The electrolytic conductance of living ceils has been used extensively as a measure of their permeability to electrolytes, and more particularly of the permeability of an hypothetical semipermeable plasma membrane supposed to delimit the protoplasm from the sur• rounding medium. There are, however, many possible sources of error in making such an interpretation, especially when suspensions of cells are studied. This paper is a critical consideration of this phase of the subject, and exposition of the precautions and corrections suggested by rather extended intensive study of the conductance of bacteria, red blood cells, unicellular algae, and yeast.