THE EFFECT OF ELECTRIC CURRENT ON THE RELATIVE VISCOSITY OF SEA-URCHIN EGG PROTOPLASM

¹ From the Zoölogical Laboratory, University of Pennsylvania, and the Marine Biological Laboratory, Woods Hole, Mass.

1. The centrifuge method was used to determine the viscosity of sea-urchin egg protoplasm after exposure to either direct or alternating electric current to a current density of 0.005 amperes/mm.² for various known intervals of time.

2. There is, on exposing eggs to either direct (curve B) or alternating (curve A) current, a transient decrease followed ultimately by a progressive increase in the centrifuging value (Fig. 1).

3. Since the data for the action of electric current, as employed in these experiments, show a striking similarity to those results as obtained by the use of certain other stimulating agents on Amoeba and Arbacia egg protoplasm, it is suggested that the mechanism offered by Heilbrunn (1937) may be applicable here.