The viscosity of the protoplasm of the unfertilized sea-urchin (Arbacia punctu-lata) eggs was detd. by the centrifuge method. Both alternating and direct electric currents were employed as stimulating agents. There is during the first 2 secs. of current flow a progressive decrease in viscosity, which reaches a flat minimum at 66% of the control. On further application of the current the viscosity begins to increase after 5 secs. The expts. were discontinued after 15 secs. The experimentally induced changes in viscosity are reversible and on insemination of the eggs normal membrane elevation and cleavage occur. These results with electric stimulation are in line with those already obtained for the action of this and other stimulating agents (mechanical agitation, heat and U-V irradiations) on Amoeba and Arbacia egg protoplasm.