The sciatic nerve of 8 cats and 6 frogs was studied. Following the injn. of Lissephen, there was little or no change in the rheobase, chronaxie, galvanic tetanus ratio and repetitive stimuli ratios, even after toxic doses were admd. Following the injn. of curare, there was a definite increase in rheobase and threshold for repetitive stimuli. It was concluded that Lissephen does not act on the myoneural junction as does curare.