The synergism of ether and curare was tested on rats by recording action currents and tension of the gastro-cnemius during the separate and combined admn. of the 2 agents. Maximal stimuli were applied to the motor nerve after central section. Under deep ether alone the anoxia resulting from respiratory depression accounts for about half the slight depression of muscle activity observed. Deep ether increases the effect of curare on the gastrocnemius more than can be accounted for by anoxia, and may block respiration in a dosage that shows no effect on respiration under light ether. Since the curare effect on the gastrocnemius was tested by peripheral nerve stimuli and must have consisted entirely of the usual block at motor endplates, a peripheral action can also be inferred on respiratory musculature as the source of failure, and the slowing of rate was presumably secondary to central anoxia.