Summary. Rhazidine. a monoquaternary alkaloid, exhibited considerable ganglion lilotking property, Responses of the nictitating membrane to pre-gaiiglionic sympathetic .stimulation were abolished without affecting post-ganglionic responses. Responses of the vas deferens to hypogastric nerve stimulation were impaired withotit altering the responses to intramural stimulation in the guinea-pig. Only partial inhibition of response was observed in the guinea-pig urirary bladder to hypogastric nerve stimulation. Spasms induced by nicotine were selectively inhibited in all of the test organs. Effects at adrenergic neuron and post-synaptic receptors were excluded. The results were compared with pentolinium tartarate and indicated specific ganglion blocking efFect of rhazidine.