A recent epidemic of botulism afforded us the opportunity of recording some physiological observations, made for the first time, on the effect of the toxin in man. Previous knowledge of the physiological action of the botulinus toxin was based primarily on laboratory experimentation in cold- and warm-blooded animals. The marked species differences in response to toxin suggested the importance of confirming these laboratory observations in man. In 1874 Pürkhauser1 first suggested that in "sausage poisoning" paralysis might be due to direct toxic action on the muscle and glands. This was based on his clinical observations in patients. Schübel2,3 described a curare-like action of botulin toxin in frogs. These animals showed marked susceptibility to repetitive stimulation with fatiguing. He was impressed, however, with the neuronal changes in the spinal cord of the frogs and felt the lesion was central. He clearly established the fact that there was a latency