A survey of the results of these experiments shows, we believe conclusively, that in botulinus intoxication in cats, dogs, and rabbits there is a specific effect upon the portions of the autonomic nervous system which Gaskell (14) described as the bulbosacral and prosomatic outflows of connector fibers respectively, which results in a blocking of the nerve impulses of these nerves. The experimental as well as the clinical evidence indicates that there is no damage to the nerves of the thoracicolumbar outflow. The exact location of the damage has not been ascertained nor has the mechanism by which the nerve impulse is blocked been determined. The experiments show, however, that the lesions in these portions of the nervous system are not of central distribution but are peripheral, and that the block cannot be due to an organic break in the conduction apparatus but must be due to some derangement which is relatively unstable. If it were otherwise it would not be possible to induce a physiological response even by massive stimulation, nor could the response be subsequently repeated by stimuli which lie within the limits of normal intensity. The application of the results of these experiments to the clinical manifestations of botulism will be discussed in a later report after the effect of the toxin upon the skeletal motor nerves has been described.