One of the authors (Kuru; '40,'49,'50,'57) has elucidated the existence of powerful connections between the sacral division of the cord and the medulla oblongata. These two parts of the central nervous system are known as origins of parasympathetic ontflows (Langley,'03) in which, as is well known, the vagus and the pelvic nerves occupy predominant situations. The sacro-bulbar centripetal connections are made up of two types of fibers. The one, i.e. the pelvic sensory vagus, is composed of

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... neurons and ascends in the paramedian superficial layer of the posterior funiculus. It connects the sensory endings in the pelvic organs directly with the gray substance in the medulla. On filling the urinary bladder action potentials can be recorded from fibers of the pelvic sensory vagus (Kuru, Yamamoto and Sugihara;'53). The other, the sacro-bulbar tract, is composed of the deuteroneurons and ascends in the lateral funiculus. The fibers of this tract, originating in the dorsal group of the nucleus intermediolateralis (Kuru and Takase;'47), terminate in several areas of gray matter close to the vagal nuclei. These anatomical and physiological facts suggest the existence of medullary centers for the pelvic organs too. Therefore studies were carried out by Kuru and Hukaya ('54) on vesico-rectal responses resulting from electrical stimulations of the medulla. Two kinds of responses, facilitatory and inhibitory, could be evoked by electrical stimulations of the medulla closely adjacent to the terminations of the above-mentioned sacro-bulbar connections. However, since in these experiments the separation of the vesical response from the rectal response was insufficient and the exclusion of the influence of the striate muscles was unsatisfactory, further experiments were made. The results are described here. MATERIAL AND METHODS Adult cats were used after starvation for more than 18 hours. They were anesthetized by subcutaneous injection of urethane, at a dose of 1.5g. per kilo body weight. By suprapubic median incision the urethra was exposed and at its most distal part a small incision was made to insert a catheter into the bladder. When the tip had just entered the bladder the catheter was fixed to the latter with a single suture. Then the recti muscles were freed from the