The response to stimulation of the abdominal viscera and the mechanism involved has been a subject of unusual interest and considerable controversy for laboratory and clinical investigators for a long time. Many years ago, Mayer and Pribram1 and, later, Brodie and Russell2 observed a rise in the arterial blood pressure with an increase or a decrease in the heart rate following distention of the stomach. Davis and co-workers3 and Schrager and Ivy4 in still later reports showed that stretching of the biliary and cystic ducts produced apnea and a variable change in the blood pressure as well as in the heart rate. It was believed that stimulation of the vagus and right splanchnic nerves was responsible for the phenomena observed. Luckhardt and associates5 noted the appearance of apnea and an immediate fall in the blood pressure following manipulation and traction on the gastrohepatic ligament. While