THE INNERVATION OF THE STOMACH AND RECTUM AND THE ACTION OF ADRENALINE IN ELASMOBRANCH FISHES

¹ From the Mount Desert Island Biological Laboratory, Maine and the Physiological Laboratory of Boston University, School of Medicine

1. Adrenalin chloride and extract of the chromaphil bodies caused a rise in tone and sometimes an increase in motility of all parts of the stomach of Squalus acanthias, Raia erinacea and R. diaphanes.

2. Faradic stimulation of the first sympathetic ganglion (gastric) and the anterior splanchnic nerves caused extensive contractions of the stomach beginning at the pylorus in Squalus acanthias. Similar stimulation of the vagus caused moderate activity in the region of the pylorus.

3. Adrenalin chloride and extract of chromaphil bodies caused a marked decrease in tone and inhibition of motility of the posterior end of the spiral valve and the rectum in all three elasmobranchs.

4. Faradic stimulation of the posterior splanchnic nerves caused a vigorous contraction of the rectum and adjacent part of the spiral valve in Squalus acanthias.

5. The data presented here and the evidence from the literature indicate that a general physiological distinction between the sympathetic and the parasympathetic divisions of the autonomic nervous system should not be made.