. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 220 BRENTON R. LUTZ of the relation of the vagus to the kidney, epididymis, ovary, and uterus was made. The results presented above indicate that in the elasmobranch, Scyllium canicula, the vagus carries afferent fibers from the stomach, spiral valve, and mesentery. In view of the fact that sensory stimu-. FIG. 3. Reflex cardiac inhibition. Entire cord intact, a, uterus pinched with forceps, b and c, ovary pinched, x, viscera handled, y, ovary handled. lation at a great variety of points produces reflex cardiac and respira-
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 220 BRENTON R. LUTZ of the relation of the vagus to the kidney, epididymis, ovary, and uterus was made. The results presented above indicate that in the elasmobranch, Scyllium canicula, the vagus carries afferent fibers from the stomach, spiral valve, and mesentery. In view of the fact that sensory stimu-. FIG. 3. Reflex cardiac inhibition. Entire cord intact, a, uterus pinched with forceps, b and c, ovary pinched, x, viscera handled, y, ovary handled. lation at a great variety of points produces reflex cardiac and respira- tory inhibition in Scyllium (Lutz, 1929), the failure of stimulation of the first large splanchnic ganglion to elicit these responses may be taken to indicate a lack of afferent fibers through this ganglion. The liver and testis also have no afferent fibers, stimulation of which gives either cardiac or respiratory response. Lyon (1926) likewise obtained no cardie-inhibition on stimulation of the liver in sand sharks (Carcharias). SUMMARY 1. The vagus in the elasmobranch, Scyllium canicula, is an affer- ent pathway from the stomach, spiral valve, and mesentery. 2. There are no afferent fibers passing through the first large sympathetic ganglion or from the liver and testis, stimulation of which produces either cardiac or respiratory inhibition. 3. Removal of the sympathetic ganglia or destruction of the spinal cord as high as the first vertebra fails to prevent elicitation of the inhibitory reflexes provided the visceral branches of the vagi re- main intact. 4. Faradic stimulation of the central end of a visceral branch of the vagus at the stomach produces cardiac and respiratory inhibition. I wish to thank Dr. Reinhard Dohrn and Dr. Enrico Sereni for the many courtesies extended at the Zoological Station, Naples, and Edna B. Lutz for technical assistance. BIBLIOGRAPHY BOTTAZZI, F., 1901. Arch. itul. de Biol., 36: 79. BRODIE, T. G., AND RUSSELL, A. E., 1900. Jour. PhysioL, 26: 9
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