1. Hertting, G., and Axelrod, J., Nature, 192, 172 (1961).
2. Blaschko, H., and Welch, A. D., Arch. Exp. Path. Pharmak., 219, 17 (1953).
3. Bloom, G., Östlund, E., Euler, U. S. von, Lishajko, F., Ritzen, M., and Adams-Ray, J., Acta Physiol. Scand., 53, Supp. 185 (1961).
4. Euler, U. S. von, and Hillarp, N. Å., Nature, 177, 44 (1956).
5. Schümann, H. J., Arch. Exp. Path. Pharmak., 234, 17 (1958).