1. Botelho, S. Y. (1955). J. clin. Invest., 34, 1403. _ and Cander, L. (1953). J. appl. Physiol., 6, 221.
2. Brown, G. L., and Euler, U. S. von (1938). J. Physiol. (Lond.), 93, 39.
3. Dawson, G. D., and Merton, P. A. (1956). XX Int. Congr. Physiol., Brussels, 1956. Abstracts of Communications, p. 221.
4. Denny-Brown, D. (1929). Proc. roy. Soc. B., 104, 252.
5. The Neurophysiological Basis of Mind: The Principles of Neurophysiology;Eccles, J.C.,1953