1. Hecht, S., Shlaer, S., and Pirenne, M. H., Science, 93, 585 (1941); J. Gen. Physiol., 25, 819 (1942). Hecht, S., Biological Symposia, VII, “Visual Mechanisms” (Lancaster, Pa., 1942); J. Opt. Soc. Amer., 32, 42 (1942).
2. Crawford, B. H., Proc. Boy. Soc., B, 128, 552 (1940).
3. Sherrington, C. S., “The Integrative Action of the Nervous System” (London, 1909).