1. Robison, G. A., Butcher, R. W., and Sutherland, E. W., Ann. New York Acad. Sci., 139, 703 (1967).
2. Rall, T. W., and Kakiuchi, S., in Molecular Basis of Some Aspects of Mental Activity (edit. by Walaas, O.), 1, 417 (Academic Press, New York, 1967).
3. Ho, A. K. S., Singer, G., and Gershon, S., Psychopharmacologia (in the press).
4. Krishna, G., Weiss, B., and Brodie, B. B., J. Pharmacol. Exp. Ther., 163, 379 (1968).
5. Chou, W. S., Ho, A. K. S., and Loh, H. H., Proc. Western Phar- macol. Soc., 14, 42 (1971).