1. Cremer, N. E., Taylor, D. O. N., and Hagens, S. J., J. Immunol., 96, 495 (1966).
2. Peterson, R. D. A., Hendrickson, R., and Good, R. A., Proc. Soc. Exp. Biol. and Med., 114, 517 (1963).
3. Siegel, R. V., and Morton, J. I., Immunology, 10, 559 (1966).
4. Salaman, M. H., and Wedderburn, N., Immunology, 10, 445 (1966).
5. Dent, P. B., Peterson, R. D. A., and Good, R. A., Proc. Soc. Exp. Biol. and Med., 119, 869 (1965).