1. Patterson, P. Y., Second Inter. Symp. Immunopath., 184 (Benno Schwabe and Co., Basle, 1961).
2. Möller, E., J. Exp. Med., 122, 11 (1965).
3. Brunner, K. T., Mauel, J., Cerottini, J.-C., and Chapuis, B., Immunology, 14, 181 (1968).
4. Holm, G., and Perlmann, P., Immunology, 12, 525 (1967).
5. MacLennan, I. C. M., and Loewi, G., Clin. Exp. Immunol., 3, 385 (1968).