1. Diener, E., and Armstrong, W. D., Lancet, ii, 128 (1967).
2. Diener, E., and Armstrong, W. D., J. Exp. Med., 129, 591 (1969).
3. Ada, G. L., Nossal, G. J. V., Pye, J., and Abbot, A., Austral. J. Exp. Biol. Med. Sci., 42, 267 (1964).
4. Byrt, P. N., and Ada, G. L., Immunology, 17, 501 (1969).
5. Adler, F. L., Fishman, M., and Dray, S., J. Immunol., 97, 554 (1966).