1. Binz, H., and Wigzell, H., Nature, 262, 294–295 (1976).
2. Rodkey, L. S., J. exp. Med., 139, 713–720 (1974).
3. McKearn, T. J., Stuart, F. P., and Fitch, F. W., J. Immun., 113, 1876–1882 (1974).
4. Sakato, N., Janeway, Jr, C. A., and Eisen, H. N., Cold Spring Harbor Symp. quant. Biol., (in the press).
5. Oudin, J., Ann. Immunol. (Inst. Pasteur), 125 C, 309–337 (1974).