1. Porter, R. R., in Basic Problems of Neoplastic Disease (edit. by Gellhorn, A., and Hirschberg, E.), 177 (Columbia University Press, New York, 1962).
2. Noelken, M. E., Nelson, C. A., Buckley, E. C., and Tanford, C., J. Biol. Chem., 240, 218 (1965).
3. Feinstein, A., and Rowe, A. J., Nature, 205, 147 (1965).
4. Valentine, R. C., and Green, M., J. Mol. Biol. (in the press).
5. Ishizaka, K., Ishizaka, T., and Lee, E. H., J. Allergy, 37, 336 (1966).