1. Frazer, A. C., Schneider, R., and Sammons, H. G., Gastroenterologia, 85, 146 (1956).
2. Schneider, W. C., and Hogeboom, G. H., J. Biol. Chem., 183, 123 (1950).
3. Hübscher, G., Dils, R. R., and Pover, W. F. R., Biochim. Biophys. Acta (in the press).
4. Stein, Y., Tietz, A., and Shapiro, B., Biochim. Biophys. Acta, 26, 286 (1957).
5. Dawson, A. M., and Isselbacher, K. J., Fed. Proc., 18, 212 (1959).