1. Agner, K., Acta Physiol. Scand., 2, Suppl. VIII (1941).
2. Neumann, A., Biochem. Z., 150, 256 (1924).
3. Neumann, A., Centralbl Bakt., 104, 266 (1927).
4. Kojima, S., J. Biochem., 14, 95 (1931–32).
5. Petherick, M., and Singer, E., Austral. J. Exp. Biol., 21, 221 (1943); 22, 21 (1944).