MANGANESE IN OXYGEN EVOLUTION 249 



9. Bergmann, L., Flora {Jena), U2, 493 (1955). 



10. Gerretsen, F. C, Playit and Soil, 2, 159 (1950). 



11. Kenten, R. H., and Mann, P. J. G., Biochem. J. (London), 61, 279 (1955). 



12. Allen, M. B., Arnon, D. I., Capindale, J. B., Whatley, F. R., and Durham 



L. J., J. Am. Chem. Soc, 77, 4149 (1955). 



13. Horwitz, L., and Allen, F. L., Arch. Biochem. and Biophys., 66, 45 (1957). 



14. Strehler, B. L., and Arnold, W., J. Gen. Physiol., 34, 809 (1951). 



15. Shiau, Y. G., and Franck, J., Arch. Biochem., 14, 253 (1947). 



