1. Crumpton, M. J., and Davies, D. A. L., Biochem. J., 70, 729 (1958).
2. Private communication from Prof. Robert Wheat (see preceding communication).
3. Leatherwood, E. R., Rollins, E., Kulkarni, M. V., and Wheat, R., Fed. Proc., 22, 239 (1963).
4. Barker, S. A., Stacey, M., and Williams, J. M., Bull. Soc. Chim. Biol., 42, 1611 (1960). Barker, S. A., Brimacombe, J. S., How, M. J., and Stacey, M., Nature, 189, 303 (1961).
5. Barry, G. T., Chen, F. P., and Roark, E., J. Gen. Microbiol., 33, 95 (1963).