1. Bruzzone, L., and Massimello, F. (1940). Arch. Sci. Med., 69, 236.
2. Cameron, D. G., Bensley, E. H., and Wood, P. (1951). Canad. med. Ass. J., 64, 30.
3. Cappell, D. F. (1930). J. path. Bact., 33, 175.
4. Cartwright, G. E., Lauritsen, M. A., Jones, P. J., Merrill, I. M., and Wintrobe, M. M. (1946). J. clin. Invest., 25, 65.
5. Cartwright, G. E., Lauritsen, M. A., Jones, P. J., Merrill, I. M., and Wintrobe, M. M. and Wintrobe, M. M. (1949). Ibid., 28, 86.