1. Eurich, F. W., and Hewlett, R. T., “A System of Bacteriology”, 5, 439 (Medical Research Council, London, 1930).
2. Sobernheim, G., “Handbuch der Pathogenen Mikro-organism”, 3, 1041 (Gustav Fischer, Jena, 1931).
3. King, H. K., and Stein, J. H., J. Gen. Microbiol., 4, 48 (1950).
4. Smith, H., Keppie, J., and Stanley, J. L., Brit. J. Exp. Path., 34, 471 (1953).
5. Smith, H., Keppie, J., and Stanley, J. L., Brit. J. Exp. Path., 34, 477 (1953).