1. Eppes, W., and Ludovic, E. (1951). Blood, 6,466.
2. Hargraves, M. M., Richmond, H., and Morton, R. (1948). Proc.
3. A. (1950). Blood, 5, 718.
4. Holman, S. (1951). Journal of Clinical Pathology, 4, 290.
5. C., and Pollister, A. W. (1950). Arch. Path., Chicago, 49, 503.