1. Levine, P., Koch, E., McGee, R., and Hill, G., Amer. J. Clin. Path., 24, 292 (1954).
2. Levine, P., Fifth International Congress of Blood Transfusion Congress, Reports and Communications, Paris (1954).
3. Hart, M. vander, Bosman, H., and Van Loghem, J., Vox Sang., 4, 108 (1954).
4. Layrisse, M., Arends, T., and Sisco, R. D., Acta Medica Venez., 3, 132 (1955).
5. Fernandes et al., personal communication from Dr. P. C. Junqueira, Rio de Janeiro, Brazil.