1. Cohn, C., and Wolfson, W. Q. (1947). J. Lab. clin. Med., 32, 1203.
2. Dole, V. P., and Braun, E. (1944). J. clin. Invest., 23, 708.
3. Jager, B. V., and Nickerson, M. (1948). J. biol. Chem., 173, 683.
4. Kibrick, A. C., and Blonstein, M. (1948). Ibid., 176, 983.
5. Kingsley, G. R. (1940). Ibid., 133, 731.