1. BAKER, S. (1937), Lancet, I, 1390.
2. BLACK, D., and STANBVRY, S. (1948), Ibid., 2, 101.
3. COOMBS, R., MOURANT, A., and RACE, R. (1946), Lancet, I, 264.
4. DACIE, J., and FIRTH, D. (1943), Brit. Med. Y., I, 6z6. DACIE, J., and MOLLISON, P. (1943), Lancet, I, 550.
5. DACIE, J., and MOLLISON, P. (1949), Lancet, I, 390.