1. Borchgrevink, C. F., Acta Med. Scand., 168, 157 (1960).
2. Derouaux, G., Arch. Int. Pharmacodyn., 65, 125 (1941).
3. Mitchell, J. R. A., and Sharp, A. A., Brit. H. Haematol. (in the press).
4. Honour, A. J., and Mitchell, J. R. A., Nature, 197, 1019 (1963).
5. Mustard, J. F., Canad. Med. Assoc. J., 88, 265 (1963).