1. EDWARDS j W. L., JONES, N. B., McCONNELL, R. B., PEMBERTON, H. S., and WATSON, D. C. (1952), Ibid., ii 8o8. GOODWIN, J.
2. GRIMSON K S REARDON, M. J., MARZONI, F. A., and HEND IX, J. HAMILTON, M., P. (1948), Ann. and WILSON, Surg., G. M.
3. HAMILTON, M., WILSON, G.: M., ARMITAGE, P., and BOYD, J. T. (1953), Lancet, L, 367.
4. Heart, I5, 359. B. (1950), Lancet, ii, 676.
5. MUFSON, I. (1948), Ann. intern. Med., 29, 903.