1. AGOSTAS, W. N., REEVES, N., SHANKS, E. D. and SYDENSTRICKER, V. P. (1952), New. Engl. J. Med., 246, 217.
2. Personal communication;BETTLEY, F.R.,1951
3. BLEIER, A. H., SCHWARTZ, F. (1951), Am. J. Ophth., 34, 6i8.
4. CALDWELL, W. G. D. (1953), Lancet, i, 1127.
5. CAMPBELL, C. H. (1955), Med. J. Aust., 26, 941.