1. KRAUS, J., and BRIGGS, A. W. (1945). British Journal of Ophthalmology, 29, 557.
2. LODGE, W. 0. (1945). Ibid., 29, 205.
3. SKEOCH, H. H. (1945). Ibid., 29, 113.
4. SOMERSET, E. J., and SEN, K. (1948). Ibid., 32, 13.
5. STALLARD, H. B. (1944). Ibid., 28, 105.