1. Cole, W. C. C. (1939). Surg. Gynec. Obstet., 68, 179.
2. Kotz, J. and Kaufman, M. S. (1939). J. Amer. med. Ass., 113, 2035.
3. Mackay, H. M. M. (1941). Archives of Disease in Childhood, 16, 166.
4. Dr. Naish's address is 18;Sanford, H.N.;J. Amer. med. Ass,1939