1. Krishna Iyer, P. V., Nature, 160, 174 (1948); 162, 133 (1948); J. Ind. Soc. Agric. Stat., 1 (in the press).
2. Kermack, W. O., and McKendrick, M. G., Proc. Roy. Soc. Edin., 57, 228 and 332 (1937).
3. Kendall, M. G., “The Advanced Theory of Statistics", 2, 124 (London, Griffin and Co., Ltd., 1946).
4. Batin, I. N., Ann. Math. Stat., 13, 208 (1942).
5. Anderson, T. W., Ann. Math. Stat., 14, 426 (1943).