1. Ramsey, R. W., and Street, S. F., J. Cell. Comp. Physiol., 15, 11 (1940).
2. Hill, A. V., Proc. Roy. Soc., B, 136, 420 (1949).
3. Singh, S. I., and Singh, I., Curr. Sci., 17, 306 (1948).
4. Singh, S. I., and Singh, I., Proc. Ind. Acad. Sci., B, 30, 343 (1948).
5. Singh, S. I., and Singh, I., Curr. Sci., 19, 60 (1950).