1. P. Ranganatha Koundinya and R. Ramamurthi, Ind. J. Envir. Health20, 426 (1978).
2. P. Ranganatha Koundinya and R. Ramamurthi, Ind. J. exp. Biol.16, 809 (1978).
3. Sakaguchi and Hiromi, Nippon Suisan Gakkaishi6, 38 (1972).
4. D. J. Finney, Probit analysis. Cambridge University Press, London 1964.
5. B. Mendel, A. Kemp and D. K. Myers, Biochem. J.56, 639 (1954).