1. Velat, C. A., Weinstein, P. P., and Otto, G. F., Amer. J. Trop. Med., 30, 43 (1950).
2. Svensson, R., Acta Med. Scand. Sup., 70, 15 (1935).
3. Jaswant Singh and Bhattacharji, L. M., Ind. Med. Gaz., 79, 102 (1944).
4. Jaswant Singh, Ray, A. P., and Nair, C. P., Ind. J. Mal., 7 (1953) (in the press).