1. Bigland, A. D., Lancet, London, 1920, i, 243.
2. Bray, G. W., Tr-ans. Roy. Soc. Trop. Med. L Hyg., London, 1928-29, XXII, 9.
3. Carman, J. A., ibid., 1935, XXVIII, 665.
4. Chick, H., & Roscoe, AI. H., Biochem. J., London, 1930, XXIV, 105.
5. Denton, J., Am. J. Trop. Med., Baltimore, 1925, V, 173.