REFERENCES
- Abdel-Malek, E. T. (1950). Susceptibility of the snail Biomphalaria boissyi to infection with certain strains o. Schistosoma mansoni. Amer. J. trop. Med., 30, 887.
- Abdel-Malek, E. T. (1958). Factors conditioning the habitat of bilharziasis intermediate hosts of the family Planorbidae. Bull. Wld Hlth Org., 18, 785.
- Claugher, D. (1960). The transport and laboratory culture of snail intermediate hosts o. Schistosoma haematobium. Ann. trop. Med. Parasit., 54, 333.
- De Meillon, B., Frank, G. H., and Allanson, B. R. (1958). Some aspects of snail ecology in South Africa: a preliminary report. Bull. Wld Hlth Org., 18, 771.
- Duke, B. O. L. (1952). On the route of emergence of the cercariae of Schistosoma mansoni fro. Australorbis glabratus. J. Helminth., 26, 133.
- Kendall, S. B. (1953). The life-history of Limnaea truncatula under laboratory conditions. Ibid., 27, 17.
- McCullough, F. S. (1957). The seasonal density of populations of Bulinus (Physopsis) globosus and B. forskalii in natural habitats in Ghana. Ann. trop. Med. Parasit., 51, 235.
- Mandahl-Barth, G. (1960). Intermediate hosts of Schistosoma in Africa. Bull. Wld Hlth Org., 22, 565.
- Roberts, E. W. (1950). Studies on the life-cycle of Fasciola hepatica (Linnaeus) and of its snail host, Limnaea (Galba) truncatula (Müller), in the field and under controlled conditions in the laboratory. Ann. trop. Med. Parasit., 44, 187.
- Smithers, S. R. (1956). On the ecology of schistosome vectors in the Gambia, with evidence of their rôle in transmission. Trans. R. Soc. trop. Med. Hyg., 50, 354.
- Standen, O. D. (1951). Some observations upon the maintenance of Australorbis glabratus in the laboratory. Ann. trop. Med. Parasit., 45, 80.
- Taylor, E. L., and Mozley, A. (1948). A culture method fo. Lymnaea truncatula. Nature, Lond., 161, 894.
- Watson, J. M. (1958). Ecology and distribution of Bulinus truncatus in the Middle East. Bull. Wld Hlth Org., 18, 833.
- Webbe, G. (1962). The transmission of Schistosoma haematobium in an area of Lake Province, Tanganyika. Ibid., 27, 59.
- World Health Organization (1957). Study group on the ecology of intermediate snail hosts of bilharziasis: report. Wld Hlth Org. tech. Rep. Ser., no. 120.
- Wright, C. A. (1959). A note on the distribution of Bulinus senegalensis. W. Afr. med. J., n.s., 8, 142.
- Wright, C. A. (1960). The crowding phenomenon in laboratory colonies of freshwater snails. Ann. trop. Med. Parasit., 54, 224.
- Wright, C. A. (1963). Schistosomiasis in the Western Aden Protectorate. Trans. R. Soc. trop. Med. Hyg., 57, 142.