Geographical Distribution.—East Africa: Nile Valley, Red Sea Coast, Zanzibar, Portuguese East Africa, Delagoa Bay, Natal, Port Elizabeth.
South Africa: Cape Colony, Orange Free State, Transvaal, Mauritius, Bourbon, Madagascar.
West Africa: Angola, Cameroons, Gold Coast, Gambia, Senegal, Sierra Leone, Lagos, Nigeria.
North Africa: Tripoli, Tunis, Algeria, parts of the Sahara.
Central Africa: Sudan, various portions. Uganda, Nyasaland.
It occurs with varying frequency in these regions. It is probably more widely spread than this list implies, as undoubtedly many cases are seen which are not recorded.
Isolated cases have been recorded from Arabia, India,[275] Greece, Cyprus.
Fig. 175.—Ovum of Schistosoma hæmatobium, Bilh., with miracidium, which has turned its anterior end towards the posterior end of the egg. 275/1. (After Looss.)