Distribution of Tropical Diseases in Africa, 441 
would be identical with Egyptian chlorosis, which is un- 
doubtedly due to the presence of that worm. 
Yaws or frambeesia is very frequently met with on the 
west coast of Africa, from Senegambia on the north as far 
south as Angola. 
The area of distribution of yellow fever is at present 
limited in Africa to the west coast from 19° N. to a point on 
the mainland opposite Fernando Po. 
Hirsch gives the following chronological survey of yellow 
fever epidemics on the west coast of Africa from 1816 :— 
1816. Sierra’ Leone, Congo 1859. Sierra Leone, Senegambia. 
coast. 1860. Gambia and the Congo 
1823. Sierra Leone. coast as far as Angola. 
1825. Sierra Leone. 1862. Gambia and the Congo 
1829-30. Sierra Leone. coast, Gold Coast, Benin 
1830. Senegambia. coast. 
1837-39. Sierra Leone. 1864. Sierra Leone. 
1837. Senegambia. 1865. Sierra Leone, Congo coast. 
1845-47. Sierra Leone, 1866. Sierra Leone, Senegambia. 
1852. Gold Coast. 1867. Senegambia. 
1857. Gold Coast. 1868. Sierra Leone, Senegambia. 
1858. Senegambia. 1878. Sierra Leone (7), Sene- 
gambia, 
Diphtheria and scarlet fever are unknown, but measles 
occurs from Senegambia to Angola. Diseases of the chest, 
such as bronchitis, pleurisy, and pneumonia, are met with 
all along the coast, but phthisis is extremely rare among the 
natives, although it is of course sometimes seen amongst 
the whites, who have in all probability contracted the 
disease before proceeding to the coast. Leprosy is frequently 
met with both in its anesthetic and tubercular forms in the 
native population on the whole of the West African coast. 
Syphilis and rheumatism, especially the acute form, are also 
extremely prevalent. 
Llephantiasis arabum also occurs with comparative fre- 
quency over the whole coast, being especially prevalent on 
the Gold Coast, where also ainhum is frequently seen. 
Small-pox occurs everywhere, and very severe epidemics 
