Distribution of Tropical Diseases in Africa. 435 
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in Abyssinia. Small-pox, for which, by the way, inoculation 
is employed, is exceedingly prevalent, as also is syphilis, and 
leprosy is fairly common. The people, too, suffer considerably 
from worms, this being due to their custom of eating raw 
meat. Probably phthisis hardly exists in Abyssinia, and 
diseases of the chest are on the whole infrequently met with. 
In the rainy season typhoid fever, relapsing fever, and 
epidemic influenza are common. The natives also suffer from 
scrofula and leprosy, which is especially prevalent in the 
mountains, and goitre is said to occur. Cholera has fre- 
quently visited the country. Malarial fevers occur in 
Abyssinia, but not to anything like the extent that they do 
in other parts of Africa. There are, however, a considerable 
number of places where malaria is endemic. 
III. EASTERN AFRICA. 
I include in this division of my subject the country 
between Cape Guardafui and latitude 18° N., and the coast 
inland to about longitude 36° E.; also the island of Zanzibar, 
because it really belongs to the east coast of Africa, and 
the conditions which obtain there are practically those which 
are found on the coast. 
In the northern part of this area, between 10° N. lat. and 
the equator, we find the Galla and Somali districts. Little is 
known of them from a climatological and medical point of 
view, but in all probability they have the same characteristics 
as those mentioned when referring to Abyssinia, and these. 
regions are undoubtedly healthier than any on the east 
coast farther south, if we except the highlands between 
Kilimanjaro and Mount Kenia and Victoria Nyanza. 
From the equator to Delagoa Bay there are two seasons— 
the dry season from June till October, the wet one from 
November till May, the greatest rainfall bemg from April 
to June. The amount of rainfall varies in different localities 
from 1500 to 2500 mm. The mean annual temperature is 
about 80° F. at Zanzibar. February is the hottest month, 
with a mean temperature of about 84° F.; July the coolest 
month, with a mean temperature of 77° F. The humidity is 
very marked. 
