104 



but survive perhaps for many years. Others again suc- 

 cumb to the first attack. 1 Here we have evidence of 

 individual variation with regard to immunity to malaria. 

 What now happens in the case of the inhabitants of the 

 country ? We find that there is a very high rate of mor- 

 tality from malaria among negro children on the West 

 Coast of Africa. .The mortality among adult natives is com- 

 paratively very small. We have seen that some English 

 people are able to resist malaria, temporarily at any rate, on 

 the West Coast of Africa, but it has been found impossible 

 to rear English children there. Thus apparently there is a 

 greater power of resistance in the adult than in the child 

 both in the English and in the negro inhabitants. There 

 is no reason to suppose that the negroes were more resis- 

 tant to malaria to begin with than white men are now. 

 When first attacked by the disease, individuals varied in 

 their powers of resistance, and the most resistant survived 

 and produced offspring. The offspring inherited the char- 

 acters of their parents with variations. Some varied towards 

 more, some towards less resistance ; the more resistant sur- 

 vived in their turn ; and so on from generation to generation. 

 The process of selection is still going on, and immunity has 

 not been attained by the race. Large numbers of children 

 die ; these have varied in the wrong direction. The mean of 

 the race has been raised, however, with regard to resistance 

 to malaria, for we find that after several generations have 

 lived in another country, the negro still resists malaria better 

 than the white man on the West Coast of Africa. Archdall 

 Reid quotes a letter from an officer, who died of malaria on 

 the West Coast, in which it is stated that when his regiment 

 (West Indian) arrived on the Coast, both the white officers 

 and men suffered greatly from malaria. After a single 

 season, however, the men, West Indian negroes, acquired 

 immunity, whereas the white officers continued to suffer as 

 much as ever. Now as the West Indian negroes originally 

 came largely if not entirely from the West Coast, the con- 



1 Kingsley, Mary, Travels in West Africa, Macmillan. 



