269 



6. Examine especially the conditions where 

 Anophelines, breeding-places, native huts, oppor- 

 tunity for constant importation of malaria and 

 numerous susceptible children exist, and yet there 

 is a complete absence of endemic malaria. In 

 Africa it will probably be impossible to find such 

 places, but they occur in India. 



Endemic Areas of a Country 



The map (p. 253) shews how the endemicity 

 of large areas of a country is a very variable one. 

 When opportunity offers, the endemic index should 

 be determined for each locality, and, as far as 

 possible, all the other facts detailed above. But 

 the simple taking of the blood of a number of 

 children (under ten) in any village gives at once 

 valuable information as to malaria of the district, 

 information which often is quite unsuspected. 

 Thus, as is shewn in the map, the endemic index 

 of Calcutta is o, that is to say, in the immediate 

 environs (not in the town itself) where practically 

 the condition is one of a number of isolated 

 villages, there is no malaria among the native 

 children. At Jalpaiguri the figure is low, twelve 

 per cent., but on reaching the foot of the Hima- 

 layas,we find the extremely high figure seventy-two 

 per cent. In this case we were able among other 

 differences to find a different species of Anopheles, 

 which, as we have seen, is undoubtedly an import- 

 ant factor. 



In other cases, however, all the conditions 

 may be apparently identical, but within a distance 

 of even ten miles we may get a change from an 

 endemic index of o (Madras) to ninety (Ennur). 



