48 DISCOVERY OF THE TAKASITE OF MALARIA 



of the virus — the comparatively " healtliy reser\'oirs " 

 attracting very Httle attention by the general absence 

 of symptoms and going about their daily avocations 

 much as usual. The people most infected in this way 

 were the indigenous population of the district. There- 

 fore the indigenous population who were reservoirs 

 of disease became the source of infection for the 

 anophelines breeding in the small collections of water 

 close by, and the new-comer arriving in the infected 

 zone very soon found himself struck down by malarial 

 fever as if by magic. Of course he was bitten by the 

 innumerable infected anophelines which had themselves 

 contracted the disease from the almost symptomless but 

 deeply infected native population around. 



The extent of the infection amongst the native 

 or indigenous population is very great, viz. 80-90 per 

 cent. In black populations the black are the reser- 

 voirs. In xVlgeria, Sergent has shown that it is tlie 

 native Arab tribes. With the knoAvledge of the fore- 

 going facts, the lines of defence are clear. 



1. JNIeasures to avoid the reservoirs (man) — Segre- 

 gation. 



2. JNIeasures to avoid the anophelines (choice of 

 locality, screening houses, anti-larval measures). 



3. INleasures to exterminate the anophelines by : 



{a) Use of natural enemies of larvae. 



{b) Use of culicides, oils, etc. 



(r) Drainage, etc. 



{d) Enforcement of penalties. 



{c) Education. 



4. Measures to kill the parasite in the blood of 

 infected man (quinisation). 



