4 6 



on. White men suffer more severely from malaria than 

 native adults usually do, and therefore demand more active 

 measures against mosquitoes. 



Lastly, it will generally be much more easy and cheap 

 to get rid of mosquitoes in a dry locality than in one in 

 which the ground is water-logged for a considerable part of 

 the year. 



In deciding upon the advisability of inaugurating a 

 campaign against mosquitoes, we must be guided by the 

 following principles : 



(i). The effort should always be made in every town of 

 importance, no matter how great the difficulties ; because 

 we can count at least on greatly reducing the insects, even 

 if we cannot exterminate them completely ; and because, 

 in dealing with a densely populated area, the smallest 

 effort will do good to a large number of people. 



(2). In small towns, villages, plantations, mines, and 

 isolated houses, we must be guided by local conditions. 

 Where there are numerous white men, where the pools are 

 few and easily dealt with, and where sufficient funds are 

 available, a mosquito brigade can be started at once. 

 Where these conditions do not exist it may often be better 

 to adopt other measures against mosquito-borne disease 

 (paragraph 22). 



Finally, I must protest against the idea that it is 

 impossible to reduce the number of mosquitoes anywhere 

 even in the most water-logged locality. Until the ex- 

 periment has been tried not perfunctorily, but adequately 

 and persistently and has failed, we are not entitled to 

 entertain this idea. Indeed, in one of the worst places, 

 Freetown, the experiment is now actually succeeding ; and 

 it is my opinion that there is no place in the world where 



