TEACH THE CHILDREN 97 



public to realise the importance of mosquitos as carriers 

 of disease, and to grasp the fact that malaria and yellow 

 fever can be prevented. Now, governments, munici- 

 palities, and local authorities are beginning to institute 

 mosquito-reduction in many countries and in many 

 places. It is to be hoped that fly-reduction will begin 

 soon, but experience teaches that a generation must 

 pass before the world learns the lessons which science, 

 by its constant discoveries, teaches. 



At San Antonio, Texas, a competition has been 

 started among 10,000 school-children to find out and 

 to report the mosquito-breeding places in that locality, 

 and, as a result, these insects have been greatly reduced 

 in numbers, and now malaria has disappeared. Here 

 is an excellent result. In England, the Boy Scouts 

 could be usefully employed similarly by making them 

 find out and report the fly-lairs. It would be great 

 work if fly-borne disease disappeared from Great 

 Britain. 



As in the case of mosquitos, however, it is not 

 possible to exterminate flies absolutely from any given 

 town or district. They can be reduced in numbers, 

 but not actually abolished. But they can be reduced 

 to a negligible quantity, and then the diseases carried 

 by them will disappear, as has happened at San Antonio. 

 Therefore it is necessary to persevere and to maintain 

 the fly-campaign indefinitely. It is of little use to 

 start a campaign against flies, to reduce their numbers, 

 and then to become disheartened, and allow the cam- 

 paign to lapse. Such a proceeding will bring the 

 crusade into disrepute. The fly-campaign, once started, 

 must always be kept up unflaggingly. 



Caution must be exercised in drawing hasty con- 

 clusions concerning the effects of fly-reduction. Beware 



