26 The Control of Mosquitoes 



factor in the anti-malaria campaign. Algae that 

 protected the larvse from their natural enemies 

 was often found and appeared to develop in a 

 few day's time. It was evident that work would 

 have to be done on an extensive scale and that 

 the climatic conditions would make the campaign 

 a strenuous one. One apparently discouraging 

 feature was the frequent occurrence of showers that 

 removed oil applied to breeding areas before it 

 could accomplish its purpose. 



