Campaign and Results 305 



was collected, and rain water barrels were not 

 allowed to exist. Of course this prevented the 

 continuance of breeding places favorable to mos- 

 quito development, and has been an important 

 factor in keeping yellow fever out of Panama. 

 Attention is invited to the fact that the city of 

 Havana had an excellent source of water supply, 

 and nearly all the houses in its yellow fever dis- 

 trict had water taps in houses and yards long 

 before the first American occupation. But a 

 water supply alone, or even one supplemented 

 by a proper sewer system, is not sufficient to 

 control yellow fever or Aedes calopus propagation. 

 In Havana, there was as much mosquito propaga- 

 tion in houses occupied by Americans as in those 

 occupied by natives. Systematic inspection by 

 capable and energetic inspectors, working under 

 a health officer especially trained for this work, is 

 essential for yellow fever control. 



