Campaign and Results 297 



of adult Aedes calopus became very small, no more 

 bars were used. At the present time they are 

 unnecessary and are not used by people in the 

 Canal Zone. 



We learned by experience that when mosquito 

 bars must be used, the following precautions shotild 

 be carefully observed. 



1. The bar should be ample in size, and made 

 of dtu-able material of considerable tensile strength. 



2. It should be carefully tucked under the 

 mattress, or if no mattress is used, under three 

 sides of a piece of matting laid on the bed or cot. 

 Just before entering the bed, the interior of the 

 bar should be carefully searched for mosquitoes, 

 and those within destroyed. When a mosquito 

 is hidden within a net, a small electric flash lamp 

 helps to discover it. 



3. Enter the bed quickly, disturbing the bar 

 as little as possible. 



4. Tuck in the bar carefully on the side through 

 which you enter. 



5. Sleep in a wide bed, and cultivate the habit 

 of sleeping quietly in the middle of it. 



We knew that yellow fever would occur at 

 Panania and Colon as soon as the percentage of 

 non-immune population was sufficiently high to 

 favor its propagation. As it was proposed to 



