34 The Control of Mosquitoes 



volume of rainfall, is the important factor affect- 

 ing Anopheles propagation. 



Table No. 7. — Monthly meteorological data — Colon, Sepublie of Panama, year 39H- 



1 Elevation of barometer 10 feet above si 

 1 Average for 42 years' record. 

 .'Tenths of sky. 



^May. 

 • February. 

 ' October. ^ 



The Isthmus, as may be seen by reference to the 

 map of the Canal Zone, is well supplied with 

 streams and natural watercourses. Some of them 



