22 The Control of Mosquitoes 



quito bit them, or tried to, it was captured and 

 placed in a pill-box and the date and hour written 

 on the box. It was found at that time that 

 Anopheles in the ward attacked men at rest at all 

 hours of the day, and at night they became too 

 numerous to make the work pleasant. It was 

 noticed that they did not bite as freely near the 

 doorway, where there was more light during the 

 daytime, and that they absolutely refused to fol- 

 low a man out into the bright rays of the sun. 



Before anti-malaria work was begun, a prelim- 

 inary survey was made and Anopheles production 

 areas were found near every existing settlement, 

 as well as all abandoned camps that had been 

 used by the French. The greater part of these 

 areas was covered with dense jungle, and their 

 extent could not be at once determined. There 

 were numerous seepage outcrops and their out- 

 put varied according to the rainfall; and prob- 

 ably the contour line of seepage varied also. 

 The character of the soU. was often such as to 

 retain the rainfall for relatively long periods, and 

 innumerable small depressions existed, which 

 might produce mature pupas or not according 

 to weather conditions. The survey showed that 

 it would be necessary to clear off large areas of 

 jungle near settlements before any effective results 



