104 The Control of Mosquitoes 



On the second evening, directly after the birds 

 arrived and began feeding, several were shot and 

 examined. It was found that they were catching 

 the Anopheles, some of which were found in their 

 throats. These birds are called ' ' night-jars ' ' ; they 

 were feeding between thirty and forty feet above 

 the canal and had not fed at a lower elevation. 



After the flight direction near the canal was 

 ascertained points of observation were selected 

 between it and the settlement, and the direction of 

 flight was noted to be relatively constant. When 

 the winds came in short strong puffs, the Anopheles 

 headed directly into it, but "skidded" sideways 

 and were able to fly for short intervals at right 

 angles to the direction they were facing. Some 

 remained on the wing in a fixed location and as 

 soon as they succeeded in controlling themselves, 

 and conditions were right, dashed off eastward, at 

 right angles to the direction of the wind. This 

 forward flight of Anopheles tarsimaculata and 

 Anopheles albimanus was so decidedly marked 

 that after its discovery by the senior author it was 

 easily noted by many, including those who at 

 flrst scarcely believed it could be true. No one 

 in the entire area so thickly infested noticed the 

 flight direction until instructed how to observe it. 

 It was thought that with thousands of mos- 



