Flight and Attraction of Mosquitoes 105 



quitoes traveling from the swamp to the settle- 

 ment each night, an appreciable number might fly 

 beyond the settlement. 



Large numbers passed occupied houses and 

 appeared at more distant ones; but apparently 

 none passed the houses most distant from the 

 breeding area. We remained in the shade in the 

 day and thrashed the bush for a hundred yards 

 beyond the settlement and stayed there at night 

 without securing any specimens. Yet during 

 this period they were present in practically all 

 occupied houses, and particularly numerous in 

 screened houses where the doors were frequently 

 used, as at the hotel, Y. M. C. A. building, bache- 

 lors' and laborers' barracks, etc. ' 



The results of the numerous observations showed 

 that the Anopheles knew where they desired to go; 

 that they traveled in a direct route at practically 

 right angles to a strong breeze, and that large 

 numbers went forward between 6.30 and 7.00 p.m. 

 daily. It was not ascertained whether any of them 

 made more than one forward trip to the feeding 

 ground. It may be that several trips were taken, 

 but had none returned the thousands passing out 

 daily were sufficient to continue the influx at the 

 settlement. 



' See map opposite p. loi. 



