Habits and Food 85 



than one minute. Four observers were present 

 when these tests were carried out. One of the 

 men was known to be more attractive to mos- 

 quitoes than the others, but when, having started 

 with his arms Uterally covered with Anopheles, he 

 reached the zone of a certain intensity of light not 

 one remained. They fled with a rapidity similar 

 to the movement of people or animals whose eyes 

 had been suddenly hurt. In all cases the light 

 was sufficiently distant to cause no increase in 

 temperature. It is difficult to account for the 

 instance of biting in full sunlight at Gatun (near 

 the breeding place only) as compared with all other 

 cases of absolute repulsion caused by artificial light. 

 Of course it is possible that the Anopheles at 

 Gatun bit us while in the sunlight because other- 

 wise they could never have obtained any blood. 

 Their natural instincts are difficult to determine. 

 In general, they are most ravenous at dusk and 

 soon after daylight. When numerous they bite 

 freely in shady places near the production area 

 and at places distant from it where they rest during 

 the daytime. Many were noted less than a foot 

 above the ground on the leeward side of trees near 

 the breeding area. On one tree forty-three were 

 counted. 



In a similar manner they are found on wire 



