ANOPHELES AND MAN" 207 



abdomen filled with a fatty mass, but in the early spring the fatty mass had 

 disappeared. In cellars and in attics they remain motionless on the walls, 

 or under shelves in pantries. Professor Hodge, of Worcester, Massachusetts, 

 has found them resting under such pantry shelves in winter literally by thou- 

 sands. This points out the great desirability of cellar fumigation in winter in 

 malarial regions, as will be shown under the head of remedies. In Washington, 

 adults often appear in houses during the winter when stimulated by high tem- 

 perature. Under such circumstances they have been Imown to bite even in mid- 

 winter, although it would seem that it is only a small proportion of the hiber- 

 nating individuals that become active. Giles has found that in the colder 

 portions of northern India, Anopheles hibernate, and he points out that they 

 pass the intense dry heat of the early summer in much the same condition. 

 Grassi found that Anopheles can not witlistand the same amount of desiccating 

 heat as other mosquitoes. Stephens and Christophers state that in India the 

 Anopheles pass the hot, dry season in houses, and although they feed at intervals 

 they will not lay eggs even if artificial breeding-places become available. James 

 and Liston, in India, found eggs, young larvas, and pupaB of two species during 

 the winter in newly made breeding-places and another species was able to hiber- 

 nate in the larval condition. Giles on the other hand shows that in many locali- 

 ties in India Anopheles may be found in all stages practically every month in 

 the year, decreasing in numbers in the hot weather and increasing in the rainy 

 season, the determining factor undoubtedly being the moisture conditions. 

 Hibernating larvaB have been found in Italy and Galli-Yalerio and Eochaz de 

 Jongh have demonstrated that the larvae of Anopheles hifurcatus hibernate 

 normally in Switzerland. 



FEEDING HABITS OF ANOPHELES. 



The feeding habits of the female Anopheles have an important bearing on 

 the malarial relations of these mosquitoes. It has already been pointed out that 

 certain species of Anopheles occur more or less in association with man and these 

 species are the important malaria carriers. Other species show, at least, no 

 preference for man. Thus, for example, Jennings has observed that, in Panama, 

 Anopheles eiseni is the abundant species in regions uninhabited by man, while 

 A. alhimanus, which is the chief malarial agent in the American tropics, is 

 absent from such localities. The Anopheles found in localities uninhabited by 

 man must have recourse to other animals to procure blood. Schiiffner asserts 

 that a species of Anopheles found by him in Sumatra could not be induced to 

 suck blood. On the other hand, he remarks on the extreme voracity of another 

 species, and this last species proved to be instrumental in the transmission of 

 malaria. " When the animals have an empty stomach it is sufficient, in order to 

 feed them, to put the hand into the cage. Instantly this is covered with them, 

 and one feels, from the slight burning sensation which follows immediately, how 

 rapidly they can sting. When they have once begun to suck they do not easily 

 allow themselves to be disturbed ; one can touch and shake them without succeed- 

 ing in driving them away. Therefore there is no trouble in capturing them while 



