LIFE HISTORY AND SEASONAL PREVALENCE 141 



and water of a character suitable to their needs is nowhere 

 available, so that it is certain, that though nowhere in 

 evidence, they must undoubtedly exist somewhere in hiding ; 

 and though I cannot say I have actually traced them to 

 their lairs, the unhmited accommodation for secreting them- 

 selves afforded by the structural imperfections of an Indian 

 house make this in no way astonishing, and the same is the 

 case in the cold season with Anopheles, which appear to 

 have vanished from the earth, so well are their hiding places 

 chosen. 



During the cold weather, of the twenty or thirty members 

 of the family that form the gnat family of the North-west 

 Provinces, the imagines of but two, with their larvae, and 

 the latter stage of a couple or so more, are alone to be found ; 

 and one of the former, I believe, also disappears into seclusion 

 when the fierce heat of the dry season commences, leaving 

 C. fatigans as the only adult Mosquito in evidence. Now, 

 as the insects are in no sense migratory, it is an obvious 

 conclusion that a sufficient number of adults, either 

 impregnated females only, or representatives of both sexes, 

 to maintain the breed, must be lying by somewhere. In 

 countries such as England, where buildings are carefully 

 finished and their ceilings fairly accessible, it is generally 

 possible to obtain living gnats at any period of the year, 

 provided one knows the kind of situations wherein to search 

 for them ; but in India, the ample space between the ceiling 

 cloth and the thatched roof, and the innumerable gaping 

 fissures in the rough mud plaster, that is all that covers the 

 carelessly laid bricks leave so many crannies and corners, 

 that it is by no means surprising that one may fail to un- 

 earth the insects from their hiding places without pretty 

 well pulling down the house, an operation by no means 

 unattended with risk, as one is apt to disturb other skulkers 

 of a larger and more immediately dangerous character. 



This habit is spoken of as hybernation, and in Northern 

 Europe, where the males apparently all die before winter has 

 fairly set in, only impregnated females survive the winter, and 

 it is through their agency alone that the continuity of the 

 species is maintained. In more moderate climates, where 



