IX] 



MOSQUITOES AND MALARIA 



139 



establish itself in these novel and, to the genus as a whole, 

 quite unsuitable surroundings. 



Apart from the differences in regard to the ability to flourish 

 in particular kinds of breeding places, are other habits which 

 sometimes influence very considerably the epidemiological 

 conditions under which malaria is spread. Thus many species of 





Fig. 43. Flooded Paddy Fields in Ceylon. The picture shews in the fore- 

 ground the pools formed by the hoof-marks of cattle ; in these Anophelines 

 breed. After Bahr (from the Tropical Diseases Bulletin). 



Anopheles are naturally little addicted to entering or remaining 

 in human habitations, and in nature are not found particu- 

 larly associated with man. Other species readily take up a 

 life of dependence on man and utilize his dwellings as shelter. 

 It is to this latter class that the more important malaria carriers 

 belong. Again, under ordinary circumstances, some species 

 are entirely nocturnal in their habits, whilst others bite freely 



