Results 223 



but Isthmian observations show several instances 

 to the contrary. Where Anopheles tarsimaculata 

 and Anopheles alhimanus traveled long distances 

 from the breeding to the feeding grounds their 

 number at the settlements greatly increased, but 

 the malaria rate did not rise. It is of great 

 importance to know if these facts hold true in 

 regard to other malaria-conveying species, as such 

 facts determine the right areas for malaria control 

 operations. 



Due to factors not fully ascertained the same 

 species do not always fly long distances, or even 

 a quarter of a mile, to reach a house or village. 

 Since learning how to observe and follow a flight 

 we can now decide correctly which location to 

 drain or treat for the protection of a town or 

 settlement, and leave out the unessential. 



The varying distance of mosquito flights of 

 which so much, assumed and untrue, has been said 

 and written, no longer appears impossible to 

 solve. At present the important point to decide 

 is the length of flight of different species of Anoph- 

 eles iti so far as it affects malaria transmission, 

 and this may differ from the flight length probably 

 essential for the propagation of the species. 



The decidedly brackish marshes and the edges 

 of shallow tidal flats, which were once the chief 



