Illustrations xiii 



PAGE 



A NOPBELEs Collected in the Grouni) Cracks 

 under the houses ..... 90 



The Relative Positions of Panama, Ancon, 

 corozal, and miraflores • ■ • 95 



Mosquito Trap Attached to a Window 

 Screen 96 



Mosquito Trap (Seen from Inside the 

 House) ....... 96 



Experiment Station : Corozal ... 98 



The Shore of Gatun Lake . . .100 



Map of Gatun: Showing Anopheles Propa- 

 gation Area and Houses where Stained 

 Specimens were Recaptured . . .101 



Floating Islands Blown toward Gatun 

 Lake ....... 102 



Masses of Aquatic Plants and Floating 

 Islands IN Gatun Lake . . . .102 



The Anopheles Breeding Ground near 

 Gatun ....... 106 



A Device for Determining the Flight 

 Direction OF ^ivopHELES . . .108 



Table Showing Number of Anopheles 



Caught IN Houses AT Gatun . . .110 



Staining Anopheles with Aniline Dye to 

 Determine Length OF Flight . .112 



