Smithsonian Report. 1931. — Matheson 



PLATE 5 



1. A ])(i(il with a dense bottom covering of Chara fragilis. Along the margins and about the 

 partiallysubmergedlogs wouldseem to beideal places for mosquito breeding. No mosquito 

 breeding has been found here for the past six years 



.V series of wooden tubs sunk in the ground (o test theell'ect of t'harn frdyilis under out-door 

 conditions. Some of these tubs are use<l as controls 



