31 OS QUI TOES IN GENERAL 29 



of European residents, the servants having- conscien- 

 tiously changed the tlowers every morning-, but with a cor- 

 responding- hick of conscientiousness omitted to chang-e 

 the water. I have found them breeding- in an okl tin to- 

 mato-can on the dumps in Washing-ton. Mr. W. P. Seal, 

 of Delair, N. J., Avrites that he finds the larva? of mos- 

 quitoes in rain-filled hollows in apple, maple, and other 

 trees, often at a considerable distance from the ground. 

 Mr. Pratt has found them breeding- in a hollow stump 

 near Bladensburg. Mr. Perg-ande has shown that they 

 breed in the closed sewers in Washington, entering- 

 throug-h the perforated sewer-traps and emerging- through 

 the same holes. Mr. Matheson showed me an old disused 

 well which was covered with a board cover, but on lifting- 

 the cover mosquitoes were found roosting- on the under 

 side in large numbers. There was a crack in the cover 

 sufficiently large to admit them, and they smelled the 

 water below, worked their way throug-h the crack and 

 bred in the old M^ell. They will breed in all water-tanks, 

 and the cover must be absolutely tig-lit, since g-ravid fe- 

 males are so strongly attracted by water that they will 

 work through a crack which seems almost too small to 

 admit their bodies. Dr. John B. Smith says that they 

 are found in New Jersey in great numbers in the pitchers 

 of the pitcher plants of the genus Sarraccnia. 



These statements refer for the most part, if not entirely, 

 to the common mosquitoes of the genus Culex, which we 

 assume to be comparatively harndess from the disease- 

 carrying standpoint, but they indicate plainly that where 

 one's object is to rid a house or a neighborhood of mos- 



