on Mosquito Extermination. 23 



left by branches decaying from the sides and trunks of trees, 

 in the crotches of trees, in water tanks in the greenhouses, and 

 even in a well, the water of which was no feet below the 

 surface and at a temperature of 56, while the air temperature 

 w^as 80. The cisterns we filled up and put out of use. The 

 gutters we leveled so that they pitched to the leaders without 

 interruption. The cattle hoof-prints we filled with earth, the 

 tree holes we filled with earth, and latterly with cement. The 

 salt water meadows we ditched and filled so that there were 

 no pools or spots that were not reached and drained by every 

 rising and flowing tide. The wells we screened. The green- 

 house water tanks we stocked with gold fish. The springs 

 on the hillsides we sub-drained with porous tile. The boxes 

 we broke up. Tin cans and bottles we buried. During the 

 first season, after taking most of these precautions, we still 

 had some mosquitoes, and Dr. Howard, who kindly came from 

 Washington and looked over the situation, identified them as 

 the brackish water mosquito (Culex Sollicitans), which we 

 thought we could trace to a large salt water marsh on Centre 

 Island, across the bay one mile west of us. Thither we w^ent 

 and succeeded in interesting in the movement there the two 

 most enterprising and public-spirited of its residents — Colgate 

 Hoyt and C. W. Wetmore. The movement has been ex- 

 tended and successfully carried on by such intelligent and 

 public-spirited men as Paul D. Cravath and other members 

 of the North Shore Improvement Association in a thoroughly 

 organized v-ay. 



As the result of numerous experiments that have been made 

 under the direction of the North Shore Improvement Asso- 

 ciation during the past four years, it has been pretty thoroughly 

 demonstrated that, wdth the exception of the Culex Sollicitans, 

 the flight of the mosquito is very limited, perhaps to a few 

 hundred yards at the most, and the nuisance can be controlled 

 and abated in almost any locality where intelligent co-operation 

 can be secured and a systematic inspection made of the 

 premises for the purpose of destroying the breeding places. 

 Extermination can, in my opinion, exterminate just as far as 

 the intelligent landowner is willing to carry it. It cannot be 

 done once and for all any more than weeding a garden or 

 the cropping of a lawn can be done once and for all. 



So far as my experience goes, it has been demonstrated 



