ABOLITION OF BREEDING PLACES. 19 



in the same way, except where fish are used to kill the early stages 

 of mosquitoes. In out-of-the-way places, however, where it is 

 difiicult to get good screens or where the expense of screening is 

 seriously to be considered, a cheap cover may be made for well- 

 mouths or water barrels, such as described by Button in his Report 

 of the Malaria Expedition to the Gambia, and which he states was 

 devised by Doctor Forde. 



This cover consists of a large iron hoop obtained from discarded barrels, to which 

 is fastened all around a piece of stout calico or sacking free from holes in such a manner 

 that a good deal of sag is left in the material. After water is obtained from the well 

 the hoop is thrown over the mouth, and the calico catching on the rim of the well 

 completely closes the entrance and is kept taut by the weight of the iron hoop. This 

 cover is so simple, and, however carelessly applied, must so effectually close the 

 entrance of the tub against mosquitoes that I think it is well worthy of extensive use 

 in the town. Dr. Forde has lately informed me that these covers are now being 

 made in Bathurst, and are sold to the natives for the sum of four pence.'* 



ABOLITION OF BREEDING PLACES. 



In considering this general question just as in considering so 

 many questions relating to mosquitoes, a complication arises from 

 the enormous mass of facts concerning the life histories of the differ- 

 ent species of mosquitoes; facts discovered, for the most part, in the 

 past three or four years. At the time of the publication of Bulletin 

 25, new series, of this Bureau, the specific habits of but a few mos- 

 quitoes were known and the generalizations drawn from the knowl- 

 edge of these few" species were altogether too broad and must now 

 be greatly modified. There is much diversity in the breeding places 

 of different species. Those of the two commonest household mosqui- 

 toes, namely, Culex pipiens in the North and G. quinquefasciatus and 

 Aedes (Stegomyia) calopus in the South, correspond well to generali- 

 zations formerly named, breeding as these species do in every chance 

 receptacle of water about residences, and their destruction means the 

 abolition of all such receptacles. Where the rain-water barrel or the 

 rain-water tank are necessary they should be screened. In New 

 Orleans and other southern cities the boards of health are now en- 

 forcing, such screening. This should be done with extreme care, a 

 fine mesh wire being used and the fitting being made very perfect. 



About a given house the waste places in the immediate vicinity 

 should be carefully searched for tin cans, bottles, and wooden or tin 

 boxes in which w^ater can accumulate, and all such receptacles should 

 be destroyed or carted away. The roof gutters of the building 

 should be carefully examined to make sure that they are not clogged 

 so as to allow water to accumulate. The chicken pans in the poultry 

 yard, the water troughs for domestic animals, the water cup of the 

 grindstone, are all places in which mosquitoes will breed and in them 



« 8 cents. 



