PREVENTIVE MEASURES 213 



before she lays her eggs, and it is during this period 

 that Hodge proposes to catch her. 



It is interesting to know the way in which the idea 

 came to his mind. In a paper entitled "Extermination 

 of the Typhoid or Filth Fly, a Plan of Campaign," read 

 before the annual meeting of the American Civic Asso- 

 ciation in Washington in December, 19 lo, he shows 

 that for eight years previously he had amused himself 

 in the summer by rearing native birds, especially the 

 ruffed grouse and the bob-white. The enormous quan- 

 tity of insect food required by the young chicks led him 

 to what seemed to him the most effective plan of deal- 

 ing with the fly problem. He needed flies with which 

 to feed his chicks, and the problem was to get flies in 

 the greatest numbers possible. 



Having perfected what seemed to him an excellent 

 method of accomplishing this, he began to argue as 

 to the use of his idea as a substitute for the treatment 

 or removal of the manure pile or the treatment or re- 

 moval of all substances in which flies will breed. Think- 

 ing of the enormous multiplication of the offspring of 

 a single pair in the springtime, he asks the pertinent 

 question, "Why not catch the original pair of flies in 

 April?" After studying the problem for some time, 

 he became so enthusiastic over the prospect that in his 

 address he uses the following sentence: "If, beginning 

 next spring, every family will adopt effective meas- 

 ures to kill the few hundred flies that succeed in sur- 

 viving the winter, I am convinced that we could rele- 

 gate our window screens to the scrap heap, so far 



