572 HOWARD 



isolated, and the insects bred from it were all carefully mounted, 

 preserved, and studied. At the same time the insects visiting 

 the excrement in the field were noticed and many of them cap- 

 tured. As a result of such methods, the following facts con- 

 cerning the house fly are recorded : 



In the first place specimens of this species were collected in 

 an outdoor privy at Falls Church, Virginia, in July, and a 

 month later in a privy in Alexandria. 



July 7, a child's faeces were exposed 48 hours in a woodshed, 

 under cover, about six feet from a fly-infested kitchen in north- 

 east Washington. Ten days later 22 specimens of Miisca do- 

 mestica were reared from this excrement, which in the mean- 

 time had been kept under cover. Certain other dipterous 

 insects were also reared, which are referred to elsewhere. 



On July 9, a large quantity of rather loose f^ces of a child 

 was exposed in the same way 48 hours in the same woodshed 

 and afterward isolated. Nine days later two house flies issued, 

 and others continued to issue during the next nine days until a 

 total of 97 house flies and other dipterous insects had issued 

 from the lot. 



On July 24, child's fasces were exposed in the same way at 

 the same place for three days, and 11 days later two house flies 

 issued; 31 in all making their appearance during the following 

 five days. 



July 26, fgeces of a child were exposed in a fly-infested kitchen 

 for two hours, and were placed in a jar to breed. Ten days 

 later ten house flies issued. 



On June 7, a stool was found on the Department grounds, and 

 when brought to the office insectary and placed upon one of the 

 benches, house flies were attracted to it and walked all over it. 

 They did not, however, deposit. 



June 26, a similar experiment with a similar result. 



June 24, a child's fasces were found on a floor in south Wash- 

 ington and were left exposed about four days. On the third 

 day dipterous larvas were seen crawling in it, July i, pupae 

 were observed. July 3 and 4, four small specimens of Musca 

 domes tica issued. 



July 2, specimens were captured upon faeces at Twining 

 City, Maryland. 



