44 



(2) Excrement should never be deposited in the open without being 

 immediately covered with a thick layer of earth. 



(3) In the low quarters of cities the especial attention of boards of 

 health should be directed toward such open deposits, and such a depo- 

 sition should be consid- 

 ered a punishable mis- 

 demeanor, and the reg- 

 ulation should be vig- 

 orously enforced. Of 

 course, such offenses are 

 generally committed aft- 

 er dark, and it is difficult 

 to trace the offender, but 

 the first responsible per- 

 son who notices it should 

 be required to report it 

 to the police so that it 

 may be removed or cov- 

 ered as soon as possible. 

 Dead animals are so re- 

 ported and cared for. 

 but human excrement is 

 much more dangerous 

 than dead animals. 



(4) Every effort should be made by boards of health in cities and 

 by private persons in the country to limit the breeding of the common 

 house fly. and to accomplish this result a strict supervision of stables 

 in which horses are kept 

 should be carried on. As 

 stated above, the great 

 majority of house flies 

 breed in horse manure. 

 The breeding is rapid, and 

 a small pile of horse man- 

 ure may be responsible for 

 an enormous number of 

 flies. The writer has found 

 by careful experimental 

 work with many different 

 insectieidal substances that 

 chlorid of lime is the most 

 efficient substance which 



can be applied to manure piles in order to destroy the maggots of 

 house fly. but to treat an outdoor manure pile of large size with chlo- 

 rid of lime would be an expensive matter. The writer has suggested, 

 therefore, that some receptacle for the manure from each stable be 



Fig. 24. — ^catophaga f areata (a common excrement fly): Male 

 with closed wings — enlarged (author's illustration). 



Fig. 25. — Man Ilia micans (a common excrement fly ): Broken 

 puparium at right — enlarged (original). 



