44 
(2) Excrement should neyer 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 coy- 
ered as soon as possible. 
Dead animals are so re- 
Y es 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 
insecticidal 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 
i, 
Fig. 24.—Scatophaga furcata (a common excrement fly): Male, 
with closed wings—enlarged (author’s illustration). 
Fic. 25.—Morellia micans (a common excrement fly): Broken 
puparium at right—enlarged (original). 
