THE HOUSE FLY. 15 



they will often leave the manure and pupate in the ground below 

 or crawl some distance away to pupate in debris under boards or 

 stones and the like. Hence the manure should be removed before 

 the larvae reach the migratory stage; that is to say, removal is neces- 

 sary every three days, and certainly not less frequently than twice 

 a week during the summer months. A series of orders issued in 

 1906 by the health department of the District of Columbia, on the 

 authority of the Commissioners of the District, covers most of these 

 points, and these orders, which may well serve as a model to other 

 communities desiring to undertake similar measures, may be briefly 

 condensed as follows: 



HEALTH OFFICE REGULATIONS FOR CONTROL OF HOUSE FLIES IN CITIES. 



All stalls in which animals are kept shall have the surface of the ground covered 

 with a water-tight floor. Every person occupying a building where domestic animals 

 are kept shall maintain in connection therewith a bin or pit for the reception of manure 

 and, pending the removal from the premises of the manure from the animal or animals, 

 shall place such manure in said bin or pit. This bin shall be so constructed as to 

 exclude rain water and shall in all other respects be water-tight, except as it may be 

 connected with the public sewer. It shall be provided with a suitable cover 

 and constructed so as to prevent the ingress and egress of flies. No person owning 

 a stable shall keep any manure or permit any manure to be kept in or upon 

 any portion of the premises other than the bin or pit described, nor shall he 

 allow any such bin or pit to be overfilled or needlessly uncovered. Horse manure 

 may be kept tightly rammed into well-covered barrels for the purpose of removal 

 in such barrels. Every person keeping manure in the more densely populated 

 parts of the District shall cause all such manure to be removed from the premises 

 at least twice every week between June 1 and October 31, and at least once 

 every week between November 1 and May 31 of the following year. No person 

 shall remove or transport any manure over any public highway in any of the 

 more densely populated parts of the District except in a tight vehicle, which, if not 

 inclosed, must be effectually covered with canvas, so as to prevent the manure from 

 being dropped. No person shall deposit manure removed from the bins or pits within 

 any of the more densely populated parts of the District without a permit from the 

 health officer. Any person violating any of the provisions shall, upon conviction 

 thereof, be punished by a fine of not more than $40 for each offense. 



Not only must horse stables be cared for, but chicken yards, pig- 

 geries, and garbage receptacles as well. In cities, with better methods 

 of disposal of garbage and with the lessening of the number of horses 

 and horse stables consequent upon electric street railways, bicycles, 

 and automobiles, the time may come, and before very long, when 

 window screens may be discarded. 



DISPOSAL OF MANURE IN RURAL AND SUBURBAN DISTRICTS. 



The control of flies in rural and suburban districts offers a much 

 more difficult problem. Here it is out of the question to remove all 

 manure from the premises twice a week. The problem is rather to 

 find some method of disposal or storage which will conserve the 

 fertilizing value of the manure and at the same time prevent all flies 

 from breeding or destroy such as do breed there. 



