50 THE HOUSE FLY 



the microbes of various diseases throughout the neighbour- 

 hood. Then again, we find that many people allow piles 

 of refuse of various kinds to accumulate in their back 

 yards ; their fowl-houses are in filthy condition, fowls and 

 other creatures which may die are buried under a few 

 inches of soil, through which flies can burrow and deposit 

 their eggs on the decaying carcases, and in many other 

 ways breeding-beds are provided for the fly to propagate 

 its kind. In a subsequent chapter the means of dealing 

 chemically with manure, &c., will be described. It is a 

 common sight to see flies swarming over various foodstuffs 

 which are exposed for sale in shops. The public can 

 easily remedy this by refusing to purchase goods from 

 shopkeepers who do not carefully screen all edible sub- 

 stances from contamination by flies. Apart from the 

 dangers of infection and possible death by some form of 

 disease microbe, it is the duty of every shopkeeper to 

 prevent flies from depositing their excrement upon his 

 goods. It is by no means a pleasant thought that when 

 you eat a cake, a sweet, a slice of bread, &c., that you 

 are also swallowing the filthy excrement of flies, or some 

 of the foul contents of this loathsome insect's crop which 

 has been regurgitated, and which, as likely as not, consist 

 of pus coughed up by some diseased person, or the excre- 

 ment or vomit of animals. 



