HOUSE-FLIES IN HISTORY 3 



Probably the public does not realise that several of 

 the maladies which afflict human beings can be pre- 

 vented, and that prevention is better than cure and, 

 indeed, is often cheaper and easier. 



The prevention of disease is a matter which concerns 

 established authority, and it is to those in authority that 

 appeal should be directed. But some years' experience 

 of public-health work in various parts of the world has 

 resulted in learning the lesson that established authority 

 will not move it will not even interest itself unless it 

 is pushed by the weight of public opinion. A repre- 

 sentative organisation municipality, town or parish 

 council, local committee, etc. will rarely consider a new 

 measure, even if it is for the preservation of public 

 health, unless its members think that such a measure 

 will be popular in one or other section of the com- 

 munity which it represents ; and no measure can be 

 justly popular until it is generally understood. 



It is intended, then, to describe the nature of the 

 insect known as the house-fly its life, its danger to 

 human beings, and the part it plays in causing sickness, 

 death, and misery ; and to show how this pest may be 

 best reduced in its numbers, so that its dangerous 

 influence may be lessened. 



House-flies have taken their place in the general 

 evolution of living matter. Fossils of them appear first 

 probably in the Tertiary rocks, though many fossil 

 insects have been found in the earlier strata, known as 

 the Devonian; the remains of flies have been often 

 found also in the fossil resins known as amber. Now, 

 the common house-fly is almost ubiquitous ; it is en- 

 countered and endured in almost every country in the 

 world, and is met with in both the Arctic and Antarctic 

 circles. 



