66 THE BOOK OF THE FLY 



meat, which is exceptionally attractive to the house- 

 fly and the blue-bottle, is fortunately, after cooking, not 

 so dangerous as some of those other deleterious micro- 

 organisms mentioned in the last chapter. Taking one 

 thing with another the balance of benefits and dis- 

 advantages will incline overwhelmingly in favour of 

 open dust-bins, wherein food remnants may purposely 

 become fly-blown. An improved dust-bin lid has been 

 contrived which combines with the cover a centrally 

 held wire-gauze " balloon" fly-trap, wherein flies will 

 congregate and be imprisoned when attempting to 

 leave. 



Unfortunately air-tight dust-bins have been very 

 generally recommended as a giand device of hygienic 

 value ; hence it is most necessary that unthinking people 

 at large should be informed how much better it is to use 

 open bins which can catch and secure for destruction 

 prospective fly-broods. It may be asked why not 

 trap and kill the breeding females ? The reply is that 

 to do so will be good, as is to be explained in the next 

 chapter ; but contrivances for the latter procedure are 

 apt to be less effectively put into general operation. 



The fly swarms of mews, arising from accumulations 

 of stable manure, will be difficult to alleviate without 

 stringently enforced measures, but it is a mistaken 

 notion to believe that town flies are bred in stables to 

 such an extent that the invaders of our dwellings and 

 town restaurants, shops, and markets, are merely or 

 mainly the overflow of the mews. The concentration 

 of many kinds of flies is very dense around ill-kept 

 mews, and in midsummer-time a large percentage will 

 be true house-flies. Frequent removal and cremation 



