THE HOUSE-FLY EXHIBITION. 531 



well known ; they are liorse-manure, exci-ement, rotting vegetable- 

 matter sucli as vegetables, compost heaps, rubbish heaps, and the 

 like : manure, excrement, garbage, and fermenting rubbish are the 

 danger sources for house-flies. For blow-flies animal-mattei- is 

 the chief source, even in extremely small amounts : a dead mouse, 

 a hollow bone, a putrifying whelk, a dead sparrow, a scrap of 

 meat, a fish-head, these will all nourish blow-fly maggots : you 

 will be astonished when you see what a small amount is needed 

 and what a number of blow-flies will develop from the scraps in 

 the dust-bin. 



The number of flies this year will depend very largely on the 

 extent to which this mateiial is removed or destroyed, not only 

 by the authorities but by the efforts of every one concerned. 

 Until peof)le at large realize what a danger flies are and what 

 it is that they breed in, we are certain to have quantities of 

 flies ; it is an unpleasant subject that people prefer to leave 

 alone, but there may be enough flies this year to make people 

 Avant to know about them. 



If the breeding-material cannot be disposed of, can it be 

 treated so that it will not breed flies ? Can we treat manure 

 without impairing its value, and can we show how to treat the 

 manure-heap in every gai-den ? We have the available infor- 

 mation collected, and the original papers can be consulted ; so far 

 as is possible inquirers will be advised. 



The second method is to trap, and I show to-night two-American 

 traps, with Mi-. Seth-Smith's improvement, a folding-trap made 

 in the Gardens, and two other pattei'ns of folding-ti-aj) that are 

 being tested. These and any improved ones will be shown, and 

 if any are available the prices etc. stated. Some patterns are for 

 home manufacture, some will, we hope, be available at popular 

 prices. 



We show also a ti-ap that is meant for the household dust-bin, 

 which will catch any flies going to the dust-bin and any that have 

 developed in it and that seek to escape. If a dust-bin of this 

 kind is vised to contain stable-manure it will probably be a very 

 valuable trap for house-flies generally, and the stable become a 

 means of generally i-educing flies in the neighbourhood instead of 

 adding to them. 



The third method is to poison flies, and this has yielded 

 remarkable results abroad. There are harmless liquids for use 

 indoors and poisons for use by skilled persons outside, particularly 

 for hospitals and large institutions. These will be of greater 

 interest to prof-essional men than to the public generally : we 

 have the original accounts of these, and it will be possible for a 

 health ofiicer to read quickly what has been done. 



It may perhaps sound to you as if we knew all about flies, and 

 as if we should be able to solve all the difliculties that will be 

 brought to us — I wish, indeed, it were so. It is astonishing how 

 little practical information there is ; what there is, is largely from 

 America — very little has been done here, and we are very far 

 indeed from havins: the information we need. 



