2 THE BOOK OF THE FLY 



"Simple Lessons for Home Use," were the kind of 

 cheaper works in touch with a past generation; 

 these latter and other later well-intended publications 

 will now be found to be somewhat deficient or even 

 a little misleading entomologically; they abounded 

 in pious sentimentality and mostly attempted an 

 aggravatingly grandiose literary style, but all have 

 rather failed in teaching practical economic utility, 

 in connection with which nature-knowledge can be 

 rendered as interesting as any other kind of in- 

 structive literature. The tribe of two-winged flies, in 

 particular, has not even yet received a full and adequate 

 study by scientists. A preference has ever been shown 

 towards those other branches of entomology, which 

 may be more interesting to the cabinet-specimen col- 

 lector, but which cannot pretend to have an equal 

 hygienic and economic importance to humanity. 



The presence of the house-fly in our dwellings is 

 often submitted to as an irritating but an inevitable 

 nuisance ; yet very certain remedial measures would 

 almost exterminate the creature, which is a dangerous 

 and filthy peril. To many people it will seem a most 

 incredible exaggeration when told that it is really 

 worse than any one of the less common creatures 

 universally regarded with horror and disgust as pesti- 

 ferous vermin. The surmise may be true that the 

 disgusting body louse carried bacteria, which spread 

 the " black death " ; and, even though the rat's flea 

 has been found to be the carrier transmitting bubonic 

 plague, yet amongst people living now in civilised 

 communities within the temperate zones these parasites 

 cannot be ranked as dangerous equally with the house- 



