TWO-WINGED FLIES. 229 



The superstitions associated with flies are now very 

 much things of the past, yet a few of them still linger 

 in rural districts, such as when flies bite more perti- 

 naciously than usual, it forebodes rain or wet weather. 

 If flies die in great numbers in a house, it is a sure 

 sign of death to some of the family. To dream of 

 flies denotes enemies of all sorts. If a fly falls into 

 a glass from which one is about to drink, it is a sure 

 omen of good luck. 



Many people speak of the House-fly and the Gnat 

 as if there were but two species of these insects 

 common to our habitations, whereas, as an excellent 

 naturalist observes, there are at least fifty, perhaps a 

 hundred, different sorts of gnats and flies -which 

 annually visit our apartments ; that is, regular domes- 

 tics, for, if casual visitors be included, the numbers 

 would be quadrupled. 



The economy of all the flies of the House-fly 

 type is very similar : they lay eggs in dunghills, 

 amongst putrefying vegetables, and in other places, 

 from which are hatched minute maggots of a yel- 

 lowish-white colour, and these feed and grow until 

 they attain maturity. When full-fed the larvae lie 

 dormant a few hours, during which time the skin 

 hardens until it becomes a horny case, darkening to 

 a chestnut brown, and within this transformation to 

 the perfect insect takes place. At length the fly 

 creeps out of its case by means of a lid- covered 

 opening at one end, and is then as large as at any 

 subsequent period of its existence. The abdomen is 

 often larger than afterwards, for it is distended with 

 fluid, which ultimately is discharged. When the fly 



