484 THE MICROSCOPE. 



Maggots, which afterwards become Flies, and this goes on 

 until the whole brood is destroyed by winter's cold. 



We cannot resist an apt quotation on this interesting 

 little insect : " A fly on the wing is no less curious an 

 object than one on foot; yet, when do we trouble our 

 heads about it, except as a thing which troubles us? The 

 most obvious wonder of its flight is its variety of direction, 

 most usually forwards, with its back upwards like a bird, 

 but on occasions backwards, with its back downwards, as 

 when starting from the window and alighting on the ceiling. 

 Marvellous velocity is another of its characteristics. By 

 fair comparison of sizes, what is the swiftness of a race- 

 horse, clearing his mile a minute, to the speed of the fly 

 cutting through her third of the same distance in the 

 same time 1 ? And what the speed of our steaming giants, 

 the grand puffers of the age, compared with the swiftness 

 of our tiny buzzers ; of whom a monster train, scenting 

 their game afar, may even follow partridges and pheasants 

 on the wings of steam in their last flight as friendly offer- 

 ings ? But, however, with their game the flies themselves 

 would be most in 'keeping' on the atmospheric line, a 

 principal agent in their flight, as well as in that of other 

 insects, being the air. This enters from the breathing- 

 organs of their bodies, in the nerves and muscles of their 

 wings, from which arrangement their velocity depends, not 

 alone on muscular power, but also on the state of the 

 atmosphere. ' How does a fly buzz ? ' is another question 

 more easily asked than answered. * With its wings, to be 

 sure,' hastily replies one of our readers. * With its wings 

 as they vibrate upon the air,' responds another, with a 

 smile, half of contempt, half of complacency, at his own 

 more than common measurement of natural philosophy. 

 But how, then, let us ask, can the great Dragon-fly, and 

 other similar broad-pinioned, rapid-flying insects, cut 

 through the air with silent swiftness, while others go on 

 buzzing when not upon the wing at all? Eennie, who has 

 already put this posing query, himself ascribes the sound 

 partially to air; but to air as it plays on the ( edges of 

 their wings at their origin, as with an Eolian harp-string/ 

 or to the friction of some internal organ on the root of 

 the wing nervures. Lastly, how does the fly feed ? The 



