FLY OK THE WING. 39 



is also repleated with a white viscous liquid squeezed out at 

 pleasure to glew herself to the surface." This aid of glutinous 

 secretion, except in a very slight degree, is now denied to the 

 performances of our wonderful climber ; au reste, the notion of 

 our old Philosopher knocked down by the " vacuum," as if by 

 an air gun, seems now set up again. But are we assured, 

 seeing how long mistaken notions will maintain their footing, 

 that, even now, we are perfectly correct about the footing of 

 the Fly? 



A Fly on the wing is a no less curious 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 the back 

 upwards, like a bird, but on occasion, backwards, with the back 

 downwards, as when starting from the window and alighting 

 on the ceiling.* Marvellous velocity is another of its charac- 

 teristics. 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 ?f 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 offerings? But how- 

 ever, with their game, the Flies themselves would be most 



* Mudic. t Kirby and Spence. 



