332 THE LIFE OF AN INSECT. 



told by ignorant people that the little house-flies 

 which we watch dancing in our chambers, or 

 scrambling up our windows, are only young flies 

 of the same kind as flesh-flies, and that by-and-by 

 they will grow into a large " Blue-bottle!" This is 

 a sad mistake. Let the reader try. Let a fly be 

 put under a glass, and fed with a little sugar, or 

 honey: in vain will he daily examine it, in the 

 expectation of beholding it increase in size it will 

 live and die nearly the same little being unaltered 

 to the last. If such persons only knew somewhat 

 of the life of an insect, such an absurd, and, unfor- 

 tunately, very prevalent mistake would not be com- 

 mitted. We might as reasonably call a trout a 

 young salmon ! If we were to examine any number 

 of flies of the house-fly kind, (Musca domestica,) and 

 carefully measure them, or weigh them, we should 

 find them all almost exactly of the same size ; 

 which, of course would not be the case if they 

 really grew larger as they grew older. 



But there are some insects which, after they 

 leave their pupa, increase within a very short time 

 to a size which could scarcely be believed. In 

 particular, the new-born insects of a tribe of flies 

 which produce the aphis-lion larva before spoken 



