334 THE LIFE OF AN INSECT. 



more flattened and shorter. Another beautiful 

 insect, one of the lace-winged flies, exhibits the 

 same singular phenomenon. Its pupa-case is not 

 larger than a small pea, yet the body of the insect 

 is nearly half-an-inch long, and covers, when its 

 wings and antennae are expanded, a surface of 

 an inch square. It appears, in fact, almost in- 

 credible that it could ever have been contained 

 within so small a compass. 



The cases just related may appear to be really 

 exceptions to the rule just laid down, as to the 

 non-increase of insects when once emerged from 

 the pupa ; but upon a little consideration it will 

 be found that the exceptions are more apparent 

 than real. The increase in size is not really 

 a process of growth, but is simply owing to the 

 expansion of the body of the insect to its due 

 size, only taking place in a sudden manner 

 by breathing a certain amount of air. The 

 dragon-fly gives us another instance of a similar 

 enlargement soon after leaving the pupa-case. 



