ADULT STAGE OF LIFE. 97 



For a few hours after its emergence, it is usually 

 somewhat moist, the wings being unexpanded, and, as 

 it were, crumpled up, and the body not so distinct in 

 its outline as it afterwards becomes. In some beetles 

 also, such as ladybirds, the colours are pale, and the 

 first pair of wings, which form the wing cases, are soft, 

 and of a pale uniform colour, without the spot after- 

 wards seen on them. 



It is now that the air tubes distributed through the 

 body, and particularly through the wings, perform 

 the important office of inflation ; and if a main wing- 

 rib be then cut across near the root, the part of the 

 wing to which it goes ever after remains shrivelled. 



Those who are little acquainted with insects, are 

 exceedingly apt to think they grow like other ani- 

 mals, and from this cause commit many mistakes, not 

 perhaps of great moment, but which it may be proper 

 to rectify by examples. The most common British 

 butterflies are those which are white, and all are 

 usually looked upon as of the same species, differing 

 in nothing, except, perhaps, in the size, the latter be- 

 ing erroneously ascribed to difference of age. But the 

 fact is, that there are a considerable number of species 

 of our white butterflies, and probably more varieties 

 even of these than have yet been ascertained or de- 

 scribed. It is certain indeed that butterflies do not, 

 like the larger animals, increase in size as they grow 

 older ; for every individual, from the moment it be- 

 comes a butterfly, continues invariably of the same 

 size until its death. Butterflies, indeed, seldom live 

 longer than a few days, or, at most, a few weeks, and 

 during this time they eat nothing except a sip of 

 honey : and since this is so, it would be absurd to 

 expect that they could increase in size. It must not 

 however, be understood from this, that the same species 

 will always measure or w T eigh precisely the same; for 

 though this will hold as a general rule, there are many 

 exceptions, arising from the accidents the caterpillar 



