INSECTS, 



161 



great tropical Moths and Butterflies, some of which expand 

 eight or nine inches, must be vastly more numerous, 

 since the size of the scales does not at all depend on the 

 dimensions of the wing.^Q" Jf ^ tot~r% 



The whole Class of Insects is subject to metamorphosis ; 

 that is, the same individual animal in the course of its 

 progress from infancy to adult age assumes an appearance 

 and form, with organs both external and internal, different 

 at different stages of its life. In none of the Orders are 

 these transformations more remarkable than in that which 

 we are now considering, the elegant Order Lepidopteea, 

 the Butterflies and Moths. 



The parent Butterfly, seeking on restless wing for the 

 plant which shall form a suitable food for her unborn 

 young, at length lays on its leaf an egg, cementing the 

 tiny atom to its surface by a natural glue, which imme- 

 diately hardens. In a few weeks a minute Caterpillar 

 breaks from the prison, and frequently commences exist- 

 ence by devouring with its powerful jaws the horny egg- 

 shell which it has just vacated. But vegetable matter ia 

 its proper diet, and, by the providence of its mother, it 

 finds its habitation cast on a plant which is suitable for 

 its nourishment ; it is like an ox placed in the midst of 

 an unbounded pasture. 



The little worm feeds, and feeds, and feeds, with won- 

 derful voracity : it does nothing else in short, and conse- 

 quently grows with rapidity. It soon finds its skin too 

 strait for it, for this can stretch only to a certain extent, 

 and has no power of actual growth as ours has, and the 

 horny parts, as the head and feet, cannot even expand, 

 being quite rigid. What must be done? It splits its 



