METAMORPHOSES OF INSECTS. 43 



bigness." The colorings peculiar to each species also be- 

 come defined and perfect as the wings expand. 



111. The means employed to effect a change so wonder- 

 ful with respect to the wings, and in so short a time, has 

 not been left unexplained. 



112. The wings of the young butterfly, how expanded. 

 The wings of butterflies are composed of two fine mem- 

 branes between which are little veins or ribs resembling 

 those of the leaves of some plants. These may be seen 

 by the naked eye, when the scales, or dust which colors 

 the wings is rubbed off, and are called nervures. They 

 are hollow tubes, having a communication at the insertion 

 of the wing with the body of the insect. Into these, the 

 young butterfly forces a quantity of air, and perhaps also a 

 fluid, and by the distention of which, the folds and wrinkles 

 of the soft and wet wings are in a few moments oblitera- 

 ted. The nervures, and also the fully-developed wings, are 

 shown by Fig. 35. 



Fig. 35. 



113. These when compared with Fig. 34, will show the 

 change produced by the means above described in " half a 

 quarter of an hour," and at the sight of which, Swammar- 

 dam could not help exclaiming, " O ! miracle of miracles !" 

 The whole process, indeed, from the hatching of the egg, 

 to the perfection of the butterfly, though not a miracle, 

 because the whole is in the ordinary course of nature, 

 must ever be considered among the most wonderful se- 



In what manner does the butterfly make its escape from the chrysalis ? 

 Is the insect perfect when thus disengaged ? In what manner are the new 

 wings of the butterfly unfolded and distended ? 



