62 ON THE ORIGIN AND [CHAP 



CHAPTER IV. 

 ON THE ORIGIN OF METAMORPHOSES. 



THE question still remains, Why do insects pass 

 through metamorphoses ? Messrs. Kirby and Spence 

 tell us they " can only answer that such is the will of 

 the Creator ; " 1 this, however, is a general confession 

 of faith, not an explanation of metamorphoses. 

 So indeed they themselves appear to have felt ; for 

 they immediately proceed to make a suggestion. 

 "Yet one reason," they say, " for this conformation 

 may be hazarded. A very important part assigned 

 to insects in the economy of nature, as we shall here- 

 after show, is that of speedily removing superabundant 

 and decaying animal and vegetable matter. For such 

 agents an insatiable voracity is an indispensable 

 qualification, and not less so unusual powers of multi- 

 plication. But these faculties are in a great degree 

 incompatible ; an insect occupied in the work of 

 reproduction could not continue its voracious feeding. 

 Its life, therefore, after leaving the egg, is divided into 

 three stages." 



But there are some insects as, for instance, the 



1 Introduction to Etymology, 6th ed. vol. I. p. 61. 



