48 THE INCOMPLETE METAMORPHOSIS. 



full-grown from the egg, as Minerva, according to the 

 ancient myth, sprang, armed cap-a-pie, from the cloven 

 skull of Jove, after that respectable deity had suffered 

 from an intense headache. The metamorphosis in 

 fact consists of a series of moults, during which the 

 development of the organs is gradually progressing; 

 those external organs which impress its peculiar cha- 

 racter upon the mature insect being the last to make 

 their appearance. 



That this is the case is further confirmed by the 

 circumstances presented by another form of the meta- 

 morphosis, called the incomplete metamorphosis, in 

 which the young insect leaves the egg in a form 

 more or less resembling its parent, the principal dif- 

 ference generally consisting only in the presence of 

 wings in the latter, whilst the larva is destitute of 

 those organs. With this exception, in the most typical 

 examples of this mode of change, the young larva 

 possesses exactly the same organs as the perfect in- 

 sect; its essential structure is precisely the same, and 

 the only change that takes place during its progress to 

 maturity, which is accompanied by the usual moult- 

 ings, consists in the gradual approach of the different 

 organs to a state of perfection. 



In this case, as in the complete metamorphosis, the 

 rudimentary wings make their appearance in the last 

 stage of larval existence, and become still more distinct 

 in the state which is called from analogy the pupa, 

 although in this condition the insect is as active and 

 voracious as ever, and never falls into the helpless trance 

 which is characteristic of the pupse of insects with a 

 complete metamorphosis. Besides these insects which 

 undergo a change of greater or less extent before 

 arriving at their mature or reproductive state, we find 



