18 Insect Architecture. 



state these appear in a rudimentary condition, at least in 

 such species as have wings in the mature stage of existence. 

 The pupSB are active and eat. Insects, the larvae and pupae 

 of which are so similar to the adults, are termed Ametabolous 

 (a, without, yura/3oXr;, change) ; those the larvae of which 

 undergo changes of a marked character, Metabolous (Insecta 

 ametabola and Insecta metabola, Burmeister). 



Larvae are remarkably small at first, but grow rapidly. 

 The full-grown caterpillar of the goat-moth (Cossus ligni- 

 perda) is thus seventy-two thousand times heavier than when 

 it issues from the egg ; and the maggot of the blow-fly is, in 

 twenty-four hours, one hundred and fifty-five times heavier 

 than at its birth. Some larvae have feet, others are without ; 

 none have wings. They cannot propagate. They feed 

 voraciously on coarse substances; and as they increase in 

 size, which they do very rapidly, they cast their skins three 

 or four times. In defending themselves from injury, and in 

 preparing for their change by the construction of secure 

 abodes, they manifest great ingenuity and mechanical skill. 

 The figures on the preceding page exemplify various forms 

 of insects in this stage of their existence. 



When larvae are full grown, they cast their skins for the 

 last time, undergo a complete change of form, excepting in 



b 



a. Pupa of a Water-Beetle (Hydrophilus') ; b, pupa of Fphinx Ligustri. 



the case of ametabolous larvae, cease to eat, and remain nearly 

 motionless. The inner skin of the larva now becomes con- 



