GENERATION OF ANIMALS, III. ix. 



correct, for we are bound to reckon caterpillars ** and 

 the product of spiders as a form of larva. True, some 

 of these, and many belonging to other Insects, would 

 appear to resemble eggs on account of their circular 

 shape ; but our decision must not be determined by 

 their shape nor yet by their softness or hardness (the 

 fetations of some of these creatures are hard), but by 

 the fact that the ivhole of the object undergoes change 

 — the animal is formed out of the whole of it and not 

 some part of it.*" All these larva-like objects, when 

 they have advanced and reached their full size, 

 become as it were an e^gg : the shell around them 

 gets hard, and they remain motionless during this 

 period. This is clearly to be seen with the larvae of 

 bees and wasps, and with caterpillars. The reason 

 for this is that their Nature, owing to its own imper- 

 fection, deposits the eggs as it were before their time, 

 which suggests that the larva, while it is yet in 

 gro^^•th, is a soft e^gg. A comparable thing occurs in 

 the case of all other creatures which are formed 

 independently of copulation in wool'^ and other such 

 material and in water. All of these first have the 

 nature of a larva, then they remain motionless once 

 the covering has solidified round them ; after that the 

 covering bursts and there emerges, as from an egg, 

 an animal which, at this its third genesis,** is at last 



produced. Aristotle however calls them larvae, and not eggs, 

 at this stage, because according to him the stage which really 

 corresponds to the egg-stage is not reached until later, when 

 the creature becomes immobilized as a " pupa." 



* The distinction which Aristotle makes here is an import- 

 ant one. See note on 1^-2 a 3-2. 



" See H.A. 557 b 2 ; the dustier your clothes are, the more 

 moths are produced. 



•* The stages are : larva, pupa, imago. 



329 



