Aquatic Adaptations of Insect Larvce 281 



In quickly growing animals no larger than injects 

 thesematters are very important; for even a small and 

 transient food supply may serve for the nurture of a 

 brood of larvae. And if the food supply be exhausted 

 in one place, or if other conditions fail there, the adults 

 may_ fly elsewhere to lay their eggs. The facts of 

 dominance would seem to justify this explanation, since 

 those groups that most aboiuid in the world to-day are 

 in general the ones in which metamorphosis is most 

 complete and in which the power of flight is best 

 developed. 



