INTRODUCTION 5 



body the ovipositor of the female or the clasping organs of 

 the male. 



Butterfly Transformations 



The butterflies fm-nish the best known examples of in- 

 sect transformations. The change from the egg to the 

 caterpillar or larva, from the caterpillar to the pupa or 

 chrysalis, and from the chrysalis to the butterfly or imago 

 is doubtless the most generally known fact 

 concerning the life histories of insects. It 

 is a typical example of what are called com- 

 plete transformations as distinguished from 

 the manner of growth of grasshoppers, 

 crickets, and many other insects in which 

 the young that hatches from the egg bears Egg of Baltimore 



1 11 . .1 11, !• Butterfly, much 



a general resemblance to the adult and m magnified. (From 



which there is no quiet chrysalis stage 



when the little creatiu'e is unable to eat or to move 



about. 



The Growth of the Caterpillars 



Caterpillars are like snakes in at least one respect: in 

 order to provide for their increase in size they shed their 

 skins. When a caterpillar hatches from the egg it is a 

 tiny creature with a soft skin over most of its body but 

 with rather a firm covering for its head. While we might 

 fancy that there could be a considerable increase in size 

 provided for by the stretching of the soft skin it is easy to 

 see that the hard covering of the head will not admit of 

 this. So the story of the growth of a caterpillar may be 

 told in this way: 



