THE TRIBE OF THE SOVEREIGNS 197 



pillar that escapes from the egg shell through a hole in 

 its side. After it has come out it turns around and eats 

 the remainder of the shell. It then begins feeding upon 

 the tender tissue of the leaf it is resting upon, nibbhng 

 at the sides until its appetite is satisfied. Then it retires 

 to the midrib on the lower surface where it remains quietly 

 through the day and thereafter feeds chiefly at night. 

 After about a week it becomes too large for the skin with 

 which it was born, so it moults and immediately devours 

 its cast skin. It continues these operations of feeding 

 and moulting at occasional intervals for several weeks, 

 finally becoming a rather large and curious looking cater- 

 pillar, mottled in greenish olive and light gray, with two 

 large horn-like projections from the front of the body. 



It finally becomes full grown in this larval state. Then 

 it spins a web of silk upon the bark of the twig and en- 

 tangles the hooked claws of its hind legs in the silken web. 

 It thus hangs downward until the larval skin is shuffled 

 off and the curious pupa with the conspicuous hump upon 

 the middle of its back remains in its place. This chrysalis 

 is of a mottled coloring, very similar to that of the cater- 

 pillar. A week or so later the chrysalis skin breaks open, and 

 the butterfly comes out, catching hold of the twig with its 

 legs and hanging quietly in position while its wings 

 expand. 



The butterflies of this brood are likely to appear late in 

 summer. It is the second brood of adult butterflies for 

 the season. These insects have the same leisurely habits 

 as those that were on the wing earlier in the season. In 

 a similar way the mother butterflies lay their eggs on the 

 leaves of willows and poplars, and these eggs soon hatch 

 into young caterpillars that look like those that hatched in 



