162 BUTTERFLIES 



process. It now migrates to another larger, expanded 

 leaf where it very cleverly proceeds to construct its second 

 nest. In order to do this it weakens the midrib at the 

 base of the leaf by biting nearly through it. Then it cuts 

 a hole in the blade of the leaf at the base in such a way that 

 the margins are made to droop, so that they can be fast- 

 ened together with silk to form a little tent. We thus 

 have a tent-like nest hanging down from the stem of the 

 leaf on the under side of which the caterpillar ' will find 

 shelter, while near at hand is the green tissue of the inner 

 surface of the leaf waiting to be eaten. This improvised 

 tent serves as the home during this second stage of the 

 caterpillar. Here also the second moult commonly takes 

 place, after which the caterpillar migrates to a new leaf 

 and constructs its third nest. The rest of the story of 

 the caterpillar's life consists of similar chapters. After 

 each moult a new tent is formed and even the chrysalis is 

 often hung within the last one. 



The eggs which were laid late in May develop into 

 butterflies during July. These in turn lay eggs for the 

 second brood of caterpillars most of which develop into 

 butterflies late in August or early in September, but 

 some of which apparently remain in the chrysalis stage 

 imchanged throughout the winter, and mature as butter- 

 flies about the middle of the following May. This is the 

 explanation of the fact mentioned at the beginning of this 

 discussion that one can find late in spring and early in 

 summer some butterflies which seem worn and frayed 

 while others seem peifectly fresh. They are all the 

 progeny of the midsummer brood of the previous summer, 

 but some of them have been living as full-grown butterflies 

 through eight long months of tempestuous weather, while 



