202 BUTTERFLIES 



silk. The larva, having completed its work, composes 

 itself for the winter with the hind end toward the orifice. 

 Here it remains till the catkins are in bloom the next spring 

 when it retreats from its house and commences feeding. 

 Not the least wonderful part of this phenomenon is that 

 it is only the autumnal brood of larvae that form pitcher- 

 like houses to live in during the inclement season of the 

 year — the summer brood having no occasion to shelter 

 themselves from cold." It is an interesting fact that in 

 most northern regions these winter cases are nearly always 

 made so near the ground that they are protected by snow 

 during most of the winter. 



When an insect has such a curious habit as that of mak- 

 ing these winter cases it seems comparatively easy to ex- 

 plain it as an acquired instinct brought about through the 

 conditions of life during the long period in which successive 

 generations have been laid. But, as Doctor Riley seems to 

 suggest above, it is much more diflScult to explain this sort 

 of phenomenon when it occurs only in one of two or more 

 broods during the season. 



The Banded Purple 



Basilarchia arthemis 



None of our common butterflies shows more striking 

 color markings than the Banded Purple. A broad white 

 stripe runs midway through the wings on both surfaces, 

 the white making a strong contrast to the purplish or 

 brownish black of the rest of the wings. This white band 

 is supplemented by rows of fulvous and of blue dots, 

 especially on both surfaces of the hind wings. {See plate » 

 page 203.) 



