THE QUEER CASES ON THE WILLOW TWIGS. 39 



pillars thus resting on its case is represented in Fig. 35. 



The caterpillars feed most freely after dark, when they are 

 not afraid of being seen by birds. They then leave their 

 resting-places and crawl to the neighboring leaves. 



During May the caterpillars become full-grown, when they 

 look like Fig. 36. They then change to mottled brown and 

 gray chrysalids, first fastening themselves to the branches of 

 the willow shrubs. 



The chrysalis of the viceroy butterfly is represented in Fig. 

 37. It is generally a little less than an inch long, and has a 

 peculiar, rounded, wedge-like hump near the middle of the back. 



Fig. 38. — Viceroy IJutterHy. 



During June there emerges from the chrysalis a handsome 

 reddish brown butterfly, streaked and veined with black. This 

 is the viceroy butterfly, rei)resented natural size in Fig. 38. 



The viceroy butterflies that have thus appeared in June flit 

 leisurely about in the summer sunshine, sipping the nectar of 

 flowers ajid searching out willow and i)oplar shrubs or trees. 

 Having found these, the butterflies deposit their eggs on the 



