246 THE BUTTERFLIES OF XEW ENGLAND. 



three stages, "feeding side by side, eating the leaf from the tip downward, 

 but leaving the stouter ribs. Spinning a thread wherever they go, they 

 often, in travelling from leaf to leaf, make quite a pathway of silk ; and if 

 the branch be suddenly jarred, they will drop and hang suspended in mid- 

 air, and after reassurance climb up again with the thoracic legs" (Riley). 

 In thus feeding together they completely conceal the leaf, according to 

 Edwards, but do not, as in many gregarious larvae, "rest with heads all 

 turned the same way and bodies in line and parallel . . . but form an u'- 

 regular mass, the heads mostly outside and fronting in every direction." 

 They often assume a very odd position, first noted by Edwards, in which 

 there is a sinuous bend in the middle of the body, the front half being 

 thrown by half its width to the right or left of the hinder end, but both 

 straight and parallel ; they even may have this position when fixed for 

 change of skin. They also frequently rest with the head bent over so that 

 the front lies flat upon the surface of rest, and thereby hunch a little the 

 second thoracic segment ; it is in this position, according to Mr. Edwards, 

 that they hibernate. Mr. Edwards found his larvae feeding principally at 

 night, but mine fed equally by night or day. He also states that they 

 prefer the thickest leaves, and Mr. Riley adds that they select the lower 

 branches. "From the earliest stage, the surface of the leaf about and 

 beneath these larvae was kept thoroughly clean, but just outside the group 

 was a mass of excrement in a pretty regular ridge," formed at a certain 

 active cleansing period. "When a bit of frass was encountered by [some] 

 . . . who seemed especially deputed to act as scavengers, it was seized by the 

 mandibles . . . and by a snap the frass was thrown ... at least two lengths 

 of the caterpillar. If ... it fell short, either one of the larvae on which it 

 struck seized it or it was met by one of the scavengers, and was again 

 snapped off, until . . . the obnoxious thing was gotten rid of. . . . This san- 

 itary work could only have been necessary when the larvae were in con- 

 finement, as in nature they would have rested on the under side of the 

 leaf" (Edwards). 



After the third moult, the caterpillars scatter and Hve independently ; 

 some which I had crawled to separate terminal leaves of twigs where they 

 took up their permanent abode, returning to the leaf after excursions up the 

 stalk for food, resting always upon the upper surface. After a time, ap- 

 parently by repeated zizzaggings at every return, the sides of the leaf or 

 leaf-cluster were brought toward each other to form a kind of trough, so 

 that the caterpillar was in view only from above. One, when removing 

 to new quarters, made at once of several leaves a sort of open bower which 

 concealed it well, though not completely. The skin cast at each moult is 

 devoured. 



Life-history. Thanks to Messrs. Riley and Edwards the history of this 

 butterfly is tolerably well known. The caterpillars winter when half 



