132 SOCIAL CATERPILLARS 



or beneath which they live, and to which, shoukl 

 they wander beyond its limits for food, they retire 

 for rest and moulting. Some use this web with 

 certain alterations in its structure as a winter resi- 

 dence, but then invariably leave it on the approach 

 of spring and part comi3any, though often being 

 still found in near proximity. Others leave it at 

 the hibernating season to seek, each for himself, 

 his own hiding-place. 



PerhajDS of all our caterpillars, although it con- 

 structs but a slender web, the Mourning Cloak 

 (Euvanessa antiopa) is the most preeminently so- 

 cial. The eggs are laid in a cluster of greater or 

 smaller size around a terminal twig, which they 

 leave together, and as if by common impulse range 

 themselves side by side in compact rows along a 

 chosen leaf. Even if they are separated forcibly 

 from each other, they come together again and re- 

 arrange themselves. When disturbed they will 

 simultaneously strike an attitude of alarm and turn 

 their heads in miison as if worked by a machine. 

 The web they form is sim23ly that which they make 

 as they crawl about, each following hurriedly in 

 the track of its predecessor, and as it moves adding 

 its thread to the carpet upon which it treads ; and 



