1312 THE BUTTERFLIES OF NEW ENGLAKD. 



pillars of some of the Nvinplialidae, siioh as Envanossa antiopa, Aglais 

 milberti, and Ciuclidia harrisii, will move their heads l)v simultaneous jerks 

 to one side and the other, like a regiment of soldiers shifting arms. This 

 community of action must be a very considerable safeguard, and indeed I 

 am inclined to regard the mere presence of caterpillars in considerable 

 numbers feeding in company as in itself protective, partly because it is 

 most common in the liighest family and never found in the lowest, so that 

 the habit would seem to have grown and become intensified l)y its pro- 

 tective qualities. Some certainly of the caterpillars which thus feed in 

 company will not be touched by chickens. I have several times thrown 

 twigs covered with the caterpillars of Euvanessa antiopa into a chicken 

 yard only to the alarm of the chickens, they either paying no attention to 

 the caterpillars as the)' crawled away, or regarding them with evident 

 horror, never once oftering to touch them ; of course this may be due sim- 

 ply to their spinous clothing. But besides the spined caterpillars which 

 are presumably protected by such community of action, such as Euvanessa 

 antiopa, Aglais milberti, Eugonia j-album and the Melitaeidi in their 

 earlier stages, we have, even in our own fauna, instances of naked cater- 

 pillars which enjoy the same means of protection, such as Chlorippe clyton 

 and Laertias philenor, especially in their earlier stages. 



The greatest danger to caterpillars would seem to Ije when they are in 

 motion, as they are then more readily detected by insectivorous cresitures. 

 To guard against such danger, many caterpillars, as all the Satyrinae, 

 are excessi\ely slow in their mo\ements. Most caterpillars remain abso- 

 lutely still during all times when they are not actually eating or on their 

 way to their feeding spots, but some have the habit, in passing to and 

 from their feeding grounds, of moving witii the utmost rapidity, hurrying 

 as if their safety depended upon it, as doubtless it does. Such are all the 

 Argynuidi, and I have noticed a similar habit in Polygonia prognc. 

 Others, again, among the slow movers have a very peculiar trick, which I 

 do not remember to have seen mentioned by others ; it is a sort of rock- 

 ing motion, not from side to side but forward and backward, moving for- 

 ward by little starts ; they seem to glide by little jerks in a very slow and 

 measured way. The caterpillars in which 1 have noticed this habit are 

 Oercyonis alope, Eurymus eurytheme and Euphoeades troilus ; it is most 

 conspicuous in the last. 



Perhaps of all our caterpillars there are none which have so many 

 means of defence in habit or protective device as the species of Basilarchia, 

 and tliis altogether in addition to their coloring. Attention has already 

 been drawn to this in a former excursus. It may be well, however, to 

 summarize here some of the more peculiar ways by which it protects 

 itself. In the first place it moves about with little starts, much as Euphoe- 

 -ades troilus and the others wc have mentioned, its head all tiie while 



