CH. III.] INSECTS WHICH FORM COCOONS. 61 



formed for the protection of insects which remain 

 but a few weeks in the chrysalis state, while a co- 

 coon of very flimsy construction often defends an 

 insect throughout the winter; thus one of our lar- 

 gest and rarest moths, the Glory of Kent (Endromis 

 versicolora), spins a slender, open, netlike cocoon, 

 in which it remains enclosed not less than ten 

 months, from June until April. The still rarer lob- 

 ster caterpillar (Stauropus fagi) forms a cocoon of a 

 delicate silky nature, in which it is enclosed from 

 September till June. The cocoons of the ermine 

 moth are equally slender, but they are still more ex- 

 posed than the former, being placed at the root of 

 trees, &c. There are, however, two moths already 

 noticed in this and a preceding- chapter, which 

 most completely disprove the theory alluded to. 

 The large eggar moth forms a very hard cocoon, in 

 which it only remains four weeks, from the end of 

 June to the end of July; the small eggar moth, 

 which, as we have seen, sometimes remains as 

 many years in its cocoon, and always throughout 

 the winter, is of a much less firm consistence. The 

 double-brooded moths and butterflies are also in- 

 stances in which it would be requisite, for the sup- 

 port of this theory, that those specimens which pass 

 the winter in the chrysalis state ought to be more 

 strongly defended than those which are only a few 

 weeks in the summer in that state ; and yet we find 

 not the slightest difference between the two broods 

 in this respect. 



We now come to those cocoons in which various 

 matters are introduced into the construction of the 

 cocoon besides those furnished by the body of the 

 caterpillar itself. 



Among those caterpillars which form their co- 

 coons under ground, into which they enter for the 

 first time for this express purpose, we may notice 

 the handsome one of the Cucullia scrophularia, found 

 upon the mullein and water betony, of a grayisJ- 



VOL. II. F 



