CH. III.] INSECTS WHICH FORM COCOONS. 47 



CHAPTER III. 



THE NATURAL HISTORY OF VARIOUS INSECTS WHICH FORM 

 COCOONS. 



Conical Chrysalides produce Moths, and are enclosed in Cocoons — 

 Supposed Causes of the Difference between Butterflies and Moths 

 in this respect — Distribution of Colours in Insects — Cocoons of 

 pure Silk — Slender Silken Cocoons guarded by Leaves — Mode 

 of Spinning Cocoons — Gum and Paste introduced into the Sub- 

 stance of Cocoons — Processionary Caterpillars form Cocoons in 

 Company, in which Hairs are mixed with Silk — The Great Eg- 

 gar Moth Cocoon — Assembling of Moths — Palisade Cocoon of 

 Hair and Silk — Strength of Cocoons not indicative of the Dura- 

 tion of the Chrysalis State — Rough Cocoons formed of Earth and 

 Silk — Elongate Tongue-case of Chrysalides — Polished Earthen 

 Cocoon — Cocoons formed of Chips of Wood, and of Leaves, 

 Twigs, and Moss — Extraction of the Moth from the Cocoon — 

 Contrivance of the Larvce to allow the more easy Extrication of 

 the Moth — Regidarity in the Time of Appearance of Insects — 

 Extrication of the Chrysalis from the Cocoon — Extrication of Per- 

 fect Insects from the Caterpillar Case. 



In a former chapter we have stated that, with veiy 

 few exceptions, butterflies are produced from angu- 

 lated chrysahdes, while those of moths are of a 

 conical shape. In addition to this, we may notice 

 that the chiysalides of butterflies are, for the most 

 part, naked and exposed, while those of moths are 

 generally enclosed in a case or cocoon, formed by 

 the larva previous to undergoing its change. The 

 cause of this additional variation appears to us to 

 result from the preceding, since it is evident that 

 the projections and points which arm the chrysalis 

 of a butterfly would very much annoy the inhabi- 

 tant of a dwelling in which it can scarcely turn itself, 

 while no form could be better adapted to the inhab- 

 itant of a cocoon than the conical, the base of the 



