EMPEROR-MOTH. 



321 



consequently attracted the attention of every Ento- 

 mologist. The caterpillar * feeds on fruit-trees and 

 on the willow, and spins a cocoon, in form of a Flo- 

 rence flask, of strong silk, so thickly woven, that it 

 appears almost like damask or leather. It differs 

 from most other cocoons in not being closed at the 

 upper or smaller end, which terminates in a narrow 

 circular aperture, formed by the convergence of little 

 bundles of silk, gummed together, and almost as 

 elastic as whalebone. In consequence of all these 

 terminating in needle-shaped points, the entrance of 

 depredators is guarded against, upon the principle 

 which prevents the escape of a mouse from a wire 

 trap. The insect, however, not contented with this 

 protection, constructs another in form of a canopy 

 or dome, within the external aperture, so as effec- 

 tually to shield the chrysalis from danger. We have 

 formerly remarked (page 192) that the caterpillar of 

 the /Egeria asiliformis of Stephens, in a similar way 

 did not appear to be contented with a covering of 

 thin wood, without an additional bonnet of brown 



Cocooni of the Emperor-moth, cut open to shew their simciure. 

 * Figured in Insect Transformations, p. 186. 



