EMFEROR-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 prin- 

 ciple 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 

 efl^ectually to shield the chrysalis from danger. We 

 have formerly remarked (page 192) that the cater- 

 pillar of the ^geria asil'iformis of Stephens, in a si- 

 milar way did not appear to be contented with a co- 

 vering of thin wood, without an additional bonnet of 

 brown wax. The cocoon of the emperor-moth, though 



Cocoons of the Emperor-moth cut ojjcn to show their ttructure. 



