290 THE LEPIDOPTERA. 



is perhaps no order of Insects in whicli the phseno- 

 mena of the complete metamorphosis are exhibited 

 more distinctly. Their larvse, which are commonly 

 known as caterpillars, are usually cylindrical worms, 

 composed of thirteen distinct segments, of which the 

 anterior forms a strong horny head, furnished with a 

 complete month and with powerful jaws. The an- 

 tennae, however, which in the perfect insect are greatly 

 developed, are reduced to a very minute size in the 

 caterpillar, and the large globular compound eyes 

 are represented by a small group of ocelli placed on 

 each side of the head. The labium is provided with 

 a small, slender tubular organ, the spinneret, the ori- 

 fice of which serves as the outlet to a pair of large 

 glands which secrete a viscous substance, by means 

 of which the caterpillars are enabled to spin the deli- 

 cate silk which performs so many important offices 

 in their oeconomy. The first three segments of the 

 body, representing the thorax of the perfect insect, 

 are furnished each with a pair of short jointed legs ; 

 and besides these, some of the abdominal segments 

 usually bear short fleshy feet, which attach themselves 

 very firmly to any object upon which the caterpillar 

 is walking, and thus give great security to its move- 

 ments. 



These larvae are almost all herbivorous, and their 

 voracity is so great that they are amongst the most 

 formidable enemies to vegetation, especially when ' 

 they occur in unusual numbers. They feed for the 

 most part upon leaves, but a few species live in the I 

 interior of the stems of trees and plants, devouring \ 

 the wood or pith. A few also are destructive to pre- 'i 

 served animal substances, of which the common 

 Clothes-moths present familiar examples. 



