62 THE LIFE-STORY OF INSECTS [CH. 



are usually regarded as low in the scale of organisa- 

 tion, caterpillars are very generally protected by 

 the habit of feeding in some concealed situation. 

 For example, the great larvae of the Goat Moth 

 (Cossus) and the whitish caterpillars of the Clear- 

 wing Moths (Sesiidae) burrow through the wood 

 of trees, eating the timber as they go. The little 

 irritable caterpillars of the Bell Moths (Tortricidae) 

 roll leaves, fastening the edges together with silk, 

 and thus make for themselves a shelter ; or they bore 

 their way into seeds or fruits, like the larva of the 

 Codling Moth that is the cause of 'worm-eaten' 

 apples, too well-known to orchard-keepers. Very 

 many small caterpillars mine between the two skins 

 of a leaf, eating out the soft green tissue, and giving 

 rise to a characteristic blister in form of a spreading 

 patch or a narrow sinuous track through the leaf. 

 The caterpillars of the Clothes-moths (Tineidae) make 

 for themselves garments out of their own excrement, 

 the particles fastened together by silk. In such 

 curious cylindrical cases they wander over the wool 

 or fur, feeding and indirectly supplying themselves 

 with clothing at the same time. 



The case-forming habit of the Clothes-moth cater- 

 pillars leads us naturally to consider the similar habit 

 adopted by their allies the Caddis-larvae which live 

 in the waters of ponds and streams, for the Caddis- 

 flies (Trichoptera) have much in common with the 



