MOTH-CATERPILLARS. 



221 



the insect to make up the deficiency. But the cater- 

 pillar increases in thickness as well as in length, so 

 that its first house becoming too narrow, it must 

 either enlarge it, or build a new one. It prefers the 

 former as less troublesome, and accomplishes its pur- 

 pose " as dexterously," says Bonnet, " as any tailor, 

 and sets to work precisely as we should do, slitting the 

 case on the two opposite sides, and then adroitly in- 

 serting between them two pieces of the requisite size. 



Cases, &c. of the Clothes-Moth (Tinea peUionellaJ—ap Caterillar 

 feeding in a case, which has been lengthened by ovals of different 

 colours. 6 Case cut at the ends for experiment, c Case cut open, 

 by the insect, for enlarging it. d, e The clothes-Woths in their 

 perfect state, when, as they cease to eat, they do no further injury. 



It does not, however, cut open the case from one end 

 to the other at once; the sides would separate too 

 far asunder, and the insect be left naked. It therefore 

 first cuts each side about half way down, beginning 

 sometimes at the centre and sometiiues at the end, 

 (Fig. c.) and then, after having filled up the fissure, 

 proceeds to cut the remaming half; so that, in fact, 

 four enlargements are made, and four sepai'ate pieces 

 inserted. The colour of the case is always the same 

 as that of the stuff from which it is taken. Thus, if 



VOL. IV. 19* 



