1 88 INSECT ARTIZANS AND THEIR WORK 



apex of the case from the leaf, but does not fasten 

 them together, as it requires an aperture at this 

 end of the case as well as at the basal end. After 

 this the larva crawls down to the base of the case 

 and severs it completely from the leaf by biting 

 through first one cuticle and then the other, so 

 that before the second cuticle is cut through the 

 larva is able to grasp the leaf firmly with its legs 

 and prevent itself and the case from tumbling down. 



*' The case now being complete, the larva walks 

 oflF with it in search of fresh food. Having found a 

 suitable leaf, it fastens the mouth of its case by 

 silk to the lower cuticle and then bites out a round 

 hole in the cuticle through which it enters the 

 leaf to feed on the parenchyma. When it has 

 eaten out as much as it can conveniently do with- 

 out quite leaving its case, it usually cuts this away 

 and carries it off to another suitable place, where 

 it forms a fresh mine. 



" In this manner it continues to feed and also 

 to grow longer and stouter, so that its case gets too 

 small and has to be made larger. At this period 

 of its existence this species lengthens its case by 

 adding rings of leaf cuticle to the anterior end 

 of its case. When about to remove to another leaf 

 it does not cut away the actual case, but it cuts out 

 a ring of cuticle round the mouth of the case, 

 thus freeing the case with the ring attached, so 

 that this ring becomes part of the case. . . . The 

 case, however, as the larva grows stouter, must 

 be made more spacious, so the larva unpicks the 



