14 INSECT MANUFACTURES. 



leaf to the other : she next pulls at these cables 

 with her feet ; and when she has forced the sides 

 to approach, she fastens them together with 

 stronger threads of silk. If the insect finds that 

 one of the larger nerves of the leaf is so strong as 

 to resist her efforts, she weakens it by gnawing it 

 here and there half through. What engineer 

 could act more sagaciously ? To form one of the 

 conical or horn-shaped rolls, which are not com- 

 posed of a whole leaf, but of a long triangular 

 portion cut out of the edge, some other manoeuvres 

 are requisite. Placing herself upon the leaf, the 

 caterpillar cuts out with her jaws the piece which 

 is to compose her roll. She does not, however, 

 entirely detach it ; it would then want a base. 

 She detaches that part only which is to form the 

 contour of the horn. This portion is a triangular 

 strap, which she rolls as she cuts. When the 

 body of the horn is finished, as it is intended to 

 be fixed upon the leaf in nearly an upright posi- 

 tion, it is necessary to elevate it. To effect this, 

 she proceeds as we should with an inclined obelisk. 

 She attaches threads, or little cables, towards the 



