386 



INSTINCT OF INSECTS. 



another ; and so it certainly would, had it been guided by an 

 invariable instinct. But he calculated erroneously. Like 

 one of its brother tailors of the biped race, it knew how " to 

 cut its coat according to its cloth," and immediately setting 

 about repairing the injury sewed up the rent. Nor was this 

 all. The scissars having cut olf one of the projections in- 

 tended to enter into the construction of the triangular end of 

 its case, it entirely changed the original plan, and made that 

 end the head which had been first designed for the tail. 



On another occasion Reaumur observed one of these larvae 

 to cut out its coat from the very centre of a leaf, where it is 

 obvious a series of operations wholly different must be adopted, 

 the two membranes composing it necessarily requiring to be 

 cut and sewed on tioo sides instead of on one only. But what 

 was most striking in this new procedure was the alteration 

 which the caterpillar made in the period of sewing up its gar- 

 ment. When these larvae cut out their case from the edge of 

 a leaf, they seem aware that if they were to detach it entirely 

 from the inner side before the process of sewing, lining, &c. 

 is completed, having no support on the exterior edge, it would 

 be liable to fall down ; at the same time they could not sew 

 together the membranes composing it at the inner side, with- 

 out cutting them in part from the leaf. While, therefore, 

 they divide the major part of their inner side from the leaf, 

 they artfully leave them attached to it by one of the large 

 nerves at each end ; and these supports they do not cut asun- 

 der until the intermediate space has been sewed up, and they 

 are ready to step, with their house on their back, upon the 

 terra jirma of the disk of the leaf. In this instance, therefore, 

 the larvae do not wholly separate their case from the leaf, 

 until it is sewed. But when the same larvae cut out their 

 materials from the middle of the leaf, where, though com- 

 pletely cut round, they are retained in their situation secure 

 from all danger of falling by the serratures of the incisions 

 made by the jaws of the larvae, these little tailors vary their 

 mode, and entirely detach the pieces from the surrounding 

 leaf before they proceed to set a stitch into them. 1 



1 Reanm. iii. 112 — 119. 



