INSTINCT OF INSECTS. 541 
seams of its coat; and as the little miner is not embarrassed with the 
removal of the excavated materials, which it swallows as it proceeds, a 
cavity sufficiently large is but the work of a few hours. It then lines it 
with silk, at the same time pushing it into a more cylindrical shape; and 
lastly, cutting it off at the two ends and inner side, it sews up the latter 
with such nicety that the suture is scarcely discoverable ; and is now pro- 
vided with a case or coat exactly fitting its body, open at the two ends, 
by one of which it feeds, and by the other discharges its excrement, having 
on ove side a nicely joined seam, and the other—that which is commonly 
applied to its back —composed of the natural marginal junction of the 
membranes of the leaf. 
Such are the ordinary operations of this insect, which —when it is 
considered that the case is rather fusiform than cylindrical ; that the end 
through which it eats is circular, and the other curiously three-cornered 
like a cocked hat; and that consequently its cloth requires to be very 
irregularly and artfully cut to be accommodated to such a figure, —it must 
be admitted, are the result of an instinct of no very simple kind. Compli- 
cated, however, as these manceuvres seem, our ingenious workman is not 
confined to them. By way of putting its resources to the test, Reaumur 
cut off the serrated edge from the nearly finished coat of one of them, and 
exposed the little occupant to the day. He expected that it would have 
quitted its mutilated garment and commenced 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 
scissors having cut off one of the projections intended 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 ope- 
rations wholly different must be adopted, the two membranes composing 
it necessarily requiring to be cut and sewed on two sides instead of on one 
only. But what was most striking in this new procedure was the altera- 
tion which the caterpillar made in the period of sewing up its garment. 
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, 
without 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 asunder 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 larva: cut out their materials from the middle of the leat, where, 
though completely 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 larva, these little tailors vary their mode, and entirely detach 
