It is said by Kirby and Spence,[BJ] that when these leaf-rolling insects find that the larger nervures of the leaves are so strong as to prevent them from bending, they "weaken it by gnawing it here and there half through." We have never observed the circumstance, though we have witnessed the process in some hundreds of instances; and we doubt the statement, from the careful survey which the insect makes of the capabilities of the leaf before the operation is begun. If she found upon examination that a leaf would not bend, she would reject it, as we have often seen happen, and pass to another. (J. R.) * * * * * A species of leaf-roller, of the most diminutive size, merits particular mention, although it is not remarkable in colour or figure. It is without hair, of a greenish-white, and has all the vivacity of the other leaf-rollers. Sorrel is the plant on which it feeds; and the manner in which it rolls a portion of the leaf is very ingenious. [Illustration: Leaf-rolling Caterpillars of the Sorrel.] The structure which it contrives is a sort of conical pyramid, composed of five or six folds lapped round each other. From the position of this little cone the caterpillar has other labours to perform, beside that of rolling the leaf. It first cuts across the leaf, its teeth acting as a pair of scissors; but it does not entirely detach this segment. It rolls it up very gradually, by attaching threads of silk to the plane surface of the leaf, as we have before seen; and then, having cut in a different direction, sets the cone upright, by weaving other threads, attached to the centre of the roll and the plane of the leaf, upon which it throws the weight of its body. This, it will be readily seen, is a somewhat complicated effort of mechanical skill. It has been minutely described by M. Réaumur; but the preceding representation will perhaps make the process clearer than a more detailed account. This caterpillar, like those of which we have already spoken, devours all the interior of the roll. It weaves, also, in the interior, a small and thin cocoon of white silk, the tissue of which is made compact and close. It is then transformed into a chrysalis. [Illustration: Nests of the Hesperia malvæ, with Caterpillar, Chrysalis, and Butterflies.]