of the skin; and, bending its body once more, entirely extricates its tail from it. It is now wholly out of the skin, against one side of which it is supported, but yet at some distance from the leaf; the next step it must take is, to climb up to the required height. For this purpose it repeats the same ingenious manoeuvre: making its cast skin serve as a sort of ladder, it successively, with its different segments, seizes a higher and a higher portion, until in the end it reaches the summit, where with its tail it feels for the silken threads that are to support it. The tail is provided with a number of minute hooks which catch in the meshes of the silken button, and the pupa, thrusting it into the meshes of this button, feels quite secure as to the result, and drops safely into the perpendicular position, dangling in the air as gaily as did the larva before it. But its old skin still clings to it, and seems greatly to annoy it by its presence; so much so, that it sets about attempting to cast it down altogether. As it will be remembered that the legs of this skin are still firmly attached to the silk, in consequence of their hook-like form, it will be evident, that this also is a task of some arduousness. In order to get rid of it, it jerks itself about in various directions, and spins round very rapidly,--doubtless the reader has often seen the insect in this act, and has wondered what was its object in whirling round after this manner,--by this means at length the cast-skin appears loosed from its hold and drops off. The whole proceeding from first to last is represented in our engraving. The little hooks of the tail of the pupa are represented in the adjoining cut much enlarged. Well does Réaumur exclaim,--"These manoeuvres of withdrawing its tail from the old skin, of climbing up the old skin, and of hooking its tail in the silken button,"--and, as we might add, of whirling itself, and in other ways agitating itself to get rid of its old skin,--"are manoeuvres so delicate and perilous, that we cannot help wondering how an insect which only executes them once in its life, should execute them so well; and we are led to the inevitable conclusion that it has been thus taught by a Great and All-wise Master." The manner in which other larvæ cast their skins and become pupæ when they enter their cell cannot be described, as they perform this act in all the privacy and darkness of their solitary habitations; but in all probability it differs in no respect from the manner in which the same creatures cast their skins when they moult, excepting that the new being which emerges from the cast-skin is no longer a larva, but a pupa.