The transformations to which Lepidopterous insects are subject are amongst the most remarkable phenomena of insect life. In the different states to which each is liable, a series of changes is exhibited which has been compared, by an admired writer, to what might be supposed to be undergone by an animal which for the first five years of its life, exhibited the form of a serpent, which then penetrated into the earth, spun for itself a silken coffin, contracting itself into a limbless form resembling, more than any thing else, an Egyptian mummy; and which, lastly, after remaining in this state for a length of time, burst into the air a winged bird. Of these states, it may well be conceived, that the second requires, from its inactivity and helplessness, a secure retreat, where, removed and secure from the attack of its enemies, it can rest its appointed period during which the organs of flight acquire their full development. We accordingly find that the varied manner in which the caterpillars of the different species prepare their retreats, affords one of the most interesting branches of investigation in the natural history of the Lepidoptera. And in this respect, the species now under consideration certainly exhibits one of the most interesting manoeuvres hitherto recorded amongst the insect tribes, and which is described by Mr. Peale in his beautiful "Lepidoptera Americana."[2] This moth is very abundant in the vicinity of Philadelphia, at least, judging from the number of cocoons seen hanging from the branches of the Sassafras (Laurus Sassafras), and Spice-wood (L. Benzoin); and which, by an ordinary observer, would be readily mistaken for withered leaves which had withstood the blasts of winter. After the caterpillar has attained its full size, and lost the voracious {22}appetite which had hitherto been its predominant character, it begins its preparation for the great transformation it has to undergo, by selecting a perfect leaf, the upper surface of which it covers with a fine light yellowish brown silk, extending this coating with great skill and foresight, _over the footstalk of the leaf_, and attaching it firmly to the branch, so as to secure the leaf from being separated by any accident. This preliminary operation having been accomplished, the caterpillar next draws the edges of the leaf together, thus forming a perfect external covering or mantle, in which it spins a fine strong and durable cocoon of fine silk. In this habitation the little architect passes the winter secure from birds and other enemies. As soon as the cocoon has been completed, the caterpillar sheds its skin, and is transformed into a chrysalis. At first the leaf enveloping the cocoon remains green, but soon changes to a red or brown, when it becomes brittle, and is gradually carried away by the winds and storms of winter, until, finally, nothing remains except the cocoon itself, which is firmly suspended by the silk which once covered the footstalk of the leaf.