The Larva surrounded by its Palisade.
M. Lyonnet has given a most interesting account of the proceedings of another larva which far surpasses the silk-worm in the ingenuity of its manner of forming the cocoon. This larva is very small; in fact, not more than the sixth of an inch in length, and is found on the under side of oak-leaves. M. Lyonnet observes, that beyond all the larvæ he had ever watched, he considered this creature the most inconceivably ingenious workman. Its little cocoon is of a white colour, and of a long oval form, having its upper surface ornamented with seven upright ridges. The first thing the creature begins by doing, is to erect, in the most curious manner, a series of little upright palisades of silk at a certain distance from each other, all round its body, so as to form a sort of oval fence, and probably the larva intends them to serve as a sort of hedge to keep off intruders while it is busy at work! After spinning half its case, it turns round, and begins at the opposite end, and thus forms the other half; it then unites it in the middle, and by so doing incloses itself in a very pretty cage of silken net-work, which it subsequently strengthens by adding a firm layer on the inside. The time taken in the construction of this ingenious cocoon is not more than half-an-hour. It is quite impossible to understand how the little being contrives to form the upright ridges on the surface of its cocoon; and as the larva is so minute it is almost hopeless to expect to discover it. Attempts have been made to unravel the difficulty, but not with complete success. When, looking at some magnificent works of man, we are tempted to become inflated with pride, let the remembrance of what this tiny insect can do keep us humble, and direct our admiration rather to Him who is the Author of all wisdom, the Giver of every good and perfect gift.
Upon the leaves of pear trees we may sometimes find a pretty cocoon of very slight and elegant texture, formed of silk, as shown in the cut.
Cocoon on a Pear-leaf.
A very singular cocoon is spun by the larva of a common moth, somewhat of the outline of a balloon in form. This cocoon is spun in a very slight manner, and thus offers a striking contrast to those of many other insects; in fact, it is so slight, and the meshes are so open, that the insect can be readily seen within suspended in a hammock of silk, and thus presenting a very curious appearance. In another, the inclosed insect looks just like a poor prisoner within a grating.
Cases formed of Epidermis of Bark.