the larvæ. The following figures afford examples of these different kinds of pupæ, the numerals referring to the order in which they have just been named.
On examining the interior of a pupa immediately or shortly after it is formed, it is found to consist almost entirely of a milky fluid, which soon, however, acquires the consistency of pulp, when the members of the future insect can be detected. They are not long in enlarging by the absorption of the ambient matter, and when they acquire their full size, they completely fill, in most instances, the interior of the pupa-case. The integument, as above intimated, varies greatly in its consistency. In the Lepidoptera it acquires its rigidity from a viscous fluid, which oozes out from the region of the thorax, and spreads over the whole surface, forming a hard and varnished shell. The superficies is for the most part naked. In some cases, however, it is tufted with hairs, (as in Orgyia pudibunda, Leucoma Salicis;) occasionally
