Page:Jardine Naturalist's library Entomology.djvu/136

130 being sufficiently masticated. The part last named, otherwise called the gullet, (Pl. II. figs. 2, 3, a,) is a narrow tube intermediate between the pharynx (when such exists,) and the crop, or, in the absence of the latter, the gizzard. It commonly passes through the thorax in a straight line, and terminates at the origin of the abdominal cavity; but nothing can be more variable than its length. In certain Hymenoptera, (Pimpla, Pompilus,) it forms more than half of the entire canal; in the cockchafer, (Pl. II. fig. 3, a,) a small portion behind the head, scarcely one-sixtieth of its length; and all intermediate dimensions occur. The esophagus is in all cases simple, except among the Lepidoptera, which present the remarkable peculiarity of a bifurcation anteriorly, a branch emanating from each of the two spiral sucking tubes and uniting into one conduit, usually just behind the head. The crop, (Pl. II. figs. 2, 3, b, b,) has been so named by Cuvier, Léon Dufour, and Strauss, because it occupies the same position as the organ so called in birds; by some other authors it is denominated the stomach. It appears, for the most part, as a simple dilatation of the hinder part of the esophagus into a kind of bag, which is usually on a line with the other parts of the alimentary canal, but sometimes appears suspended at the side like a pouch. Its form is most variable, even in the same species, according to the degree of its repletion or vacuity. When the gizzard, the succeeding portion of the canal, is wanting, which is very often the case, the crop appears in its simplest form, and is unprovided with any secretion to act upon the