food; but when the part alluded to exists, the crop is furnished with interior glandular organs which secrete an active juice. These glands are most conspicuous among the tiger-beetles, (Cicindela) even appearing in external rows on the obcordate shaped crop. (Plate II. fig. 2, b.) With very few exceptions besides this, the surface of the crop is quite smooth. These remarks, however, apply to this part only as it appears among masticating insects; in all other kinds, with the single exception of the Hemiptera, it becomes (or there is substituted in its place, according to the views we adopt regarding its origin,) what has not improperly been called a sucking-stomach. (Plate II. fig. 4, c.) Its function is no longer to receive the alimentary substances transmitted from the mouth, but to facilitate the rise of the fluids from the mouth to the principal receptacles of the alimentary canal. This it promotes by distending at the will of the insect, and thus rarifying the air in its interior and acting as a kind of pump. It presents various modifications of form in all the different tribes possessing it. The crop is succeeded by the gizzard, (Plate II. fig. 2, c.) which may always be recognised, when present, by having its internal surface covered with teeth, spines, or horny ridges; a structure which eminently fits it, in connection with its muscular, almost cartilaginous texture, for subjecting the food to a more complete trituration than it had previously undergone. It exists in all insects that feed on hard substances, such as wood, bark, &c., and in all carnivorous kinds; but not in those
