The crop is modified into a large and very rugose triturating apparatus, while the gizzard, thereby relieved of its function, is reduced to the utmost.
The gizzard of various birds which are addicted to eating hairy caterpillars, e.g.
In the ostrich, Struthio, the craze of overloading the stomach with pebbles which, when triturated into sand, are not voided, has brought about a dislocation, so that the enormously widened and stretched space between proventriculus and gizzard forms a bag, directed downwards, whilst the gizzard itself with part of the duodenum is rotated round its axis to more than loo°.
In the structure of the digestive system, beetles resemble most other mandibulate insects, the food-canal consisting of gullet, crop, gizzard, mid-gut or stomach, intestine and rectum.
A gizzard is present in a few forms. The buccal cavity is sometimes armed with jaws.
The oesophagus expands into a curious gizzard, which is armed internally with large horny processes, some broad and thick, others spinous, fitted to act as crushing instruments.
12, c) and a proventriculus or " gizzard," whose function is to strain the foodsubstances before they pass on into the tubular stomach, which has no chitinous lining.
The mouth opens at the tip of the retractile proboscis; it leads into a short thin-walled tube which opens into an oval muscular gizzard lined with a thick cuticle; at the posterior end of this are some minute glands and then follows a large stomach slightly sacculated in each segment, this tapers through the rectum to the terminal anus.
The digestive system has a slender gullet, a large crop and no gizzard; in some Hemiptera the hinder region of the mid-gut forms a twisted loop with the gullet.
The alimentary canal is simple and a gizzard or oesophageal diverticula rarely developed.
C, Crop (the gizzard below it).
The mouth is minute and the pharynx is always suctorial, never gizzard-like.
The mouth opens through a narrow pharynx (p) into a chamber which is (as in Crustacea) at once crop and gizzard, the mastax (ma), whose thickenings are imbedded in the posteroventral wall.
A, malleate, with crop: this is followed enlarged view of malleus above - the by the crop-gizzard, Y-shaped incus consists of a short median also ciliated except fulcrum bearing two large rami, each of behind, where it is which is in contact with a stout malleus hardened into a set consisting of a toothed uncus carried on a of articulated sclerites long manubrium; b, sub-malleate, with (trophi) to form the enlarged view of malleus - the manubria gizzard or mastax.
Behind this point there is a muscular pharynx or gizzard, which communicates with the wide intestinal tract.