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 mandible is much narrower than that of the lower. This is most readily observed in a dried skull or in a very young nestling. This peculiarity of structure is important, as it is intimately connected with the mode of nourishment of the young bird.

FIG. V.—DIGESTIVE ORGANS OF THE PIGEON. a. beak; b c. Gullet; d e. Crop; f g. Proventriculus; l. Gizzard; h i j k. Muscles of gizzard; m n o p q. Intestines; r. Vent.

The gullet c is wide and opens into a crop d e: this is equal on both sides, unlike that of the fowl. From the back part of the crop, a tube preceeds through the opening at the fore part of the chest into the interior of the body; this enlarges somewhat before reaching the gizzard, aud is termed the proventriculus or fore stomach; it is furnished with glands which secrete the true gastric or digestive fluid. The gizzard itself is strong and muscular, lined with a thick dense leathery cuticle, and capable of grinding down the food with great rapidity, when aided by the sharp-edged stones and grains of sand swallowed by the bird. The intestinal tube which receives the ground food is upwards of three feet in length, and is remark-