Fig. 92.—Stomach of crocodile. (Nuhn.)
In birds of prey, especially in the owls, the stomach walls are scarcely more massive than in other animals, and the mucous membrane is soft and devoid of a horny covering. The glandular and masticatory stomachs are less sharply divided from each other in these forms, and the entire organ conforms more to the general vertebrate type (Fig. 90).
In some birds (herons, storks, etc.) a small rounded third stomach, the so-called pyloric stomach, is placed between the muscle stomach and the pylorus (Fig. 91). It contains no gastric glands, and possibly may function as an additional absorbing chamber.
Among reptiles the stomach of the crocodile resembles the organ in birds (Fig. 92). It is flat and rounded in shape, the muscle wall carries a tendinous plate, and there is a pyloric stomach. There is, however, no glandular stomach or proventriculus, as in birds, and the mucous membrane is not covered by a horny plate, but is soft and contains the peptic glands. Figs. 93 and 94 show the stomach of Alligator mississippiensis, in the ventral view and in section.
| Fig. 93.—Stomach of Alligator mississippiensis. (Columbia University Museum, No. 1811.) | Fig. 94.—Same in section. Thin-walled cardiac segment continues into cavity of pyloric ventriculus. |
Fig. 95.—Stomach of Bradypustridactylus, three-toed sloth. I. First stomach, devoid of gastric glands, corresponding to rumen of ruminants.
II. Second stomach, the homologue of the ruminant reticulum.
III. Digestive stomach proper, provided with gastric glands connected by a gutter with the œsophagus.