Ornithological biography, Vol. 4 (of 5)

by John James Audubon

Fig. 1.

A male bird, from Nova Scotia, examined. The upper mandible internally has a longitudinal median ridge; the palate is convex, with two lateral ridges. The tongue is 5 1/2 twelfths long, emarginate and serrulate at the base, very much flattened, tapering to a horny point. The heart, Fig. 1, a, is of a very elongated narrow conical form, 2 twelfths in length, 4 twelfths in breadth at the base. The lobes of the liver, b, c, are equal, 6 1/2 twelfths long. The œsophagus, d, e, is 1 inch 10 twelfths long, of a uniform diameter of 2 1/2 twelfths; behind the liver, it enters as it were a large sac, f, g, h, 9 twelfths of an inch long, which gradually expands to a diameter of 6 twelfths, forming a broad rounded fundus g, then curves forwards on the right side, and at h terminates in a small gizzard, about 3 twelfths long, and nearly of the same breadth, from the left side of which comes off the intestine. The latter passes forward, curving to the right, behind and in contact with the posterior surfaces of the liver, then forms the duodenal fold, h, j, k, in the usual manner. The intestine, on arriving at the right lobe of the liver, at k, receives the biliary duct, curves backward beneath the kidneys, and forms several convolutions, which terminate above the proventriculus. It then becomes much narrower, and passes directly backward, in a straight course to the rectum, which is only 4 twelfths of an inch long. The cœca are oblong, 1 1/4 twelfth in length, and 1/2 twelfth in diameter. The intestine is 8 1/2 inches long, its diameter diminishing gradually from 2 twelfths to 3/4 of a twelfth.

Fig. 2.

In Fig 2. are represented:—the lower part of the œsophagus, d, e, f; the proventricular sac, f, g, h; the very small gizzard, h; the duodenal fold of the intestine, i, j, k. Here the parts are viewed from the left side.

Fig. 3.

Fig. 3. represents:—the proventricular sac thrust forward, f, g, h, the gizzard, h; the duodenum, i, j, k, pulled to the right side; the convolutions of the intestine, l, m, under the kidneys, the cœca, n; the rectum, o, and the cloaca, p.

The proventricular glands are very numerous, but not so closely placed as is usual, although scattered over a much larger extent, from e to g in Fig. 2. Between the termination of the glands and the stomach there is a portion destitute of glandules. The stomach or gizzard has its muscular coat thick, its tendons moderate, its inner surface covered with a rather thick but not very hard epithelium, which is more prolonged on two opposite sides, although in the fundus it is complete.

This curious digestive apparatus agrees very nearly with that described and figured by Sir Everard Home as that of Alca Alle. The stomach, it is seen, is excessively large in proportion to the size of the bird; but why it should be so, and moreover be curved in this manner, is not very obvious. Conjectures are easily made, and might run in this form. This little bird, which wanders over the face of the ocean, subsisting upon garbage, oily and fatty substances, small fishes, and even sea-weeds, requires a large stomach for the reception of its heterogeneous fare, which not being always very nutritious or easily digestible, must be very plentifully intermixed with the gastric juices, and detained a considerable time; which conditions are accordingly provided for by the very great number and extensive dispersion of the proventricular glandules, and the curve of the organ. Should any hard substances, as crustacea, be introduced, they are pounded by the gizzard; but as the bird is little addicted to feeding on such substances, that organ is reduced to a very small size.