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Show 342 MR. A. H. GARROD ON THE [Apr. 4, termination of the oesophagus, the epithelium in that part being smooth and apparently squamous. This further development in Plotus of a special and well-differentiated gland-organ from what in other birds is a zone or a simple circular patch of glands, is very similar to the equally uncommon development of the cardiac gland-organ in the stomach of the Manatee, which is most certainly only a modification of the similarly situated gland-patch in the Dugong. The stomach i3 not developed into a gizzard, its walls in no part exceeding one sixth of an inch in thickness. It is divided into two compartments, a cardiac and a pyloric, as is that of the Pelican. The former of these corresponds to the gizzard in most birds, the latter to the imperfectly formed cavity associated with the pyloric valve in the Storks, Gannet, &c. (vide Plate XXVIII. fig. 2). Of the stomach of the Pelican, Hunter tells us* that "it is oblong, much in the direction of the oesophagus, with a little curve, smallest at the lower end : it makes a quick turn and swells again into a round bag ; or it may be supposed that from the side near the lower or smaller end is attached a bag whence the duodenum arises." In the Catalogue of the Museum of the Royal College of Surgeons (1852), Prof. Owent remarks, with reference to a specimen (No. 519) of the stomach of a Pelican (Pelecanus onocrotalus), " The oesophagus is continued into the proventriculus or glandular cavity, without any marked constriction; and the latter passes insensibly into the part analogous to a gizzard. This part communicates by a transverse aperture with a small globular cavity, which is lined by a vascular membrane, and communicates with the duodenum by a very small oblique aperture. This superadded cavity renders the analogy between this stomach and that of the Crocodile complete, with the exception of the absence in the latter of distinctly developed gastric glands. These, in the Pelican, are simple elongated follicles, closely compacted together, and extended over a large surface." In Plotus the second cavity is similarly situated, intervening between the stomach proper and the duodenum. The dense yellow epithelium of the one, however, extends into the other, right up to the pyloric valve. [It may be that in the specimen described by Prof. Owen the lining had been previously stripped off, which may have led to the term vascular being applied to the mucous membrane of the second stomach.] Hunter, in his dissection of Sula and Phalacrocorax, does not mention the existence of a second stomach ; and I have not observed or found recorded such an arrangement in either of those genera, or in Phaethon, or in Fregata. In Plotus there is still another peculiarity which, as far as I know, is found in only one other bird, namely Cathartes aura. In Audubon's ' Ornithological Biography ' j, Mr. Macgillivray tells us that in the stomach of C. aura " there is a pyloric lobe [second com- * Essays and Observations, Owen's edition, 1861. t Vol. i. " Organs of Motion and Digestion," p. 148. • J Vol. v. p. 340. |