What authorizes this supposition is the di versity of opinions which exists relative to the number of the stomachs of the common Dolphin and common Porpoise, some counting only three, others four, others five, and others six, &c. Now it is certain that these differences of number proceed simply from the manner in which this organ is viewed. When it is only judged of by its exterior, and its globulous parts alone are called stomach, only three or four can be reckoned ; and then the more or less tubular passages, situated amongst those more or less spherical cavities, are considered as mere intercommunicating canals. But if the interior of these stomachs be studied, it is seen that several amongst them have a special organization, and are separated from one another by small openings, which do not invariably establish a direct communica tion between them : hence the tubular parts cannot be considered as simple passages, but must necessarily be admitted as essential parts of the stomach, which, like the others, impress their peculiar action upon. the food. It has also been the case that the dilated sac into which the biliary and pancreatic juices are poured, has not been admitted as belong ing to the stomach ; but besides its not being without example that in Mammalia the bile may be poured immediately into the stomach, the difference in the nature of the membranes ought to suffice for deciding whether the part which receives these secretions belongs or not to the duodenum. Now in the Dolphins it is evidently at the termination of the last stomach that their duet opens. In this state of things it is impossible to decide with precision in what particulars the Zoophagous Cetaceans differ from one another in the structure of the sto mach. It appears, however, that this organ in the common Dolphin, the common Porpoise, the Globiceps, and the Platanist, is formed upon the same type, and is composed of five parts ; and if they differ one from another, it is only by modifications of secondary importance. If to these facts we add what Meckel states re specting the Narwhal, in which he recognizes five stomachs, and what Hunter says of the Grampus and Piked Whale, in which he like wise found five, we have three species more to add to the first. In fact, when we consider that only three or four stomachs have been re cognized in the Carinated Porpesse and the Beluga, which are true Phoceenw, and that Baussard saw three, and Hunter seven in the Hyperoodon (Great Bottle-nose Whale), we believe ourselves authorized in thinking that these differences depend entirely upon the manner in which this organ is viewed, and we -,.onsider it very probable that the number of stomachs in these Cetaceans, as in the others, is five. However, from this small number of facts, and fi-om all the conjectures with which we have been obliged to approach the subject, we shall draw no precise conclusion as to the structure which may be common to the Zoo phagous Cetaceans. But this undoubted great complication of the stomach in animals which , are nourished with the most animalized food, is an anomaly the cause of which it would be very important to investigate ; for from the ascertained facts which we have to reason from, we are not led by any analogy to an explanation of this subject.
[In our examinations of the stomach of the Porpesse ( fig. 263), we have not been able to distinguish more than four compartments. This complex digestive organ, besides the structure of the internal surface, differs from that of the Ruminant Animals in the compara tively small size of the first cavity, and the mode of inter-communication of the other compart ments, which succeed one another, and are not appended to the extremity of the cesopha gus : instead, therefore, of the cesophagus communicating with all the four cavities, it opens only into the first, and consequently no rumination can take place. The first cavity
is continued in the same line with the cesopha gus, having the same structure, and not being divided from it by any sensible constriction ; its commencement is indicated by the orifice leading into the second stomach, beyond which orifice it is continued in the form of a dilated ovate cavity (a). It is lined with a cuticle, and its inner surface is beset with small rugw. A number of large irregular projections sur round the aperture leading to the second ca vity, and are calculated to prevent the passage into the second of any substances save such as are of very small size. Notwithstanding the nature of the lining membrane the di gestive processes are considerably advanced in this cavity, which does not act simply as a reservoir. It is probable that the secretion of the second stomach, which is highly glandular, regurgitates into the first and assists in pro ducing the dissolution of the carneous parts of the fishes, the remains of which are usually found in it. The thick cuticular lining terminates abruptly at the small ori fice leading into the second stomach (b). The interior of this cavity presents a series of close-set thick longitudinal wavy rugw, laterally indented into one another. The internal layer is thick and of a peculiar structure : according to Sir David Brewster, " it seems, in its wet state, to consist of tubes or fibres perpendicu lar to the two membranes which inclose them, and the upper surface of one of the membranes is covered,with hollows or depressions corres ponding with the extremities of the tubes or fibres. A more minute examination, conducted in a different way, proves these perpendicular portions to be tubes. In order to. dry it, I pressed it between folds of paper, and the effect of the compression was to press together nearly all the tubes, and make the whole one dense mass, of a dark brown colour ; but when it be came dry and slightly indurated, I drew it out as if it had been India-rubber, and the tubes opened, and the mass became white." The membrane next the cavity of the sto mach is perfectly smooth ; the one external to the fibres is a vascular and cellular tunic, and is inverted by the layer of muscular fibres continued from the preceding cavity. The communication with the third stomach is near the lower end of this cavity. The third com partment is a small round vascular cavity, into which the second opens obliquely : it is lined by a smooth and simple villous tunic. It is not visible exteriorly, and does not exceed an inch in length in the Porpesse, but in the Hyperoodon is about five inches long. The fourth cavity (c, c) is long and narrow, and passes in a serpentine course almost like an intestine; the internal surface is smooth and even, but villous. It opens on the right side into the duodenum (d), which is much dilated, and, as in the human subject, is without valvulw conniventes at its commencement. The pylo rus is a smaller opening than that between the third and fourth cavities.] Some authors speak affirmatively of a con siderable bladder, which in the Rorquals, after death, comes up into the mouth and forces the two jaws asunder. Now what is the nature of this vesicular mass, of which other authors say nothing ? To what organic system does it be long ? This has never been made a subject of enquiry. It has been considered as belonging to the respiratory system, or as an air-bladder analogous to that of fish. Is it not more proba bly a portion of the.stomach distended by the crases formed there ? In general the Spouting Whales have no ccecum. However, a trace of this gut has been found in an oval elevation in the Plata nist; a ccecum exists also in the Piked Whale and in' the Whale-bone Whale. The variations in form or affinity of the spleen and the liver appear to have no essential relation with the forms of the stomach.