OCR Text |
Show 5G MR. A. H. GARROD ON HALMATURUS LUCTUOSUS. [Feb. 2, the pyloric extremity, with the walls of the pyloric end smooth and much thickened. The cardiac caecal extremity, like that in Dendrolagus as described by Prof. Owen, consists of a single cul-de-sac, not a bifid one like that in Macropus giganteus. In the subgenus Petrogale the stomach is not bifid at its cardiac extremity, in which respect it resembles Dorcopsis. In other respects, however, it presents considerable differences; it is more capacious opposite the oesophageal orifice, and the cardiac portion is bent on the rest nearly at right angles, which is not the case in Macropus giganteus and Dorcopsis. The character of the mucous membrane also deserves attention. In Macropus giganteus, as is well known, the squamous epithelium of the oesophagus spreads over most of the stomach also, the pyloric extremity and one of the two cardiac caeca (which is itself bifid) being alone lined with a columnar coating. In Petrogale this latter is absent, the digestive mucous membrane being confined to the pyloric region. Of Dendrolagus inustus Prof. Owen remarks*, " the epithelium is continued from the oesophagus, for a breadth of 2 inches down the posterior surface of the stomach, and of 1| inch down the anterior surface, and thence is continued, slightly diminished in breadth, 3 inches towards the pyloric end of the stomach, and 2 | inches towards the cardiac end. The rest of the cavity is lined with the usual gastric vascular membrane, the surface of which is diversified by patches of follicular apertures along the upper curvature of the stomach, which patches increase in breadth as they approach the true digestive portion." A very similar condition maintains in Dorcopsis luctuosa, the only difference being that the squamous lining covering the whole of the cardiac cul-de-sac is also found to spread from the oesophageal orifice along the lesser curvature for a short distance towards the pylorus. As in Dendrolagus inustus, two strong parallel longitudinal folds run from the oesophageal opening, in this squamous-covered mucous membrane, for some distance on the way to the pyloric compartment, gradually disappearing before they reach it. The small intestine is 97 inches in length, with numerous oblong Peyer's patches distributed throughout its whole distance, averaging 1^ inch long, by 3 inch across. The caecum and large intestine are not sacculated ; the former has a length of 2\ inches, and its circumference is the same ; the latter is 32 inches long, being one third the length of the small intestine, which is the same proportion that Prof. Owenf observed between the same-named viscera of Dendrolagus inustus. The equally short caecum in the Hypsiprymni differs in having two lateral longitudinal bands which scarcely sacculate it. The spleen is perfectly Macropine, being narrow and elongate, with a well-developed third lobule. The liver very closely resembles that of the different species of Macropus. In comparing the livers of different animals it is my habit to estimate by sight, and therefore only approximately, the the bulk of the different lobes, and to write down the results in the * P. Z. S. 1852, p. 105. t P. Z. S. 1852, p. 106. |