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Show 1876.] MUCOUS MEMBRANE IN KANGAROOS. 167 Obvious characters of the Mucous Membrane. With the unassisted eye three distinct regions can be detected in the stomachs of both animals, the mucous membrane presenting well-marked differences in feel, appearance, and, as will be presently seen, in microscopic structure. For the most part they are marked off from each other by distinct lines of demarcation ; these, however, are more obvious between the first and second regions than between the second and third, although, in the latter case also, especially in Dorcopsis, the distinction can be made out even with the naked eye. In the two species examined these three regions have somewhat different distributions, as is indicated in the accompanying diagrams. Thus, in Dorcojms (Diagram 1) the first or cardiac region (A), which Diagram 1. Stomach of Dorcopsis luctuosa. is covered with an epithelium obviously continuous with and similar to that of the gullet, occupies more than a third of the inner surface of the organ, lining the whole of the cardiac fundus, and terminating towards the middle of the stomach by a well-marked line of demarcation ( X ), which extends from the lesser curvature obliquely downwards and to the left along the anterior and posterior walls to end in the greater curvature about opposite to the opening of the gullet, or a little to the right of that point. Commencing on either side of the cardia two parallel ridges or folds of the mucous membrane (not represented in the diagram) pass for about 3 inches along the lesser curvature, depending into the cavity of the organ. They are little more than half an inch apart, and not quite half an inch in depth ; they become less prominent and gradually subside towards their termination. They bring to mind the ridges which are found in a somewhat similar situation in the Ruminant stomach, but they are by no means so strongly muscular. The second region ( B ) commences at the oblique line above traced out, which separates it from the first or cardiac region, and extends from here to the left, as far as the pylorus, comprehending all the rest of the inner surface of the organ except a circular patch (C) about 2 | inches in diameter, which occupies the |
