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Show 1876.] MUCOUS MEMBRANE IN KANGAROOS. 171 tinued also into the openings themselves. Tracing it further into the gland, we find the cells, still columnar, less tapering at their fixed extremities ; and, moreover, while in the mouths of the glands, as on the general surface, they stand vertical to the basement membrane with their free ends on the same level, in the throat of the glands, on the other hand, they slant upwards, so that they more or less overlap one another (fig. 2, n). Further downwards in the tube the cells become gradually shorter, so as to appear quadrangular or cubical in form ; at the same time the lumen of the tube becomes much narrowed, and, indeed, in vertical sections of the mucous membrane is in some parts hardly perceptible. These shortly columnar or cubical epithelium-cells occupy the greater part of the length of the tube (ni). They have each a very distinct round or oval nucleus with one or two nucleoli; and the protoplasm of the cell, which is granular in appearance, becomes stained by logwood, although not nearly so intensely as the nucleus. Towards the fundus (b) of the gland the cells undergo a change. They become gradually larger, and rounded or polyhedral in shape; their outlines become more distinct; and the substance of the cell acquires a clear or very faintly granular aspect, and, moreover, becomes hardly at all stained by logwood. Further, the nuclei, for the most part, have not their usual characteristic vesicular appearance, but in most of the cells (which line, and in some cases almost fill, the fundus) appear as intensely stained, shrunken or compressed bodies, usually situated excentrically in the cell, and not frequently flattened up against the basement membrane. In short, the appearance of these polyhedral cells of the fundus of the gland brings strongly to mind the cells which occupy the alveoli of the salivary gland (submaxillary) ; and it is not impossible that the clear, swollen-out aspect they present may be due to a cause similar to that to which the salivary cells are believed to owe their characteristic appearance, the presence, namely, within the cells at the time of death of mucus or some similar substance, which swells up on the addition of fluid. Or it may be that the protoplasm of these lowermost cells is younger and less changed than that of the other cells of the gland, and consequently that they are more readily acted upon by reagents, or by the secretion of the gland itself after death, than the rest. At any rate there seems a close analogy between the structure of the deeper parts of these tubular glands and the alveoli of the compound racemose glands. At the same time it must be remembered that some of the latter class of glands, the pancreas for example, do not exhibit the clear, swollen-out cells with excentrically placed nuclei, but their alveolar walls resemble more, on the contrary, the cubical cells of the middle parts of the tubular glands above described ; and it is worthy of note that in some parts of the second region of the Kangaroo stomach, those for instance in the neighbourhood of the pylorus, the tubular glands, which are here very long, are lined in the deeper as well as in the middle parts, by cubical or shortly columnar cells which are similar throughout. The substance of the mucous membrane between the tubular |