Finally: This membrana propria sends out from the alveolar walls, processes, ensheathing—how complete I cannot say—the gland cells. I cannot otherwise explain the glistening lines, which we see in examining sections VI extending from the alveolar wall between the cells, resembling altogether the sections of the alveolar walls. To investigate this matter more accurately, I have stained sections with carmine, also with log-wood, and have found that the alveolar wall and these lines stain the same way. Further breaking up such a section by manipulation with cover-glass, one can obtain fragments of these processes, thus demonstrating that these lines are not merely optical illusions. The nuclei of this membrana propria are situated on its inner surface and could be distinguished in the gland of the cat, mentioned above, not only by their more oval, oblong or elliptical form, from the more roundish nuclei of the gland cells, but just as plainly by the lighter red or pinkish staining which they take on the nuclei of the gland cells being stained a deeper red. Compressing very small fragments of gland-substance (always of course in glycerine), by means of the cover-glass, beating and pushing it from side to side, thus bursting the alveolus and tearing the membrane and isolating it from the contained gland cells, one can prepare for examination greater or smaller pieces of this membrane. There are by such means obtainable fragments with all sorts of processes and fringes, short and long, many and few, which undoubtedly may remind one of “connective tissue cells.” (See fig. 4.) More convincing than these are membraneous pieces, which may be obtained of various sizes. (See figs. 5, 6.) I have a drawing of such a fragment, which, if enlarged as figs. 1 and 2, would cover over one-quarter of the page, and to which a number of nuclei, more than six, are attached. As a rule, this membrane will, by the manipulations with the cover-glass, not be spread out, but rather folded up, huddled together inclosing some of the gland cells, forming an indescribable nest.