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Show 1895.] HYDBACHN1D POUND IN COENWALL. 197 organs in my species fairly correspond with those described by Schaub; but here the resemblance suddenly ceases: instead of the large simple bundle of striped muscles filling up the interior of the cap and arising from the other genital organs, w e have an entire absence of muscles within the cap, although some small muscles are attached round it. The inner side of the chitinous cap rests upon the distal ends of a number of columnar radiating cells forming an even layer about "016 m m . thick; these cells take stain very deeply and rapidly, so much so that it is difficult to prevent their staining too darkly if other parts are to be stained at all. The proximal ends of these cells rest upon a basal membrane (mb.) about *003 m m . thick, which does not stain at all, and which is continuous with the external membrane of a solid pyriform mass of large elongated cells. Each cell is largest at its inner extremity and diminishes outward. All the cells converge toward the smallest part of the organ, i. e. the point where it passes through the hole in the cuticle; they then spread out again a trifle, and their distal ends abut on the inner side of the basal membrane before mentioned; the distal portion of each cell, i. e, the part between the hole in the cuticle and tbe basal m e m brane, stains darkly and rapidly; the rest of the cell much more slightly and slowly. Each cell near its larger (inner) end contains a large clearly defined nucleus with a distinct nucleolus, those in the respective cells being very regularly arranged. The whole organ has a formation entirely different from what would be expected in a sucker, and indeed has much more the appearance of a sense-organ of some kind ; e. g. it looks not unlike the simple ocellus of an insect. I do not for a moment suggest that such is its function; such a thing would be unlikely in the extreme; and I do not detect any sufficient nerve-supply to justify it if it were not; but I do suggest that, in this species at all events, the organs are not suckers, and that it seems not impossible that they may have some sensory function. It struck m e at first whether they could be glandular, but I do not find any point of discharge, nor any signs of cells breaking clown and emitting their contents ; and it has to be remembered that they are present equally developed in both sexes. Of course I at once admit that the position of the organs is such as to render it most probable that they perform some office in connection with the genital organs. Glands of unknown Function (Plate IX. fig. 28). Lying immediately below the lateral portions of the hollow square of the ventriculus, immediately above the genital organs in both sexes, and about the middle (longitudinally) of the latter organs, exist a pair of almost globular, or slightly elliptical, organs of about *04 m m . diameter in the male and about *05 to *1 m m . in the female. These organs (fig. 19, gu.) have every appearance of being glands ; they are composed of distinctly-nucleated closely- |
