The valve is small and steeply inclined, with its free posterior edge abutting against a semicircular, deeply depending collar.  It is moderately transparent, and bears two pairs of short stiff bristles, in the same position as in the other species.  The presence of these four bristles, in contrast with the absence of those on the antennae and collar, indicates that they are of functional importance, namely, as I believe, to prevent too large animals forcing an entrance through the valve.  The many glands of diverse shapes attached to the valve and round the collar in the previous species are here absent, with the exception of about a dozen of the two-armed or transversely elongated kind, which are seated near the borders of the valve, and are mounted on very short footstalks.  These glands are only the 3/4000 of an inch (.019 mm.) in length; though so small, they act as absorbents.  The collar is thick, stiff, and almost semi-circular; it is formed of the same peculiar brownish tissue as in the former species.

The bladders are filled with water, and sometimes include bubbles of air.  They bear internally rather short, thick, quadrifid processes arranged in approximately concentric rows.  The two pairs of arms of which they are formed differ only a little in length, and stand in a peculiar position (fig. 28); the two longer ones forming one line, and the two shorter ones another parallel line.  Each arm includes a small spherical mass of brownish matter, which, when crushed, breaks into angular pieces.  I have no doubt that these spheres are nuclei, for closely similar ones [page 435] are present in the cells forming the walls of the bladders.  Bifid processes, having rather short oval arms, arise in the usual position on the inner side of the collar.

These bladders, therefore, resemble in all essential respects the larger ones of the foregoing species.  They differ chiefly in the absence of the numerous glands on the valve and round the collar, a few minute ones of one kind alone being present on the valve.  They differ more conspicuously in the absence of the long bristles on the antennae and on the outside of the collar.  The presence of these bristles in the previously mentioned species probably relates to the capture of aquatic animals.

Fig. 28. (Utricularia montana.) One of the quadrifid processes; much enlarged.

It seemed to me an interesting question whether the minute bladders of Utricularia montanaserved, as in the previous species, to capture animals living in the earth, or in the dense vegetation covering the trees on which this species is epiphytic; for in this case we should have a new sub-class of carnivorous plants, namely, subterranean feeders.  Many bladders, therefore, were examined, with the following results:—­