and the other up the middle of the ventral surface. In full-grown
bladders the ventral bundle divides close beneath the collar, and the
two branches run on each side to near where the corners of the valve
unite with the collar; but these branches could not be seen in very
young bladders.
FIG. 23. (Utricularia vulgaris.) Longitudinal section through a young
bladder, 1/100 of an inch in length, with the orifice too widely open.
The accompanying figure (fig. 23) shows a section, which happened to be
strictly medial, through the footstalk and between the nascent antenn
of a bladder of Utricularia vulgaris, 1/100 inch in diameter. The
specimen was soft, and the young valve became separated from the collar
to a greater degree than is natural, and is thus represented. We here
clearly see that the valve and collar are infolded prolongations of the
walls of the bladder. Even at this early age, glands could be detected
on the valve. The state of the quadrifid processes will presently be
described. The antenn at this period consist of minute cellular
projections (not shown in the above figure, as they do not lie in the
medial plane), which soon bear incipient bristles. In five instances
the young antenn were not of quite equal length; and this fact is
intelligible if I am right in believing that they represent two
divisions of the leaf, rising from the end of the bladder; for, with
the true leaves, whilst very young, the divisions are never, as far as
I have seen, strictly opposite; they [page 426] must therefore be
developed one after the other, and so it would be with the two antenn .
At a much earlier age, when the half formed bladders are only 1/300
inch (.0846 mm.) in diameter or a little more, they present a totally
different appearance. One is represented on the left side of the
accompanying drawing (fig. 24). The young leaves
FIG. 24. (Utricularia vulgaris.) Young leaf from a winter bud, showing
on the left side a bladder in its earliest stage of development.
at this age have broad flattened segments, with their future divisions
represented by prominences, one of which is shown on the right side.
Now, in a large number of specimens examined by my son, the young
bladders appeared as if formed by the oblique folding over of the apex
and of one margin with a prominence, against the opposite margin. The
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