processes contained transparent, often yellowish,
more or less confluent, spherical or irregularly shaped,
masses of matter. Some of the processes, however,
contained only fine granular matter, the particles
of which were so small that they could not be defined
clearly with No. 8 of Hartnack. The delicate
layer of protoplasm lining their walls was in some
cases a little shrunk. On three occasions the
above small masses of matter were observed and sketched
at short intervals of time; and they certainly changed
their positions relatively to each other and to the
walls of the arms. Separate masses sometimes
became confluent, and then again divided. A single
little mass would send out a projection, which after
a time separated itself. Hence there could be
no doubt that these masses consisted of protoplasm.
Bearing in mind that many clean bladders were examined
with equal care, and that these presented no such
appearance, we may confidently believe that the protoplasm
in the above cases had been generated by the absorption
of nitrogenous matter from the decaying animals.
In two or three other bladders, which at first appeared
quite clean, on careful search a few processes were
found, with their outsides clogged with a little brown
matter, showing that some minute animal had been captured
and had decayed, and the arms here included a very
few more or less spherical and aggregated masses;
the processes in other parts of the bladders being
empty and transparent. On the other hand, it
must be stated that in three bladders containing dead
crustaceans, the processes were likewise empty.
This fact may be accounted for by the animals not having
been sufficiently decayed, or by time enough not having
been allowed for the generation of proto- [page 413]
plasm, or by its subsequent absorption and transference
to other parts of the plant. It will hereafter
be seen that in three or four other species of Utricularia
the quadrifid processes in contact with decaying animals
likewise contained aggregated masses of protoplasm.
On the Absorption of certain Fluids by the Quadrifid
and Bifid processes.—These experiments
were tried to ascertain whether certain fluids, which
seemed adapted for the purpose, would produce the same
effects on the processes as the absorption of decayed
animal matter. Such experiments are, however,
troublesome; for it is not sufficient merely to place
a branch in the fluid, as the valve shuts so closely
that the fluid apparently does not enter soon, if at
all. Even when bristles were pushed into the
orifices, they were in several cases wrapped so closely
round by the thin flexible edge of the valve that
the fluid was apparently excluded; so that the experiments
tried in this manner are doubtful and not worth giving.
The best plan would have been to puncture the bladders,
but I did not think of this till too late, excepting
in a few cases. In all such trials, however, it
cannot be ascertained positively that the bladder,
though translucent, does not contain some minute animal
in the last stage of decay. Therefore most of
my experiments were made by cutting bladders longitudinally
into two; the quadrifids were examined with No. 8 of
Hartnack, then irrigated, whilst under the covering
glass, with a few drops of the fluid under trial,
kept in a damp chamber, and re-examined after stated
intervals of time with the same power as before.