Evening capital. (Annapolis, Md.) 1884-1910, 1884-10-27

There Is little plant, common enough
in our ponds and known as the bladder
wort, which has suddenly sprung into
Importance for breeders OF carp. The
bladder-wort (genus Utricularia) Is root
less plant, and of still water, and usually
found floating half in and half out of the
water, the branching and stem-like leaves
forming the submerged float from which
rises the flower stem. To the leaves are
attached curiously nsect-like bladders
filled with water, and varying in size in
the different species, reaching at times
diameter of one fifth OF an inch.
1t was formerly, and with much prob
ability, supposed that these bladders
served the purpose of floats; for until a
few years ago it was taken for granted
that air and not water filled them. 1t is
now known, however, that the bladders
serve a more useful purpose than merely
to keep the head of the plant above
water; they are the digestive organs of
the Utricularia, and at the same time are
SO constituted as to form very ingenious
but extremely simple trap for catching
food. 1t is into these bladders that
thousands. of carp eggs find their I'M
whiting way, together with many insects,
crustacea, and other tiny objects, both
animate and inanimate.
1t is only recently that the Utricularia
has been accused of destroying carp
eggs. but for nearly thirty years it has
been known as receiver of small insects
and crustaceans, and it has been known
as an insect feeder for at least twenty
years.
The bladder is pear-shaped. with an
opening at the small end. Around the
mouth are antenna-like projections or
bristles, which. according to Darwin, are
for the purpose of warding off and keep
ing out insects of too great size. The
mouth is closed by valve which yields
readily to light pressure. but offers an
immOvable barrier to the once captured
creature The utmost strength compat1.
BILE with such structure has apparently
been attained. The valve is a thin and
transparent plate, and, by means of the
water behind it, is made to stand out a
bright spot, which Darwin thinks may
attract prey. Something certainly at
tracts the tiny denizens of the water, for
they swim up to the mouth and crawl
into the bladder by the readily yielding
door. As there is no seductive secretion
here, as in the case of many insect-de-
stroying plants, the great naturalist's sur
mise is probably correct.
Some of the insectivorous plants, on
catching their prey, at once pour out a
digestive fluid analogous to the gastric
Juice Of the human stomach, but with
the Utricularia it is not so. The insects
or other food when caught in the blad-
der are merely captives. and swim about
in their confined quarters with eager &C
tivity in their endeavor to find an outlet,
until asphyxia for lack of oxygen comes
on. Even now the plant makes no effort
to digest the animal food, but waits pa
tiently until decay takes place, and the
animal matter is putrefaction resolved
into fluids which the numerous papille
lining the bladder can absorb.
Examination and repeated experiment
proved conclusively that the greedy lit
tie bladders were making sad havoc with
the fish, and in consequence carp breed
ers are hidden to open war vigorously
on Utricularia and all its species. 1t may
seem at hasty glance that the small
bladders can hardly be responsible for
any very extensive destruction of eggs
or small fish, but the doubters of the
ability of Insignificant agents, acting to-
gether, to produce stupendous effects
may be referred to the microscopic rhizo-
pods or the earth worms, each in their
own way performing wonderful feats in
the way of earth building and earth pre-
serving. Scientific american.