The Mankato free press. [volume] (Mankato, Blue Earth County, Minn.) 1879-1924, 1902-03-21
SENSITIVE TO SOUND
ACUTE POWERS OF HEARING WITH
WHICH FISH ARE ENDOWED.

ACUTE POWERS OF HEARING WITH
WHICH FISH ARE ENDOWED.
some Interesting Experiments That
Were Made to Determine Just What
Manner of Noises or Motions Would
Start1e Trout.
There are three phases of sense In
fish particularly interesting to the an
gler-their exquisite powers Of hearing,
Of seeing and their subtle, abnormal
sensitiveness to atmospheric influence.
With all our experience and study it is
doubtful if we have arrived at any
thing like full estimate of the acute
sensitiyeness with which fish are en-
dowed. l devote this article to hear
ing. By hearing l must obviously be
understood to mean their power of ap-
preciating the vibration caused by
sound, the conductor being either solid,
aerial or liquid.
In man sound detonates the eardrum,
and in that way when we are under
water we discover little Ineligible
meaning from sounds. But the same
vibrations are undoubtedly received by
the exquisitely sensitive hearing intel
Hgence of a fish. If l may use the
term, in a different and far more i'm
pressive way. By intelligence mean
an instructive recognition by their
bodies of some disturbance, just as
man recognizes passing breath Of air.
|. takes the form Of feeling.
l came to the conclusion that /
would make few experiments. Here
are one or two facts: A friend entered
into it with me, and we bethought our
selves of certain we'll known trout in
our preserve which were always
there Then we placed matched hur-
dies a day or two beforehand so that
the fish might get accustomed to them
in such a way that we could approach
close to their haunts without being
seen and watch the unsuspecting trout
through a small hole cut in the straw.
When one was not at home, the other
generally was. My friend undertook
the noise making, the observation.
From the sound of a gunshot 500
yards away, which made our trout dis
tinctly start, to the breaking of twig
three yards from the fish, which did
the same, we tried all kinds of sounds.
shrill and dull and at varying dis
tances, and the sum of our experiments
convinced US Of this: That our sensi-
lively organized friends felt the dis
placements of molecules through ether.
which we call sound, and the further
vibrating disturbance through what we
call water, which l verify believe con-
ducts sensation to the fish as readily
as glass permits the penetration Of
light to this paper, in proportion to the
distances and the character of the
sound. but that they did hear, or feel
rather. and with incredible quickness,
too, was conclusively demonstrated.
What they heard and were not alarm
ed at cannot tell, but when they were
alarmed it was evident enough by the
same kind of start they give when their
chief enemy suddenly peeps over the
bank. In only two cases could l dis
CONGI dCludI Lie
sends them down-a gunshot behind
the hurdle and a heavy stamp of the
foot near by. 1t is noteworthy that the
shrill sounds seemed to startle them
most. For instance, policeman's whis-
tie at ten yards sent one out into the
stream as If looking about for some
source Of danger, whereas a shout at
6ntnofoH
movement. Their way of shifting a
little farther from the bank when they
| have an inkling of danger is very
pretty side movement, well known nc
doubt. 1t seems for the purpose OF
watching the bank at better angle.
The common manner of showing
their alarm was by sudden culver,
! sometimes followed by sinking down
an inch or two, as much as to say
whats upw / very much doubt If
| ever crept up to my peephole without
| being detected, and yet l was careful
for, if you notice, trout once on the
| qui vive gives no sign of alarm at q
second movement or noise. Once pre-
pared he is immovable till he suddenly
darts off. You may throw your great
coat at him, and he either braves it stol
idly or bolts cleans away. Five minutes
perfect stiffness and they settle back to
confidence, and then they were again
easily startled. fancy the laws of re
fraction had something to do with II
and that even from the sky they some
times perceived my movements. hao
| often suspected this before.
| Another conclusion: l believe they
heard much th& appeared not to. A
sudden smack of the hands together
and there was decided culver, but
bird rattle, begun very softly and grad
ually brought up to its very loudest
and no notice seemed to be taken. Blu
doubtless, like ourselves, however lout
the noise, the gradient robs it OF 1t!
startle. However fanciful 1t ma!
sound, Of this I am thoroughly con
vinced-that water is such an immedi
ate transmitter Of vibration to fish tina
they recognize sound from the air near
~ as quickly as man. 1t is no argu
ment to say we do not when in it. W.
have no need. Fish have. And be
cause they have they are providentiall.
endowed with supersensitiveness to tina
particular nervous influence amonI