The morning news. [volume] (Savannah, Ga.) 1887-1900, 1896-01-26
A CHAPTER ON EARS.
Some of the Curious Organs of the
Lower Animals.
From the New York Post.


We are accustomed to associate hearing
with visible ears. Not very long ago an
article was going the rounds Of the jour
nails treating the external ear as an in
dex OF temperament With that this pa
per has nothing to do. for its object is not
to discuss human ears. but to give hint
or two as to the different kinds of ears
met with in the animal kingdom.
1t is we'll known that, according to the ac-
cepted theories of light and sound, these
phenomena are the results of undulations
Of a universal medium to which wave
motion can be communicated. Just as
when you drop a stone into a vessel con-
tanning water Wave-motion is set up, and
is continued until it strikes the margin,
so Wave-motion is set up by extended en-
ergy in the medium, and is continued
until its course is stopped in some way
or other. The fluctuations of light travel
at the rate of $4,000 miles Gin round num-
bers) per second, while those of sound
travel over LOO feet lin round numbers
again) in the same time. Not only is
there a wonderful difference in the rate
of travelling, but also in the length of
the waves. The wave-length of the
sound produced by a G tuning-fork is PA
| inches, while for the production of white
| light( sunlighD there will be A, 400 waves
| in an inch; for red light, $780, and for
violet, $3.50. Then again, while the sound
of the tuning-fork makes only 512 vibra-
tons in a second, white light makes al
millions of millionss red, 45S millions OF
millions, and violet III millions OF mill
| ions.
1t is reasonable. to expect, therefore,
that the organs of man and the other ami
mails which are prepared to yield impress
ions of light and sound will be very differ
| ent in obstruction; and so it is with eyes
and ears-eyes for light, ears for sound.
And not only so. When the conditions
/ under which any creature lives demand
| consciousness of light or of sound, or
both, we shall find that the organs CORE
I s1sxaa nFa a n
the demands.
Most readers are acquainted with, at all
events, the general principles on which the
| human ear is constructed-an outer ear;
| an external opening and passage; mem
/ brane across that passage called the
| drum" a chain OF bones, one OF which Is
/ called 1.-The hammer" the second 1.-The an
| VIII" and the third 1.-The stirrup:" an oval
| opening in the partition of bone between
| the drum-chamber and the brain, which
| receives the flattened plate of the stirrup;
and the labyrinth. The simple mechanism
of sound strike the drum, are communicat-
ed by. it to the chain Of bones, and are
passed on by them to the brain. The laby-
| rinth deals with differences of pitch" in
/ sounds and of motion.
Now, Just as we find lowly forms OF 9TH
er organs among the lower animals" so
| do we meet with lowly ears some of which
i are very curious. The lowest animals do
not appear to have any organs which can
| definitely be called ears, although, as in
| the case Of earthworms, they are very SEN
sitfve to the vibrations of solid objects,
such as may be caused by some one walk
| ly, however, we find evidences of organs
| of hearing among the jelly-fish, Of which
you may see specimens stranded on the
| seashore after every tide. And, what is
/ very remarkable-so far as we know at
| present-there is no case where both Or
gans for hearing and organs Tor seeing are
| developed in the same species among these
medusae. Taking the species winch nave
| auditory organs, we md In some open
mouthed pits provided with sensitive hairs,
| In, he nj a. chain
| small bones, but a lump or series or Jumps,
| of secreted lime which are called otoliths
or ear-stones: while in others again the
pits are not open, but closed. In one me
| dusae there are no less than from thirty
| to fifty ear-stones arranged IN a double
! line in the cell so as to form a crescent.
| In another species the number of sepa-
/ rate ears amounts to no less than eighty!
| A sea-cucumber which lives in the depths
of the ocean has fifty-six of these auditory
A crustacean not unlike q shrimp In
| form has its ears in it's tail, If we may so
| call the terminal segment, while another
| the crayfish-has them at the base of the
! feelers on the head. In the craynsh the
/ ear is open, but bristles prevent foreign
| with a gelatinous fluid, in which otoilths
| float These are affected by the Vlbra-
! tions communicated by sound in the
| water; in their turn they convey the VI
| brations to certain hairs which line the
| cavity; these forward the message to the
! nerves, and finally 1T reaches the nerve
I
! Insects like grasshoppers, crickets and
! locusts have their ears in strange places
! some on the middle of the body, others
| on the legs. Whatever other uses the
! creature may make of the organs, they
| are veritable auditory organs. In them
| we find a membrane stretched across a
cavity with an opening to the external
| air, and within the cavity is a nerve-mass
! development at the end OF the AUDITORY
nerve. 1t would be hard, indeed, II the
! chirping cicada, "the cricket on the
| hearth" and the querulous katydid could
not be heard by their companions. 1t is
! said that those pests in the house-the
hies-can hear by means of some rows
| of corpuscles on the knobbed threads
/ which represent the hind wings of other
insects. It is uncertain whether bees can
hear If not. then al the labor of the
old-fashioned bee-keeper in beating tin
/ kettle at swarming time is in vain. some
naturalists who nave tired them WIN WIN
| every kind of sound and noise deny that
! they can hear. Others, equally conhdent,
! assert that they are very sensitive TO the
| calls of their queen at least.
Some of the mollusks have very remark
! able organs for hearing. A good instance
! is the garden slug. In its neck you would
| see under a microscope a pair of globules
! iIIed with a. clear fluid. In these are mi
mute ear-stones which swing to and fro,
| rotate and start off, first in one direction
/ and then in another but in no instance
| striking the walls of the cavity. If the
! globules are ruptured, the motions cease.
! The Imagination will ask whether she'll
| fish, or mollusks, can produce sounds
Il
may be true of the division as a whole,
| it is certainly true that some can emit
sounds. Two sea slugs were found by
! prof Grant to make sounds which he
| compared to 1.-The clink of steel wire
on the side of the jar" Cuttlefish have
| ears which follow the plan of the mol
| iusk's organ, and, indeed, as one watches
| the uncanny-looking octopus in a corner
| If a rock cavity, it is easy to imagine
! that while looking at you with that CLASSY
| eve he is also listening to what you say.
A careful angler tells you not to talk
while YOU are fishing Probably a quiet
| conversation will do no harm, but it must
| he remem bered that fishes have ears, al
| though sounds from the air may not reach
! them one of the oldest arrangements of
| ali is found in some fishes The air-blad-
1 der sends off fibres which are attached to
/ T,1eDohra mes stretched across cavities in the
/ skull, and from these membranes the vi
4 b1ations of sound are conveyed to the air.
/ bladder. Such is the case with the perch;
/ while. more strange still, in the carp
! three little bones aid the transmission of
/ THE ears of frogs and toads begin to ap-
/ Droach the type with which we are most
] familiar. and very effective ears they are
! too for a pet toad kept for several years
/ vyould always come from his hldlng-piace
lou sound