The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1882-02-23
ABOUT SPONGEs.

|
ABOUT SPONGES.
Sponges are so common and so famil-
lar that many of us have used them all
our lives without stopping to admire
their curious and interesting structure,
or to inquire into the history of their
past lives. We may, indeed, have no.
ticed that they can be squeezed into a
very small space, and that they will re-
| turn to their natural shape when the
pressure is removed. We have perhaps
noticed also that they are full of little
holes or pores, and that they win alb
sorb an astonishing quantity of water.
You know there has been a doubt
whether sponges belong to the animal
or to the vegetable kingdom. For a
long time naturalists were in doubt about
the matter, but it is now settled that
they are animals, living and growing on
the bottom OF the ocean. The only part
OF the sponge that reaches us is the
skeleton. The living sponge is a very
different object. Shall we see what we
can find out about it?
Upon naming the word "animal.'' a
picture comes before our minds of some
| creatures having a mouth to eat with.
and eyes to see with, and possessing
feet or wings, or some other means Of
moving about; but the sponges are far
from this. They are probably the low
est animals with which you are ac-
quainted. They have no nerves. no
heart, no lungs, no mouth and no stom-
ach.
Live sponges consist Of ielly-like
bodies, united in mass, and supported
by a framework of horny fbers, and
needle-shaped objects called "spicules. -
This jelly-like flesh, covering all parts
OF the skeleton, is about as thick as the
white OF an egg, but it decays irnmedi-
ately after the death of the sponge.
During life the flesh presents many
bright colors; in some species it is of q
brilliant green. while in others it is or
ange, red, yellow. etc.
The frame work varies in different
kinds of sponge. In those which are
valuable for our use it consists of horny
fibers interviewer in all directions until
they form mass of lacy network. This
you can easily see with the naked eve,
but by looking through a microscope
you will see beauty you had not mag
lned, and which but for this valuable
instrument would never have been
dreamed of. In our ordinary sponees
these hberS are all that remain of the
former living animal, the soft flesh hay
ing been removed. 1t is found that the
horny fibers are composed of a substance
very similar to the silk of a silk-worm's
cocoon. They are exceedingly tough
and durable. Most of us have discover
ed that good sponge becomes like an
old and tried friend, and that unless it
is abused it seems as if it might never
wear out. rs.
In looking at any sponge you win
notice large holes through it, with many
small pores scattered between them.
The living sponge is constantly drawing
in water at the small pores. This water
passes through set of branching canals,
and is thrown out from the large holes
on the surface. With a microscope little
fountains may be seen constantly play
ing from the large holes of a living
sponge. The circulation is kept up in
the canals by the movement of :" cilia.,'
which are delicate threads waving gent
~ but continually. The word ella
means "eyelashes;' let usremember it,
Tor this is name we shall often want to
use. The stream of water thus PASSING
through the sponge brings to every part
OF it small particles of food, and all the !
air it needs for breathing purposes.
Everything that lives must eat and
breathe, but how is the sponge to eat
without a mouth? When the food
touches any part of its body, the soft.
lelly-like flesh sinks in to form little
bag; at the same time the surrounding
parts creep out over the morsel of food.
until it is entirely covered and dipested.
After this the flesh returns to it's ORIGINAL
position, and any shell or other refuse
that remains from the meal is washed
away.
Sponges have a curious manner of
producing their young. At certain sea-
sons very small oval masses of jelly are
formed ON the inner surface of the ca
mails, which finally drop off. They re-
main in the canals for time, and. be-
come perfect eggs, after which thew are
thrown out by the stream issuing from
the fountains, and instead of falling to
the bottom, as we might suppose such
helpless masses of jelly would do, they
SWIM around as if they meant to have q
little sport before commencing the sober
realities of life,
You will be interested to know that
while these jellydike eggs were resting
IN the canals of the parent sponge, deli
cate ella (Which we learned about lust
now were forming at one end of the
egg. These ella strike the water with
a rapid motion, and the eggs are rowed
about through it until they settle down
and attach themselves to some rock or
shell on the bottom of the ocean, and
finally grow up into the perfect sponge.
The waters are swarming with these
eggs at certain seasons, and great guam