The Pulaski citizen. [volume] (Pulaski, Tenn.) 1866-current, 1875-07-08
Commercial Sponges.

1t is sad to consider how much VIZ
! lose in every walk of life through Iacl
| of little observation. There are few
| stonemasons who, like Hugh Miller, are
led to become noted geologists by no
| ting and studying the beautiful fossils in
| stones they chisel. A butcher may cut
up beeves and porkers by the hundreds s.
or fisherman spend long life on the
shore, without noticing the most OBJ
vious points of interest and instruction
In the physical structure of his victims
and only when a Daturalists calls his at
tention to the beautiful adaptations,
which have before passed unnOticed,
will he have his interest profoundly ex-
cited which may ever after give him q
new motive and zest in his work. The
most of us will use sponges in an in
definite variety of ways, all our lives,
without even once stopping to think
how they were formed whether they
are plants, animals, or neither, or what
are their history and habits.
The ordinary sponges of comm cree.
which We use so extensively, have but
little resemblance to animals or plants,
and belong to a class of organic bodies
concerning the affinities and proper
classification of which there has been
much doubt. And this doubt has led
naturslists to apply the question-b
ging appellation of zoophytes, or plant
animals, to these aud similar organisms
They are now generally considered mem
bers of the animal kingdom. The parts
we use are the mere skeletons, com
posed of a kind of horny subs ance
The animal itst If is a soft, jelly.ike,
amorphous mass, which fills up all the
intercellular spaces, lines the tubular
canals, and forms a jet black or some
times dark purplish skin on the out
side, covering the whole skeleton, ex-
oepting the larger openings, which pro-
iect beyond its general surface. In
this form the sponge exists in the water,
and, out of its native element, is hard
and glistening on the outside, and very
strongly resembles a piece of liver.
The mode of life in this low order of
existence, which is regarded as a COM
pound animal, is very simple, and we
wOuld be disposed to call it extremely
uneventfnl. Sponges grow, by a kind
of hchen like root, TO some foreign OBJ
ject on the sea-hoor, and never move
from their position they have no
power to contract or expand their body
as a whole, or any part of it and they
are quite insenslble to every sort of
be that of absorbing large quantities
of water, which they again yield up on
pressure without any injury to their
texture. The water, which perneates
their whole mass, and maintains con.
stant circulation thIough it, keeps the
skeleton soft and elastic, brings to the
animals the air and food ON which they
subsist, and carries away waste matter
from the body.
On examination of a sponge skeleton,
it will be seen that the porus surface
is finer and of closer texture than the
interior, that there are large aperturcs
scattered Unfortunately over the sur
face, and between these are much
finer openings, covering the complete
outer surface of the sponge. The lat
ter are called pores, and serve as chan
nels of entrance to the water, which,
after circulating through the body by
means of the torturous and branching
canals which make up its inner skeleton,
passes out at the larger openings.
These chimney-like apertures are called
oscuLd, but the name is a misnomer, for
they are, in reality, vents. They vary
in number in the different species, and
are sometimes reduced to a single one.
By what force the water is made to cir
culate through the sponge mass is not
definitely known. Some have attributed
it to vibratile cili@, planted within the
porus canals which, by their motion,
create q circulation in the water. 9th
ers ascribe it to the principle of osmo-
sis, by which membranes of all animals,
aud many other porus substances trans
nit fluids and gases according TO their
density and power to act on the trans
mittinp substance.
When obtained for commercial pur-
poses, the animal matter can be re-
moved by soaking it long time in salt
water and then-Rfter it Is rotted by
this nleans-rinsing it out. This leaves
the horny skeletons just as we use
them.
The finest sponges of commerce come
| from the Mediterranean sea Our best
! bath sponges are doubtless from this
! locality. but the coarser sponges We
see most commonly are largely from
| the coast of Florida or the Bahama Is
| lands. Sponges are found abundantly
! in tropical waters generally, anu per
haps nowhere more abundant than II
| the seas of the Australian islands.
They gradually decrease IN numbers
towards the colder latiiudes till they
! become entirely extinct. They vary
much In shape. Some are beautifully
/ shaped like a vase, others are semi
! cylindrical, others nearly flat like al
| open fan some are braL ched like tn,
| opened fingers OF a hand, and are calleC
glove spOnges, and in others thes'
branches seem to be reduced to only
one, which is shaped somewhat Ike
club. These different shapes may be
long to one species, and the difference
are due, so far as known, TO the FAC
| that the first mentioned are found II
deep water, and they grade, IN tn,
order described, mp to the last, whicl
grow in much shallOwer water,
Sponges are not confined to recen
seas. though the commercial ones art
not known to have existed earlier, be
cause the ktratOse matter furnlshe
hardly favorable conditions for petrl
faction. In the Oolite and chalk Tor
nations, spOnges contslnlng hinty spl
cuies were very abundant; and IN mos
of the earlier formations, large sponge
containing calcareous spicules abound
ed. These very closely resemble corals
and have been mistaken for them o
some of our best geologists. The sp
cule or needle shaped particles, Whio
are often microscopic in size, are nc
thrown in without order, but are Al
ranged TO support the skeleton. In
horny sponges do not secrete OF az
posit spicules, but these are sometime
, found within the skeleton in broke
I and disordered form, which shows the
| vvara taken IN from without