الْأَسْفَنْجَ .. كتاب في سبيل موسوعة علمية .. الدكتور أحمد ذكي

The sponge..

For centuries, man thought that the sponge was a plant.

⏺ Sponges originate in the sea
Units of animals.
It consists of colonies.

What would a boy do if you gave him a small piece of sponge?

Most likely, he gets up and dips it in the water, then takes it out, then squeezes it to get the water out of it, then returns it to the water, then returns to squeezing it, and so on. In all of this, he enjoys what he does. The boy is constantly expanding his experience by experiencing the things of this earth, and he finds in every experience
New and fun, he repeats it and finds the pleasure of playing in it.

The sponge is the only common material on earth that man uses for such a purpose. He gives it water and it drinks it until there is no room for more of it. Then he extracts the water from it easily and completely, until hardly a drop of it remains.

This is how man created and benefited from the sponge from the day he knew it. If he wants, use a cup of water. If he wants, he can use a paint brush, or if he wants, he can spread a liquid on a surface, or remove any excess from it, or if he wants, then he can wash what he does not want to scratch in an office, kitchen, bathroom, or car. And many other matters in industries that are far from people’s familiarity.

The reason for this is that it has many different pores
Tract.

- Division of sponges

Sponges form a phylum of animals
They are scientifically known as Porifera, meaning they contain pores, and we call them sponges, which is a lighter name. We took our Arabic word (the sponge) from what other European languages ​​took, from the Greek and Roman languages.

The sponge, as it is a phylum, is divided into:
Classes. Finally, to types.

- The sponge is an animal, not a plant

We said that sponges form a group of animals, and the reader is surprised that the sponge is an animal. His astonishment will diminish and his belief in what we say will become closer if we say that the animal that was in the sponge while it was alive is gone, and that what remains of it to us is its skeleton. The reader is surprised because he must know that there is something at the bottom of the sea sponge that does not move. Since it does not move, the closest thing that is thought to be a plant. Silence is the first characteristic of plants. People thought this until the year 1765. In this year, the British scientist John Elliss revealed the animal character of this living organism, the first to reveal it.

The animal character of the sponge will become clear from the description
Installing one of its units.

Sponges live in colonies, and each colony has a common structure

We said the spongy unit. This expression must have suggested to the reader that the sponge lives as a unit next to one unit next to another, and that they are units that live together in a colony that has a common solid structure that holds it and secretes it. Most of the sponges live in the shallow waters of seas and oceans, and a few in fresh water.

The structures of sponges have several shapes, including:
Symmetrical, including asymmetrical, which is the one that branches and expands.

Some of the structures are made of calcareous matter, which here is calcium carbonate, or of silica, meaning calcium oxide, or of the solid protein substance called spongin, which is the substance that remains in the sponge when it reaches our hands after its manufacture, and we call it sponge, and they are only the structure of some of its groups. .

- Installing a sponge unit

We start with the illustration, and the right part of it
It represents the simple spongy unit: it has the shape of a flask. What appears in the drawing are dots that are pores through which water enters the cavity of the unit, carried by the bacteria that are the food of the sponge, as well as by the oxygen dissolved in it, which is necessary for the life of the sponge and all life. The letters indicate:

(A) A section of the wall showing one of these pores through which water enters.
(b) The nozzle of the unit, from which water emerges after passing through its cavity.
(c) The cavity of the spongy unit, which is filled with running water.
In the left part of the picture we cut out a part of the wall of the foam unit and enlarged it. This is a description
It contains:
(1) A porous opening through which water enters.
(2) A door with an opening like the previous one, as it appears on the wall from the outside.
(3) The cavity of the spongy unit that contains water. (4) Cells with collars line the cavity of the spongy unit, and you can see in them what resembles whips that strike the water and push it to run towards the mouth of the spongy unit to emerge from it.
(5) Objects such as thorns and needles create the structure of the sponge, strengthening it and holding it together.
(6) A cell that covers the unit from the outside
(7) A cell like an amoeba that moves in a substance like a model.
(8) The typical substance that fills the space between the cells that cover the spongy unit from the outside, and between the cells with collars and flagella.

(An illustrative image, the right one depicts the shape of the sponge unit as a whole, and has the shape of a beaker, and the left one is a part cut out of the wall of the sponge unit, and enlarged to show its details.)

From this it appears that the most dangerous task of this spongy unit is to push sea water into it with force, and the whips help in pushing it. This water comes out of the unit's nozzle forcefully. The food in the water is captured by the cells with collars, and some of it goes to the amoeboid cells that move along the model, and these transport it to various parts of the body, as they are constantly in motion. This way the animal is fed. The animal takes its oxygen from...
Water, it is dissolved in it.