Snail

After a rain, you can see several rounds, gray shells moving slowly everywhere in the street, with a small wet head sticking out of it and wonderfully long pointed tentacles on the head.

They drag the huge shell on their backs all year round, unlike earthworms that move freely and easily, earthworms can burrow into the earth, protected by the earth, butterflies dance and fly freely, protected by the sky, only they do not help it, the earth does not help it, they only rely on themselves, only by their only protection - the heavy shell on their backs! to protect!

They are snails, to put it mildly, sometimes after the rain, walking in the street, not will also trample a few it!

After another rain, the street was again covered with snails of different sizes and colors, from a distance, like a round pearl is slowly sliding. I squatted down to observe, the snail's body is soft and collapsed without a skeleton, the whole body relies on the shell to protect, but I looked east, look west, how can not find the snail's eyes were no eyes how to see the road ah?

Oh! What are these two long, sharp things on the head of the snail, I gently touch it with my hand, and this long thing like a strip will immediately shrink back, I was also amazed, and hastily retracted my hands, with the "long" retraction, the snail also stopped crawling, the whole body curled up in the shell, after a while the long strip seems to know that there is no danger, as well as After a while the long strip seems to know that there is no danger, and "grow" out again, the snail also probe out of the shell.

Could it be that the snail's eyes are growing here? I was so amazed by this strange appearance that I went home and got a glass jar with a few snails in it, so I could study it!

I put his favorite vegetable leaves in the glass jar, I was more curious about how he could eat without a mouth?

Watching this little thing wriggling little by little, I had a question in my mind, how can a snail breathe without a nose? You know you can't survive without breathing!

Driven by curiosity, I decided to ask the omniscient computer.

The computer's answer: The snail's outer membrane cavity forms an opening at the mouth of the shell, called the "breathing hole", which is where the gas enters and leaves. When the snail retracts into its shell, it still leaves the opening at the mouth of the shell for breathing.

The membranes often form a cavity between the foot or visceral mass that is connected to the outside world, called the "coat cavity". Sometimes, through the snail's shell, you can see the dense network of pulmonary vessels underneath the shell, mostly on the front side, near the head, which is the location of the coat cavity.

So snails can breathe too! It seems that every animal has its unique breathing method, but we just don't observe and understand it carefully.

When I left the computer and came to the snail, I saw that there were several small openings on the leaves, which were bitten by the snail, and I saw that the snail stopped on the leaves for a while before he left slowly.

After observation, the snail does eat with its stomach, and there are many white particles under its stomach, that is its teeth, looking at the dense teeth, indeed some seepage.

A small snail, with only a thin shell how can it work? The shell as long as I gently press will immediately break into powder, a small snail does not have any protection, and does not need any protection, no matter what awaits them on the road ahead is death or survival, they rely on their steadfastness to go on.

And what about us? We have parents' care and help at home, relatives' care outside, and have not experienced any storms, how can we know how clear the world is after the storm?