Pupil

To create a visual organ, the first thing was to find a way to interact with light—a so-called photochemical reaction.

The difficulty of creating a visual organ lay in the retina, which could receive light and convert it into comprehensible bioelectrical signals. Human eyes could see the vast world precisely because they possessed such a vital component.

"To carry out photoreactions, mitochondria must be involved, converting matter from its ground state through 'photoactivation' into an excited state. The excited matter is then brought into the mitochondria for processing, returning from the excited state to the ground state. In and out, that creates an electronic signal."

"Since light has wavelengths of varying degrees, the number of photons participating in photochemical reactions per unit of time will differ. This can be used to map images of the outside world through electronic signals."

"Then, by building continuity from those rapidly rendered images, like film movies from the eighties and nineties, a dynamic visual system can be formed."

As its self-exploration deepened, the structure of the visual system in Huo Gu's mind gradually became clearer.

Speaking of mitochondria, Huo Gu thought of that single-celled organism it had captured before, the one that used sulfur for its life processes.

"The mitochondria that process sulfur don't meet my requirements..."

"Even hypochlorous acid would require ultraviolet light for photolysis..."

"Wouldn't that mean I could only see the world from an ultraviolet perspective?"

Huo Gu thought for a moment.

"It's still necessary to modify the mitochondria."

Time passed bit by bit. Huo Gu did not know exactly how much time had gone by; it only knew that the cell colony had undergone more than four hundred generations.

During that time, the number of cells had not increased much from before, mainly for safety reasons.

With a potentially active volcano nearby, Huo Gu needed the cell colony to retain a basic level of mobility. Excessive numbers would only be a burden at a time like this.

At last, the blueprint for the visual system took shape in Huo Gu's mind, and the new mitochondria had also been designed.

These mitochondria primarily processed hydrochloric acid, combining it with carbon dioxide to convert the hydrochloric acid into hypochlorous acid.

After calming itself, Huo Gu's attention became intensely focused.

Over this period, it had discovered that as long as it concentrated intensely on one matter, it could enter the same state it had reached when fighting the bacteriophages. Its thoughts would become exceptionally fast.

Naturally, this came at a cost. The cells' metabolism accelerated significantly, and their average lifespan shortened.

Huo Gu estimated that this was the result of the cells speeding up both energy release and energy absorption.

Though it could not bear to do so, Huo Gu still had to proceed for the safety of the whole.

The cells divided. They had received the command: the collective needed new members.

The cylindrical organisms drifting through the liquid gradually began opening and closing their mouths in a regular rhythm, gathering enough material to build the visual system they required.

As time passed, a small bulge protruded from the side of the cylindrical organisms. Gradually, after some time, the little bulge grew into a thin pillar.

After another period of time, the pillar stopped lengthening and instead grew thicker.

At the very center of this pillar were countless fine threads formed from cells. They were the "optical cables" that transmitted the retina's electrical signals.

Next came the inner cells that transported nutrients, wrapping around those "optical cables."

Then came the outermost layer: wall cells that formed a Great Wall against invading viruses.

The pillar was the final preparatory step. While it grew, Huo Gu also gathered enough chlorine to construct a retina capable of receiving ultraviolet light.

The wall cells at the tip of the pillar began dividing, growing into a sphere.

Then, within the secure space built by the wall cells, the inner cells transported the gathered chlorine into this sphere.

Finally, the cells serving as the "optical cables" also began dividing. Some of the cells they produced transcribed DNA; their cytoplasm turned acidic, and they gained mitochondria capable of producing hypochlorous acid.

These were the retinal cells Huo Gu had prepared.

Starting from one half of the sphere's far end, the cells gradually became transparent, like crystal-clear glass. This was so the gathered light could be refracted onto the retina.

The work of the wall cells and inner cells did not change; Huo Gu merely adjusted the pigments within their cytoplasm.

At the instant the retina officially began operating, Huo Gu's perspective changed.

It gained an additional viewpoint, yet it did not feel abrupt at all. Huo Gu felt no sense of incongruity. It seemed inborn, as though this was how its viewpoint was meant to be.

Compared to the perspective that allowed it to comprehensively analyze the entire cell colony, this viewpoint was extremely narrow.

It could only see one hundred and eighty degrees. The other one hundred and eighty degrees were completely invisible.

However, Huo Gu did not find this troubling. The issue of restricted vision would be easy to solve. It only needed to grow another similar visual system on the other side to achieve a full three-hundred-and-sixty-degree view without blind spots.

Huo Gu began surveying its surroundings.

How should it put this...

You never knew until you looked. Once you did, you were shocked.

Not far from Huo Gu, a colossal column of smoke rose from below, drifting straight upward. Countless bubbles, impurities, and all sorts of other debris accompanied it.

From time to time, Huo Gu could also see a bright gleam at the source of the smoke column.

It was an active underwater volcano!

While grieving that its guess had been right, Huo Gu also felt fortunate.

If it had not created the visual system and had simply drifted through this area on a wing and a prayer, it might have ended up buried in that active volcano at any moment.

The currents everywhere could now be explained as well. Underwater active volcanoes erupted intermittently. These eruptions were not explosions of force from beneath the crust, but pressure releases caused by blocked vents.

After these small waves were reflected by the jagged rocks around them, they formed erratically surging turbulent currents.

"Eh? Something's not right..."

"Doesn't that mean the cells are organisms suited only to living in acidic liquid?!"

An active volcano inevitably polluted the water. Judging from the microorganism that used sulfur in its life processes, the liquid nearby should all be acidic.

In other words, since the cell colony could frolic about so energetically here, that meant they were actually organisms that lived in acidic environments.

At that thought, Huo Gu's head began to ache—if it still had a head.