Fantastic Voyage - By Isaac Asimov Page 0,45

before it can leak back, the red blood corpuscles have picked it up. Meanwhile carbon dioxide wastes leak out in the other direction from blood to lungs. Dr. Duval is waiting to watch that happen. That's why he didn't answer."

"No excuses are necessary. I know what it is to be absorbed in one thing to the exclusion of another." He grinned broadly. "I'm afraid, though, that Dr. Duval's absorptions are not mine."

Cora looked uncomfortable but a cry from Owens blocked off her answer.

"Straight ahead!" he called. "Watch what's coming."

All eyes turned ahead. A blue-green corpuscle was bumping along ahead of them, scraping its edges slowly against the walls of the capillary on either side. A wave of faint straw made its appearance at the edges and then swept inward, until all the darker color was gone.

Other blue-green corpuscles making their way past them turned color likewise. The headlights were picking up only straw color ahead and the color deepened into orange-red in the distance.

"You see," said Cora, excitedly, "as they pick up the oxygen, the hemoglobin turns into oxyhemoglobin and the blood brightens to red. That will be taken back to the left ventricle of the heart now and the rich, oxygenated blood will be pumped all over the body."

"You mean we have to go back through the heart again," said Grant, in instant concern.

"Oh, no," said Cora. "Now that we're in the capillary system, we'll be able to cut across." She didn't sound very certain of it, however.

Duval said, "Look at the wonder of it. Look at the God-given wonder of it."

Michaels said, stiffly, "It's just a gas exchange. A mechanical process worked out by the random forces of evolution over a period of two billion years."

Duval turned fiercely, "Are you maintaining that this is accidental; that this marvelous mechanism, geared to perfection at a thousand points and all interlocking with clever certainty, is produced by nothing more than just the here-and-there collision of atoms?"

"That's exactly what I want to tell you. Yes." said Michaels.

At which point both, facing each other in belligerent exasperation, looked up with a snap at the sudden raucous sound of a buzzer.

Owens said, "What the devil ..:'

He flicked at a switch desperately but a needle on one of his gauges was dropping rapidly toward a red horizontal line. He shut off the buzzer and called out, "Grant!"

"What is it?"

"Something's wrong. Check the Manual right over there." Grant followed the pointing finger, moving quickly, while Cora crowded behind.

Grant said, "There's a needle in the red danger zone under something marked TANK LEFT. Obviously, the left tank's losing pressure."

Owens groaned and looked behind. "And how. We're bubbling air into the blood-stream. Grant, get up here quickly." He was shucking his harness.

Grant scrambled toward the ladder, making room as best he might for Owens to squeeze past on the way down.

Cora managed to make out the bubbles through the small rear window. She said, "Air bubbles in the blood-stream can be fatal ..."

"Not this kind," said Duval, hastily. "On our miniaturized scale we produce bubbles that are too tiny to do harm. And when they de-miniaturize they will have become too well distributed to do harm then either."

"Never mind the danger to Benes," said Michaels grimly. ''we need the air."

Owen called back to Grant, who was seating himself at the controls. "Just leave everything as it is for now, but watch for any red signal flashes anywhere on the board."

He said to Michaels as he passed him. "There must be frozen valve. I can't think of anything else." I le moved back and opened a panel with a quick wrench I one end, using a small tool he had removed from the ticket of his uniform. The maze of wires and circuit breakers was revealed in frightening complexity.

Owens' skilled fingers probed through them quickly, testing and eliminating with an ease and certainty that could have marked the ship's designer. He tripped a switch, checked it quickly and let it snap shut, then moved forward to look over the auxiliary controls underneath the windows in the bow of the ship.

"There must have been some damage outside when we scraped into the pulmonary artery, or when the arterial blood-surge hit us."

"Is the valve usable?" asked Michaels.

"Yes. It was jarred a little out of alignment, I think, and then something forced it open just now, maybe just one of the pushes of Brownian movement, it stayed that way. I've realigned it now and it will give no further trouble, only-"

"Only