Fantastic Voyage - By Isaac Asimov Page 0,36

themselves into their seats, still watching their surroundings in absorption.

"I think it's a shame that we'll only have a few minutes for this," said Cora. "Dr. Duval, what are those?"

A mass of very tiny structures, clinging together and forming a tight spirally-shaped pipe, passed by. Several more followed, each expanding and contracting as it went.

"Ah," said Duval, "I don't recognize that."

"A virus, perhaps," suggested Cora.

"A little too large for virus, I think, and certainly like none I've seen. -Owens, are we equipped to take samples?"

Owens said, "We can get out of the ship, if we have to, doctor, but we can't stop for samples."

"Come now, we may not have this chance again." Duval rose testily to his feet. "Let's get a piece of that into the ship. Miss Peterson, you ..."

Owens said, "This ship has a mission, doctor."

"It doesn't matter to ..." began Duval, but then broke off at the firm grip of Grant's hand on his shoulder.

"If you don't mind, doctor," said Grant, "let's not argue about this. We have a job to do and we won't stop to pick up anything or turn aside to pick up anything or as much as slow down to pick up anything. I take it you understand that and will not raise the subject again."

In the uncertain flickering light reflected from the arterial world outside, Duval was clearly frowning.

"Oh, well," he said, ungraciously, "they've gotten away anyhow."

Cora said, "Once we complete this job, Dr. Duval, there will be methods developed for miniaturization for indefinite intervals. We can then take part in a real exploration."

"Yes, I suppose you're right."

Owens said, "Arterial wall to the right.

The Proteus had made a long, sweeping curve and the wall seemed about a hundred feet away, now. The somewhat corrugated amber stretch of endothelial layer that made up the inner lining of the artery was clearly visible in all its detail.

"Hah," said Duval, "what a way to check on athero-sclerosis. You can count the plaques."

"You could peel them off, too, couldn't you?" asked Grant.

"Of course. Consider the future. A ship can be sent through a clogged arterial system, loosening and detaching the sclerotic regions, breaking them up, boring and reaming out the tubes. Pretty expensive treatment, however."

"Maybe it could be automated eventually," said Grant. "Perhaps little housekeeping robots can be sent in to clean up the mess. Or perhaps every human being in early manhood can be injected with a permanent supply of such vessel-cleansers. Look at the length of it."

They were closer still to the arterial wall now, and the ride was growing rougher in the turbulence near it. Looking ahead, though, they could see the wall stretching ahead for what seemed unbroken miles before veering off.

Michaels said, "The circulatory system, counting all its vessels to the very smallest, is as I told you earlier, a hundred thousand miles long, if it were strung out in one long line."

"Not bad," said Grant.

"A hundred thousand miles in the unminiaturized scale. On our present scale, it is," he paused to think, then said, "over three trillion miles long-half a light year. To travel through every one of Benes' blood-vessels in our present state would be almost the equivalent of a trip to a star."

He looked about haggardly. Neither their safety thus far, nor the beauty of their surroundings, seemed to have consoled him much.

Grant strove to be cheerful. "At least the Brownian motion isn't at all bad," he said.

"No," said Michaels. Then, "I didn't come off too well a while ago when we first discussed Brownian motion."

"Neither did Duval just now in the matter of samples. I don't think any of us are doing really well."

Michaels swallowed. "That was typically single-minded of' Duval to want to stop for specimens."

He shook his head and turned to the charts on the curving desk against one wall. It, and the moving dot of light upon it, was a duplicate of the much larger version in the control tower, and of the smaller version in Owens' bubble. He said,

"What's our speed, Owens?"

"Fifteen knots, our scale,"

"Of course, our scale," said Michaels, pettishly. He lifted his slide-rule from its recess and made a rapid calculation. "We'll be at the branch in two minutes. Keep the wall at its present distance when you turn. That will bring you safely into the middle of the branch and you can then move smoothly into the capillary net without further branching. Is that clear?"

"All clear!"

Grant waited, watching always through the window. For a moment, he caught the shadow of