his
report.

"Air pressure about 20 psi at the surface; temperature around
ninety-five Fahrenheit. Composition: eighteen percent oxygen,
seventy-five percent nitrogen, four-tenths of one percent carbon
dioxide, residue--inert gasses. That's not including water vapor, of
which there is a fair amount.

"I put a canary into the air, and the bird liked it, so I imagine it's
quite safe except for bacteria, perhaps. Naturally, at this altitude the
air is germ-free."

"Good," said Morey, "then we can take our swim and work without worrying
about spacesuits."

"Just a minute!" Fuller objected. "What about those germs Wade
mentioned? If you think I'm going out in my shorts where some flock of
bacteria can get at my tender anatomy, you've got another think coming!"

"I wouldn't worry about it," Wade said. "The chances of organisms
developing along the same evolutionary line is quite slim. We may find
the inhabitants of the same shape as those of another world, because the
human body is fairly well constructed anatomically. The head is in a
place where it will be able to see over a wide area and it's in a safe
place. The hand is very useful and can be improved upon but little.
True, the Venerians have a second thumb, but the principle is the same.

"But chemically, the bodies are probably very different. The people of
Venus are widely different chemically; the bacteria that can make a
Venerian deathly ill is killed the instant it enters our body, or else
it starves to death because it can't find the kind of chemical food it
needs to live. And the same thing happens when a Venerian is attacked by
an Earthly microorganism.

"Even on Earth, evolution has produced such widely varying types of life
that an organism that can feed on one is totally incapable of feeding on
another. You, for instance, couldn't catch tobacco mosaic virus, and the
tobacco plant can't catch the measles virus.

"You couldn't expect a microorganism to evolve here that was capable of
feeding on Earth-type tissues; they would have starved to death long
ago."

"What about bigger animals?" Fuller asked cautiously.

"That's different. You would probably be indigestible to an alien
carnivore, but he'd probably kill you first to find out. If he ate you,
it might kill him in the end, but that would be small consolation.
That's why we're going to go out armed."

Arcot dropped the ship swiftly until they were hovering a bare hundred
feet over the waters of