ry wonderful. But it's a _silly_ thing to
say."

"It's holiday time," I reminded her. "The necessity of sprinkling our
remarks with thoughtful words like 'economic' and 'sporadic' is over for
a bit. Let us be silly." I scratched in the rock the goal to which I was
urging my limpet and took out my watch. "Three thirty-five. I shall get
him there by four."

Celia was gazing at two baby fishes who played in and out a bunch of
sea-weed. Above the sea-weed an anemone sat fatly.

"I suppose they're all just as much alive as we are," she said
thoughtfully. "They marry"--I looked at my limpet with a new
interest--"and bring up families and go about their business, and it all
means just as much to them as it does to us."

"My limpet's business affairs mean nothing to me," I said firmly. "I am
only wrapped up in him as a sprinter."

"Aren't you going to try to move him again?"

"He's not quite ready yet. He still has his suspicions."

Celia dropped into silence. Her next question showed that she had left
the pool for a moment.

"Are there any people in Mars?" she asked.

"People down here say that there aren't. A man told me the other day
that he knew this for a fact. On the other hand, people in Mars know for
a fact that there isn't anybody on the Earth. Probably they are both
wrong."

"I should like to know a lot about things," sighed Celia. "Do you know
anything about limpets?"

"Only that they stick like billy-o."

"I suppose more about them _is_ known than that?"

"I suppose so. By people who have made a speciality of them. For one who
has preferred to amass general knowledge rather than to specialize it is
considered enough to know that they stick like billy-o."

"You haven't specialized in anything, have you?"

"Only in wives."

Celia smiled and went on, "How do you make a speciality of limpets?"

"Well, I suppose you--er--study them. You sit down and--and watch them.
Probably after dark they get up and do something. And of course, in any
case, you can always dissect one and see what he's had for breakfast.
One way and another you get to know things about them."

"They must have a lot of time for thinking," said Celia, regarding my
limpet with her head on one side. "Tell me, how do they know that there
are no men in Mars?"

I sat up with a sigh.

"Celia, you do dodge about so. I have barely brought together and
classified my array of facts about things in this world, when you've
dashed up to anot