Earth, but it is not unknown in the Space Service annals."

The colonel pursed his lips and kept his silence. He knew that what the
biologist said was true.

"The trouble is," said Petrelli snappishly, "that we are starving in the
midst of plenty. We are like men marooned in the middle of an ocean with
no water; the water is there, but it's undrinkable."

"That's what I wanted to get at," said Colonel Fennister. "Is there any
chance at all that we'll find an edible plant or animal on this planet?"

The three scientists said nothing, as if each were waiting for one of
the others to speak.

* * * * *

All life thus far found in the galaxy had had a carbon-hydrogen-oxygen
base. Nobody'd yet found any silicon based life, although a good many
organisms used the element. No one yet had found a planet with a halogen
atmosphere, and, although there might be weird forms of life at the
bottom of the soupy atmospheres of the methane-ammonia giants, no brave
soul had ever gone down to see--at least, not on purpose, and no
information had ever come back.

But such esoteric combinations are not at all necessary for the
postulation of wildly variant life forms. Earth itself was prolific in
its variations; Earthlike planets were equally inventive. Carbon,
hydrogen, and oxygen, plus varying proportions of phosphorus, potassium,
iodine, nitrogen, sulfur, calcium, iron, magnesium, manganese, and
strontium, plus a smattering of trace elements, seem to be able to cook
up all kinds of life under the strangest imaginable conditions.

Alphegar IV was no different than any other Earth-type planet in that
respect. It had a plant-dominated ecology; the land areas were covered
with gigantic trees that could best be described as crosses between a
California sequoia and a cycad, although such a description would have
made a botanist sneer and throw up his hands. There were enough smaller
animals to keep the oxygen-carbon-dioxide cycle nicely balanced, but the
animals had not evolved anything larger than a rat, for some reason. Of
course, the sea had evolved some pretty huge monsters, but the camp of
the expedition was located a long way from the sea, so there was no
worry from that quarter.

At the time, however, the members of the expedition didn't know any of
that information for sure. The probe teams had made spot checks and
taken random samples, but it was up to the First Analytical Expedition
to make su