Farrow got his machinery unloaded and ready to run. Among other things, there was a land vehicle on light caterpillar treads capable of running where there were no roads and carrying a load of several tons. And there was an out-and-out tractor with multiple attachments.

Beeson was busy in his laboratory working on samples from the soil.

David brought in the one new point that was of interest. He had been out hunting among the boulders again, and it was almost dark when he returned. He told Renner about it at the supper table, with the others listening in.

"I think the natives eat the lichen," he said.

"I haven't seen much else they could eat," Beeson muttered.

"There's more of the lichen than you might think," David said, "if you know where to look for it. But, even at that, there isn't very much. The thing is, it looks like it's been cropped. It's never touched if the plants are small, or half grown, or very nearly ready. But just as soon as a patch is fully mature, it is stripped bare, and there never seems to be any of it dropped, or left behind, or wasted."

"If that's all they have to live on," Thorne said, "they have it pretty thin!"

The natives began to be seen nearer to the camp. At first there were just glimpses of them, a hairy face or head seen at the edge of a rock, or the sight of a stocky figure dashing from boulder to boulder. As they grew braver, they came out more into the open. They kept their distance, and would disappear into the rocks if anyone made a move toward them, but, if no attention was paid them, they moved about freely.

In particular, they would come, each evening, to stand in a ragged line near one of the nests of boulders. From there, they would watch the crewmen eat. There were never more than twelve or fifteen of them, a bandy-legged lot, with thick, heavy torsos, and hairy heads.

It was on one of these occasions that Dr. Thorne happened to look up.