Although the planet had much in common with Luna as regarded size, mass, and airlessness, its landscape was extremely different. The daily terrific heatings which it underwent, followed by abrupt and equally intense temperature drops each night, had formed an excellent substitute for weather; and elevations that might at one time have rivaled the Lunar ranges were now mere rounded hillocks like that containing Cunningham’s cave. As on the Earth’s moon, the products of the age-long spalling had taken the form of fine dust, which lay in drifts everywhere. What could have drifted it, on an airless and consequently windless planet, struck Cunningham as a puzzle of the first magnitude; and it bothered him for some time until his attention was taken by certain other objects upon and between the drifts. These he had thought at first to be outcroppings of rock; but he was at last convinced that they were specimens of vegetable life — miserable, lichenous specimens, but nevertheless vegetation. He wondered what liquid they contained, in an environment at a temperature well above the melting point of lead.

The discovery of animal life — medium-sized, crablike things, covered with jet-black integument, that began to dig their way out of the drifts as the sun warmed them —

completed the job of dragging Cunningham’s attention from his immediate problems. He was not a zoologist by training, but the subject had fascinated him for years; and he had always had money enough to indulge his hobby. He had spent years wandering the Galaxy in search of bizarre life forms — proof, if any were needed, of a lack of scientific training — and terrestrial museums had always been more than glad to accept the collections that resulted from each trip and usually to send scientists of their own in his footsteps.