for the flying creatures that fluttered helplessly over an utterly changed landscape. Here and there little bands of stragglers moved busily over the denuded earth, searching for some fragment of food that might conceivably have been overlooked by the main body.
Burl was putting forth his last ounce of strength. His limbs trembled, his breathing was agony, sweat stood out upon his forehead. He ran, a little, naked man with the disjointed fragment of a huge insect's limb in his hand, running for his insignificant life, running as if his continued existence among the million tragedies of that single day were the purpose for which the universe had been created.
He sped across an open space a hundred yards across. A thicket of beautifully golden mushrooms (Agaricua coelareus) barred his way. Beyond the mushrooms a range of strangely colored hills began, purple and green and black and gold, melting into each other, branching off from each other, inextricably tangled.
They rose to a height of perhaps sixty or seventy feet, and above them a little grayish haze had gathered. There seemed to be a layer of tenuous vapor upon their surfaces, which slowly rose and coiled, and gathered into a tiny cloudlet above their tips.
The hills, themselves, were but masses of fungus, mushrooms and rusts, fungoids of every description, yeasts, "musts," and every form of fungus growth which had grown within itself and about itself until this great mass of strangely colored, spongy stuff had gathered in a mass that undulated unevenly across the level earth for miles.
Burl burst through the golden thicket and attacked the ascent. His feet sank into the spongy sides of the hillock. Panting, gasping, staggering from exhaustion, he made his way up the top. He plunged into a little valley on the farther side, up another slope. For perhaps ten minutes he forced himself on, then collapsed. He lay, unable to move further, in a little hollow, his sharp-toothed club still clasped in his hands. Above him, a bright yellow butterfly with a thirty-foot spread of wings fluttered lightly.
He lay motionless, breathing in great gasps, his limbs refusing to lift him.
The sound of the army ants continued to grow near. At last, above the crest of the last hillock he had surmounted, two tiny antennæ appeared, then the black, glistening head of an army ant, the forerunner of its horde. It moved deliberately forward, waving it antennæ ceaselessly. It made its way toward Burl, tiny clickings coming from the movements of its limbs.
A little wisp of tenuous vapor swirled toward the ant, a wisp of the same vapor that had gathered above the whole range of hills as a thin, low cloud. It enveloped the insect—and the ant seemed to be attacked by a strange convulsion. Its legs moved aimlessly. It threw itself desperately about. If it had been a animal, Burl would have watched with wondering eyes while it coughed and gasped, but it was an insect breathing through air-holes in its abdomen. It writhed upon the spongy fungus growth across which it had been moving.
Burl, lying in an exhausted, panting heap upon the purple mass of fungus, was conscious of a strange sensation. His body felt strangely warm. He knew nothing of fire or the heat of the sun, and the only sensation of warmth he had ever known was that caused when the members of his tribe had huddled together in their hiding place when the damp chill of the night had touched their soft-skinned bodies. Then the heat of their breath and their bodies had kept out the chill.
This heat that Burl now felt was a hotter, fiercer heat. He moved his body with a tremendous effort, and for a moment the fungus was cool and soft beneath him. Then, slowly the sensation of heat began again, increased until Burl's skin was red and inflamed from the irritation.
The thin and tenuous vapor, too, made Burl's lungs smart and his eyes water. He was breathing in great, choky gasps, but the period of rest—short as it was—had enabled him to rise and stagger on. He crawled painfully to the top of the slope, and looked back.
The hill-crest on which he stood was higher than any of those he had passed in his painful run, and he could see clearly the whole of the purple range. Where he was, he stood near the farther edge of the range, which was here perhaps half a mile wide.
It was a ceaseless, undulating mass of hills and hollows, ridges and spurs, all of them colored, purple and brown and golden-yellow, deepest black and dingy white. And from the tips of most of the pointed hills little wisps of vapor rose up.
A thin, dark cloud had gathered overhead. Burl could look to the right and left and see the hills fading into the distance, growing fainter as the haze above them seemed to grow thicker. He saw, too, the advancing cohorts of the army ants, creeping over the tangled mass of fungus growth. They seemed to be feeding as they went, upon the fungus that had gathered into these incredible monstrosities.
The hills were living. They were not upheavals of the ground, they were festering heaps of insanely growing, festering mushrooms and fungus. Upon most of them a purple mould had spread itself so that they seemed a range of purple hills, but here and there patches of other vivid colors showed, and there was a large hill whose whole side was a brilliant golden hue. Another had tiny bright-red spots of a strange and malignant mushroom whose properties Burl did not know, scattered all over the purple with which it was covered.
Burl leaned heavily upon his club and watched dully. He could run no more. The army ants were spreading everywhere over the mass of fungus. They would reach him soon.
Far to the right the vapor thickened. A column of smoke arose. What Burl did not know and would never know was that far down in the interior of that compressed mass of fungus, slow oxidation had been going on. The temperature of the interior had been raised. In the darkness and the dampness deep down in the hills, spontaneous combustion had begun.
Just as the vast piles of coal the railroad companies of thirty thousand years before had gathered together sometimes began to burn fiercely in their interiors, and just as the farmers' piles of damp straw or hay suddenly burst into fierce flames from no cause, so these huge piles of tinder-like mushrooms had been burning slowly within themselves.
There had been no flames, because the surface
