across. A thicket ofbeautifully golden mushrooms (_Agaricus caesareus_) barred his way.Beyond the mushrooms a range of strangely colored hills began, purpleand green and black and gold, melting into each other, branching offfrom each other, inextricably tangled.
They rose to a height of perhaps sixty or seventy feet, and above them alittle grayish haze had gathered. There seemed to be a layer of tenuousvapor upon their surfaces, which slowly rose and coiled, and gatheredinto a tiny cloudlet above their tips.
The hills, themselves, were but masses of fungus, mushrooms and fungoidsof every description, yeasts, "musts," and every form of fungus growthwhich had grown within itself and about itself until this great mass ofstrangely colored, spongy stuff had gathered in a mass that undulatedunevenly across the level earth for miles.
Burl burst through the golden thicket and attacked the ascent. His feetsank into the spongy sides of the hillock. Panting, gasping, staggeringfrom exhaustion, he made his way up the top. He plunged into a littlevalley on the farther side, up another slope. For perhaps ten minutes heforced himself on, then collapsed. He lay, unable to move further, in alittle hollow, his sharp-toothed club still clasped in his hands. Abovehim, a bright yellow butterfly with a thirty-foot spread of wing,fluttered lightly.
He lay motionless, breathing in great gasps, his limbs stubbornlyrefusing to lift him.
* * * * *
The sound of the army ants continued to grow near. At last, above thecrest of the last hillock he had surmounted, two tiny antennae appeared,then the black glistening head of an army ant, the forerunner of itshorde. It moved deliberately forward, waving its antennae ceaselessly.It made its way toward Burl, tiny clickings coming from the movements ofits limbs.
A little wisp of tenuous vapor swirled toward the ant, a wisp of thesame 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 bya strange convulsion. Its legs moved aimlessly. It threw itselfdesperately about. If it had been an animal, Burl would have watchedwith wondering eyes while it coughed and gasped, but it was an insectbreathing through air-holes in its abdomen. It writhed upon the spongyfungus growth across which it had been moving.
Burl, lying in an exhausted, panting heap upon the purple mass offungus, was conscious of a strange sensation. His body felt strangelywarm. He knew nothing of fire or the heat of the sun, and the onlysensation of warmth he had ever known was that caused when the membersof his tribe had huddled together in their hiding place when the dampchill of the night had touched their soft-skinned bodies. Then the heatof their breaths and their bodies had kept out the chill.
This heat that Burl now felt was a hotter, fiercer heat. He moved hisbody with a tremendous effort, and for a moment the fungus was cool andsoft beneath him. Then, slowly, the sensation of heat began again, andincreased until Burl's skin was red and inflamed from the irritation.
The thin and tenuous vapor, too, made Burl's lungs smart and his eyeswater. He was breathing in great, choking gasps, but the period ofrest--short as it was--had enabled him to rise and stagger on. Hecrawled painfully to the top of the slope, and looked back.
The hill-crest on which he stood was higher than any of those he hadpassed in his painful run, and he could see clearly the whole of thepurple range. Where he was, he was 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 andspurs, all of them colored, purple and brown and golden-yellow, deepestblack and dingy white. And from the tips of most of the pointed hillslittle wisps of vapor rose up.
A thin, dark cloud had gathered overhead. Burl could look to the rightand left, and see the hills fading into the distance, growing fainter asthe haze above them seemed to grow thicker. He saw, too, the advancingcohorts of the army ants, creeping over the tangled mass of fungusgrowth. They seemed to be feeding as they went, upon the fungus that hadgathered into these incredible monstrosities.
The hills were living. They were not upheavals of the ground, they werefestering heaps of insanely growing, festering mushrooms and fungus.Upon most of them a purple mould had spread itself so that they seemed arange of purple hills, but here and there patches of other vivid colorsshowed, and there was a large hill whose whole side was a brilliantgolden hue. Another had tiny bright red spots of a strange and malignantmushroom whose properties Burl did not know, scattered all over thepurple with which it was covered.
Burl leaned heavily upon his club and watched dully. He could run nomore. 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 Burldid not know and would never know was that far down in the interior ofthat compressed mass of fungus, slow oxidization had been going on. Thetemperature of the interior had been raised. In the darkness and thedampness deep down in the hills, spontaneous combustion had begun.
Just as the vast piles of coal the railroad companies of thirty thousandyears before had gathered together sometimes began to burn fiercely intheir interiors, and just as the farmers' piles of damp straw suddenlyburst into fierce flames from no cause, so these huge piles oftinder-like mushrooms had been burning slowly within themselves.
There had been no flames, because the surface remained intact and nearlyair-tight. But when the army ants began to tear at the edible surfacesdespite the heat they encountered, fresh air found its way to thesmouldering masses of fungus. The slow combustion became rapidcombustion. The dull heat became fierce flames. The slow trickle of thinsmoke became a huge column of thick, choking, acrid stuff that set thearmy ants that breathed it into spasms of convulsive writhing.
From a dozen points the flames burst out. A dozen or more columns ofblinding smoke rose to the heavens. A pall of fume-laden smoke gatheredabove the range of purple hills, while Burl watched apathetically. Andthe serried ranks of army ants marched on to the widening furnaces thatawaited them.
They had recoiled from the river, because their instinct had warnedthem. Thirty thousand years without danger from fire, however, had lettheir racial fear of fire die out. They marched into the blazingorifices they had opened in the hills, snapping with their mandibles atthe leaping flames, springing at the glowing tinder.
* * * * *
The blazing area widened, as the purple surface was undermined and fellin. Burl watched the phenomenon without comprehension and even withoutthankfulness. He stood, panting more and more slowly, breathing more andmore easily, until the glow from the approaching flames reddened hisskin and the acrid smoke made tears flow from his eyes.
Then he retreated slowly, leaning on his club and looking back. Theblack wave of the army ants was sweeping into the fire, sweeping intothe incredible heat of that carbonized material burning with an openflame. At last there were only the little bodies of stragglers from thegreat ant-army, scurrying here and there over the ground their comradeshad denuded of all living things. The bodies of the main army hadvanished--burnt to crisp ashes in the furnace of the hills.
There had been agony in that flame, dreadful agony such as no man wouldlike to dwell upon. The insane courage of the ants, attacking with theirhorny jaws the burning masses of fungus, rolling over and over with aflaming missile clutched in their mandibles, sounding their shrill warcry while cries of agony came from them--blinded, their antennae burntoff, their lidless eyes scorched by the licking flames, yet going madlyforward on flaming feet to attack, ever attack this unknown andunknowable enemy.
Burl made his way slowly over the hills. Twice he saw small bodies ofthe army ants. They had passed between the widening surfaces theircomrades had opened, and they were feeding voraciously upon the hillsthey trod on. Once Burl was spied, and a shrill war cry was sounded, buthe moved on, and the ants were busily eating. A single ant rushed towardhim. Burl brought down his club, and a writhing body remained to beeaten later by its comrades when th
ey came upon it.
Again night fell. The skies grew red in the west, though the sun did notshine through the ever present cloud bank. Darkness spread across thesky. Utter blackness fell over the whole mad world, save where theluminous mushrooms shed their pale light upon the ground and firefliesthe length of Burl's arm shed their fitful gleams upon an earth offungus growths and monstrous insects.
Burl made his way across the range of mushroom hills, picking his pathwith his large blue eyes whose pupils expanded to great size. Slowly,from the sky, now a drop and then a drop, now a drop and then a drop,the nightly rain that would continue until daybreak began.
Burl found the ground hard beneath his feet. He listened keenly forsounds of danger. Something rustled heavily in a thicket of mushrooms ahundred yards away. There were sounds of preening, and of delicate feetplaced lightly here and there upon the ground. Then the throbbing beatof huge wings began suddenly, and a body took to the air.
A fierce, down-coming current of air smote Burl, and he looked