remained intact and nearly air-tight. But when the army ants began to tear at the edible surfaces despite the heat they encountered, fresh air found its way to the smouldering masses of fungus. The slow combustion became rapid combustion. The dull heat became fierce flames. The slow trickle of thin smoke became a huge column of thick, choking, acrid stuff that set the army ants that breathed it into spasms of convulsive writhing.
From a dozen points the flames burst out. A dozen or more columns of blinding smoke rose to the heavens. A pall of fume-laden smoke gathered above the range of purple hills, while Burl watched apathetically. And the serried ranks of army ants marched on to the widening furnaces that awaited them.
They had recoiled from the river, because their instinct had warned them. Thirty thousand years without danger from fire, however, had let their racial fear of fire die out. They marched into the blazing orifices they had opened in the hills, snapping with their mandibles at the leaping flames, springing at the glowing tinder.
The blazing areas widened, as the purple surface was undermined and fell in. Burl watched the phenomenon without comprehension and even without thankfulness. He stood, panting more and more slowly, breathing more and more easily, until the glow from the approaching flames reddened his skin and the acrid smoke made tears flow from his eyes.
Then he retreated slowly, leaning on his club and looking back. The black wave of the army ants was sweeping into the fire, sweeping into the incredible heat of that carbonized material burning with an open flame. At last there were only the little bodies of stragglers from the great ant-army, scurrying here and there over the ground their comrades had denuded of all living things. The bodies of the main army had vanished—burnt to crisp ashes in the furnace of the hills.
There had been agony in that flame, dreadful agony such as no man would like to dwell upon. The insane courage of the ants, attacking with their horny jaws the burning masses of fungus, rolling over and over with a flaming missile clutched in their mandibles, sounding their shrill war-cry while cries of agony came from them—blinded, their antennæ burnt off, their lidless eyes scorched by the licking flames, yet going madly forward on flaming feet to attack, ever attack this unknown and unknowable enemy.
Burl made his way slowly over the hills. Twice he saw small bodies of the army ants. They had passed between the widening surfaces their comrades had opened, and they were feeding voraciously upon the hills they trod on. Once Burl was spied, and a shrill war-cry was sounded, but he moved on, and the ants were busily eating. A single ant rushed toward him. Burl brought down his club and a writhing body remained, to be eaten later by its comrades when they came upon it.
Again night fell. The sky grew red in the west, though the sun did not shine through the ever-present cloud bank. Darkness spread across the sky. Utter blackness fell over the whole mad world, save where the luminous mushrooms shed their pale light upon the ground and fireflies the length of Burl's arm shed their fitful gleams upon an earth of fungus growths and monstrous insects.
Burl made his way across the range of mushroom hills, picking his path with 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 for sounds of danger. Something rustled heavily in a thicket of mushrooms a hundred yards away. There were sounds of preening, and of delicate feet placed lightly here and there upon the ground. Then the throbbing beat of huge wings began suddenly, and a body took to the air.
A fierce, down-coming current of air smote Burl, and he looked upward in time to catch the outline of a huge body—a moth—as it passed above him. He turned to watch the line of its flight, and saw a strange glow in the sky behind him. The mushroom hills were still burning.
He crouched beneath a squat toadstool and waited for the dawn, his club held tightly in his hands, and his ears alert for any sound of danger. The slow-dropping, sodden rain kept on. It fell with irregular, drum-like beats upon the tough top of the toadstool under which he had taken refuge.
Slowly, slowly, the sodden rainfall continued. Drop by drop, all the night long, the warm pellets of liquid came from the sky. They boomed upon the hollow heads of the toadstools, and splashed into the steaming pools that lay festering all over the fungus-covered earth.
And all the night long the great fires grew and spread in the mass of already half-carbonized mushroom. The flare at the horizon grew brighter and nearer. Burl, naked and hiding beneath a huge mushroom, wondering, with wide eyes, what this thing was, watched it grow near him. He had never seen a flame before.
The overhanging clouds were brightened by the flames. Over a stretch at least a dozen miles in length and from half a mile to three miles across, seething furnaces sent columns of dense smoke up to the roof of clouds, luminous from the glow below them, and spreading out and forming an intermediate layer below the cloudbanks themselves.
It was like the glow of all the many lights of a vast city thrown against the sky—but the last great city had moulded into fungus-covered rubbish thirty thousand years before. Like the flitting of airplanes above a populous city, too, was the flitting of fascinated creatures above the glow.
Moths and great flying beetles, gigantic gnats and midges, grown huge with the passing of time, they fluttered and danced the dance of death above the flames. As the fire grew nearer to Burl, he could see them.
Colossal, delicately-formed creatures swooped above the strange blaze. Moths with their riotously-colored wings of thirty-foot spread beat the air with mighty strokes, and their huge eyes glowed like carbuncles as they stared with the frenzied gaze of intoxicated devotees into the glowing flames below them.
Burl saw a great peacock moth soaring above the burning mushroom hills. Its wings were all of forty feet across, and fluttered like gigantic sails
