He continued to move with caution. There were dangers here, but he went forward steadily. He still held a great mass of edible mushroom under one arm and from time to time broke off a fragment, chewing it meditatively. But always his eyes searched here and there for threats of harm.

Behind him the faint, shrill outcry had risen only slightly in volume. It was still too far away to attract his notice. Army ants, however, were working havoc in the distance. By thousands and millions, myriads of them advanced across the fungoid soil. They clambered over every eminence. They descended into every depression. Their antennae waved restlessly. Their mandibles were extended threateningly. The ground was black with them, each one more than ten inches long.

A single such creature, armored and fearless as it was, could be formidable enough to an unarmed and naked man like Burl. The better part of discretion would be avoidance. But numbering in the thousands and millions, they were something which could not be avoided. They advanced steadily and rapidly; the chorus of shrill stridulations and clickings marking their progress.

Great, inoffensive caterpillars crawling over the huge cabbages heard the sound of their coming, but were too stupid to flee. The black multitudes blanketed the rank vegetables. Tiny, voracious jaws tore at the flaccid masses of greasy flesh.

The caterpillars strove to throw off their assailants by writhings and contortions—uselessly. The bees fought their entrance into the monster hives with stings and wing-beats. Moths took to the air in daylight with dazzled, blinded eyes. But nothing could withstand the relentless hordes of small black things that reeked of formic acid and left the ground behind them empty of life.

Before the horde was a world of teeming life, where mushrooms and other fungi fought with thinning numbers of cabbages and mutant earth-weeds for a foothold. Behind the black multitude was—nothing. Mushrooms, cabbages, bees, wasps, crickets, grubs—every living thing that could not flee before the creeping black tide reached it was lost, torn to bits by tiny mandibles.

Even the hunting spiders and tarantulas fell before the black host. They killed many in their desperate self-defense, but the army ants could overwhelm anything—anything at all—by sheer numbers and ferocity. Killed or wounded ants served as food for their sound comrades. Only the web spiders sat unmoved and immovable in their collossal snares, secure in the knowledge that their gummy webs could not be invaded along the slender supporting cables.


3. THE PURPLE HILLS

The army ants flowed over the ground like a surging, monstrous, inky tide. Their vanguard reached the river and recoiled. Burl was perhaps five miles away when they changed their course. The change was made without confusion, the leaders somehow communicating the altered line of march to those behind them.