"If it were not for this thistle-down—" began the leader.

But now a big globe came drifting past within a score of yards of them. It was really not an even sphere at all, but a vast, soft, ragged, filmy thing, a sheet gathered by the corners, an aerial jelly-fish, as it were, but rolling over and over as it advanced, and trailing long cobwebby threads and streamers that floated in its wake.

"It isn't thistle-down," said the little man.

"I don't like the stuff," said the gaunt man.

And they looked at one another.

"Curse it!" cried the leader. "The air's full of lit up there. If it keeps on at this pace long, it will stop us altogether."

An instinctive feeling, such as lines out a herd of deer at the approach of some ambiguous thing, prompted them to turn their horses to the wind, ride forward for a few paces, and stare at that advancing multitude of floating masses. They came on before the wind with a sort of smooth swiftness, rising and falling noiselessly, sinking to earth, rebounding high, soaring—all with a perfect unanimity, with a still, deliberate assurance.

Right and left of the horsemen the pioneers of this strange army passed. At one that rolled along the ground, breaking shapelessly and trailing out reluctantly into long grappling ribbons and bands, all three horses began to shy and dance. The master was seized with a sudden, unreasonable impatience. He cursed the drifting globes roundly. "Get on!" he cried; "get on! What do these things matter? How can they matter? Back to the trail!" He fell swearing at his horse and sawed the bit across its mouth.

He shouted aloud with rage. "I will follow that trail, I tell you," he cried. "Where is the trail?"

He gripped the bridle of his prancing horse and searched amidst the grass. A long and clinging thread fell across his face, a grey streamer dropped about his bridle arm, some big, active thing with many legs ran down the back of his head. He looked up to discover one of those grey masses anchored as it were above him by these things and flapping out ends as a sail flaps when a boat comes about—but noiselessly.