; he would return now as nearly as possible over the same
route. He selected a gully that seemed to wind in that general
direction, and climbing down into it, started off along its floor.

The gully was some forty feet deep and seemed to average considerably
wider. Its sides were smooth and precipitous in some places; in others
they were broken. The Very Young Man had been walking some thirty
minutes when, as he came abruptly around a sharp bend, he saw before him
the most terrifying object he had ever beheld. He stood stock still,
fascinated with horror. On the floor of the gully, directly in front of
him, lay a gigantic lizard--a reptile hideous, grotesque in its
enormity. It was lying motionless, with its jaw, longer than his own
body, flat on the ground as though it were sunning itself. Its tail,
motionless also, wound out behind it. It was a reptile that by its
size--it seemed to the Very Young Man at least thirty feet long--might
have been a dinosaur reincarnated out of the dark, mysterious ages of
the earth's formation. And yet, even in that moment of horror, the Very
Young Man recognized it for what it was--the tiny lizard the Chemist had
sent into the valley of the scratch to test his drug!

At sight of the Very Young Man the reptile raised its great head. Its
tongue licked out hideously; its huge eyes stared unblinking. And then,
slowly, hastelessly, it began coming forward, its great feet scratching
on the rocks, its tail sliding around a boulder behind it.

The Very Young Man waited no longer, but turning, ran back headlong the
way he had come. Curiously enough, this new danger, though it terrified,
did not confuse him. It was a situation demanding physical action, and
with it he found his mind working clearly. He leaped over a rock, half
stumbled, recovered himself and dashed onward.

A glance over his shoulder showed him the reptile coming around the bend
in the gully. It slid forward, crawling over the rocks without effort,
still hastelessly, as though leisurely to pick up this prey which it
knew could not escape it.

The gully here chanced to have smooth, almost perpendicular sides. The
Very Young Man saw that he could not climb out; and even if he could, he
knew that the reptile would go up the sides as easily as along the
floor. It had been over a hundred feet from him when he first saw it.
Now it was less than half that distance and gaining rapidly.

For an instant the Very Young Man slackened hi