He was near the middle when he was alarmed at finding the ground giving way beneath him. It was sinking rapidly downward, and he clutched desperately at the bushes to save himself, but those that he grasped yielded and went, too. In his terror and despair he cried out, and fought like a madman to save himself; but there was nothing firm or substantial upon which he could lay hold, and he was helpless to check his descent. Down, down, down he went in the pulseless darkness, lower and lower, until he found himself going through the dizzying air--to where? CHAPTER XXV. WITHIN THE EARTH It was like a terrible dream, and, for an instant or more, during which Fred Munson was descending through the gloom and darkness, he believed it was such indeed; but he was quickly recalled from his error by his arrival at the end of his journey. The truth was that the boy, in crawling beneath the clump of bushes for shelter, would have crawled head first into the mouth of the cave, but for the fact that the ground immediately surrounding the opening gave way beneath his weight before he reached it. His fall was not very far, and when he struck the ground, it was so soft and yielding that he was scarcely conscious of a jar; but the nervous shock was so great that, for a few minutes, he believed that he was fatally injured. When he was able to recall his scattered senses, he looked around him in the hope of gaining some idea of where he was; but he quickly saw that he was in a place where his eyes were of no service. The darkness was as impenetrable as that which plagued Pharoah and his Egyptians. Only when he looked upward was the blackness of darkness relieved. Enough straggling rays worked their way through the bushes to give the opening a dim, misty appearance, such as is sometimes observed when that orb is rising in a cloud of fog and vapor; but in every other direction he might as well have been blind, for all the good his eyes did him. One of the first things that struck the lad was the sound of the waterfall which he had heard so distinctly when stretched upon the earth. It was somewhere near him--so close, even, that he fancied he could feel the dampness from it, but the soft, rippling character showed that it did not amount to much. It was a mere cascade, the water of which entered and passed out the cavern by some means which the boy could only surmise. How extensive was this cave? Had it any outlet other than that by which Fred had entered? Was the flow even or irregular? Were there pitfalls and abysses about him, making it too perilous to attempt to grope about in the gloom? Having entered, how was he to make his way out again? Such questions as these presented themselves to the boy, as he stood alone in a world of night, and endeavored to consider the situation calmly. Stooping down, he felt of the soil. It was of a cold, sandy nature, and so yielding that, when he struck it, he went below his ankles.