They were almost to the top when suddenly the ground gave way from under Joe's dromedary. The animal fell to its knees, struggled for a moment, and fell backward. With a wild shout Joe plunged from the animal's back and went rolling helplessly down the hill! CHAPTER XIV Falling Helplessly Down the steep slope Joe went, powerless to catch himself. There were no shrubs or stalks to grip, no hard soil to cling to. His mind was in a whirl. Where would he land? How far had he yet to go? He comforted himself in the thought that there were no rocks or tree trunks to dash against, but if the soil at the bottom of the hill happened to be hard, his doom might be sealed. Already he could feel the jar and pain of suddenly coming to an abrupt stop on unyielding ground. Down, down he went, past the pack camels that were still slowly climbing the steep side of the mound, lucky enough to have been missed by the falling camel. Joe caught a momentary glimpse of his own dromedary, which was also rolling rapidly down. Suddenly he felt a severe jar and gradually came to a stop in the soft sand at the foot of the dune. A moment later he glanced up fearfully, as he saw his dromedary coming down at him with lightning rapidity. He tried to rise and dash to one side, but his feet failed to respond to his efforts. They had been numbed by the jar of striking the ground. The falling camel was almost upon him now. Something must be done at once! Summoning all his strength, he threw his body to the right of the oncoming animal. It was an act of desperation, and he felt sure that it would fail. But a moment later there was a rush, the sound of swishing sand, and the animal whisked past, stirring up a dense cloud of fine soil. Joe gave a sigh of relief and for a brief period sank back down on the sand, as though waiting for his strength to be restored. Then he was up, looking for the fallen camel. It had come to a stop in a drift of loose sand and appeared to be uninjured. But it was snorting and kicking furiously, its anger visibly heightened to a high degree. Joe ran over to it and attempted to give aid, but the furious dromedary kicked at him in a rage. Mr. Lewis and Bob came running down, finding footholds with difficulty. "Wait!" cautioned the naturalist. "Don't hurry the camel. Let him take his time. His fit of anger will be over in a few minutes," and then added: "That was some fall! We were afraid you'd be hurt seriously. No bones broken, are there?" "I guess not," Joe replied. "Just shaken up a bit. I'm afraid the dromedary is hurt more than I. Don't see what could prevent it." "You may be right," his father said solemnly. "We'll find out in a minute." Before long the animal's anger lessened, and it tried to rise. But its legs refused to move, despite the frantic efforts. Mr. Lewis's face took on an expression of anxiety. He bent down and felt of the struggling legs. Then he straightened up and shook his head hopelessly.