“But how is the opening hidden?” asked Jerry.
“By means of a great wooden door covered with concrete on the outside, so that it looks like part of the rocky wall,” answered the professor. “I know about the location of it. It should be easy to find.”
“We’ll have a try at it!” murmured Jerry. “But how did you manage to get away, Professor?”
“By a stroke of good luck. The rustlers had brought in some of the choice cattle from Square Z, and as they had a market to which the steers must be sent in a hurry they decided to get them out of the valley after dark. I saw then my chance to escape. There were, lying about the camp, any number of old hides, taken off the cattle that had died or been slain for food. I wrapped one of these about me one dark night when the herd was to be driven out, and mingled with the cattle. It was taking a chance, I knew, but I managed to keep from being trampled on and went in the midst of the cattle through the woods to the secret outlet of the valley. Once outside I lay down under a bush to wait until morning. My one regret was that I had to leave behind my lovely specimens. But I dared not carry them.
“Since that night I have been tramping about trying to find Square Z ranch. But I must have gone away from it instead of toward it for I became lost. My clothes and shoes began to wear out. I managed to get enough berries and roots to live on, for I had made a careful study of botany and knew what was best for me. But I was so hungry for a ham sandwich!” said the professor, pathetically.
“Have another!” begged Bob, offering one.
The professor munched it while concluding his narrative. He had wandered on and on, finally becoming so footsore, weary and ragged that he was the tramp the boys beheld him. But in his misery he did not forget his collection mania and made boxes of bark to hold his specimens.
Finally, he reached the great rock, not knowing where he was and scarcely able to go on. Then he had heard the hum of the aircraft engine above him, and had recognized the ship of his friends.
“You are to be congratulated on getting away from those rustlers,” said Jerry. “It wasn’t easy, I imagine.”
“Indeed it wasn’t,” said the professor fervently, and the boys admired him for his pluck.