"But look over there, and you'll see a lot of white bones, Elmer," pursued Lil Artha.
"That's a fact. Some animal must have fallen in here, starved to death, and been eaten up by the rats."
"But, Elmer, are you sure they are animal bones?"
"I noticed the skull, and I think it must have been a large dog," replied Elmer.
Then he and the tall scout scrambled hastily to their feet, for Chatz had suddenly given utterance to an exclamation that seemed to contain much of both surprise and mystification.
CHAPTER V.
THE TRAIL GROWS WARMER.
"Say, just look up there, fellows!"
Chatz pointed a quivering finger upward as he gave utterance to these words.