he could do it anyhow. I don't think he could pull it off
either; besides, it's a clean cut; it doesn't look as if it had been
pulled off."

"No," said Mark, gravely; for both boys had visited the traps on this
occasion. "I don't suppose he could have gnawed off, or pulled off, his
own head. He must have taken his jack-knife from his pocket, quietly
opened it, deliberately cut off his head, and calmly walked away."

"I have it!" exclaimed Frank, after a few minutes of profound thought,
as the boys paddled homeward.

"What?" asked Mark--"the otter?"

"No, but I know who stole him. It's one of the very fellows that tried
to get me."

"Alligators!" shouted Mark.

"Yes, alligators; I expect they're the very thieves who have been
robbing our traps."

The next day at noon, when Mark finished his work at the mill, he
hurried back to the ferry to see what Frank meant when he called him
that morning, and said he had something to tell him.

Frank had gone to the other side of the river with a passenger, but he
soon returned.

"Well, what is it?" asked Mark, as he helped make the boat fast.

"It's this," said Frank. "I've seen a good many alligators in the river
lately, and I've had my eye on one big old fellow in particular. He
spends most of his time in that little cove down there; but I've
noticed that whenever a dog barks, close to the river or when he is
crossing on the ferry, the old 'gator paddles out a little way from the
cove, and looks very wishfully in that direction. I know alligators are
more fond of dog-meat than anything else, but they won't refuse fish
when nothing better offers. Now look here."

Going to the other end of the boat as he spoke, Frank produced a coil
of light, but strong Manila line that he had obtained at the house. To
one end of this rope were knotted a dozen strands of stout fish-line,
and the ends of these were made fast to the middle of a round hickory
stick, about six inches long, and sharply pointed at each end. These
sharp ends had also been charred to harden them.

"There," said Frank, as Mark gazed at this outfit with a perplexed
look, "that's my alligator line; and after dinner, if you'll help me,
we'll fish for that old fellow in the cove."

"All right," said Mark; "I'm your man; but where's your hook?"

"This," answered Frank, holding up the bit of sharpened stick. "It's
all the hook I want, and I'll show you how to use it when we get ready."

After dinner the boys fo