hrough the passage of the reef
and once the boys thought they were going to ship a good deal of
water. But the two men who were rowing knew their business and brought
them into the horseshoe harbor without mishap. They helped the lads to
land, on a small sandy strip close to some palms, and then started
back to the steam yacht.

"Treasure Isle at last!" cried Dick, when they were left alone. "So
far our quest has been successful. Now to locate the cave and unearth
that treasure!"

"And may it prove to be worth all that has been said of it," added Sam

CHAPTER XX

THE BOYS MAKE A DISCOVERY

The boys had landed at a spot that was particularly inviting in
appearance, and they stopped for several minutes to take in the
natural beauty surrounding them. There were tall and stately palms,
backed up by other trees, trailing vines of great length, and numerous
gorgeous flowers. A sweet scent filled the air, and from the woods in
the center of the isle came the song of tropical birds.

"What a fine camping place!" murmured Sam. "A fellow could spend
several weeks here and have lots of fun, bathing and boating, and
hunting birds, and fishing," and his brothers agreed with him.

Yet the beauty of Treasure Isle was soon forgotten in their anxiety to
locate the cave. They had a general idea that it was in the center of
the horseshoe curve, and that center was quite a distance from where
they had been brought ashore.

"The best we can do is to tramp along the water's edge," said Dick.
"Then when we reach the center we can go inland."

"We haven't over an hour," replied his youngest brother. "By that time
it will be too dark to do much more. And we'll have to find some
suitable place to camp for the night."

"Oh, we can camp anywhere," cried Tom. "It's good enough--just for
one night."

They began to trudge along the edge of the horseshoe curve, over
smooth sand. But this did not last, and presently they came to a muddy
flat and went down to their ankles. Dick was ahead and he cried to the
others.

"Stop! It's not fit to walk here!"

"Why, it's like a bog!" declared Sam, after testing it.

"We'll have to go inland a distance," said Tom. "Come on," and he
turned back and struck out for the palms and bushes beyond.

It was then that the Rover boys began to realize what was before them.
Scarcely had they penetrated the interior for fifty yards when they
found themselves in a perfect network of trailing vines. T