naturally very much worried. And Grace was worried too. If she
could have engaged actively in a search for her brother perhaps she
might not have fretted so. But it was harassing to sit idly by and let
others do the work.

"Especially when we have already done so much," said Betty, agreeing
with her chum's view of the case.

Watching the work of gathering oranges, occasionally themselves helping
somewhat, taking walks, drives and trips in the motor boat, made time
for the girls pass quickly.

Then, one day, Betty said:

"Girls, we must go on a picnic. Take our lunch and go down the river in
the boat. Go ashore and eat. We will do some exploring."

"And perhaps find the fountain of youth that Ponce de Leon missed,"
added Mollie.

"If you find it, bring some of the water back," begged Mr. Stonington.
"You girls will not need it--I do."

"We'll bottle some for you," promised Amy, laughing.

Soon they were off in the _Gem_ again, Grace, at least, keeping a wary
eye out for alligators. But they saw none of the unprepossessing
creatures.

"Though perhaps we may meet with a sea-cow," suggested Betty, as she
looked for a pleasant place whereon to go ashore for lunch.

"What's a sea-cow?" asked Mollie.

"One that eats sea-weed," cried Amy.

"No, I mean a manatee," went on Betty. "Don't you remember the big
creatures we saw in the New York aquarium a year or so ago?"

"Oh, yes!" exclaimed Amy. "Well, they're not as bad as alligators--at
least they haven't such large mouths."

"And they only eat--grass," added Mollie.

Betty was sending her boat ahead at good speed, scanning the shores of
the river for some quiet cove into which to steer. The day was warm, and
the sun shone down unclouded. From the banks came the odor of flowers.

Suddenly, as the boat chugged along, there came a momentary halt, as
though it had struck something.

"What's that?" cried Grace.

"Maybe an alligator has us," suggested Mollie with a laugh. For the
_Gem_ went on as though nothing had happened.

"Don't be silly!" chided Grace. "It was certainly something."

Betty looked back a bit nervously, and glanced at the engine.

"I hope the gasoline isn't giving out," she murmured.

"The idea!" cried Grace.

Then with a shock that threw all the girls forward in their seats the
_Gem_ came to a sudden halt, and the engine raced furiously. Betty at
once shut off the power.

"Oh, oh!" cried Grace. "What is it? Has an alligator got hold