getting on your nerves, Ned, and I didn't know you had any. Let's
go back and turn in. I'm dog-tired and the mosquitoes are beginning to
find that we're here. Let's get under the nets. Then the black
shadows won't get you."

Not at all unwilling to leave so gloomy a scene, Ned, after a brief
glance up and down the dark river, followed his chum. They found
Professor Bumper and Mr. Damon in their tent, a separate one having
been set up for the two men adjoining that of the youths.

"Bless my fountain pen!" exclaimed Mr. Damon, as he caught sight of Tom
and Ned in the flickering light of the smudge fire between the two
canvas shelters. "We were just wondering what had become of you."

"We were chasing shadows!" laughed Tom. "At least Ned was. But you
look cozy enough in there."

It did, indeed, look cheerful in contrast to the damp and dark jungle
all about. Professor Bumper, being an experienced traveler, knew how
to provide for such comforts as were possible. Folding cots had been
opened for himself, Mr. Damon and the guide to sleep on, others,
similar, being set up in the tent where Tom and Ned were to sleep. In
the middle of the tent the professor had made a table of his own and
Mr. Damon's suit cases, and on this placed a small dry battery electric
light. He was making some notes, doubtless for a future book. Jacinto
was going about the camp, seeing that the Indians were at their duties,
though most of them had gone directly to sleep after supper.

"Better get inside and under the nets," advised Professor Bumper to Tom
and Ned. "The mosquitoes here are the worst I ever saw."

"We're beginning to believe that," returned Ned, who was unusually
quiet. "Come on, Tom. I can't stand it any longer. I'm itching in a
dozen places now from their bites."

As Tom and Ned had no wish for a light, which would be sure to attract
insects, they entered their tent in the dark, and were soon stretched
out in comparative comfort. Tom was just on the edge of a deep sleep
when he heard Ned murmur:

"I can't understand it!"

"What's that?" asked the young inventor.

"I say I can't understand it."

"Understand what?"

"That shadow. It was real and yet----"

"Oh, go to sleep!" advised Tom, and, turning over, he was soon
breathing heavily and regularly, indicating that he, at least, had
taken his own advice.

Ned, too, finally succumbed to the overpowering weariness of the first
day of travel, and he, too,