“Now for the fun,” smiled Joe, as he cranked the movie camera and looked expectantly into the green depths of the bordering jungle.

“I suppose you’re referring to hunting,” said Mr. Lewis. “Well, we’ll do plenty of that a little later. But first we want to penetrate a large distance from any outposts of civilization.”

At the start, the river was rather wide, but it promised to narrow later.

They glided swiftly on for perhaps three hours. Then Mr. Lewis suggested that they stop for the noon meal. Meanwhile, the crew could be resting.

The boats were brought to a stop at a large sand bank, and all climbed out to stretch their legs after such a long journey in more or less one position. Bob and Joe felt like running and shouting.

“Like to go in for a swim,” said Bob, wiping the perspiration from his streaming brow.

“So would everyone else,” returned Mr. Lewis. “But with the alligators and piranhas and other dangerous aquatic forms it’s absurd even to think of such a thing.”

“Are they this close to the Purús?” asked Joe. “I thought they were found deeper in the jungle.”

Mr. Holton shook his head.