“I’m not going very far,” replied the professor. “All I want is my net and box,” and with these only he started off.

It was about an hour later when Jerry observed:

“Doesn’t it seem as if the monkeys were making more noise than usual?”

The boys listened for a few seconds. It was evident that something had disturbed these nimble inhabitants of the forest, for they were yelling and chattering at a great rate.

“Maybe another jaguar is after them,” suggested Bob.

“No; it doesn’t sound like that,” said Jerry. “They seem to be yelling more in rage than in fear.”

“Maybe they’re having a fight,” put in Ned.

Just then there came a crashing, as if several trees were being crashed down by a tornado. There was a crackling of the underbrush and a rustling in the leaves. Then, above this noise and the yells of the monkeys, sounded a single cry:

“Help, boys!”

“The professor’s in trouble again!” cried Jerry. “I wonder what it is this time?”