“I can’t, not yet,” said Rob huskily. “I am trying, Mr Brazier, and I will master it all soon.”

Just then the peculiar cry they had first heard rang out again from a distance.

“Was that Joe?” whispered Rob, with a ghastly look. “He must be in peril.”

“No, no; it was a jaguar, I think. There goes Naylor again! Whistle! whistle!”

Rob only gazed at him piteously, and Brazier responded to the signal himself.

“Come, come, Rob,” he whispered, “be a man!”

The lad made a tremendous effort to conquer his weakness, and turned away from the tree with his lips compressed, his eyes half closed, and forehead wrinkled.

“That’s right,” cried Brazier, clapping him on the shoulder. “Who says our English boys are not full of pluck?”

He whistled again in response to a signal from Shaddy, and then they listened and answered in turn for quite half an hour, during which the guide’s whistles and cries came from further and further away, but sounded as if he were at last keeping about the same distance, and working round so as to come back in another direction.

Then for a time all signals ceased, and they heard the cry of the wild beast, followed by quite a chorus of shrieks and chatterings, which ceased as suddenly as they had begun.