“That’s it,” rejoined Mr. Mainwaring; “they’re harmless enough unless their particular territory is invaded. No white man has ever penetrated far into their country and come back to tell the tale. But they say that back among the forests and mountains to which they alone know the way are deposits of emerald and gold of priceless value.”

“I should think somebody would form an expedition and raid the place,” said Tubby in a war-like manner.

“More easily said than done,” Mr. Raynor struck in; “it’s been tried, but fever and poisoned arrows wiped out all but a few poor, half-crazed wretches who struggled back to civilization more dead than alive.”

“Do they ever come down to this part of the country?” asked Merritt.

“Only occasionally, when a hunting expedition has led them far afield,” rejoined Mr. Mainwaring. “This Rio Chepalto that we are going to try to diverge runs back into their country; but where it joins the Chagres is not forbidden ground. Their territory begins higher up.”

Suddenly there came another soft bump.

“Aground again!” cried Rob, stopping the engine. “Shall I reverse?”

“Yes; do so at once,” was the order.

But this time the matter of getting off the sand bank was not so simple. The two tow ropes attached to the canoe became entangled in the paddle wheel as the Pathfinder backed up, and they came to a stop. An investigation showed that it might take some time to get it free. Tubby was prompt in asking permission to go into the forest to see if he couldn’t bring down some game of some kind.

“You and Fred will have to go alone then,” said Mr. Mainwaring, “and don’t go far from the river. We’ll recall you by three blasts on the whistle. Rob and Merritt will be needed to help us get untangled and to work the engine.”