“The biggest and most dangerous animal of South America,” chimed in Mr. Lewis.
At once the skin was ripped off and then placed in a bag carried by the crew.
A little later Bob was several score feet behind the others, examining a peculiar plant that had small blue flowers. As he started to pluck one he suddenly heard a faint cry that seemed to come from the direction of the river.
At first he thought it was some strange bird, but when he heard it again he was immediately on the alert. That a bird? Absurd. But what could it be?
Then a thought struck him, and he almost turned pale. It was Professor Bigelow!
He called to the others to follow and then turned and ran with all speed to the boats.
CHAPTER XX
Fighting Against Heavy Odds
BOB had often run in track races at high school, but never had he equaled the pace that was now taking him to the boats. It was as though wings had suddenly lifted him through space at an alarming rate of speed.