He had read of hippos swamping boats by seizing the narrow bows or keel in their vast jaws, and he wished to be prepared for a possible attack.

Presently the boat again rocked as another animal took to the water, then the new-comer dislodged the other with a snap of the jaws, and the first, with a complaining grunt, surged down the channel.

Venning could see nothing in the inky blackness, but he knew the beast had seen the Okapi from the short note of alarm it sounded.

Immediately the alarm was repeated.

Snorts and splashes arose from all sides.