"He's going to spring!" said Jim, in a low voice. At the same moment he brought his gun up, ready to fire.

An instant later the lion launched itself forward, propelled by muscles like steel springs, straight at the group, anger blazing in its eyes.

Bang! spoke Jim's rifle, and the big cat seemed to turn completely over in the air.

But the momentum of the spring was not checked by the bullet which had struck it in the throat. On it came, and Jim yelled:

"Duck boys!"

He had no time to do so himself, so, before he could throw himself to one side, the lion was upon him and the cowboy went down in a heap, the beast, snarling and growling, on top of him. There was a confusion of man and lion, a vision of flying legs, fast-working claws and the sight of a yellow body in convulsions.

"Fire at the lion!" yelled Jack.

"Don't! You might shoot Jim!" exclaimed Nat.

"Get your knives out!" cried John, drawing his own blade.

But they were not needed. A moment later the big cat rolled over off Jim, and, in a few seconds the cowboy rose from the ground, covered with dirt and blood, but, apparently unhurt.