Again a tiny arrow traveled towards them in a graceful parabola.  This one fell short.  Missing the tarpaulin, it almost dropped on the girl’s outstretched hand.  She picked it up.  The fish-bone point had snapped by contact with the floor of the ledge.

She sought for and found the small tip.

“See,” she said.  “It seems to have been dipped in something.  It is quite discolored.”

Jenks frowned peculiarly.  A startling explanation had suggested itself to him.  Fragments of forgotten lore were taking cohesion in his mind.

“Put it down.  Quick!” he cried.

Iris obeyed him, with wonder in her eyes.  He spilled a teasponful of champagne into a small hollow of the rock and steeped one of the fish-bones in the liquid.  Within a few seconds the champagne assumed a greenish tinge and the bone became white.  Then he knew.

“Good Heavens!” he exclaimed, “these are poisoned arrows shot through a blowpipe.  I have never before seen one, but I have often read about them.  The bamboos the Dyaks carried were sumpitans.  These fish-bones have been steeped in the juice of the upas tree.  Iris, my dear girl, if one of them had so much as scratched your finger nothing on earth could save you.”

She paled and drew back in sudden horror.  This tiny thing had taken the semblance of a snake.  A vicious cobra cast at her feet would be less alarming, for the reptile could be killed, whilst his venomous fangs would only be used in self-defence.

Another tap sounded on their thrice-welcome covering.  Evidently the Dyaks would persist in their efforts to get one of those poisoned darts home.

Jenks debated silently whether it would be better to create a commotion, thus inducing the savages to believe they had succeeded in inflicting a mortal wound, or to wait until the next arrow fell, rush out, and try conclusions with Dum-dum bullets against the sumpitan blowers.

He decided in favor of the latter course.  He wished to dishearten his assailants, to cram down their throats the belief that he was invulnerable, and could visit their every effort with a deadly reprisal.

Iris, of course, protested when he explained his project.  But the fighting spirit prevailed.  Their love idyll must yield to the needs of the hour.

He had not long to wait.  The last arrow fell, and he sprang to the extreme right of the ledge.  First he looked through that invaluable screen of grass.  Three Dyaks were on the ground, and a fourth in the fork of a tree.  They were each armed with a blowpipe.  He in the tree was just fitting an arrow into the bamboo tube.  The others were watching him.

Jenks raised his rifle, fired, and the warrior in the tree pitched headlong to the ground.  A second shot stretched a companion on top of him.  One man jumped into the bushes and got away, but the fourth tripped over his unwieldy sumpitan and a bullet tore a large section from his skull.  The sailor then amused himself with breaking the bamboos by firing at them.  He came back to the white-faced girl.