The muscles knotted beneath the smooth, brown skin of his arms andshoulders, the veins stood out upon his temples from the force ofhis exertions--a strand parted, another and another, and one armwas free. Then from the jungle came a low guttural, and the ape-manbecame suddenly a silent, rigid statue, with ears and nostrilsstraining to span the black void where his eyesight could not reach.

Again came the uncanny sound from the thick verdure beyond the camp.A sentry halted abruptly, straining his eyes into the gloom. Thekinky wool upon his head stiffened and raised. He called to hiscomrade in a hoarse whisper.

"Did you hear it?" he asked.

The other came closer, trembling.

"Hear what?"

Again was the weird sound repeated, followed almost immediatelyby a similar and answering sound from the camp. The sentries drewclose together, watching the black spot from which the voice seemedto come.