The soft padding of unseen feet, the rustling of leaves and grasses to the passage of fierce beasts, the sheen of opalesque eyes flaming through the dark, the million sounds which proclaimed the teeming life that one might hear and scent, though seldom see, constituted the appeal of the nocturnal jungle to Tarzan.
Tonight he had swung a wide circle—toward the east first and then toward the south, and now he was rounding back again into the north. His eyes, his ears and his keen nostrils were ever on the alert. Mingled with the sounds he knew, there were strange sounds—weird sounds which he never heard until after Kudu had sought his lair below the far edge of the big water-sounds which belonged to Goro, the moon—and to the mysterious period of Goro's supremacy. These sounds often caused Tarzan profound speculation. They baffled him because he thought that he knew his jungle so well that there could be nothing within it unfamiliar to him. Sometimes he thought that as colors and forms appeared to differ by night from their familiar daylight aspects, so sounds altered with the passage of Kudu and the coming of Goro, and these thoughts roused within his brain a vague conjecture that perhaps Goro and Kudu influenced these changes. And what more natural that eventually he came to attribute to the sun and the moon personalities as real as his own? The sun was a living creature and ruled the day. The moon, endowed with brains and miraculous powers, ruled the night.
Thus functioned the untrained man-mind groping through the dark night of ignorance for an explanation of the things he could not touch or smell or hear and of the great, unknown powers of nature which he could not see.