"As you will," said Tarzan. "I am listening."

For half an hour Jason Gridley read excerpts from the manuscript before him. "This," he said, when he had completed the reading, "is what convinced me of the existence of Pellucidar, and it is the unfortunate situation of David Innes that impelled me to come to you with the proposal that we undertake an expedition whose first purpose shall be to rescue him from the dungeon of the Korsars."

"And how do you think this may be done?" asked the ape-man. "Are you convinced of the correctness of Innes' theory that there is an entrance to the inner world at each pole?"

"I am free to confess that I do not know what to believe," replied the American. "But after I received this message from Perry I commenced to investigate and I discovered that the theory of an inhabitable world at the center of the earth with openings leading into it at the north and south poles is no new one and that there is much evidence to support it. I found a very complete exposition of the theory in a book written about 1830 and in another work of more recent time. Therein I found what seemed to be a reasonable explanation of many well-known phenomena that have not been satisfactorily explained by any hypothesis endorsed by science."

"What, for example?" asked Tarzan.

"Well, for example, warm winds and warm ocean currents coming from the north and encountered and reported by practically all arctic explorers; the presence of the limbs and branches of trees with green foliage upon them floating southward from the far north, far above the latitude where any such trees are found upon the outer crust; then there is the phenomenon of the northern lights, which in the light of David Innes' theory may easily be explained as rays of light from the central sun of the inner world, breaking occasionally through the fog and cloud banks above the polar opening. Again there is the pollen, which often thickly covers the snow and ice in portions of the polar regions. This pollen could not come from elsewhere than the inner world. And in addition to all this is the insistence of the far northern tribes of Eskimos that their forefathers came from a country to the north."