"And I venture to trust we may not," I observed. The Professor only raised his great eyebrows, as the schoolmaster meets the irrelevant observation of the naughty boy. "Perhaps Professor Summerlee may have an observation to make," he said, and the two savants ascended together into some rarefied scientific atmosphere, where the possibilities of a modification of the birth-rate were weighed against the decline of the food supply as a check in the struggle for existence. That morning we mapped out a small portion of the plateau, avoiding the swamp of the pterodactyls, and keeping to the east of our brook instead of to the west. In that direction the country was still thickly wooded, with so much undergrowth that our progress was very slow. I have dwelt up to now upon the terrors of Maple