It is imperative t is imperative that now at once, while these stupendous events are still clear in my mind, I should set them down with that exactness of detail which time may blur. But even as I do so, I am overwhelmed by the wonder of the fact that it should be our little group of the "Lost World"— Professor Challenger, Professor Summerlee, Lord John Roxton, and myself—who have passed through this amazing experience.