In 1914 explorers in the Congolese rain forest discovered animal species unknown to science. In 1909 Robert Peary pushed toward the North Pole, excited by what might await him. In 1919 the prehistoric remains of an 18-foot Baluchitherium were unearthed by zoologists in the Gobi Desert. The Jesup North Expedition crossed the Bering Strait in 1897 determined to penetrate the mysteries of Siberia.
Accounts of these expeditions are vivified with journal excerpts from the earliest explorers. Historical background is provided by Perkins, who animates half his text with photographs. As the curtain rises over these ''last hidden places,'' the world, rather than appearing diminished, seems a more compelling and mysterious - marvelous place to live.