The Prehistoric World; or, Vanished Races by Emory Adams Allen is a fascinating study of ancient civilizations and extinct species that will appeal to readers of all ages. In his book, the author reveals the mystery of the prehistoric world, telling about the life and customs of extinct races, their achievements in science, art and technology. Readers will have the opportunity to travel through time, discovering new facts and information about the period of history when mysterious civilizations and mysterious creatures existed on Earth. The book "Prehistoric World; or, Vanished Races" will captivate you with its interesting information and make you think about what secrets the past hides.