The Treks of Early Man 4 Out of Noah’s Ark and Over Bering Strait 13 The Land-Bridge to the New World 18 A Great-Circle Route to North America 19 Migration Routes 22 Glaciers and Ice Fields as Barriers to Early Man 26 and 27 The Life Story of the Earth 44 The Ice Fields of the Last Glaciation 48 The Age of River Terraces 51 The Four Great Glaciations 55 Glaciation Through Warmth 58 The First Hand Ax Found and Recognized 62 Time Scale of Early Man 65 The “Dawn Stones” of Early Man 66 Paleolithic Types and Industries 70 Man’s First Perfected Tool 71 Ancient Implements of Bone and Wood 74 Java Man—_Pithecanthropus erectus_ 82 _Gigantopithecus_—Giant Ancestor of Man? 83 Three Types of Old World Man 89 Man’s First Spear Points 90 Percussion Flaking 91 The Second Step in Flint Knapping 92 The Third Step—Pressure Flaking 93 Sculpture of the Old Stone Age 98 How Blades Were Split off a Core 100 Upper Paleolithic Tools 101 Three Aurignacian Types 102 The Meaning of Scrapers 103 The Tanged Point 105 A Laurel-Leaf Solutrean Point 106 A Tool to Make a Tool 107 Magdalenian Harpoon Head 108 The First Illustration of a Blade 108 Our First Machine, the Spear-Thrower 109 The First Paintings 110 Bowmen from Africa 112 Archers from Spain 113 Magdalenian Engravings 114 A Chart of Old Stone Age Cultures 116 and 117 A Spear Point Found Near Trenton, N.J. 144