In this particular collection, Rudolf Steiner deals with topics ranging from crystals to crocodiles! He discusses, among other things: speech and languages; left-handedness; dinosaurs; Lemuria; turtles and crocodiles; oxygen and carbon; ancient giant oysters; the moon, sun and earth; the Old Testament; the real nature of Adam; breathing and brain activity; dreams; sugar; the liver and perception; brain cells and thinking; cancer and its origin; diabetes; the eyes of animals; Paracelsus; alcohol, and migraine.