Over three quarters of a century ago, Charles Darwin published a book titled The Formation of Vegetable Mould, through the Action of Worms, with Observations on Their Habits. In it he gave the world its first understanding of the fundamental role of earthworms as geologic agents for the transport of soil—a picture of surface rocks being gradually covered by fine soil brought up from below by the worms, in annual amounts running to many tons to the acre in most favorable areas.
