Once upon a time, many years ago—when our grandfathers were little children—there was a doctor; and his name was Do-little—John Dolittle, M.D. “M.D.” means that he was a proper doctor and knew a whole lot. He lived in a little town called, Puddleby-on-the-Marsh. All the folks, young and old, knew him well by sight. And whenever he walked down the street in his high hat everyone would say,“There goes the Doctor!—He’s a clever man.