J.R.R. TOLKIEN'S ESSAY "ON FAIRY-STORIES," with its presentation of the essential features of the fantasy genre, and his story "Leaf by Niggle," which I intend to show is a re-telling of the story of the late fifteenth century play Everyman, were both first separately published, Tolkien explains in his "Introductory Note" to their re-publication together in Tree and Leaf. My primary purpose here is to present a reading of "Leaf by Niggle" with reference to its apparent source and to terms Tolkien defines in "On Fairy-Stories," but, since Tolkien tells the Everyman story in ways that can readily be related to his own life story, I will also give attention to this story as Humphrey Carpenter and T.A. Shippey tell it in J.R.R. Tolkien: A Biography and J.R.R. Tolkien: Author of the Century; as Wayne G. Hammond and Christina Scull tell it in J.R.R. Tolkien: Artist and Illustrator; and as it can be read in Carpenter and Christopher Tolkien's edition of The Letters of J.R.R. Tolkien. As the following sequence of parallels shows, Tolkien re-tells the basic Everyman story in "Leaf by Niggle."