The story which runs through and makes up the bulk of this book is my own. The intention has been, however, to make it conform to the laws governing certain beings commonly regarded in this country as mythical, as those laws are revealed in the folk-lore of many peoples, and particularly of the Irish people. The shorter stories wherewith the main story is interspersed are all, to the best of my information and belief, genuine Irish folk-tales. I have told them in my own way, of course. I have sometimes condensed and sometimes elaborated them, but I have seldom, if ever, I think, materially changed their substance.