This book falls under the category of descriptive poetics (librarians and compilers of bibliographies, please note). That is, it does not aspire to contribute to literary theory, although there is plenty of theory in it—too much for some people, no doubt, and not nearly enough for others. Nor does it aim to establish interpretations of particular texts, although it incorporates a good deal of mostly incidental interpretation. But what this book primarily aspires to do is to construct the repertory of motifs and devices, and the system of relations and differences, shared by a particular class of texts.