as trolls turning to stone, are to be found in the story. The book is popularly called (and often marketed as) a fantasy novel, but like Peter Pan and Wendy by J. M. Barrie and The Princess and the Goblin by George MacDonald, both of which influenced Tolkien and contain fantasy elements, it is primarily identified as being children's literature. The two genres are not mutually exclusive, so some definitions of high fantasy include works for children by authors such as L. Frank Baum and Lloyd Alexander alongside the works of Gene Wolfe and Jonathan Swift, which are more often considered adult literature. The Hobbit has been called "the most popular of all twentieth-century fantasies written for children". Jane Chance, however, considers the book to be a children's novel only in the sense that it appeals to the child in an adult reader. Sullivan credits the first publication of The Hobbit as an important step in the development of high fantasy, and further credits the 1960s paperback debuts of The Hobbit and The Lord of the Rings as essential to the creation of a mass market for fiction of this kind as well as the fantasy genre's current status. Style Tolkien's prose is unpretentious and straightforward, taking as given the existence of his imaginary world and describing its details in a matter-of-fact way, while often introducing the new and fantastic in an almost casual manner. This down-to-earth style, also found in later fantasy such as Richard Adams' Watership Down and Peter Beagle's The Last Unicorn, accepts readers into the fictional world, rather than cajoling or attempting to convince them of its reality. While The Hobbit is written in a simple, friendly language, each of its characters has a unique voice. The narrator, who occasionally interrupts the narrative flow with asides (a device common to both children's and Anglo-Saxon literature), has his own linguistic style separate from those of the main characters. The basic form of the story is that of a quest, told in episodes. For the most part of the book, each chapter introduces a different denizen of the Wilderland, some helpful and friendly towards the protagonists, and others threatening or dangerous. However the general tone is kept light-hearted, being interspersed with songs and humour. One example of the use of song to maintain tone is when Thorin and Company are kidnapped by goblins, who, when marching them into