Soon after their appearance in the mid-1920s, Thomas Mann's Der Zauberberg and André Gide's Les Faux-monnayeurs attracted considerable critical attention as significant contributions to innovative forms of novel-writing. Both works were discussed in the context of the "crisis of the novel" and seen as particularly convincing responses to the problems experienced by the genre. Mann's and Gide's novel were linked with each other on a number of occasions; in these discussions, however, the emphasis was normally placed on one aspect only, leaving the question of the breadth of their achievement in the context of the modern novel unanswered. The comparative study of Der Zauberberg and Les Faux-monnayeurs undertaken in this thesis is designed to evaluate their many-faceted contributions to the development of new fictional forms. The discussion of the novels ensues with respect to five areas which have emerged as decisive in describing innovative trends in the novel genre in the 1920s and beyond. These are: the introduction of significant reflexive or self-reflexive elements; the subsequent weakening of the plot and changes in the handling of temporality; the yielding of an omniscient narratorial stance in favour of a more nuanced, ambivalent use of perspective; the increased rôle given to the reader in the elaboration of meaning; the appropriation of structures from other art forms, notably music, and the response to the ascendant medium film as offered by the two novels in question. The discussion of the works themselves, in particular the examination of temporality, invites reflections on Mann's and Gide's concepts of history. The innovations in plot structure, which form one of the most striking aspects of both novels, are strongly determined by the experiences of the First World War and reveal themselves as reflections of an altered sense of history.