Amazonia: A Laboratory for Fiction, analyzes the process and the forms through which Amazonia became a literary topic in the twentieth century. This dissertation proposes that the emergence of modern literature about the region articulates a distrust of the discourses and practices of imperial and neo-colonial territorial apprehension. It proposes the study of a regional tradition, looking at Hispanic and Brazilian texts in dialogue, and it focuses on the self-referential practices of this tradition. By doing so, this dissertation claims that Amazonia has served as a laboratory of representation and fiction that has contributed to the transformation and evolution of the Latin American novel. Ultimately, what is at stake in this research is the emergence of modern literature as a means to destabilize the imageries and practices that have forced Amazonia's integration into processes of modernization. To this extent, this dissertation is an inquiry into the relationship between aesthetics, science, and politics, and constitutes a critique of History. It intervenes in debates on theory of the novel, postcolonial studies, and eco-criticism. The first chapter shows how Euclides da Cunha's À margem da história (1909) forges a new national language informed by science and poetics that ultimately creates a new imagery of the region as an inapprehensible space. Da Cunha's essays inaugurate a literary tradition that the "novelas de la selva" further develop by continuing to challenge the modes through which it has been portrayed. To this extent, the second chapter focuses on how José Eustasio Rivera's La vorágine (1924) questions the domestication of nature rendered by the aesthetic of modernismo and stages a crisis of representation from which Amazonia surfaces as a disorienting and unconquerable site. The creation of the novel La vorágine itself is the outcome. Rivera's novel consolidates the modern literature of the region as a self-referencing tradition that underscores its own aesthetic practices, becoming a site that debates and questions the discursive constructs through which the Amazon has been imagined. Following this, the third chapter studies how Alejo Carpentier's Los pasos perdidos (1953) constructs the "selva" as an artifice through a mechanism of quotation of previous texts like La vorágine, thus generating a critical gap between the text and the "real" geographical referent. The fourth chapter analyzes Milton Hatoum's Órfãos do Eldorado (2008) as a critique of the inscription of Amazonia into western "civilizing" discourses of History through the idea of memory as a means to reconstruct the ruins of the present left by modernization.