Many current paradigms of world literature, aligned to world-systems theory or Casanova’s “world republic of letters,” assume a diffusionist model of literature that situates the origins of literary modernity in the West. This model has found particular favour in the privileged case of the novel, but how do things stand with other genres? This essay examines the physiology, a popular quasi-journalistic genre dedicated to the taxonomic description of mores, customs and social types. Popularly associated with the figure of the urban flaneur and subsequently critiqued by Walter Benjamin, the physiology peaked under the July Monarchy in France and gained unprecedented success in Russian letters where it served to generate the basis of a non-bourgeois public sphere, after which it was also adapted to the circumstances of Russia’s own imperial borderlands. This paper outlines the essential contours of the physiology as it arose in France, in terms of its internal poetics as well as its social currency, and compare its French life with its Russian metropolitan counterpart, where it was transformed from a paraliterary genre to one that would occupy the centre of the Russian literary life in the transition from romanticism to realism. Its subsequent life in the Caucasus region reveals the rise of a colonial urban aesthetics of the picturesque. Does this story confirm or confound the diffusionist model? The essay’s external trajectory confirms the European origins of the genre and its subsequent circulation throughout the Russian empire, from metropole to periphery. A discussion of genre, however, requires more than an account of its its immanent structural features or its subordination to a singular external socio-spatial logic. The social life of circulating genres points to their divergent role in different literary systems, and to the distinct formal and ideological solutions they propose within regional or local contexts. It would appear, then, that the diffusionist model is pertinent to the movement of some hegemonic genres in the modern era, but that the centre/periphery model needs to be complemented by greater attention to the trans/regional and the local as defining levels of geographic scale in the realm of cultural production. Only a trans-scalar analysis, moving between multiple spatial levels, allows us to honour what humanists celebrate as cultural specificity without sacrificing the global perspective offered by world-systems theory.