In or around 1923, we thought we knew what the short story was. Or, rather, Edward J. O’Brien did, and as editor of the influential Best American Short Stories anthology since 1915 his words carried considerable weight in the newly professionalizing field of literary publishing. Taking stock of a genre that had evolved along with the expanding print culture of the nineteenth century, O’Brien was concerned that even as luminous examples of its literary artistry had found fertile ground in America, the modern, industrial conditions that birthed the form had left an indelible mark upon it that impeded its development and marred it in the eyes of readers. For O’Brien, a true “short story” was a rare and precious beast, to be nurtured and distinguished from a mass of American short fiction that was disqualified wholly from the sanctified realm of “art,” either because of its unruly form or because of its deployment of hackneyed tropes directed solely to the demands of the marketplace. His definition enacted a tendency present in short story criticism since Edgar Allan Poe first started to describe an emergent commercial style, upon which he relied to pay the bills, which was to characterize the form negatively, by what it was not: the novel, poetry, the folk tale, and so on. So much “fiction that is merely short” was an abomination for O’Brien; it was especially prone, relative to other genres, to the charge of committing nothing less than literary “heresy.” In The Advance of the American Short Story (1923; revised 1931), O’Brien wrote that “almost every American short story is the product of one or more of four heresies, the heresy of types, the heresy of local color, the heresy of ‘plot,’ and the heresy of the surprise ending” (1931, 6).