A disquieting short-story collection that transposes the inner workings of the human body with the ethereal outer world, Shelley Jackson's The Melancholy Of Anatomy pulses around a single defining phrase: "In this investigation, invisibility is evidence." Best known for her hypertext novel Patchwork Girl, Jackson borrows her premise from The Anatomy Of Melancholy, a 17th-century work that sought to observe the "the rust of the soul" through a vaguely scientific lens. Jackson separates her stories by the body's four humorscholeric, melancholic, phlegmatic, and sanguinewhile entertaining her writerly fascination with impressionistic confusion. In the book's best story, "Egg," a woman happens upon a mysterious red orb, which grows from a small dot to the size of a room. The so-called egg is an overtly pregnant symbol of the growing despondence between the woman and her lesbian lover. But it's also a deftly rendered embodiment of metaphor itself, a stand-in for the unknowability that serves as Jackson's main muse. The rest of Melancholy follows suit, working like a poetic account of a metaphysical game of Operation. The book's bizarre apparitions include buffalo-size sperm-beasts, a cancer that overtakes a house like a vine, and a city that menstruates through its underground sewage ducts. Jackson occasionally stretches her premise too thin, yielding inconsequential low points that read like creative-writing workshop exercises. But when she mingles her conceits with pure storytelling, Melancholy throbs with observations that juggle dark humor with creepily pointed understanding. A crackling riff on the science of despair, "Nerve" stars George, a worker in a "nerve factory" whose therapy sessions intersperse with a tale of manufactured nerves bundling together, with grim consequences. "Somewhere inside George was another George: spiderlike, avid, flexible. Like grammar, but physical," Jackson writes, sizing up the analytic obsession at the root of her character's torment. The author falls prey to similarly clinical deconstruction at points, but more often, The Melancholy Of Anatomy breathes the sort of inspired sigh that George heaves near his story's end: "We drop dead cells by the billions and go racing on in a flurry of dandruff... there is no economy to our carrying on, nor should there be."