Just as embattled as Yurick's earlier novels, The Warriors, Fertig, more ambitious and to be sponsored as such, The Bag wraps up a great many hard. core facts of life taken from the urban underside of New York City. Some of it is no more edifying than the refuse on the city dump. Yurick, a vocal, implosive writer, belts it all out--via Sam Miller, writer manque on the payroll of the Welfare Department, but also being helped by his longsuffering and supportive Helen; I troublemaker of his caseload is the whining, snarling Minnie Devlin, a Negro woman who has had a clutch of children via different men, among them the drug-hungry Alonso and his artist brother Hinton; then there's Faust, the slumlord, with the gratification of his fine arts collection and the disappointment of his only daughter, a dyke; (etc., etc. A long book, filling in a good deal of the apparatus of the Welfare Department as well as the political and racial lifestyles of poverty, this primarily deals with Miller's attempt to beef up an article by establishing ""contact with the real world"" he is writing about--namely with the sexually volcanic Minnie. And the book closes with further bursts of violence and rhetoric (""Welcome me with open thighs because I want to wake you up and set you free and freaking out of your alienation shelters"") on the streets. . . . A searing, smearing job which is carried, not all the way to conviction, by Yurick's rampantly energetic prose.