While Stradlater is on his date with Jane, Holden agrees to write an essay for him. But instead of fulfilling the requirements for the assignment, Holden writes a lengthy reflection on his deceased brother's baseball glove. When he returns and reads the essay, Stradlater is furious, and cites the paper as evidence that Holden is incapable of following rules. "No wonder you're flunking...out of here," he tells Holden, who responds by ripping the paper out of his hands and tearing it to pieces. The incident escalates into a brawl between the two roommates when Holden persistently asks him what happened on his date.
Source: J.D. Salinger, The Catcher in the Rye (New York: Bantam Books, 1965) 41.