The nature and evolution of intertextuality was studied in 2 urban primary-grade classrooms, focusing on read-alouds of an integrated science-literacy unit. The study provides evidence that both debunks deficit theories for urban children by highlighting funds of knowledge that these children bring to the classroom and the sense they make of them and demonstrates how intertextuality in classroom discourse creates learning opportunities as teachers and students interact with texts broadly defined. Changes over time of the various forms of intertextuality emerged in the 2 classes, thereby showing how intertextuality is both an act of discourse and an act of mind. A particular type of intertextuality-event intertextuality-dominated throughout the read-alouds and revealed how hybrid classroom discourse, incorporating both narrative and scientific genre features, allowed the emergence of classroom discourse that shared characteristics with scientific language.