Inflectional morphology has figured prominently not only in debate about the nature of linguistic knowledge, but also in the foundational debate between proponents of symbolic and of connectionist accounts of cognition. We present two experiments designed to test predictions of Tinker's (1991) dual-route account of inflection, the central component of which is a symbolic rule. Contrary to the predictions of the dual-route account, we find evidence of both frequency and similarity effects on the regularization of novel items (i.e., pseudo words).