Midway through Terence's Eunuchus a young man commits rape in explicit imitation of an erotic painting. Modern critics have tended to dismiss the relevance of the painting as a transparently adventitious excuse offered in bad faith, but the first chapter of this dissertation elucidates the careful emphasis Terence lays on the harmlessness of the young man's plan prior to the painting's intervention. The second chapter endeavors to explain how a painting could ever have been thought to have such an influence. Throughout antiquity one of the most persistent discursive poles for formulating the effect of visual art is a pattern I call "mimetic contagion," in which works of art draw viewers into direct imitation. Ancient votive practices, provocative images in various cultural contexts, Hellenistic theories of the pedagogical role of art, and mid-2^nd century BCE Roman anxieties about the deleterious effects of Greek art all contribute to how Terence's audience would have understood this painting's persuasive intervention. As in other instances of mimetic contagion, there is a metatheatrical dimension to the painting in the Eunuch, which ultimately seems to be a figure for the dangerously adhesive nature of role-playing within the play. In several cases the dramatic art of the characters' deceptions exceeds its own boundaries and, like the painting, becomes indistinguishable from reality. Implicit in this kind of performative copying is an allusion to the genre of mime, and the third chapter draws out the many and unexpected mimic resonances of this same scene. The fourth chapter revisits the old question of contaminatio in Terence and shows that the more recent definitions fail to account for all the relevant evidence. A broader reading of Terence's poetics of hybridity shows the significance of literary and ethical contagion for the themes of the second and third chapters.