Three works by Peter Paul Rubens (1577–1640) entail mythologized scenes of spontaneous generation, or the creation of species from nature’s raw matter: Head of Medusa (ca. 1613–1618), The Discovery of Erichthonius (ca. 1616), and the oil sketch Deucalion and Pyrrha (ca. 1636). In these works Rubens naturalizes the life of painting within its materials, implying matter—paint, with its pigments and ... [Show full abstract] mediating liquids—as an intrinsic, animating quality of his images and even as a counterpart to or collaborator with the artist. This essay explores these ideas to show how Rubens’s technical and artisanal understanding of painting and its materials could have informed his interpretation of ancient myths.