The most important contemporary development in rhetoric for the theory of argumentation is Jeanne Fahnestock's program of figural logic, the ruling insight of which is that figures epitomize arguments. Working primarily with the antimetabolic formula at the heart of Gregor Mendel's paper “Experiments in Plant Hybridization,” I investigate the figural bases of the logic anchoring this foundational essay in genetics. In addition to antimetabole, the formula also depends crucially on ploche, polyptoton, onomatopoeia, antithesis, synecdoche, reification, and metaphor.