The ArgumentThe last two plates of Aby Warburg's unpublished picture-atlasMnemosyne, which is thought today to be among Warburg's most innovative contributions to the study of art history, are here analyzed in detail. These plates were assembled in the summer before his death in 1929; they reflect experiences of the time he spent in Rome during 1928 and 1929 and are here understood as Warburg's attempt to visualize his theory of the symbol.TheBilderatlaswas to have a two-fold function: Warburg planned it to (...) be a summary of his life's work; he also wanted its plates to reflect his theory of pictures and images. I argue here that particularly plate 79 is indeed an attempt tovisualizethe theoretical foundation of Warburg's view of the representational function of pictures. It refers to the origin of the power of images in sacrificial rituals and to the limits of this power. Warburg singles out the Eucharist and the doctrine of transsubstantiation to illustrate the role of the symbol in rituals.With this emphasis on ritual as a necessary complement for the functioning of the symbol, Warburg reaffirms his theory of the image to include the social act. This inclusion can be shown to be motivated by contemporary political concerns. (shrink)