 Given that Schwann and Schleiden were masters of microscopy (as witnessed by their drawings based on their microscopic observations), and that other equally competent microscopists reported cells dividing, their claim that cells form like crystals seems anomalous. Bechtel (1984) argues that Schwann’s strong commitment to developing mechanistic accounts of vital processes may have played a major role in how he interpreted what he saw—the crystal formation metaphor provided a mechanistic model whereas at the time there were no mechanical models for cell division. In any case, Schleiden’s and Schwann’s accounts of cell formation were soon set aside as more researchers reported on cell division and Schwann’s concerns with mechanism were supplanted by other concerns. Virchow (1855), a pathologist, offered a theoretic argument that only a process like cell division could explain the transmission of disease and coined the oft-cited dictum “omnis cellula e cellula” (all cells come from cells).