Natural representations: diagram and text in Darwin's "On the origin of species"

This article examines Darwin's use of diagram and text in the "Origin" by focusing on their interacting roles in his discussion of natural relations, extinction, and time. Each medium presented opportunities and challenges that depend on the topic in question; indeed, a medium's dimensionality could undermine one claim and make self-evident another. While Darwin divides representational labor between diagram and text, he also creates a constitutive interplay between media. The resulting dynamic alliance of form and content recalls his early evolutionary reflections on representation; image and word could be used not simply to argue for, but also as evidence of, his theory.