Although The Origin of Species contained just a single visual illustration, Charles Darwin's other books, from his monograph on barnacles in the early 1850s to his volume on earthworms in 1881, were copiously illustrated by well-known artists and engravers. In this 2006 book, Jonathan Smith explains how Darwin managed to illustrate the unillustratable - his theories of natural selection - by manipulating and modifying the visual conventions of natural...