In this first-ever examination of Charles Darwin's sketches, drawings, and illustrations, Julia Voss presents the history of evolutionary theory told in pictures. Darwin had a life-long interest in pictorial representations of nature, sketching out his evolutionary theory and related ideas for over forty years. Voss details the pictorial history of Darwin's theory of evolution, starting with his notebook sketches of 1837 and ending with the illustrations in "The Expression of Emotions in Man and Animals (1872)". These images were profoundly significant for Darwin's long-term argument for evolutionary theory; each characterizes a different aspect of his relationship with the visual information and constitutes what can be called an 'icon' of evolution. Voss shows how Darwin 'thought with his eyes' and how his pictorial representations and the development and popularization of the theory of evolution were vitally interconnected. Voss explores four of Darwin's images in depth, and weaves about them a story on the development and presentation of Darwin's theory, in which she also addresses the history of Victorian illustration, the role of images in science, the technologies of production, and the relationship between specimen, words, and images.