D’Arcy Thompson’s groundbreaking book On Growth and Form (1917) pioneered the science of mathematical biology. Its literary qualities have been frequently commented upon but arguably more influential have been its illustrations, particularly the famous transformation diagrams. This article discusses the origins and context of these iconic images, exploring D’Arcy Thompson’s own artistic and scientific interests, the long development of his controversial theories and the other collaborators involved, including illustrators Doris MacKinnon and Helen Ogilvie. It explores the various influences that the images have had in science, geography and particularly in art. Many notable artists have been drawn to the images and visual analogies of D’Arc...