Henry S. Horn (1941–2019) was professor emeritus of ecology and evolutionary biology at Princeton University. He was the author of The Adaptive Geometry of Trees and the coeditor of Molds, Molecules, and Metazoa: Growing Points in Evolutionary Biology (both Princeton). An ecologist's investigation of the social lives of butterflies Throughout his career, Henry Horn took a unique approach to the study of butterflies. This book brings together...