The Hidden World of a Gall: Trotter, Forti, and Photomicrography in Early-20th Century Botany

Alessandro Trotter (1874–1967) and Achille Forti (1878–1937), both students of the botanist Pier Andrea Saccardo, were prominent figures in early twentieth century Italian botany. Despite their different research interests—cecidology (or the study of galls) and algology, respectively—Trotter and Forti shared a common research network and collaborated extensively through exploratory trips and sample exchanges. Their collaboration was particularly significant due to their shared interest in scientific photography, which was becoming growingly important in scientific research and communication, especially in botany. This chapter examines Trotter’s and Forti’s use of photomicrography to illustrate anatomical studies of plant galls in the early twentieth century. Drawing on archival sources, publications, and Forti’s photomicrographic plate collection, it explores how Forti’s expertise in photomicrography complemented Trotter’s research on the anatomy of galls, also reflecting on the roles of photography and drawing as competing yet complementary illustration techniques in early twentieth century botany.