Dame Helen Gwynne-Vaughan (1879-1967) was a prominent British mycologist, specialising in the sexual process of fungi. In 1909 she was appointed Head of the Department of Botany at Birkbeck College, becoming Professor of Botany when Birkbeck College joined the University of London in 1920. This volume was first published in 1922 as part of the Cambridge Botanical Handbooks series. The introduction provides a detailed description of the structure, sexual reproduction, parasitism and symbiosis of all fungi, with subsequent chapters describing fully the morphology and reproduction of genera within the phylum ascomycetes and the orders ustilaginales and uredinales on which Gwynne-Vaughan based her research. Illustrations and a bibliography accompany each chapter. This volume provides an insight into the study of mycology in the early twentieth century, before technological advances in the field of cytology revolutionized the discipline.