Synopsis This book is intended more particularly for the use of students of agriculture and horticulture, who must deal more or less fully with the subject of fungi and plant diseases. Experience has shown that students differ greatly in their capacity for perceiving and assimilating the essential points in lectures, and it is hoped that many will derive benefit from what may be considered somewhat extended lectures in book form; the book may also be useful to these who desire a working knowledge of the subject but are unable to avail themselves of the facilities afforded by schools and colleges.