This book is based on symposium addresses given at the 5th International Symposium on the Microbiology of the Phyllosphere, held in Madison, Wisconsin, from 31 July to 3 August 1990. The conference brought together about 100 scientists with diverse interests pertinent to the study of leaves and microbes, including bacteriology, mycology, medical microbiology, ecology, plant pathology, physiology, anatomy, molecular biology, statis tics, aerobiology, and meteorology. What has been learned since the first conference of the series was convened in 1979 at Newcastle-upon-Tyne, England, by T. F....