This book is about the growth and differentiation processes underlying the growth and differentia­ of filamentous fungi. The impetus for this work tion of fungi and that it provides the reader with stems from our perception that the coverage of adequate source references for further information. this highly diverse and important group of organ­ It is estimated conservatively that there are more isms has been neglected in recent years, despite than 1. 5 million species of fungi - more than five many significant advances in our understanding of times the number of vascular plants and second the underlying mechanisms of growth. This situ­ only in diversity to the insects. The extreme ation contrasts with the treatment of Saccharomyces diversity of form in the fungi has always been a cerevisiae, for example, which because of its ideal source of inspiration for mycologists. This book is properties for genetic analyses, has established concerned mainly with those systems that have itself as the model eukaryote for the analysis of the been well characterized from the biochemical, cell cycle, and basic studies of biochemical and physiological or genetic points of view. Although genetic regulation. This book does not deal with it has not been possible to illustrate the breadth of the detailed growth phYSiology of S.