Bringing together a wide variety of examples of functional amyloid in a single volume, this book explores the importance of amyloid fibrils in fungi, bacteria, algae, invertebrate, and vertebrate animals for providing environmental protection, structural integrity, and regulating biochemical processes. It highlights many of the extraordinary examples of functional amyloid found to date. It provides an exciting perspective for the study of amyloid deposits as important and useful protein structures widespread in nature.