Ciliates are a group of protozoans with hair-like organelles (cilia), which are identical in structure to the flagella of eucaryotes, but typically shorter and present in much larger numbers with a different undulating pattern than flagella. This book presents a contemporary and imaginative synopsis of diverse biological aspects of cilia/flagella and ciliates/flagellates. It comprises contributions by a dozen of renowned experts from all over the world, which summarize our current understanding, essentially the results obtained and progress made during the last five decades of research of cilia/flagella and the ultrastructure, cell biology, organellar function, motility, taxonomy/systematics, symbiosis, and biodiversity of ciliates and flagellates. The book provides various suggestions for future research. It is lavishly illustrated by numerous line drawings and light- and electron-microscopic images. This publication addresses advanced students of biology and zoology, and all scientists teaching and working in cell biology and protistology.