This book, like other monographs of the Cellular Organelles series, is not a comprehensive review, but an introduction to the study of cytoskeleton. Accordingly, we describe only the main facts and concepts related to cyto skeleton. Needless to say, selection and interpretation was influenced by the personal interests and opinions of the authors, although we attempted to be as fair as possible. We wished to familiarize the reader not only with well established facts, but with current unsolved problems. Therefore, the words "possibly," "maybe," "not known," and "not clear" are much more...