Many books from symposia describe the current status in well established fields of research, where much is known and where the loose ends are only details in the picture. The topic dealt with here does not fall into this pattern. The study of time as a parameter in its own right is difficult, and the loose ends tend to do minate the present picture. Although the book does provide the reader with an overview of the field, its main value is probably to act as a source of "food for thought" for those interested in the function of sense organs and nervous systems as substrates for behaviour. The...