Volume 5 of Cerebral Cortex completes the sequence of three volumes on the individual functional areas of the cerebral cortex by covering the somatosensory and motor areas. However, the chapters on these areas lead naturally to a series of others on patterns of connectivity in the cortex, intracortical and subcortical, so that the volume as a whole achieves a much broader viewpoint. The individual chapters on the sensory-motor areas reflect the considerable diversity of interest within the field, for each of the authors has given his or her chapter a different emphasis, reflecting in part topical interest and in part the body of data resulting from work in a particular species. In considering the functional organization of the somatosensory cortex, Robert Dykes and Andre Ruest have chosen to concentrate on the nature of the mapping process and its significance. Harold Burton, in his chapter on the somatosensory fields buried in the sylvian fissure, shows how critical is an understanding of this mapping process in the functional subdivision of the cortex. A frequently overlooked subdivision of the cortex, the vestibular region, is given the emphasis it deserves in a chapter by John Fredrickson and Allan Rubin. The further functional subdivisions that occur within the first somatosensory area are given an anatom- ical basis in the review by Edward Jones of connectivity in the primate sensory- motor cortex.