These books are the result of a conviction held by the editors, authors, and publisher that the time is appropriate for assembling in one place information about functions of the hippocampus derived from many varied lines of research. Because of the explosion of research into the anatomy, physiology, chemistry, and behavioral aspects of the hip pocampus, some means of synthesis of the results from these lines of research was called for. We first thought of a conference. In fact, officials in the National Institute of Mental Health suggested we organize such a conference on the hippocampus, but after a few tentative steps in this direction, interest at the federal level waned, probably due to the decreases in federal support for research in the basic health sciences so keenly felt in recent years. However, the editors also had come to the view that conferences are mainly valuable to the participants. The broad range of students (of all ages) of brain behavior relations do not profit from conference proceedings unless the proceedings are subsequently published. Furthermore, conferences dealing with the functional character of organ systems approached from many points of view are most successful after participants have become acquainted with each other’s work. Therefore, we believe that a book is the best format for disseminating information, and that its publication can be the stimulus for many future conferences.