The reproductive system is composed of complex sub-systems, which are driven by sophisticated biochemical processes, whereas their performance is controlled by the same physical laws that exist in any mechanical process on Earth (e.g., Newton's laws). Accordingly, the understanding of any physiological phenomenon, including the development of a pathologic condition, requires comprehensive evaluation of the biophysical and biomechanical aspects of reproduction in concert with the biological and clinical features. Several of the scientists from around the world who investigate the physical aspects of the reproductive system have contributed to the eight sessions resulting in this volume. These reports encompass the following areas of inquiry: non-pregnant uterine peristalsis, placental vasculature and blood flow, myometrial contractility and calcium transport, mechanics of the uterus and cervix in pregnancy, mechanics of embryonic development, penile mechanics and hemodynamics, sperm propulsion, and pelvic floor mechanics. NOTE: Annals volumes are available for sale as individual books or as a journal. For information on institutional journal subscriptions, please visit www.blackwellpublishing. com/nyas. ACADEMY MEMBERS: Please contact the New York Academy of Sciences directly to place your order (www.nyas.org). Members of the New York Academy of Science receive full-text access to the Annals online and discounts on print volumes. Please visit http://www.nyas.org/MemberCenter/Join.aspx for more information about becoming a member