The selection of prolactin as the subject of the Midwest Con ference on Endocrinology was not only dictated by the recent ad vances in prolactin research but also by the long tradition in that particular area of Endocrinology in the laboratory of C.W. Turner at the University of Missouri. Therefore, it seems only appropri ate that these proceedings of the Tenth Midwest Conference on En docrinology are dedicated to the memory of this scientist, deceased in August 1975 before completion of this volume, whose pioneer in vestigations have contributed substantially to the advancement of our knowledge in many areas of Endocrinology and who played a major role in the early phases of prolactin research. This volume contains a review of the early studies in Turner's laboratory and the latest results obtained by some of the leading research workers in this area and should be a fitting memory to C.W. Turner. Some of the manuscripts printed here were prepared after the conference was held and include material of more recent origin. Much of the delay in publication was due to the length of time de voted to preparation of these manuscripts. To the other authors and participants, and to Plenum Press, we express our appreciation for their patience and cooperation. We also with to thank Mrs."