Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by TPRC at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemina­ tion phases of the activity was transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we have concluded that it will be in the interest of all concerned if the printing and distribution of the volume were handled by a well-known publishing house to assure improved service and better communication. Hence, effective with this Volume 18, Masters Theses in the Pure and Applied Sciences will be disseminated on a worldwide basis by Plenum Publishing Corporation of New York. All back issues can also be ordered from Plenum. As we embark on this new partnership with Plenum, we also initiate a new venture in that this important annual reference work now covers Canadian universities as well as those in the United States. We are sure that this broader base will greatly enhance the value of these volumes.