Rossman F. Giese is Professor, Department of Geology, University at Buffalo, State University of New York. The author or coauthor of numerous publications on phyllosilicates, the defect structure of kaolin minerals, and the surface properties of clay minerals, Dr. Giese received the B.A. degree (1956) from Columbia College, New York, New York, and the M.A. (1959) and Ph.D. (1962) degrees from Columbia University, New York, New York. Carel J. van Oss is Emeritus Professor of Microbiology and Adjunct Professor of Chemical Engineering and Geology, University at Buffalo, State University of New York. He is the holder of eight patents; author or coauthor of over 340 articles and book chapters; and author, coauthor, editor, or coeditor of 12 books, including Immunological and Molecular Diagnosis of Infectious Disease, Transfusion Immunology and Medicine, Immuno chemistry, lnterfacial Forces in Aqueous Media, and Molecular Immunology. Dr. van Oss is founding editor and former editor-in-chief of Preparative Biochemistry & Biotechnology and Separation and Purification Methods and editor­ in-chief of Immunological Investigations (all titles, Marcel Dekker, Inc.). A member of the American Chemical Society and its Division of Colloid and Surface Chemistry and the American Association of Immunologists, he received the Ph.D. degree (1955) in physical biochemistry from the University of Paris (Sorbonne).