RichardJ. Winzler died ofa heart attack on September 28, 1972. He was a versatile, internationally renowned biochemist, gifted with bound­ less energy and a great breadth of view. After early work on respiratory enzymes, he developed a lifelong in te rest in complex carbohydrates and, particularly, glycoproteins. He early recognized the important role of the latter substances in membrane function and developed the now widely accepted model for the structure of major erythrocyte membrane glyco­ pro teins. He expanded this model to include the possible general roles of membrane glycoproteins in specific membrane functions, particularly cell recognition phenomena. Richard Winzler possessed a broad and critical perception of the ftux of biomedical progress. He thus appreciated very early that general recognition of the complexity of membrane-associated phenomena would foster a new, rapidly expanding, interdisciplinary membrane technology. He also recognized the need for means to bridge the communication barriers inevitably genera ted by such an evolution, and this conviction largely stimulated us to write this book. Membrane technology is a vast field and we cannot treat all its aspects. Instead, we concentrate on those areas that, in our view, have evolved most rapidly. In this, we pay primary but not exclusive attention to the plasma membrane, but where relevant, consider other biomem­ branes and diverse model systems. Moreover, we focus on animal cells, but include information derived from microbial and artificial membranes where germane.