For many years studies of the structure and biosynthesis of saccharides formed a specialised and somewhat abstruse part of biochemistry, with little or no place in molecular biology. In recent years this has changed profoundly, as has the character of much of carbohydrate biochemistry. Saccharides are now seen as generally possessing specific structures, which are potentially informational-though there is little firm evidence, as yet, as to the nature and expression of this information. Biosynthetic studies, especially upon glyco­ proteins, have provided major new insights into the ways by which specific sugar sequences can be assembled and the relationship of this to membranes and membrane flow. While the study of polysaccharide 'biosynthesis has developed more slowly, its future progress will be profoundly affected by the new knowledge of glycoproteins and this, in turn, will have major implications in the understanding of biological matrices and microenvironments. With this rapid growth and change, ever more scientists - of increasingly diverse backgrounds - are needing to understand something of carbohydrate biochemistry. This book is directed towards them, not with the intention that it should compete with existing text books, or simply be an elementary introduction, but with the intent that it should provide a bridge between the rather disparate and diverging lines of development in the subject and to bring out the important principles of saccharide assembly that are emerging.