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...