wood glycocon­ jugates, whieh likely have an important influence on the formation of wood, pulping behavior, pulp quality and digestibility by ruminants. Most plants contain both hydrophilie polysaccharides and hydrophobie lignins in their tissues. Lignins have been recognized to not only give mechanieal strength or rigidity to a tree or wood, but also to prevent invasion by fungi, and provide cell wall material, especially in the tracheids and vessels that deliver water extracted from the soil to the top of woody plants. How­ ever, in trees, lignins have been found to interact with the polysaccharides, partieularly hemicelluloses, with whieh they coexist, leading to the forma­ tion of another chemical component, a kind of glycoconjugate. Therefore, it is necessary to inc1ude lignin or p-hydroxycinnamie acids in any discus­ sion on wood hemieelluloses.