2. Barley endosperm cell walls have a cellulose content of 2-4% and are rich in (l-»3,l-»4)-B-D- glucan (Fincher, 1975), and the arabinogalactan-rich walls of the mesophyll cells of the cotyledons of Lupinus angustifolius cv. Unicrop contain only a trace of cellulose (Cranshaw and Reid, 1984).