We have previously reported the presence of isoditryosine cross-links in hydrolyzates of cotton fiber primary cell wall proteins (1). Another class of cell wall cross-link occurs in higher plants. Phenolic acids can be coupled to pectins via ether or ester linkages (2). The occurrence of phenolic acids in cotton fiber has been examined by base hydrolysis of immature (14-20 days post-anthesis) cotton fiber cell walls. Butanol-soluble components were derivatized and analyzed by gas chromatography-mass spectroscopy. No phenolic compounds were identified in the hydrolyzate, however, hexadecanoic acid (C(16)) and octadeconoic acid (C(18)), principal components of the mature fiber cuticle, were identified. Phenolic acid cross-links do not appear to be a significant cross-linking mechanism in cotton fiber. Identification of cuticular material during early stages of fiber development must be accounted for in our working model of factors limiting the expansion of the cotton fiber cell.