The present study was undertaken to ascertain whether regional dermal specificity could be demonstrated at the molecular level. Dermis was obtained from the following areas of White Leghorn roosters: comb, wattle, trunk (feathers), leg (scales) and ear lobes. There were significant differences in the concentration of water, collagen and acid mucopolysaccharides (AMP). There were qualitative differences in the patterns of distribution of non-fibrous proteins. Two pools of AMP were noted: those of the ground substance and those insoluble or presumably bound to collagen. Differences in concentration and patterns of distribution of AMP, among the regions analyzed, supports the concept of dermal specificity.