Pea plants (Pisum sativum cv. Melbourne Market), each with a single developing pod, were pulse-fed with [14C]asparagine supplied through the cut stem at stages ranging from 12 to 31 d after full blossom. The hull and seed tissues were removed after 24 h and frozen for later analysis. The hull retained a higher proportion of the total label in the fruit than the enclosed seeds until after 19 d, i.e. until the total nitrogen content of the hull had begun to decline. The distribution of label in soluble metabolites of the hull, seedcoats, embryo sac liquid and embryo was determined by paper chromatography and radioautography. The results confirm that the metabolism of asparagine is more rapid in the seedcoats than in the hull. In the youngest stages, label from the seedcoats is transmitted to the embryo sac mainly in forms other than asparagine, notably as glutamine, alanine and sucrose.