The leaf and pod at the lowest reproductive node are responsible for providing approximately two-thirds of the carbon required by seeds ripening at that node. Leaflets and stipules of this leaf furnish respectively 174 and 74 mg C to the seeds, 85 per cent of these amounts consisting of photosynthetically fixed carbon, the remainder carbon available from mobilization of dry matter. The pod donates 154 mg C to its seeds, some of this derived from the atmosphere, some from organic reserves established early in pod life, but most from assimilation of carbon dioxide lost to the pod's interior by the respiring seeds. The pod is virtually totally committed in export to its seeds. Leaflets and stipules are less deeply committed; they export assimilates some days before their subtended flower is pollinated and they then maintain an active export to all regions of the plant whilst supplying the developing seeds. The stipules, in particular, are very active in the nutrition of the root and fruits higher up the stem. Highest rates of export from leaf and pod take place when the seeds show their greatest demand for carbon, and at this time a relatively large proportion of the exported assimilates are diverted to the seeds.