The sequences of developmental events and of reserve deposition stages have been examined in developing seeds of Cercis siliquastrum. Ripe seeds have a massive persistent endosperm with living cells. Both endosperm and embryo store lipids and proteins; in the endosperm, polysaccharides are also deposited in the cell walls and between the cells. Starch is not stored during seed maturation. Oil and protein accumulation occurs synchronously and with the same pattern in endosperm and embryo. Gel electrophoresis shows roughly a similar composition of storage proteins in both.