Lecithin–water systems display a variety of phases. Several of these phases, observed at a high temperature in the presence of small amounts of water, belong to a class of structures recently discovered in the anhydrous divalent cation-soaps. In these structures the polar groups are clustered in rod-shaped regions, embedded in a disordered paraffin matrix. In one of the phases the rods are infinitely long; in two others the rods are of finite length, and join three by three, forming two and three-dimensional networks.