A theory of ionic transport through membranes in which the phospholipid molecules play the role of ion-carriers is developed. The transport of ions is accompanied by a membrane asymmetry. Expressions for stationary-state ion-fluxes in the case of one sort of ions transport, and in the case of coupled transport of ions of two sorts, are obtained. In the latter case near equilibrium the cross-coefficients are equal in accordance with Onsager's law. The possible role of phospholipids as ioncarriers in native membranes is discussed.