A model is considered in which an even number of nucleons of the same kind are confined to a single j shell, and in which the residual interaction force is assumed to consist of a pairing'' force plus a long-range quadrupole'' force. This residual interaction is considered in terms of the quasi-particle and random-phase approximations. The model is shown to afford a qualitative interpretation of gamma transition probabilities to the lower 2/sup +/ and 4/sup +/ excited states of even-even spherical nuclei. (T.F.H.)