[en] Orbital degeneracy of f electrons leads to new kinds of fluctuation effects; one by interaction with condition electrons, and the other by intersite interaction of multipoles. It is shown that the Kondo effect can have two energy scales over a wide temperature range in the presence of spin and orbital degrees of freedom. Concerning the interacting multipoles we investigate such effects as anomalous magnetic-field dependence of specific heat C and elastic constants C_ij, which have been observed in Ce_xLa_1-xB₆. Fluctuation of quadrupole moments is responsible for the field-dependent tail of C above the transition temperature, and for the contrasting behaviors of softening and hardening of C_ij depending on the strain components. As a candidate to identify the phase IV with no magnetic anisotropy, a pseudo-scalar order of octupole moments is proposed. (author)