  We consider spin and orbital Kondo effect in a parallel arrangement of two
strongly electrostatically coupled quantum dots. Increasing the exchange of
electrons between the dots through the attached leads induces a smooth
crossover between SU(4) spin- and orbital Kondo effect and SU(2) spin Kondo
effect. Being the same for the SU(4) and SU(2) symmetry points, the Kondo
temperature drops slightly in the intermediate regime. Experimentally, two
kinds of Kondo effect can be discriminated by the sensitivity to the
suppression of the spin Kondo effect by Zeeman field. The dependence of the
Kondo temperature and of the differential conductance on the strength of
electronic exchange through the leads and Zeeman field is analyzed in detail.
