Within the framework of the kinetic equation, the assumption of the existence of a relaxation tensor Τ is introduced. From the Onsager relationships in the zeroth approximation with respect to the magnetic field it follows that Τ commutes with matrix where v is the velocity of the electron or the hole. This permits one to reduce matrix Τ to diagonal form. The ratios Τ1/Τ2 and Τ3/Τ2 were evaluated from data on the anistropy of the hole mobility in anthracene. Since the zone structure for holes in naphthalene and anthracene is practically the same, it is possible to calculate in advance the anisotropy of the hole mobility in naphthalene. The results obtained agree better with the experimental data than do the known literature data.