The theory is corrected to include relaxation processes fundamentally different in character from the configurational diffusion considered before. These processes involve relatively persistent intramolecular "cryptocrystallites." Viscous flow-places stress on these clusters of van der Waals bonds, storing free energy. Dissipation of this energy during the ensuing drift toward equilibrium contributes to the viscous losses, These quasichemical, scalar processes and the vectorial process of configurational diffusion proceed independently of one another. In systems in which many "cryptocrystallites" tend to form, these clusters make a contribution to viscosity almost directly proportional to the concentration of the polymer. If formation of persistent clusters is less likely, the contribution of clusters to the viscosity will increase with increasing molecular weight, finally becoming proportional to polymer concentration. All processes contributing to viscosity and viscoelasticity of these solutions are treated as relaxation phenomena. The inherent incompatibility with this theory of steady-state hydrodynamic expressions such as Stokes' law or the Oseen tensor is stressed.