Following Peebles (Ap.J. 155, 393; Astron.Astrophys. 11, 377)and Efstathiou and Silk (Fund.Cosm.Phys. 9, 1) we assume that a developing proto-galaxy of mass M=1011M⊙ gains angular momentum during a first Phase 1 exten ding from recombination to the maximum expansion and then a second Phase 2 from the maximum expansion to a relaxed virialized structure passing through an intermediate Phase I.A very simple model is proposed in which a first mechanism connected with increasing density perturbatio ons leading to a torque ∼ t2/3, is applied to a spherical homogeneus structure. The initial conditions for its dynamical evolution are taken from a cosmological flat model (Ω = 1) with an isothermal perturbation mass spectrum. Phase 2 begins when the proto-galaxy is completely separated from the background and until this Phase it has been recognized that the initial spherical symmetry turns out to be well preserved, provided the angular momentum gained does not exceed 3.6 1073 g cm2 sec−1.