  The spin polarization versus temperature at or near a fully filled lowest
Landau level is explored for finite-size systems in a periodic rectangular
geometry. Our results at $\nu=1$ which also include the finite-thickness
correction are in good agreement with the experimental results. We also find
that the interacting electron system results are in complete agreement with the
results of the sigma model, i.e., skyrmions on a torus have a topological
charge of $Q \ge 2$ and the Q=1 solution is like a single spin-flip excitation.
Our results therefore provide direct evidence for the skyrmionic nature of the
excitations at this filling factor.
