  We study nucleon structure functions within the bosonized
Nambu--Jona--Lasinio model where the nucleon emerges as a chiral soliton. We
discuss the model predictions on the Gottfried sum rule for electron--nucleon
scattering. A comparison with a low--scale parametrization shows that the model
reproduces the gross features of the empirical structure functions. We also
compute the leading twist contributions of the polarized structure functions
$g_{1}(x)$ and $g_{2}(x)$ in this model. We compare the model predictions on
these structure functions with data from the E143 experiment by GLAP evolving
them appropriately.
