  We calculate the isosinglet unpolarized quark-- and antiquark distributions
at a low normalization point in the large--$N_c$ limit. The nucleon is
described as a self-consistent soliton solution of the effective chiral theory.
The ultraviolet cutoff is implemented by a Pauli-Villars subtraction. The quark
and antiquark distributions satisfy the momentum as well as the baryon number
sum rule, corresponding to ``constituent'' quarks whose structure is not yet
resolved at the low scale. Already at this level a sizable number of antiquarks
is present.
