  The mass splittings of the baryons belonging to the $[{\bf 70},1^-]$-plet are
derived by using a simple group theoretical approach to the matrix elements of
the mass formula. The basic conclusion is that the first order correction to
the baryon masses is of order $1/N_c$ instead of order $N^0_c$, as previously
found. The conceptual difference between the ground state and the excited
states is therefore removed.
