  We obtain a formal solution of an integral equation for $q\bar q$ bound
states, depending on a parameter \eta which interpolates between 't Hooft's
(\eta=0) and Wu's (\eta=1) equations. We also get an explicit approximate
expression for its spectrum for a particular value of the ratio of the coupling
constant to the quark mass. The spectrum turns out to be in qualitative
agreement with 't Hooft's as long as \eta \neq 1. In the limit \eta=1 (Wu's
case) the entire spectrum collapses to zero, in particular no rising Regge
trajectories are found.
