Subsidiary Conditions and Ghosts in Dual-Resonance Models

We investigate the possible subsidiary conditions compatible with the equations of motion of dual-resonance models for the unrealistic choice of (0) =1. In the language of four-dimensional harmonic oscillators, we find one subsidiary condition for each mode of oscillation. All time components (in the c. m. system) can therefore be eliminated. We discuss the possibility of relaxing the condition (0) =1.