The Naked Truth about Hadronic Regge Trajectories
  We have reconstructed Regge trajectories (RT), using all existing data on masses and spin-parities of all currently known hadrons. In this resonance energy region meson and baryon RT are grossly nonlinear, and only 12% of all RT could be classified as a linear, with $\sigma=0$, $\alpha'\simeq 0.9$ GeV${}^{-2}$. 
A. E. Inopin