Exchange Degeneracy andSU(3)

It is hypothesized that the imaginary parts of the contributions of exchange-degenerate Regge trajectories cancel in hadron-hadron states of internal quantum numbers for which no resonances exist. A recent work by the author on $\mathrm{SU}\left(3\right)\mathrm{}$-symmetric baryon trajectories in meson-baryon states is generalized to include all trajectories and all meson-meson, meson-baryon, and baryon-baryon states. Consistency is possible for these states. The difficulty concerning baryon-antibaryon states is discussed. The large, observed $\pi \pi N$ decay of the $j^P={\frac{3}{2}}^{-}{\Delta }^{*}\mathrm{}\left(1670\right)\mathrm{}$ is predicted from the consistency conditions. The magnitude of the coupling to baryons of any singlet meson is predicted in terms of the octet interactions. This result includes the prediction that $\varphi \mathrm{NN}$ vertices of all spin dependences vanish. The modification imposed by the baryon exchange-degeneracy hypothesis on the Regge analysis of meson-baryon scattering is discussed. The relation of the results to the bootstrap hypothesis is discussed.