  The present status of the thermal model is reviewed and the recently
discovered sharp peak in the $K^+/\pi^+$ ratio is discussed in this framework.
It is shown that the rapid change is related to a transition from a baryon
dominated hadronic gas to a meson dominated one. Further experimental tests to
clarify the nature of the transition are discussed. In the thermal model the
corresponding maxima in the Xi/pi and Omega/pi ratios occur at slightly
different beam energies.
