  We show that universality near a critical end point implies a characteristic
relation between third- and fourth-order baryon susceptibilities $\chi_3$ and
$\chi_4$, resulting in a banana-shaped loop when $\chi_4$ is plotted as a
function of $\chi_3$ along a freeze-out line. Including the individual
enhancements of $\chi_3$ and $\chi_4$ near a critical point, these features may
be a consistent set of observations supporting the interpretation of baryon
fluctuations data as arising from criticality.
