  In a recent interesting Letter Contucci {\it et al.} have investigated
several properties of the three-dimensional (3d) Edwards-Anderson (EA) Ising
spin glass. They claim to have found strong numerical evidence for the presence
of a complex ultrametric structure similar to the one described by the replica
symmetry breaking solution of the mean field model. We illustrate by numerical
simulations that the relations used by Contucci {\it et al.} as evidence for an
ultrametric structure in the 3d EA model are fulfilled to similar accuracy in
the two-dimensional EA model, which is well-described by the droplet picture
and has no spin glass phase at finite temperature. We conclude that the data
presented in the Contucci {\it et al.} Letter is not sufficient to dismiss the
possibility that, e.g., the droplet model might describe the behavior of the 3d
EA model.
