  In a recent paper (cond-mat/9901130), the spatial distribution of unvisited
sites in the one-dimensional single-species annihilation process was
investigated. It was claimed that this distribution is characterized by a new
length scale, and that the corresponding dynamical exponent depends upon the
initial concentration. We show numerically that this assertion is erroneous.
Regardless of the initial concentration, this spatial distribution is
characterized by the diffusive length scale.
