A model of simplicial quantum gravity in three dimensions is investigated
numerically based on the technique of the dynamical triangulation (DT). We are
concerned with the surfaces appearing on boundaries (i.e., sections) of
three-dimensional DT manifold with S3 topology. A new scaling behavior of
genus distributions of boundary surfaces is found.Furthermore, these surfaces
are compared with the random surfaces generated by the two-dimensional DT
method which are well known as a correct discretized method of the
two-dimensional quantum gravity.Comment: 12 pages, Latex, 7 Postscript figures, uses psfig.sty and cite.st