We analyse with simple real-space statistics the Virgo consortium's
cosmological N-body simulations. Significant clustering rapidly develops well
below the initial mean interparticle separation \Lambda_i, where the
gravitational force on a particle is dominated by that with its nearest
neighbours. A power-law behaviour in the two point correlation function
emerges, which in the subsequent evolution is continuously amplified and
shifted to larger scales, in a roughly self-similar manner. We conclude that
the density fluctuations at the smallest scales due to the particle-like nature
of the distribution being evolved are thus essential in the development of
these correlations, and not solely, as usually supposed, the very small
continuous (fluid-like) fluctuations at scales larger than \Lambda_i >.Comment: 12 pages, 3 figures, some revisions to match the published version
and corrected some typos. To be published in Astrophysical Journal Letters
(December 20, 2002
