  This paper continues a numerical investigation of orbits evolved in `frozen,'
time-independent N-body realisations of smooth time-independent density
distributions corresponding to both integrable and nonintegrable potentials,
allowing for N as large as 300,000. The principal focus is on distinguishing
between, and quantifying, the effects of graininess on initial conditions
corresponding, in the continuum limit, to regular and chaotic orbits. Ordinary
Lyapunov exponents X do not provide a useful diagnostic for distinguishing
between regular and chaotic behaviour. Frozen-N orbits corresponding in the
continuum limit to both regular and chaotic characteristics have large positive
X even though, for large N, the `regular' frozen-N orbits closely resemble
regular characteristics in the smooth potential. Viewed macroscopically both
`regular' and `chaotic' frozen-N orbits diverge as a power law in time from
smooth orbits with the same initial condition. There is, however, an important
difference between `regular' and `chaotic' frozen-N orbits: For regular orbits,
the time scale associated with this divergence t_G ~ N^{1/2}t_D, with t_D a
characteristic dynamical time; for chaotic orbits t_G ~ (ln N) t_D. At least
for N>1000 or so, clear distinctions exist between phase mixing of initially
localised orbit ensembles which, in the continuum limit, exhibit regular versus
chaotic behaviour. For both regular and chaotic ensembles, finite-N effects are
well mimicked, both qualitatively and quantitatively, by energy-conserving
white noise with amplitude ~ 1/N. This suggests strongly that earlier
investigations of the effects of low amplitude noise on phase space transport
in smooth potentials are directly relevant to real physical systems.
