  In this paper, we investigate the multiplicity fluctuations of charged
particles observed in high-energy nuclear collisions and relate them to the
size of hadronizing systems which happen during such processes. We use the
average multiplicities $\langle N\rangle $ and variances $Var\left(N\right)$ of
multiplicity distributions of charged particles produced in centrality selected
collisions of relativistic heavy-ion nuclei to evaluate the dynamic variable
$\Omega$ and study its dependence on the size of colliding nuclei. We connect
the observed system-size dependence of multiplicity fluctuations with the
clustering phenomena and the finiteness of the hadronizing sources and the
thermal bath.
