K-S(0), Lambda, Xi, Omega and negative particle h(-) yields and transverse
mass spectra, measured at central rapidity in p-Pb and Pb-Pb collisions at
158 A GeV/c, are presented and discussed, Yields are studied as a function
of the number of nucleons participating in the collision N-part, which have
been estimated using the Glauber model. From p-Pb to Pb-Pb collisions the
particle yields per participant increase substantially. Such an enhancement
is more pronounced for multiply strange particles, and reaches an order of
magnitude for a. For a number of participants N-part > 100, however, all y
ields per participant appear to be constant.