> I've dug up some examples of [r'] > [z] and of [Z] > [z]. I found
> them at http://www.linguistlist.org/issues/6/6-1627.html . The
> description goes,
> 'Similarly, it is not hard to get from a palatal /r'/ to /z/.
> Some Polish dialects change */z^/ to /z/ and later most Polish
> dialects change */r'/ to /z^/. If the changes had occurred in the
> reverse order, then we would had have a change of */r'/ to /z/ over
> a large area of Poland. In reality, we do find this ordering in
> some score of villages located around the periphery of the /z^/ to
> /z/ change.'
Of course the falling together of /s ~ s' ~ s./ as /s/ is a familiar
phenomenon in the Indic Prakrits, e.g. Old Indic s'atam '100' > saya
'100', vRs.abHa- 'bull' > vasaha-. As for the Polish situation, all the
the rural dialects of Mazovia (the historical province that includes
Warsaw) and Malopolska ('Little Poland', which includes Krakow, SE
Poland and the southern highlands) are characterised by the so-called
'Mazurian pronunciation' (Pol. mazurzenie), i.e. the merger of
historical /S, Z, tS, dZ/ with /s, z, ts, dz/ (the former series merges
into the latter). The reported peripheral change of /r'/ > /r^/ (rhotic
fricative) > /Z/ > /z/ is a fact.