  The propagation of scalar and spinor fields in a spacetime whose metric
changes signature is analyzed. Recent work of Dray et al. on particle
production from signature change for a (massless) scalar field is reviewed, and
an attempt is made to extend their analysis to the case of a (massless)
spin-half field. In contrast to their results for a scalar field, it is shown
here---for $SL(2,C)$ spinors---that although there are inequivalent forms of
the Dirac equation that can be used to propagate a spinor in a signature
changing spacetime, none of these forms gives rise to a conserved inner product
on the space of solutions to the field equations.
