  After formulating the frequency-domain Maxwell equations for a homogeneous,
linear, bianisotropic material occupying a bounded region, we found that the
axionic piece vanishes from both the differential equations valid in the region
and the boundary conditions, thereby vindicating the Post constraint. Our
analysis indicates that characteristic effects that may be observed
experimentally with magnetoelectric materials are not the consequences of the
axionic piece but of an admittance that describes surface states.
