  It is shown that negative electric permittivity and magnetic permeability
recently discovered in a photonic crystal in the vicinity of the Gamma-point
are properties of propagating modes only. The evanescent modes rather decay
than increase in the bulk of the crystal though they may be amplified by
surface waves. If surface support such waves, the evanescent waves may improve
the image of a thin Veselago lens. It is shown that a ``perfect lens''
contradicts to the wave optics and a criterion of ``superlensing'' is
formulated.
