  The Feynman-Schwinger representation is used to study the behavior of
solutions of scalar QED in (2+1) dimensions. The limit of zero photon mass is
seen to be smooth. The Bethe-Salpeter equation in the ladder approximation also
exhibits this property. They clearly deviate from the behavior in the
nonrelativistic limit. In a variational analysis we show that this difference
can be attributed to retardation effects of relativistic origin.
