  We give a proof of the classical Schwarz reflection principle for
Jenkins-Serrin type minimal surfaces in the homogeneous three manifolds
$E(\kappa, \tau)$ for $\kappa \leqslant 0$ and $\tau \geqslant 0$. In our
previous paper we proved a reflection principle in Riemannian manifolds. The
statements and techniques in the two papers are distinct.
