  In this paper, we study the space of translational limits T(M) of a surface M
properly embedded in R^3 with nonzero constant mean curvature and bounded
second fundamental form. There is a natural map T which assigns to any surface
M' in T(M), the set T(M') in T(M). Among various dynamics type results we prove
that surfaces in minimal T-invariant sets of T(M) are chord-arc. We also show
that if M has an infinite number of ends, then there exists a nonempty minimal
T-invariant set in T(M) consisting entirely of surfaces with planes of
Alexandrov symmetry. Finally, when M has a plane of Alexandrov symmetry, we
prove the following characterization theorem: M has finite topology if and only
if M has a finite number of ends greater than one.
