Let Tg be the Teichmüller
space of a compact Riemann surface R of genus g with g ≧ 2. In the present paper it
is shown that the Weil-Petersson Iength of a large class of rays is finite, deduced that
the metric is not complete and indicated how the proof can be extended to the
Teichmüller space of an arbitrary finitely generated Fuchsian group of the first
kind. The proof is carried out by estimating the Weil-Petersson length of
Teichmüller geodesic rays in directions corresponding to a certain class of quadratic
differentials.