  A sample of 45 symbiotic stars observed in the direction of the galactic
bulge are classified in spectral type using TiO $\lambda \lambda 6180, 7100
\AA$ and VO $\lambda \lambda 7865 \AA$ absorption feature indices and visual
comparison. The effective temperatures obtained are used together with K data
from the literature to estimate the bolometric luminosity of the giant
components if located at d=8.5 kpc. The ($T_{eff}$, $L/L_{\odot}$) pairs are
plotted on the HR diagram together with evolutionary tracks for metal rich
intermediate mass stars. The mass of the giant components seem to be scattered
in the interval ($\sim 1.5 - \sim 4 M_{\odot}$). The giant components of D-type
symbiotics appear as if they were more evolved objects than the corresponding
giants in S-type systems. Nevertheless, it is unlikely that they form an
evolutionary sequence. The results point also to the restriction of the
symbiotic phenomenon to the thermally pulsating phase of the AGB, strengthening
an accelerated mass loss scenario for the latest evolutionary stages of
intermediate mass stars.
