  We study the photometric parameters of the bulges of galaxies of different
Hubble types including ellipticals, lenticulars, early and late type spirals
and early type dwarf galaxies. Analyzing the distributions of various
photometric parameters, and two- and three-dimensional correlations between
them, we find that there is a difference in the correlations exhibited by
bright (M_K < -22) and faint bulges, irrespective of their Hubble type.
Importantly, the bright bulges, which include typically E/S0 galaxies and
bulges of early type spirals, are tightly distributed around a common
photometric plane (PP), while their fainter counter parts, mainly bulges of
late type spirals and dwarf galaxies show significant deviation from the planar
distribution. We show that the specific entropy, determined from the bulge
structural parameters, systematically increases as we move from late to early
Hubble types. We interpret this as evidence for hierarchical merging and
passive evolution scenarios for bright and faint bulges respectively.
