  We present kinematics and stellar population properties of 17 dwarf
early-type galaxies in the luminosity range -14> M_B> -19. Our sample fills the
gap between the intensively studied giant elliptical and Local Group dwarf
spheroidal galaxies. The dwarf ellipticals of the present sample have constant
velocity dispersion profiles within their effective radii and do not show
significant rotation, hence are clearly anisotropic. The dwarf lenticulars,
instead, rotate faster and are, at least partially, supported by rotation. From
optical Lick absorption indices, we derive metallicities and element
abundances. Combining our sample with literature data of the Local Group dwarf
spheroidals and giant ellipticals, we find a surprisingly tight linear
correlation between metallicity and luminosity over a wide range: -8> M_B> -22.
The alpha/Fe ratios of our dwarf ellipticals are significantly lower than the
ones of giant elliptical galaxies, which is in agreement with spectroscopy of
individual stars in Local Group dwarf spheroidals. Our results suggest the
existence of a clear kinematic and stellar population dichotomy between dwarf
and giant elliptical galaxies. This result is important for theories of galaxy
formation, because it implies that present-day dwarf ellipticals are not the
fossiled building blocks of giant ellipticals.
