Growing evidence for the existence of two classes of ellipticals calls for a comparison of the properties of their globular cluster systems .
I compiled information on the properties of 53 globular cluster systems of faint and bright early-type galaxies , and investigated them in the light of the properties of the parent galaxies .
The properties of globular cluster systems appear to separate into two classes rather than to follow continuous relations with their host galaxy properties .

The “ faint ” systems have a low specific frequency ( less than about 5 ) , less than roughly 1500 globular clusters , a relatively low metallicity ( [ Fe/H ] < -1.2 ) , and a steep density profile that follows the galaxy light .
These systems appear essentially unperturbed , and are hosted by faint ( about M _ { V } > -21.5 ) , disky early–type galaxies with unresolved cores .

On the other hand , “ bright ” globular cluster systems had a higher efficiency in producing globular clusters and have higher specific frequencies ( higher than 5 ) .
They have larger number of globular clusters ( more than 2000 ) , have flat density profiles ( \alpha > -1.7 ) and their color distributions are often broad , and show several peaks or gradients in many cases .
Finally the mean metallicity is higher than in “ faint ” globular cluster systems .
“ Bright ” globular cluster systems show all signs predicted for globular cluster systems that experienced a merger event , and are associated with bright ( about M _ { V } < -21.5 ) boxy ellipticals with resolved cores .

I conclude that every galaxy is likely to have formed globular clusters during the early proto–galactic collapse , but “ bright ” systems were enriched and disturbed during merger events .
These two classes of globular cluster systems support the idea that major merger events could be a cause for the dichotomy of early–type galaxies .