  Globular cluster systems of 17 elliptical galaxies have been studied in the
Coma cluster of galaxies. Surface-brightness fluctuations have been used to
determine total populations of globular clusters and specific frequency (S_N)
has been evaluated for each individual galaxy. Enormous differences in S_N
between similar galaxies are found. In particular, S_N results vary by an order
of magnitude from galaxy to galaxy. Extreme cases are the following: a) at the
lower end of the range, NGC 4673 has S_N = 1.0 +/- 0.4, a surprising value for
an elliptical galaxy, but typical for spiral and irregular galaxies; b) at the
upper extreme, MCG +5 -31 -063 has S_N = 13.0 +/- 4.2 and IC 4051 S_N = 12.7
+/- 3.2, and are more likely to belong to supergiant cD galaxies than to
"normal" elliptical galaxies. Furthermore, NGC 4874, the central supergiant cD
galaxy of the Coma cluster, also exhibits a relatively high specific frequency
(S_N = 9.0 +/- 2.2). The other galaxies studied have S_N in the range [2, 7],
the mean value being S_N = 5.1. No single scenario seems to account for the
observed specific frequencies, so the history of each galaxy must be deduced
individually by suitably combining the different models (in situ, mergers, and
accretions). The possibility that Coma is formed by several subgroups is also
considered. If only the galaxies of the main subgroup defined by Gurzadyan &
Mazure (2001) are used, a trend in S_N arises in the sense of S_N being bigger
in higher density regions. This result needs further confirmation.
