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We use a variant of the surface brightness fluctuations (SBF) method to detect the globular cluster populations around NGC~4874 and NGC~4889 in the $I$ band. The feasibility of this technique was recently demonstrated by different authors using $V$-band images of M87. The fluctuations due to globular clusters (``GCF''), a nuisance factor in the standard SBF technique, provide a means for studying that portion of the globular cluster population which cannot be observed directly. We confirm an earlier finding that NGC~4874 has a significantly higher specific frequency of globular clusters than NGC~4889. By measuring the GCF at several radii, we find that the specific frequency increases outward from the center of both galaxies, indicating that the globular cluster systems are more extended than the halo light, in accord with previous studies of NGC~4874 and nearby ellipticals. For these Coma galaxies, we can also directly count the number of clusters occupying the bright end of the globular cluster luminosity function (GCLF). The direct counting and GCF measurements together provide a constraint on the width of the GCLF, which in turn decreases the uncertainty in the inferred specific frequencies.
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