A subset of 150 globular clusters ( GCs ) in M87 has been selected for abundance and age determinations from the sample of Paper I ( Cohen & Ryzhov 1997 ) .
This has been done solely on the basis of the signal-to-noise ratios of the spectra .
Indices that measure the strength of the strongest spectral features were determined for the M87 GCs and from new data for twelve galactic GCs .
Combining the new and existing data for the galactic GCs and comparing the ( U - R ) colors and the line indices gave qualitative indications for the ages and abundances of the M87 GC system .

Quantitative results , which confirm and extend the qualitative ones , were obtained by applying the Worthey ( 1994 ) models for the integrated light of stellar systems of a single age , calibrated by observations of galactic globular clusters , to deduce abundances and ages for the objects in our sample .

We find that the M87 GCs span a wide range in metallicity , from very metal poor to somewhat above solar metallicity .
The mean [ Fe/H ] of -0.95 dex is higher than that of the galactic GC system , and there is a metal rich tail that reaches to higher [ Fe/H ] than one finds among the galactic GCs .
Excluding the very metal rich tail , there is marginal evidence for a bimodal distribution over the single one at the 89 % significance level .
The two “ subpopulations ” in this model are located at - 1.3 and - 0.7 dex and contain 40 % and 60 % of the total , respectively .
The dispersion in [ Fe/H ] for each of the model subpopulations is \sigma { = } 0.3 dex .

The mean metallicity of the M87 GC system is about a factor of four lower than that of the M87 stellar halo at a fixed projected radius R .
The metallicity inferred from the X-ray studies is similar to that of the M87 stellar halo , not to that of the M87 GC system .

We infer the relative abundances of Na , Mg , and Fe in the M87 GCs from the strength of their spectral features .
The behavior of these elements between the metal rich and metal poor M87 GCs is similar to that shown by the galactic GCs and by halo stars in the Galaxy .
The pattern of chemical evolution in these disparate old stellar systems is , as far as we can tell , identical .

Superposed on a very large dispersion in abundance at all R , there is a small but real radial gradient in the mean abundance of the M87 GCs with R , but no detectable change in the H _ { \beta } index with R .

We obtain a median age for the M87 GC system of 13 Gyr , similar to that found for the galactic GCs .
The dispersion about that value ( \sigma = 2 Gyr ) is small .