stellar remnants. In any event, an inversion of this last expression yields $${{M_{\rm gcs}}\over{M_{\rm stars}}} = 4.0\times10^{-4}\,S_N\,
\left({{\langle m\rangle_{\rm cl}}\over{2.4\times10^5\,M_\odot}}\right)\,
\left({{\Upsilon_V}\over{7\,M_\odot\,L_\odot^{-1}}}\right)^{-1}\,
\sim\,2\times10^{-3}\,\left({{S_N}\over{5}}\right)\ ,
\label{eq:23}$$ where $S_N\approx5$ is suggested by the studies cited above as a representative value for early-type galaxies ranging in luminosity from $M_V^T\simeq-15$ to $M_V^T\simeq-22$. Of course, there is some uncertainty in this “mean” $S_N$, and some intrinsic scatter about it. Moreover, the data suggest that $S_N$ varies systematically with $L_{V,{\rm gal}}$—the simple scaling ${\cal N}_{\rm tot}\propto L_{V,{\rm gal}}$ that corresponds to a constant specific frequency is not strictly obeyed—particularly among dwarf ellipticals and between brightest cluster galaxies. These issues have been discussed in detail in the literature, and they are revisited here, in §2.2. With this caveat in mind, however, $M_{\rm gcs}/M_{\rm stars}\sim 2\times
10^{-3}$ is useful as a crude, order-of-magnitude guide to a “typical” global GCS mass ratio in galaxy halos.

The advantage of working in terms of this [*mass*]{} ratio is that, whatever its precise value in any one system at the current epoch, it is expected to be a fairly well conserved quantity that has not changed drastically over the course of GCS and galaxy evolution in a Hubble time. [*This is true even 