Total cold gas mass, M_cg, (in M_⊙) in the most massive satellite vs. the stellar mass of the most massive satellite galaxy, M_*mms. The left, middle, and right panels show log M_*C = 10.160–10.405, log M_*C = 10.453–10.715, and log M_*C = 10.931–11.288 bin halos. As in Figure 3, respective quartiles and 1σ ranges are marked. Since some most massive satellites are totally devoid of any cold gas, we explicitly set their y-axis values to 10⁶ M_⊙. The amount of cold gas contained within each most massive satellite gradually increases as we move from low-mass to high-mass halos.