From left to right are shown the differential (dN/dlog M) clump mass distributions of the entire sample, IR-dark clumps, and IR-bright clumps. In all panels the mass bin size is Δlog (M/M_⊙) ≃ 0.44. The error bars correspond to the standard Poisson  counting uncertainties. The solid lines indicate the best-fit power-law functions of the form dN/dlog M ∝ M^−Γ, where the slope is given in each panel. The fits refer to masses above  ~2400 M_⊙ for both the entire sample and IR-dark clumps, and above  ~1500 M_⊙ for the IR-bright clumps. We note that the Salpeter IMF has a slope of Γ = 1.35.