Comparison of the velocity dispersion of different molecular lines. Cores listed as having two components (see Table 3) are shown as red symbols, cores that appear to have blended components are shown in black, and the rest are shown as blue symbols. Dashed and dotted lines show the expected velocity dispersion for the cases where the nonthermal velocity dispersion, σ_NT, equals c_s(10   K) or 2   c_s(10   K), where c_s(10   K) is the sound speed of the average molecule at 10 K (for a mean molecular weight of μ_m = 2.33).