Ratio of as a function of clump column density N_H2. We divide the leaves into three groups, one group contains the clumps that belong to the spiral arm of the cloud (red crosses), and the other group contains clumps that are outside the spiral arm (blue crosses). The third group contains clump 2, 4 and 7, which exhibit clear evidences of ongoing star formation (red stars with numbers). IDs of the clumps are indicated. Lines of different virial parameters are included.