  We study the evolution of dense clumps and provide argument that the
existence of the clumps is not limited by the crossing time of the clump. We
claim that the lifetimes of the clumps are determined by the turbulent motions
on larger scale and predict the correlation of the clump lifetime and its
column density. We use numerical simulations and successfully test this
relation. In addition, we study the morphological asymmetry and the
magnetization of the clumps as a function of their masses.
