We study the cosmic density perturbations induced from fluctuation of the
amplitude of late-decaying scalar condensations (called \phi) in the scenario
where the scalar field \phi once dominates the universe. In such a scenario,
the cosmic microwave background (CMB) radiation originates to decay products of
the scalar condensation and hence its anisotropy is affected by the fluctuation
of \phi. It is shown that the present cosmic density perturbations can be
dominantly induced from the primordial fluctuation of \phi, not from the
fluctuation of the inflaton field. This scenario may change constraints on the
source of the density perturbations, like inflation. In addition, a correlated
mixture of adiabatic and isocurvature perturbations may arise in such a
scenario; possible signals in the CMB power spectrum are discussed. We also
show that the simplest scenario of generating the cosmic density perturbations
only from the primordial fluctuation of \phi (i.e., so-called ``curvaton''
scenario) is severely constrained by the current measurements of the CMB
angular power spectrum if correlated mixture of the adiabatic and isocurvature
perturbations are generated.Comment: 31pages, 14figure