  We investigate quintessence cosmologies with a matter component consisting of
particles with an increasing mass. While negligible in early cosmology, the
appearance of a growing matter component has stopped the evolution of the
cosmon field at a redshift around six. In turn, this has triggered the
accelerated expansion of the Universe. We propose to associate growing matter
with neutrinos. Then the presently observed dark energy density and its
equation of state are determined by the neutrino mass.
