  The dynamical mass of clusters of galaxies, calculated in terms of modified
Newtonian dynamics, is a factor of two or three times smaller than the
Newtonian dynamical mass but remains significantly larger than the observed
baryonic mass in the form of hot gas and stars in galaxies. Here I consider
further the suggestion that the undetected matter might be in the form of
cosmological neutrinos with mass on the order of 2 eV. If the neutrinos and
baryons have comparable velocity dispersions and if the two components maintain
their cosmological density ratio, then the electron density in the cores of
clusters should be proportional to temperature to the 3/2 power, as appears to
be true in non-cooling flow clusters. This is equivalent to the ``entropy
floor'' proposed to explain the steepness of the observed
luminosity-temperature relation, but here preheating of the medium is not
required. Two fluid (neutrino-baryon) hydrostatic models of clusters, in the
context of MOND, reproduce the observed luminosity-temperature relation of
clusters. If the beta law is imposed the gas density distribution, then the
self-consistent models predict the general form of the observed temperature
profile in both cooling and non-cooling flow clusters.
