  Dark matter is obtained from a scalar field coupled conformally to
gravitation; the scalar being a relict of Dirac's gauge function. This
conformally coupled dark matter includes a gas of very light ($m\approx
2.25\times 10^{-34} eV$) neutral bosons having spin 0, as well as a
time-dependent global scalar field, both pervading all of the cosmic space. The
time-development of this dark matter in the expanding F-R-W universe is
investigated, and an acceptable cosmological behaviour is obtained.
