  In general relativity g_ab;c=0 implies that the wave equation
(\Box^2-M)g_ab=0 always has M=0. If the underlying geometry is generalized to
include non-metricity this incurs M \neq 0, and the above wave equation can be
rewritten as M(x)+\td{\na}_a Q_.^a+(\ep+\fr{d}{2}-2)Q_a Q_.^a=0, where \ep=0,
1, 2, or 3, d is the dimension of the spacetime, and Q is the object of
non-metricity. The consequences of this equation and the properties of M are
investigated.
