  New stellar models which track the production and destruction of $^3$He (and
D) have been evolved for a range of stellar masses $(0.65\leq M/M_{\odot}\leq
100)$, metallicities $(0.01 \leq Z/Z_{\odot} \leq 1)$ and initial (main
sequence) $^3$He mass fractions $(10^{-5} \leq X_{3,MS} \leq 10^{-3})$. Armed
with the $^3$He yields from these stellar models we have followed the evolution
of D and $^3$He using a variety of chemical evolution models with and without
infall of primordial or processed material. Production of new $^3$He by the
lower mass stars overwhelms any reasonable primordial contributions and leads
to predicted abundances in the presolar nebula and/or the present interstellar
medium in excess of the observationally inferred values. This result, which
obtains even for zero primordial D and $^3$He, and was anticipated by Rood,
Steigman \& Tinsley (1976), is insensitive to the choice of chemical evolution
model; it is driven by the large $^3$He yields from low mass stars. In an
attempt to ameliorate this problem we have considered a number of non-standard
models in which the yields from low mass stars have been modified. Although
several of these non-standard models may be consistent with the $^3$He data,
they may be inconsistent with observations of $^{12}$C/$^{13}$C, $^{18}$O and,
most seriously, the super-$^3$He rich planetary nebulae (Rood, Bania \& Wilson
1992). Even using the most extreme of these non-standard models (Hogan 1995),
we obtain a generous upper bound to pre-galactic $^3$He: X$_{3P} \leq 3.2
\times10^{-5}$ which, nonetheless, leads to a stringent lower bound to the
universal density of nucleons.
