  We discuss systematically the consistency of light gluinos with data on
perturbative QCD from deep inelastic scattering, quarkonia, jets at LEP, and
the total hadronic cross-section in ${e^+ e^-}$ annihilation on the $Z$ peak
and elsewhere. We demonstrate that, in addition to the well-known increase in
the value of $\alpha_s(m_Z)$ inferred from lower-energy data due to the slower
running of $\alpha_s$ in the presence of light gluinos, the value of
$\alpha_s(m_Z)$ extracted from the LEP data must also be $increased$, as a
result of including the effects of virtual light gluinos. The effect of these
increases in other estimates of $\alpha_s(m_Z)$ is to make them more consistent
with the value extracted from the total $e^+ e^-$ cross-section, which would
otherwise appear distinctly higher. We discuss the possibility of looking for
light gluinos in four-jet events at LEP, and their possible implications for
scaling violations at HERA.
