  We suggest that the quark-confining force is related by crossing symmetry to
a color-singlet glueball ${\cal G}$ which is well described as a loop of one
quantum of color magnetic flux. Electron pair annihilation as high as $\approx
2 GeV$ above the $\Upsilon$ mass could produce $\Upsilon \rightarrow
\ell^+\ell^-$ accompanied by ${\cal G}$ or one of its excited states.
