Study of the orientation and energy partition of three-jet events in hadronic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>Z</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>decays

We have measured the distributions of the jet energies in ${e}^{+}$${e}^{\ensuremath{-}}$\ensuremath{\rightarrow}qq\ifmmode\bar\else\textasciimacron\fi{}g events, and of the three orientation angles of the event plane, using hadronic ${Z}^{0}$ decays collected in the SLD experiment at SLAC. We find that the data are well described by perturbative QCD incorporating vector gluons. We have also studied models of scalar and tensor gluon production and find them to be incompatible with our data.