Measurements of the Q

The structure functions g1p and g1n have been measured over the range 0.014 < x < 0.9 and 1 < Q2 < 40 GeV2 using deep-inelastic scattering of 48 GeV longitudinally polarized electrons from polarized protons and deuterons. We find that the Q2 dependence of g1p (g1n) at fixed x is very similar to that of the spin-averaged structure function F1p (F1n). From a NLO QCD fit to all available data we find Gamma{sub 1}{sup p} Gamma{sub 1}{sup n}=0.176 {+-} 0.003 {+-} 0.007$ at Q2=5 GeV2, in agreement with the Bjorken sum rule prediction of 0.182 {+-} 0.005.