Novel tests of quantum chromodynamics in electro-production

We discuss a number of ways in which single arm and coincident measurements of electroproduction on proton and nuclear targets can test fundamental QCD phenomena and provide constraints on hadronic wavefunctions. The topics include tests of color transparency, predictions for charm production at threshold, formation zone phenomena, and non-additive nuclear effects. We particularly emphasize the need for measurements which probe the short-range structure of hadronic and nuclear wave functions. In addition to the 'extrinsic' gluonic and sea-quark contributions associated with radiation from single partons, perturbative QCD predicts an 'intrinsic' hardness of the high-mass fluctuations of the wave function. These contributions can dominate heavy particle production at large x in the target fragmentation region and can be further enhanced in nuclear target reactions. Intrinsic hardness can also provide a possible explanation of the anomalous nuclear phenomena referred to as 'cumulative' production. (orig.)