The paper generally discusses turbulent mixing, chemical reactions, and combustion in fully developed shear layers and jets. More specifically, it reviews results of experiments that appear to have important implications for understanding and modeling these flows, with possible implications for dealing with turbulent transport in general. Conclusions include: molecular transport coefficients play a significant role in turbulent mixing phenomena, even in fully developed turbulent flows; large-scale structure dynamics dictate entrainment, which in turn provides the environment for subsequent turbulent cascade and mixing processes; and turbulent shear layers and jets are essentially unsteady at the largest temporal and spatial scales in the flow. (Copyright (c) American Institute of Aeronautics and Astronautics, Inc., 1985.)