It is well known that the radial distributions of atomic and molecular gas differ markedly in spiral galaxies, including our own (e.g. Burton & Gordon 1978, Sofue et al. 1995). We have recently begun a program to obtain multifrequency observations of several nearby galaxies in order to determine whether H I is needed to replenish the H2consumed by star formation and, if so, how this might be accomplished. Here we present initial results on the nearby RSab galaxy NGC 4736, known for its

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... t ring of H II regions and recently shown to have a central stellar bar (Möllenhoff et al. 1995). We have mapped the distribution of CO (1-0) emission withinr=1′ (1.8 kpc atD=6.2 Mpc) with the BIMA interferometer at ~5″ resolution, and added data from the NRAO 12-m telescope to recover zero-spacing information.