  We compare the molecular cloud properties in sub-galactic regions of two
galaxies, barred spiral NGC 1313, which is forming many massive clusters, and
flocculent spiral NGC 7793, which is forming significantly fewer massive
clusters despite having a similar star formation rate to NGC 1313. We find that
there are larger variations in cloud properties between different regions
within each galaxy than there are between the galaxies on a global scale,
especially for NGC 1313. There are higher masses, linewidths, pressures, and
virial parameters in the arms of NGC 1313 and center of NGC 7793 than in the
interarm and outer regions of the galaxies. The massive cluster formation of
NGC 1313 may be driven by its greater variation in environments, allowing more
clouds with the necessary conditions to arise, although no one parameter seems
primarily responsible for the difference in star formation. Meanwhile NGC 7793
has clouds that are as massive and have as much kinetic energy as clouds in the
arms of NGC 1313, but have densities and pressures more similar to the interarm
regions and so are less inclined to collapse and form stars. The cloud
properties in NGC 1313 and NGC 7793 suggest that spiral arms, bars, interarm
regions, and flocculent spirals each represent distinct environments with
regard to molecular cloud populations. We see surprisingly little difference in
surface densities between the regions, suggesting that the differences in
surface densities frequently seen between arm and interarm regions of
lower-resolution studies are indicative of the sparsity of molecular clouds,
rather than differences in their true surface density.
