  Results from the modelling of bars in nearly 300 galaxies are used to test
predictions from theoretical work on the evolution of bars. Correlations are
found between bar ellipticity and boxiness, between bar strength and normalised
size, between the normalised sizes of bars and bulges, and between normalised
bar size and bulge-to-total ratio. Bars with different ellipticities follow
parallel lines in the latter two correlations. These correlations suggest that,
formed with different sizes and ellipticities, bars slow down and grow longer
and stronger, in agreement with theoretical work. As a consequence, bar pattern
speeds should become lower with time, and towards galaxies with more prominent
bulges.
