  The level statistics of pseudointegrable fractal drums is studied numerically
using periodic orbit theory. We find that the spectral rigidity $\Delta_3(L)$,
which is a measure for the correlations between the eigenvalues, decreases to
quite small values (as compared to systems with only small boundary roughness),
thereby approaching the behavior of chaotic systems. The periodic orbit results
are in good agreement with direct calculations of $\Delta_3(L)$ from the
eigenvalues.
