  Geometric characteristics of random fields are exploited to test the
consistency of density perturbation model spectra with COBE data. These CMB
maps are analyzed using the number of anisotropy hot spots and their boundary
curvature. CMB maps which account for instrumental effects and sky coverage are
Monte Carlo generated. These simulations show that a scale invariant
Harrison-Zeldovich primordial Gaussian density fluctuation spectrum is
consistent with the data. The CMB fluctuation coherence angle, based on
boundary curvature, gives a spectral index n = 1.2 +- 0.3.
