The magnetic radius vs flux relation for spots is distinct, with larger radii at one and the same flux than those for pores, while the curve for the dark radius is continuous with that for pores.
Spots differ from pores only in the nature of their sheaths.
We suggest these relations to be universal. The temporal magnetic evolution for two developing pores and a decaying spot in the radius-flux plane traces the universal dark radius curve for both types of features. The evolution of an AC into a pore, perhaps via a bifurcation, follows the universal curves for dark and magnetic radii. Any bifurcation in the transition from pores to spots must appear via a transition in the magnetic sheath. The National Center for Atmospheric Research is sponsored by the National Science Foundation.