Glitches and pinned vorticity in the Crab pulsar.

We suggest that the glitch behavior observed in the Crab pulsar is associated with vorticity jumps induced by a starquake or a comparable external fluctuation in the weakly pinned vortex region expected in the crust of a young neutron star, and that the differences in the glitch behavior of the Crab, Vela, and older pulsars may be explained on evolutionary grounds.