WÜRTTEMBERG consists of 63 independent realms, each centered on one of the large oases dotting this otherwise arid planet.  Seven seasons of the year are recognized:  Blume, Wiese, Heiß, Obst, Nebel, Regen, and Sturm.  At the beginning of each season, nine families from each realm must pack their belongings and migrate to one of the neighboring realms.  This choreographed movement follows a Grand Tour pattern that eventually leads back to any given origin, but because different families are chosen each season it would take many lifetimes to return to an ancestral home.  In contrast to this deliberate mixing of the population, Württembergers have very strict laws against most genetic mutations.  Those found to possess proscribed genes must submit to either sterilization or imprisonment.