Equal Rites by Terry Pratchett

In this book Terry Pratchett traces the humorous circumstances that result from a wizard bequeathing his powers on the eighth son of an eighth son only to discover that the son is a daughter. I found this book much funnier than the previous Discworld novels. The satire on gender conventions and on schools of wizardry was particularly good. I look forward to seeing more of Granny Weatherwax.