Possible Clues:

• Might a rotten, learned one have the mice in bits?
• One that's learned what's not relevant
• Of theoretical interest, no practical application
• How a learned rotter will have the mice in pieces
• Scholar - relating to a college
• Scholarly; irrelevant
• Teacher has a small volume, taking in a half
• It's not practical for an accountant to get half a hundred like this
• Scholarly - unrealistic
• A century followed by a halfcentury, at least in theory