1: Poles suffer internally - they're hard (5)

3: He wrote a bit of poetry! (3)

5: Mineral springs start to moderate involuntary muscular contraction (5)

7: Odds of niece being born (3)

8: Essays about old dramatic works (9)

9: Mann's 'Death in Venice' Dorothy sent up (3)

10: Drunk held firmly (5)

12: In no state to contain a pregnant virgin? (3)

13: A cow further down? (5)

1: Greek characters suggest dawn (3)

2: Dairy stock entails wrangling around 2000 (9)

3: Piano finale not determined (7)

4: We turned up with endless Irish pitchers (5)

6: Freedom of action in desert (7)

8: All the performers express disapproval about it (5)

11: Start reducing salt? (3)