My memory gave me a nudge in the ribs.
Close to the top I said that Isaak Walton wrote a book with a song in it, but I got the name wrong. Walton wrote 'the Compleat Angler.'
'Treatys...' was, I think, written by a lady, a prioress called Dame something, but again I'm working from a 50-y-o memory.

The song was about life, the fist verse saying basically that life was 'worry and trouble and care' and the second and last verse saying 'we don't care anyway, because we're going fishing!'

Just in the interest of accuracy on the WWW.