Yeats - caught short

All that googles as far as I can see are references to the line as used in Auden's In Memory of WB Yeats. So for the moment I can only tell you that it is on page 111 of a Collected Poems of WB Yeats volume sitting on a shelf in Dolcettos cafe in Yass, which I hope to revisit soon. Caught short on my annotations! Later: It's not even on page 111! Wot the... If anyone stumbles into this blog could you let me know which Yeats poem I'm after please. Me and my broken memory