Derek said
"I've just about given up reading all these messages in the thread, which has now developed into a bad-tempered conversation between 3 people, and very occasional inputs from another couple of people."

The vast majority of posts in the last few days have been from two people. If Derek is including me or any of the others who have made occasional contributions, I am disappointed. Mine have been mostly seeking clarification of comments that I had failed to understand: if they have come across as bad tempered I apologise.

GUEST,Jerome Clark mentioned one of his books with 'an extended discussion of the lore out of which "Thomas the Rhymer" grew'.
Reference, please!