Dear WW: all of these entries are taken from Brewer's Dictionary of Phrase and Fable. Over a
hundred years old, but many of the etymolgies give would be hard to find elsewhere. I have
been disappointed that there have been so few comments, which are most welcome. Sorry
you felt otherwise.
Did you hear about the scot who on his way home late from the bar lost his tam in a
cow pasture and had to try on several before he found one that fitted?

http://www.bootlegbooks.com/Reference/PhraseAndFable/data/115.html