Just googled that as hadn't heard of it - apparently Hemingway had well over 50 cats running free in his gardens and it was thought at one time that interbreeding was the reason for a number of them having 'thumbs'! The number of polydactyls is today kept to about 40 or so around the gardens of his old Quay West home which is retained as a museum in his honour.
Yeah I did a wee bit of reading up too. Seemingly they're common on the south coast of England and also the east coast of America (Boston). Possibly to do with the shipping years ago.
Trying to think of a good name for her. Thumbs/Fingers are the favourites so far

