A Polydactyl describes a type of cat with a genetic mutation causing it to be born with six toes on one or more of its paws.  Popular in history to sailors as good luck charms, legend has it that a ship’s captain once gave cat-loving (at one point he had fifty-seven) author Ernest Hemingway a six-toed cat, the descendants of which currently reside at his home in Key West.  Because of his love for them, “Hemingway Cat” has become a term that describes polydactyls…

from The Ernest Hemingway Home & Museum

The Ernest Hemingway Home and Museum is home to approximately 40-50 polydactyl (six-toed) cats. Cats normally have five front toes and four back toes. About half of the cats at the museum have the physical polydactyl trait but they all carry the polydactyl gene in their DNA, which means that the ones that have 4 and 5 toes can still mother or father six-toed kittens. Most cats have extra toes on their front feet and sometimes on their back feet as well. Sometimes it looks as if they are wearing mittens because they appear to have a thumb on their paw.

Ernest Hemingway was given a white six-toed cat by a ship’s captain and some of the cats who live on the museum grounds are descendants of that original cat, named Snowball. Key West is a small island and it is possible that many of the cats on the island are related. The polydactyl cats are not a particular breed. The trait can appear in any breed, Calicos, Tabbies, Tortoise Shell. White, Black, etc. They vary in shapes, sizes, colors and personalities.

Hemingway named all of his cats after famous people so we follow that same tradition today. Cats are capable of learning and responding to their names, particularly if they have an affectionate relationship with the person who calls them.

(The Ernest Hemingway Home & Museum)