The cats at Hemingway’s former Key West home have acquired an unusual collection of human paperwork: a museum history, genetics studies and a federal appellate opinion. Their extra toes connect those stories, but each source answers a different question.
The cats living at the museum
The Ernest Hemingway Home and Museum currently describes a colony of nearly sixty cats, with about half displaying extra toes. This is a changing population rather than a permanent census. The museum also describes its veterinary care and its tradition of naming cats after famous people.
“Polydactyl” describes extra digits; it is not the name of a single breed. The mitten-like appearance of some paws is one reason the animals are so recognizable.
Snow White, Snowball and the limits of the record
The museum says a ship’s captain gave Hemingway a white six-toed cat named Snow White and that some current residents descend from that cat. The 2012 court opinion recounts a gift from Captain Stanley Dexter but calls the cat Snowball.
Those accounts should be attributed, including their difference in names. It would be wrong to say the story exists only on a tourist plaque: it appears in an institutional account and a judicial record. Equally, a later judicial summary is not a contemporary diary entry or a genetic parentage study of every cat now on the property.
The careful version is neither a complete debunking nor an unqualified pedigree claim. The museum tells a particular founding story; the surviving sources used here do not establish every detail of the colony’s ancestry.
A small regulatory change can alter a paw
Research by Laura Lettice and colleagues, published in 2008, connected feline polydactyly with changes in a regulatory sequence called ZRS. This sequence helps control the limb-development activity of the Sonic hedgehog gene.
The study included the Hemingway cats and identified different variants associated with extra digits. The broader lesson is that changing where or when a developmental gene is active can change anatomy; the change need not be inside the protein-coding gene itself.
A 2020 study of Maine Coon cats found a more complicated genetic picture, including incomplete penetrance, variable expression and more than one genetic background. The visible appearance of a paw does not tell the entire inheritance story.
In particular, dominance does not guarantee that half of any colony will show a trait. Population proportions depend on mating patterns, genotypes and how the trait is expressed. The museum’s approximate count should not be presented as a simple consequence of Mendelian inheritance.
Why a museum’s cats reached a federal court
On 7 December 2012, the Eleventh Circuit upheld the museum’s regulation as an animal exhibitor under the Animal Welfare Act. The issue was the museum’s activity, not a declaration that a cat was itself interstate commerce.
The court considered the exhibition’s commercial role and its attraction of paying visitors from outside Florida. The opinion also records that the museum had held an exhibitor’s license since August 2008. These details come from the published decision, rather than a general rule about keeping cats.
Three stories worth keeping separate
The museum’s account describes its residents and traditions. Genetics studies investigate how extra digits develop and are inherited. The court opinion explains a dispute about regulatory jurisdiction.
None needs the claim that these are the only cats ever mentioned in a law report, or that a particular toe pattern proves a voyage across the Atlantic. Those flourishes make the opening sound spectacular while adding questions the evidence has not answered.
The reliable story is already unusual: a living colony at a writer’s former home became both a scientific example and part of a legal dispute. The cats did not need to leave the garden to become interesting.
For another example of feline inheritance, our calico-cat genetics article examines coat color. For cats living alongside a different kind of public institution, see our history of library cats.
Visit the Pudgy Cat Shop for cat-inspired goodies, or find our illustrated books on Amazon.
