Upon learning of the author’s interest in these cats, a sea captain gifted Hemingway with a charming white polydactyl cat with six toes, whom Hemingway’s sons named Snow White.

A “Hemingway cat” isn’t a specific breed. It’s actually a genetic trait, so any breed of cat can be a Hemingway cat. The name simply refers to any cat with extra toes. Typically, cats have ...