Dr. Jekyll and Mr. Hyde (Rouben Mamoulian, 1931; Victor Fleming, 1941)
MGM's 1941 Dr. Jekyll and Mr. Hyde is a virtual remake of Paramount's 1931 version of the Robert Louis Stevenson novella: John Lee Mahin's screenplay is clearly based on the earlier one by Samuel Hoffenstein and Percy Heath. The similarities are so obvious that MGM, having bought the rights to Paramount's version, tried to buy up all prints of it.* Seeing the two versions back-to-back is a pretty good lesson in how things changed in Hollywood over ten years: For one thing, the Production Code went into effect, which means that the "bad girl" Ivy (Miriam Hopkins in 1931, Ingrid Bergman in 1941) ceased to be a prostitute and became a barmaid. Hopkins shows a good deal more skin than does Bergman, and in the 1931 we see the scars on her back, inflicted by Hyde's whip, whereas in 1941 we see only the shocked reaction of those who witness them. As for Jekyll/Hyde (Fredric March in 1931, Spencer Tracy in 1941), the earlier version gives us a lustier Jekyll -- we sense that he's so eager to marry the virtuous Muriel Carew (Rose Hobart) because he wants to go to bed with her. Tracy's Jekyll indulges in a little more PDA with his fiancée, Beatrix Emery (Lana Turner), than her Victorian paterfamilias (Donald Crisp) would like, but there's no sense of urgency in his attraction to her. It's widely known that the original casting had Turner playing Ivy and Bergman as Beatrix, but that Bergman wanted to play the bad girl for a change -- it's clearly the better part -- and persuaded director Victor Fleming to make the switch. March's Hyde is a fearsome, simian creature with a gorilla's skull and great uneven teeth; Tracy's is just a man with a lecherous gaze, unruly hair, bushy eyebrows, and what looks like an unfortunately oversize set of false teeth. March's Jekyll -- pronounced to rhyme with "treacle" -- is a troubled intellectual, whereas Tracy's -- pronounced to rhyme with "heckle" -- is a genial Harley Street physician who genuinely wants to find a cure for bad behavior. March won an Oscar for his performance, and he does lose his sometimes rather starchy manner in the role. Tracy, I think, was just miscast, though in real life he had his own Jekyll/Hyde problems: The everyman persona hid a mean drunk.
*MGM did the same thing to Thorold Dickinson's 1940 film of Gaslight when it made its own version, directed by George Cukor, in 1944, but didn't succeed in either case.