Willis O. Brien's special effects are still surprisingly good and way ahead of the 1960 version even if he was to perfect them further in King Kong (for which this film feels almost like a dress rehearsal at times), giving the film an epic scale in the volcanic eruption and stampede sequences, while Wallace Beery is a perfect choice for Professor Challenger, embodying the gruff, belligerent nature of the character to a tee. There are changes to the novel  not only is Bessie Love brought along on the expedition to search for her lost father (with none of the comic relief chauvinism from Challenger found in the 1960 version) but the pterodactyl that terrifies the streets of London has been changed to a lumbering Brontosaurus, which is certainly a change for the better  but then Doyle's book is rather light on plot to begin with. The dinosaurs aren't as well integrated into the story as you might hope  usually it's cutaways to herds of dinosaurs in their natural habitat  and the racial stereotyping from Jules Cowles' blackface routine as 'Zambo' is painfully embarrassing and horribly unfunny (sample dialogue on seeing campfire smoke from the plateau: "That means our folks is still alive." "It may mean dat some of those cannibules dat drop dat rock down on us yistiddy am cookin' 'em in dar stew-pot!"). But it's hard not to like a film with dialogue like "What are you thinking of, Paula  in this lost world of ours?" or Challenger's immortal "My brontosaurus has escaped! Keep off the streets  until I recapture it!" and where our hero's rival for his girl back home's affections is called Percy Bumberry!