Moria says it's "one of the genuine genre classics to emerge out of the 1930s Golden Age of Horror." 1000 Misspent Hours calls it "a miserable old clunker". from the New York Times review from its release:
It is all very well in its way to have a mad scientist performing operations in well-told stories, but when a melodrama depends upon the glimpses of covered bodies in a morgue and the stealing of some of them by an insane modeler in wax, it is going too farClassic-Horror.com says,
After witnessing this unhealthy film, it is very agreeable to gaze upon a short subject dealing with the wonders of Yellowstone Park.
it was one of the earliest experiments with color film as well as one of the earliest treatments of a now well-known mystery plot, topped with an intriguing visual style and some horror icons in fine form for good measure.10/29/2008: House of Mirth and Movies has a review.