The movie The Ape (1940) is an American horror film directed by William Nigh. The film is based on Adam Hull Shirk’s play The Ape, which was previously adapted by Nigh as The House of Mystery (1934). The film stars Boris Karloff as Dr. Bernard Adrian who is seeking to cure a young woman’s polio through experiments involving spinal fluid. Meanwhile, a vicious ape has been terrorising the towns locals, and breaking into Adrian’s lab¹.
The movie The Ape (1940) tells the story of Dr. Bernard Adrian, a benevolent scientist, who is compelled to serve as a small-town doctor after his theories are dismissed by the broader medical community. Despite this setback, he remains committed to his nerve regeneration experiments, driven by his determination to cure the local girl, Frances Clifford, of her polio-induced paralysis. He hopes that once cured, she can marry her beloved, Danny Foster. After extensive research, Dr. Adrian concludes that human spinal fluid is the missing ingredient needed to complete his experimental serum.
Simultaneously, a ferocious circus ape named Nabu escapes its cage after fatally injuring its handler, causing havoc among the townspeople. Eventually, the ape finds its way into Dr. Adrian’s lab. In the ensuing struggle, Dr. Adrian manages to kill the ape, but not before all his vials of spinal fluid, crucial for his experiments, are destroyed.
In the aftermath, Dr. Adrian devises a plan while performing an autopsy on the circus handler. He decides to strip the ape’s flesh and use its skin as a disguise, allowing him to masquerade as the escaped circus animal. This enables him to murder townspeople to extract their spinal fluid without arousing suspicion, as the murders would be attributed to the ape. His resolve to execute this plan is further solidified when he observes significant improvements in Frances’ condition after administering the remnants of his experimental formula.
However, during one of his attacks towards the end of the film, Adrian is shot and critically wounded, causing him to collapse in front of his own doorstep. The concerned townsfolk, fearing the ape might have harmed the doctor, rush to the scene, where the ape’s “true identity” is revealed. Just before he passes, the dying doctor witnesses Frances walking for the first time, bringing a smile to his face as he draws his last breath. The movie concludes with Danny and a now-mobile Frances cherishing life and optimistically looking forward to their future.
- Boris Karloff as Dr. Bernard Adrian
- Maris Wrixon as Miss Frances Clifford
- Gene O’Donnell as Danny Foster
- Dorothy Vaughan as Mother Clifford
- Gertrude Hoffmann as Jane, Adrian’s Housekeeper
- Henry Hall as Sheriff Jeff Halliday
- Selmer Jackson as Dr. McNulty
The Ape (1940) is the final film in Boris Karloff’s six-picture contract with Monogram. 
Filming began on July 29, 1940. 
One review from horrornews.net states: “Despite the overall silliness, the movie didn’t become unintentionally funny. If it had, then it would have been a far more enjoyable experience. Instead, it just was a dull melodrama with horror aspects. There was no real tension or scares to be found. It just plods along, not doing enough to make anyone care about what happens next. The only thing I ended up caring about was how quickly the film ended.” 
Another review from andrew-mccaffrey.medium.com states: “THE APE is a badly made and badly written film, but one which I am happy to report is actually entertaining.”