It's another idyllic day in the jungle for the family of Tarzan (Johnny Weissmuller), and his adopted son Boy (Johnny Sheffield) is riding on the back of a baby elephant of his acquaintance along with Cheeta the chimp. After playing around together, they hear Tarzan's call and rush to the lake where they go for a swim and while underwater, Boy collects more of those distinctive yellow stones for his slingshot. When he asks Jane (Maureen O'Sullivan) about them, she tells him they are gold and are extremely valuable in the outside world - which intrigues the child...
For the fifth film in the Tarzan series, the formula was pretty much set in stone, but the introduction of Boy had rendered the films more an entertainment for younger audiences, and indeed he has almost as much screen time as the titular hero, if not more. As ever, the tension between the jungle man's simple, back to nature ways and the encroaching civilisation is ever-present, yet this time it was made clearer by having Boy find the prospect of living in a world of aeroplanes - which he covets - more attractive than the one he has grown up in.
So it is that Boy opts to leave, although he doesn't want to be gone forever, just long enough to turn his gold nuggets into material goods, but he slips away in the night with only a note to Tarzan and Jane to indicate where he has gone. This first act is all about him as he stumbles upon a counterpart in Tumbo (Cordell Hickman), a young member of a tribe which is afflicted by a plague. To underline the connections between these two new friends, we are there when Tumbo's mother expires, meaning that predictably but endearingly he will become one of the Tarzan family by the end.
However, there are the requisite white hunters among this tribe, scientists actually, led by Professor Elliott (Reginald Owen) in an expedition to uncover a lost people, and while he is perfectly moral, when two of his party, Medford (Tom Conway) and Vandermeer (Philip Dorn) get wind of the, if you will, secret treasure up on Tarzan's plateau then the stage is set for greed to overcome them and yet another clash between the white man and our hero to get underway. We've been here before, and with all the reused footage from previous adventures implemented, this was starting to look like a rerun instead of anything new.
Take that into account and accept there will be no surprises and this instalment might not be one of the better ones, but it's still a pleasant enough way to while away eighty minutes. Not only does Boy get the lion's share of screen time, but so does Cheeta as the comic relief, walking on his hands and getting drunk on the whiskey of the supposed comic relief O'Doul (Barry Fitzgerald) who does not let a minute go by without reminding us he's Irish. What with all the animals on display this film more than the others looks like a trip to the circus circa 1941, and yet again it's the elephants who save the day from a gang of crocodiles (yes, we see those clips of Tarzan fighting the crocodile once more). The differences between supposed civilisation and the jungle life would be even more pronounced in the next movie - which didn't feature Tumbo. Bad luck Tumbo. Music by David Snell.