By the turn of the 1970s, the shine was starting to come off the Carry On films. There were plenty of laughs to come but nothing like the sustained brilliance of Cleo (1964), Screaming! (1966) or Up the Khyber (1968). The jokes would become coarser, the core team would slowly drift apart and raunchier fare like the Confessions and Adventures films, freer with the nudity than the comparatively chaste Carry Ons were prepared to be. Carry on Up the Jungle, in which writer Talbot Rothwell, producer Peter Rogers and director Gerald Thomas took aim at Tarzan, Hammer’s prehistoric “slave girls” films and those interminable jungle adventure movies that we seemed to get on television and at the cinema an almost weekly basis in the 1960s, is often hailed as one of the better entries but it’s all starting to feel a bit laboured by this point, lacking the sprightliness of earlier films.

The film is leant a touch of additional comedic class by the presence of the great Frankie Howerd in his second and final Carry On (the first had been Doctor in 1967), here playing ornithologist Professor Inigo Tinkle whose tales of his search for the fabled Oozlum bird, said to fly in ever decreasing circles until it disappears up its own back side, in deepest, darkest Africa is financed by Lady Evelyn Bagley (Joan Sims) who is hoping to find some trace of the baby son she lost in the jungle many years earlier. “Rattlesnake” Bill Boosey (Sid James) and local guide Upsidasi (Bernard Bresslaw in blackface) are their guides and Tinkle’s assistant, Claude Chumley (Kenneth Connor) and Lady Bagley’s maid June (Jacki Piper) are also along for the ride. The cast would have known better than to expect a trip to anywhere genuinely exotic so they wouldn’t have been disappointed to find that the eponymous jungle was built entirely on the sound stages of Pinewood Studios.

As with a good many of the later Carry Ons, there really isn’t much of a plot to speak of, just a series of vaguely connected sketches. Lady Evelyn’s son has survived, been raised by the animals and is now the fully grown Ug (Terry Scott), an inept Tarzan-alike (Rogers had wanted to call the film Carry on Tarzan the estate of Edgar Rice Burroughs objected) who falls for June when he kidnaps her; the explorers are captured by the Noshers, a tribe of cannibals (man-eaters had been around British cinema since at least 1914 when Winky and the Cannibal Chief and Lieutenant Pimple, King of the Cannibal Islands were released); they’re rescued, when the film takes a turn back towards a different strain of the Hammer films that they’d spoofed in Carry on Screaming!, by a tribe of Amazonian warriors led by Leda (Valerie Leon); and they finally meet the only male member of the tribe from the Lost World of Aphrodisia King Tonka, “Tonka the Great, King of Lovers, Father of Countless” who turns out to be Lady Evelyn’s long-missing husband Walter (Charles Hawtrey).

Rothwell had originally written the part of Tinkle for Kenneth Williams and Ug for Jim Dale butr the former was busy working on his short-lived television series The Kenneth Williams Show (1970) and the latter wasn’t impressed by Ug’s lack of dialogue. What the team was able to do though was lure back the much-missed Kenneth Conner who hadn’t been in a Carry On since Cleo in 1964 and Howerd in particular gives a very fine performance (“my gast has never been so flabbered”), his back and forth with James and Conner being among the film’s best moments. Sims gets more to do than usual and makes the most of the opportunity and Scott is a riot as the dorky Tarzan stand-in, constantly mistiming his rope swings and crashing face first into trees and cliffs, having run-ins with a very dodgy looking gorilla and getting saucy with June as she tries to teach him English. A scene where he almost throws June in the lake might even be a tip of the hat to James Whale’s Frankenstein (1931).

But despite the nice performances, the simple joy of seeing a budget version of a jungle built on a sound stage and the always welcome presence of supporting acts like Valerie Leon and Jacki Piper, Carry on Up the Jungle never really gets up the head of steam it needs. There’s an aimlessness to it that prevents it from scaling the heights attained by better scripted pieces like Cleo which had an actual story to go along with the innuendo, sight gags and pratfalls. Not that this particularly bothered the fans, who flocked to the film anyway and Carry on Up the Jungle was among the top eight biggest earners at the UK box office in 1970.