Heston and the director Franklin J Schaffner showed up, as did Edward G Robinson, who underwent full make-up for his five-minute read-through as the arrogant chimp Dr Zaius. The part was his, though he would surrender it to Maurice Evans, cursing, “That make-up is a bitch. My heart’s just about gone to hell as it is; I couldn’t stand it.”The test reassured Fox slightly, but they weren’t completely placated until their latest science-fiction adventure, Fantastic Voyage, opened spectacularly. Come early 1967, Planet of the Apes was ready to roll, and Heston was limbering up for action. “I’m in firm pursuit of those last few pounds of flab,” he panted.The shoot went fairly smoothly, despite Fox shaving ten days off the schedule to cut costs, and actors passing out from heat exhaustion. The performers cast as humans noticed that their hairier colleagues, who lunched separately because their make-up restricted them to liquid foods consumed through a straw, had begun to establish cliques based on species: gorillas at one table, chimps at another, orang-utans over in the corner.

“I had people come up and poke my face, asking what it felt like,” recalls Kim Hunter, who played Zaia. “It was like we were creatures in the zoo, except that they could touch us. It was wild.” As the production progressed, Heston took Schaffner aside and confided, “I thought from the beginning we’d have a hit, but we may have a helluva picture, too.”The potential for social comment in this ambiguous movie had clearly struck the actor. And it is precisely these ambiguities that have made it so enduring, and so malleable in the hands of its admirers, despite four lame sequels, and two television series. In its time, the film has had every metaphorical meaning projected onto it from the banal (racial inequality) to the spurious (in his book Planet of the Apes as American Myth, Eric Greene argues that the picture explores the confusion of the Vietnam era).

Michael Clarke Duncan, the gargantuan black star of The Green Mile, appears in the 2001 version, but denies any subtext “Nothing ever came into my mind about politics or race … I’m an actor and this is what we do to get paid.”It may be that Burton will exploit the stark primal terror of the scenario and nothing more. But others who came close to presiding over this new Planet of the Apes would undoubtedly have encouraged vastly different readings. For a long time, it was Oliver Stone’s baby; we can only wonder at how he might have shoehorned political skullduggery and conspiracy theories into the film. Less promisingly, interest was expressed by two of modern cinema’s most humdrum practitioners: Chris Columbus, who recently directed Harry Potter and the Philosopher’s Stone, and James Cameron, who had the prosaic idea of putting Arnold Schwarzenegger in the Heston loincloth.The most lip-smacking entry in this “Fantasy Planet of the Apes” has to be the one that the Hughes Brothers would have made. These young, stylish, attitude-heavy directors of Menace II Society and Dead Presidents lobbied long and hard to land the job, and would perhaps have teased out the racial tensions contested by Duncan, but were fobbed off with a consolation prize – From Hell, a Jack the Ripper thriller starring Johnny Depp, which will be released in November.In this story of what-ifs and what-might-have-beens, it seems only fitting that even the script which finally secured Burton’s commitment is not the one that made it to the screen.