I read this for book my book group. I had high hopes. I have read some excellent science fiction from the 1960s - and have concluded it was something of a golden age for the genre. I also remember the Planet Of The Apes television series, and the original films, which I also enjoyed as a child. The first couple of chapters were very promising however by the end of the book I had concluded this was, at best, a short story that had been stretched to a 200 page novel. The basic idea is a good one, and the book highlights issues like slavery, animal experimentation, racism and closed-mindedness, but Pierre Boule labours these themes and the story. As stated this book would have made a much better short story.
After finishing the book I discovered that Pierre Boulle was a Prisoner of War during World War 2, being held captive by the Japanese. He wrote 'The Bridge on the River Kwai' based on his experiences. I think it's interesting to speculate the extent to which his wartime experiences might have informed the story.