Jack London was another 20th-century naturalist, writing about the force of nature and Man’s reaction. His most known book is The Call of the Wild (1903) which describes how a domesticated creature turns to a primitive state in order to (per) survive. The story is set (ha luogo) in the extreme conditions of the Yukon during the 19th-century Klondike Gold Rush (corsa all’oro). Buck – the dog protagonist – is a domesticated dog sold into a brutal life as a sled dog (cane da slitta). The novel is about his struggle (lotta) to survive, the cruel treatment he receives from human beings, other dogs, and nature. He eventually (alla fine) goes back (ritorna) to primordial instincts to become a respected and feared (temuto) leader in the wild. The book is based on J. London’s real experience in the Yukon where sled dogs were in high demand (molto richiesti). The story attracts for the simplicity with which he presents the themes in an almost mythical manner. It falls into (ricade) the genre of animal fiction in which an animal is given human traits. London was influenced by the naturalism of European novelists such as Emile Zola, in which the hero returns to nature and symbolizes a reaction against industrialization and social convention with a return to nature. The first film adaptation was directed by D. W. Griffith in 1908. Other films were shot (girati) in 1923 – another silent movie; in 1935 – the first talkie movie by William A. Wellman ; in 1972 – the version by Ken Annakin filmed in Finland.