Samuel Butler was once one of Darwin’s fiercest opponents.The exploration of the theory of evolution is the motive and source of Butler’s novels.The theory of unconscious memory is not only Butler’s unique contribution to Lamarck’s "inheritance of acquired characteristics",but also the core of Butler’s theory of evolution.By demonstrating the relationship between the novel,The Way of All Flesh(1903),and Butler’s four books about evolution,and finding the connection between the novel and Darwin’s works,especially The Variation of Animals and Plants Under Domestication(1868),we may conduct a comprehensive study of Butler’s works and gain a holistic understanding of his evolutionary ideas.