In 1944, he wrote "What Is Life?", which contains a discussion of negentropy and the concept of a complex molecule with the genetic code for living organisms. According to James D. Watson's memoir, "DNA, the Secret of Life", Schrödinger's book gave Watson the inspiration to research the gene, which led to the discovery of the DNA double helix structure in 1953. Similarly, Francis Crick, in his autobiographical book "What Mad Pursuit", described how he was influenced by Schrödinger's speculations about how genetic information might be stored in molecules.