Maurice Wilkins by James Watson. During the second phase, 1951–52, Wilkins produced clear "B form" "X" shaped images from squid sperm, images he sent to James Watson and Francis Crick, causing Watson to write "Wilkins... has obtained extremely excellent X-ray diffraction photographs" [of DNA]. In 1953 Wilkins' colleague Rosalind Franklin instructed Raymond Gosling to hand over to Wilkins a high quality image of "B" form DNA ("Photo 51"), which she had made in 1952 but had “put it aside” as she was leaving King's College London. Wilkins showed it to Watson. This image, along with the knowledge that Linus Pauling had proposed
Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid which subsequently turned out to be incorrect. Both Crick, and particularly Watson, thought that they were racing against Pauling to discover the structure of DNA. Max Delbrück was a physicist who recognized some of the biological implications of quantum physics. Delbruck's thinking about the physical basis of life stimulated Erwin Schrödinger to write, "What Is Life?" Schrödinger's book was an important influence on Crick and Watson. Delbruck's efforts to promote the "Phage Group" (exploring genetics by way of the viruses that infect bacteria) was important in the early development of molecular biology in general and the development of Watson's scientific