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
Francis Crick 1953, Crick's thesis advisor, Max Perutz, gave Crick a copy of a report written for a Medical Research Council biophysics committee visit to King's in December 1952, containing data from the King's group, including some of Franklin's crystallographic calculations. Franklin was unaware that photograph 51 and other information had been shared with Crick and Watson. She wrote a series of three draft manuscripts, two of which included a double helical DNA backbone. Her two A form manuscripts reached Acta Crystallographica in Copenhagen on 6 March 1953, one day before Crick and Watson had completed their model. The X-ray diffraction images