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
Non-helical models of DNA structure as evidence that the strands were plectonemically wound together ("i.e.," topologically linked). The publication of the Rodley structure produced a small but significant ripple of interest in the molecular biological community. However, the level of interest was sufficiently high so that Crick - by that time one of the world’s most influential scientists - publicly suggested that the SBS structure (whose existence he doubted) should be laid to rest by intentionally creating it. Then, he reasoned, its properties could be ascertained, and then shown to be abnormal with respect to the known properties of native DNA. An investigation by Stettler