Correspondence regarding the William T Sedgwick Memorial Lecture, delivered at Massachusetts Institute of Technology, 22 January, 1965, with the title (supplied by Alexander Rich) "The General Nature of the Genetic Code".
Crick's letter to Rich (7 January, 1965, mistakenly typed as 1964), agreeing the lecture title, concludes: "It would be nice to have the direction of messenger reading cleared up. Sydney and the others are working hard trying to discover the codon for the amber and ochre mutants. We have a good idea what they are and perhaps by the time I reach MIT we shall know rather more definitely." Rich had written (4 January) that he hoped "we will have completed the work dealing with the direction of messenger reading by the time you are here."
Amongst the correspondence is a letter from Crick to Watson (7 January, 1965, but again mistakenly typed as 1964), asking if he would be his host whilst in the Boston area, and playfully refers to an invitation to take tea with "beautiful young women" of Amherst during his visit.