August 2, 1955 Dear Rosalind: Many thanks indeed for your manuscripts of papers on the structure of TMV. They have been of great interest to some of us here, and I have passed them around to several people. Perhaps the density anomaly should not bother us unduly. When one considers the unlikelihood that the "density" of TMV can even be defined, let alone measured according to the definition, it appears that a discrepancy in the calculated and measured density values need not be taken as a certain indication that a given model is wrong. I enclose a manuscript which you may have heard rumors about. It has occurred to me that you might be interested in examining the x-ray pattern of some of this reconstituted virus. It would be particularly useful to have x-ray evidence as to the localization of the RNA in the re-polymerized material. The pelleted material from the reconstitution experiments will have rods of an average length not much less than TMV, and it might well be subject to satisfactory parallel alignment. If you would like some of this material, let me know, and I will send over at least the minimum quantity that you specify. With best regards, Sincerely, Robley C. Williams