29 May 1951
Dear Josh and Esther,
Have sent under separate cover two reprints of the Enzyme crossover paper.  If you need more, I can send them on since I have a few left.  I'm certainly glad to hear about the Lac "alleles" crossing over.  It means that [...] isn't so special.  Pontecorvo wrote me that he appears to have similar cases in [...].  I'm working on another focus at present which from the preliminary results looks like another [...] case.
Glad you are planning to be in Minneapolis for we hope to attend the meetings too.  Our regards to Crow, Irvin et. al.
Mel and Kathleen