Now at the same time, we were working still on mutagenesis, so you have to imagine that one went from one thing to the other. We were doing... we were doing the whole project, it all had a whole... though today you would say, 'Well, what are you doing density gradient with the one hand and genetics with the other? But it had this… it had this whole, because what we were interested in was what is the connection between what's written in the DNA and what's written in the protein. That's all we wanted to know and we would use any… we would use anything... any method to try to get to that root. Now the mutagenesis thing which was going on simultaneously is quite… is interesting in the sense that at one point Francis decided that he would start to do genetics.