Since we had undertaken in Cambridge to build the kind of infrastructure of the work, that is that we had done the complete anatomy, and that later John Sulston did the complete development of the... of the worm, following each cell during development and we had opened up the genetics. That said, by the 1970, '72, when I published the first paper on C. elegans [Caenorhabditis elegans], just said that you know, we would... we would pursue this. But I knew that in fact that one would have to get down to the molecular basis. And of course it just seemed daunting, we hadn't any idea how many proteins were involved... how many proteins were involved. And one of the things that I did was a very early study on C. elegans, which is part of the first paper, which actually tried to estimate the number of genes, estimated the number of indispensable genes. And actually found there were relatively few. And since many people believed there would be tens of thousands and hundreds of thousands, this was very reassuring. Wasn't believed by anybody. I think we rather... we underestimated it a bit, because I think there are lots of genes that are not lethal, so to speak, but are needed. But nonetheless, the idea that you could build something as complicated as a nematode with, say, 10,000 genes, was absolutely not thought possible by many people. And I think this whole thing of trying to estimate the genetic complexity of things has become very important today.