We thought that biological systems were... were three-dimensional pattern organisations, and of course what we had to do then was to try to ask how did you create patterns in three dimensions? But... we found that in most of the cases that we could look at, the pattern was really created in two dimensions, and the third dimension was obtained in another way either by rolling a sheet into a tube or by actually multiplying the cells, so that biological systems were essentially two-dimensional. And of course at one stage we thought, well, two dimensions is quite hard to deal with. Possibly there exist one-dimensional systems. And so the one-dimensional system that I had remembered again from my reading into strange microorganisms, was a blue-green algae. Namely, there were these algae, anabaena was the name, that the cells divided, and at regular places along this filament little differentiated cells appeared, called heterocysts. And the question is how did something know to be a heterocyst and how did it know to be placed in exactly this way. There was a group in London that worked on this, a man called Fogg, and I went to see him, and he worked at a thing which I think alas is now defunct, Westfield College, which is in North London, he was a teacher of botany at this place. And so I went to see him to get some cultures of this organism and I grew them. They had to be grown in the light, and indeed, if you broke off the thing, you started with this, and you could actually watch the heterocysts appear. And I managed to persuade two young men, one Mike Wilcox, who had come to join us and whose work had been in... strictly in molecular biology, he'd been originally trained as a chemist, and then he'd moved into molecular biology. And he wanted to do something different, and so I persuaded him and a theoretician, a young... young algebraic topologist called Graham Mitchison to take a look at this. Now, I think it's important to... to realise that... that one of the things that we did and which ran through all of our work, and which I think came, at least from my background of always having a microscope around and always having a look, in fact I had invented something called HAL biology. HAL, that's H-A-L, it stood for have a look biology. I mean, what's the use of doing a lot of biochemistry when you can just see what happened? This actually stemmed from an experience of mine many years before when I worked on protoplasts. Sol Spiegelman had claimed that when he took ribonuclease and had added these to the protoplasts they stopped making protein. And he thought... he took that as evidence that RNA was involved in protein synthesis. But I always looked at the protoplasts with a microscope, and when I added ribonuclease they disappeared, which of course was a very good reason why they stopped making proteins, stopped doing everything. The, the ribonuclease lysed them. Presumably it went in, hydrolysed the RNA and that created some osmotic effect and they blew up. So I think that one has to be... and so have a look biology did this. And one of the interesting things they did, which of course we kept... we did a lot of was simply, just to look at these filaments as they grew. So that when you got to a certain state you had the entire history of how that state was reached. So instead of looking at filaments at one stage, we looked then at their history, and you could do statistics on the history as well.