It's very clear, we were discussing both development and the nervous system as a... as an issue at the time. The nervous system... I had a long interest in, because of... I actually reconstructed a brain of galago when I was a science student in South Africa. We had a good centre of neuroanatomy. I was an extremely good neuroanatomist at the time, because my teachers were neuroanatomists. And so... and with my relationship with Seymour Papert, where I taught him neurophysiology, and I taught neurophysiology in the physiology class, so I was not a novice at this. But I had no idea at that time how you would connect this up with genes. However, why I finally chose an animal was because animals have nervous systems... and not choose a plant. Although I have to say just in passing, I was also very interested in Arabidopsis and had become a foundation member of the Arabidopsis Newsletter, had in fact got some of these plants, grown them, but it seemed to me plants, as I used to say then, were not real animals. And the nervous system is attractive, it's attractive as part of an animal because it embodies so many things that you feel are not going to have a simple explanation. That is... one felt you can't do this with... you could not explain nervous systems with simple things that you used to explain beta-galactosidase induction. At least that's how it seemed there. Now, Seymour Benzer was also interested in the nervous system, but he had decided to go from the gene to behaviour. And I know for certain that at a very early stage I did not see that as a feasible issue, just largely on theoretical grounds, but also because I had become very clear that the units of development were cells, the units of the nervous system were cells. And I know this because I recall very clearly a student coming up to me and said: ‘Doctor Brenner, what is going to be the next breakthrough in the nervous system?’ And I said to him, ‘you are 50 years too late, it's already happened, it's called the neuron hypothesis’. Because of course prior to that people thought that nervous systems were continua and the triumph of actually showing that they were built of nerve cells connected to each other, that was the breakthrough.