When I finally came to leave the army, I had to decide what to do next. The art schools at the time were pretty awful – hidebound, traditional – and it didn't appeal to me at all. But I was by... at this point, obsessed with my surrealist painting and drawing and I decided that what I would do is I would combine my two interests of animals and art and I would go and do a degree in zoology, but with the primary aim of doing thousands of drawings under the microscope – because I was fascinated by microscopic shapes and I wanted to spend hours drawing them. And I did. It wasn't actually my intention, much as I loved animals, to go on and become a professional zoologist. There was a reason for this. It's because I happened to like animals and I wasn't prepared to do experiments on animals. Now zoology is an experimental science and I would – if I went on to become a professional zoologist – I would be expected to do experiments on animals and I wasn't prepared to do that. So I wasn't serious about a career of zoology, but I was very serious about the wonderful shapes and images that I found under the microscope. And I've got a huge pile of old notebooks of those drawings still.

And then something very strange happened. My professor, who was a young man called Peter Medawar, who was utterly brilliant – another great wordsmith incidentally, and I learnt a huge amount from him about scientific writing, he had a wonderful way with words, like Dylan and... but in his case, they were... it was... it was scientific eloquence. And in fact the research he was doing when he was my professor was research for which he later received the Nobel Prize. It was research on immunology, and it was that research that led eventually to heart transplant, so it was very important. And his brain was at its peak and his lectures were wonderful. And he knew that I was interested in animal behaviour and he was such an acute observer of people that he spotted that... I think he must have spotted that I wasn't really happy with experimental work and that I was an observer of animal behaviour. And one day he said to me, look, there's a Dutch professor, Niko Tinbergen, coming over to give a talk at the medical department here and I think you ought to hear him.

I was very flattered and he actually drove me over in his car. I was only a student but anyway, I thought, this is wonderful. And I sat with him and listened for one hour to Tinbergen and that was, for me, a great moment because here was a man who had found a way to do respectable, quantitative, scientific analysis of animal behaviour which was based on observation rather than experiment. You didn't have to do nasty things to the animals, you just simply sat and watched them. But you didn't just watch them like a naturalist, you sat and watched them analytically and you analysed everything they did and you recorded it, you described it and you measured it, and then you made predictions and then you measured those predictions. So it was... it was scientific analysis of animal behaviour of a naturalistic kind. It was exactly what I wanted. And thanks to the brilliance of Medawar's brain, which impressed me so much, and thanks to Tinbergen's philosophy of observing animals, I was able to continue with my zoological career. I didn't stop... I didn't stop painting. I managed to keep both things going and in 1950, I – for example – I had an exhibition in London with the Spanish artist Miró and later got to know him.

And so I was active in the art world, but I was also now becoming seriously active in the scientific world of zoology.