I had great difficulty in publishing papers about animal locomotion in the '50s. I... I would never have been able to publish this story about the stability of flight if Haldane hadn't bullied the editor of Evolution into publishing it. It was rejected when I submitted it, on the grounds that the author clearly didn't know anything about aerodynamics, which did slightly annoy me, I have to say. If they'd written and said the author clearly doesn't know anything about birds, I would have thought, well, fair enough, but damn it. Then I tried to publish a paper about... about Animal Gaits. It was one of the first optimisation papers every written, I think, in which I showed that the gaits of animals optimised their expenditure of energy at a given speed. And to prove this, I actually differentiated something, and I had an equation, d²w by dj² = 0, or something. And the referee actually said, 'Why doesn't the author cancel the ds?' I mean, in those days, it was just impossible. And there was a deep anti-theoretic... anti-theoretical sort of culture in... in biology. You were not allowed to have theoretical ideas, except, perhaps in population and genetics, because Haldane and Fisher had made it respectable in population genetics. But in morphology, which I was tampering with, you know, why are animals the shapes they are, you just couldn't do it. It'd be different now.