The botany was what really interested him. He would steer the tin boat towards the bank having discerned a single pale blue flower or purple berry that hadn’t been there the day before. To my eyes it wasn’t there today either. I couldn’t keep up with him. I simply couldn’t see what he saw. And, when I could, I couldn’t like it. It was good to be back in pandanus country again, for all that the pandanus here was of the climbing variety, like everything else in the fiercely competitive world of the rainforest, a clamberer and leap-frogger. And I formed a special attachment to the egrets with their question mark heads and necks – a perfect shape for all Australians, I thought; one that would sort perfectly with their inflexions. But the rest was all brutality; one long tale of parasitism and strangulation. ‘That’s Wait-a-while, otherwise known as Lawyer Cane, because once you become entangled in its hooks . . . And that over there is a strangler fig . . .’ Throttling. Suffocation. Death by mangrove. It was pure Darwinism out there. It was like being back in England.

And at last, to cap it all – to top it off, as the man at the caravan park put it – we found our crocodile. A twelve- or fourteen-foot brute, that had done well to escape the slaughter, sunbathing on a muddy bank with its jaws open. What is the fascination with creatures that can saw you in half in seconds? We steered as close as we could and stared and stared. And then a little while later we found a baby one – ‘Ah!’ everybody said – and we stared again.

He grew lyrical, David, on our return to the jetty, describing the sights and sounds he loved most on this murderous river. ‘My favourite is the Orange Footed Jungle Fowl, otherwise known as the large-footed mound builder,’ he said. ‘It has a lovely melancholy call.’ His eyes went misty, his voice actually trailed off in a melancholy way itself, just recalling it. ‘Very much the sound of the Daintree rainforest, I always think.’

I envied him. He is a lucky man who can hear a sweet plangency in the furious life and death struggle of a tropical rainforest.

Before we left the boat a little mute contest was fought out between that not so rara avis, the bright-as-a-button Sydney Uni student and the fat comatose girl from Melbourne, the latter having for too long now allowed the boyfriend of the Sydney student to feast his eyes upon the creamy softness of her idle inner thigh. Ostensibly the girl from Sydney was only showing affection to her lover, putting an arm around his shoulder and letting her hair caress his cheek. But I had learnt a few lessons on the Daintree River. I now knew a strangler fig when I saw one.