“I dashed into the crevice in the rock. It was not a moment too soon, for as I turned to look at the source of the noise, two vast creatures came quickly into my field of view. They were more of the dinosaurs I had seen throughout this underground land, but of a more draconic visage. Perhaps evolution in these caves beneath the earth has taken a different path here, or maybe these creatures are the origins of the myths of dragons in our surface civilisations?

“One was a bright, emerald green, and the other sapphire blue. The green dragon was being chased by the other, in what I assumed first was a battle for dominance: these were clearly two males, from their size and body form. But the manner of the emerald dragon was unusual, and I came to think more of the teasing play of the dogs on the farms I had visited in my youth. He was never straying far from his sapphire-hued pursuer, and often turn back to look at him, to grimace and wait, to roar and cry in his direction.

“I pondered what this behaviour might mean, but in moments it became apparent. My comparison to playing dogs had been quite accurate it seemed for, right in front of my hiding place, the blue dragon finally caught his prey. And what I witnessed next was a sight unlike anything I have seen before or since. For this has clearly been, not just play, but a mating dance. Scant metres from my narrow crevice, the blue dragon mounted the green, and proceeded into a display that was most spectacular. If I had hoped that the mating would be quick, and that the creatures would swiftly depart, I was to be disappointed. I had no watch to pass the time, but the mating seemed to last for a very long time indeed, full of motion of the most energetic kind. The cavern echoed with roars and cries.

“It was, I dare say, beautiful, and I feel honoured to be one of the few of the surface world to have witnessed such noble creatures of the underworld in such a private act. How my distant ancestors must have felt when they first saw the mating of elephants, or the great rhinoceros! This experience will stay with me, I am sure, for the remainder of my short earthly sojourn.”

– Deleted extract from “Journey to the Centre of the Earth”, Jules Verne, 1864. Recovered in 2066 from a previously lost autograph manuscript discovered at Euronext Paris.