![wolf eel life cycle wolf eel life cycle](https://i.pinimg.com/736x/fa/3d/0d/fa3d0d6746b9cdb9f5226598c9d9e8d4.jpg)
This was, of course, precisely what happened with sexual reproduction, with the man’s seed containing the pneuma but provided the right material conditions were present, it could also happen spontaneously, in the wild. When it interacted with ‘elemental matter’ – the stuff of which all living beings were composed – it caused life to emerge. This contained within it a type of ‘vital heat’, which – like that of the sun – could make things grow. As he explained in De generatione animalium, all creatures owed their existence to pneuma – literally, the ‘breath of life’. If they didn’t have sex, he reasoned, they must generate spontaneously, out of non-living matter. How, then, did such creatures reproduce? Once again, it was Aristotle who came up with an answer. A mainstay of European cuisine since the earliest times, no specimen had ever been landed bearing ova and no diner had ever found their dish marred by milt. They did not even seem to have genital organs. Though they looked very much like snakes, and behaved a lot like a fish, they were the only sanguineous creature never to have been observed laying eggs or giving birth to live young. But by far the most interesting were catadromous eels. Flies, earthworms, sponges and conches were all examples. Though they reproduced somehow, they didn’t appear to do so sexually – either because they had never been caught in flagrante, or because no one had been able to identify male and female varieties. People might quibble about the details but that two easily distinguishable sexes were required was obvious.įor some animals, however, this didn’t seem to be the case. In his view, the female provided the flesh and blood, while the male’s seed infused it with life and gave the offspring its ‘form’. Perhaps the first to approach the subject systematically was Aristotle. Exactly what each sex contributed to the process was, admittedly, somewhat unclear. New examples of a species were produced through the coupling of a biological male and a biological female. Since the beginnings of Greek science, it had been recognised that all animals owed their origins to some form of reproduction. Far from being merely a matter of zoological curiosity, the existence of an eel’s gonads threatened to shake the foundations not just of reproductive theory, but of the scientific method itself. But Freud was determined to prove that he had the cojones to be a real scientist – and he knew how much was at stake. Even for the most enthusiastic researcher, it must have been an unenviable task: slimy, smelly and beset by frustration. Settling himself into the university’s new institute of marine biology, Freud spent the next month dissecting more than 400 specimens. Recently, however, a Polish scientist, Simone de Syrski, claimed to have solved the puzzle and Freud, then a promising medical student at the University of Vienna, was despatched to see if he was right. Despite the most intensive – not to say intimate – research, no one had managed to track them down. For centuries past, these troublesome organs had proved elusive. In March 1876, the young Sigmund Freud arrived in Trieste, looking for the testicles of an eel.