Sigmund and His Eels

If someone asks you to imagine Sigmund Freud, what do you see? An older gent with a well-trimmed white beard, cigar in hand? Is he perhaps listening to a patient who talks freely about personal issues while laying on a couch?

This is the Freud most know as the famous neurologist and founder of psychoanalysis. But well before Freud developed theories such as the “Oedipus complex” or “Penis envy,” he studied zoology, and had quite a time with European eel (Anguilla anguilla) sex specifically.

Until somewhat recently, the reproductive life of the European eel was a great mystery. No one had seen them laying eggs, giving birth, or mating. To add to the mystery, eels lack genitalia and determining their sex requires dissection and careful examination of their gonads. The surprise to early scientists was that males appeared to not exist.  

Without two sexes, how did these things reproduce? This was a question tossed around for millennia, quite literally. Aristotle reasoned that they must generate spontaneously, out of non-living matter, from the interaction of elements in the right conditions. This “spontaneous generation” theory was quite popular for centuries. Ideas on how eels reproduced came from everyone from Pliny the Elder to Hildegard of Bingen, explanations involving eels coiling around each other, foaming, spitting seeds, or scales falling from their bodies to grow into baby eels.

It wasn’t until the Renaissance that folks began to question spontaneous generation, and started to make connections that would explain a creature’s inception in ways we recognize today. The invention of the microscope and the new insights it gave to scientists would help put spontaneous generation to rest.

In the beginning of the 18^th century, an Italian doctor had managed to locate ovaries in a female. But without the discovery of male organs, reproduction was still elusive. Freud would change this.

At the ripe age of 17 in 1873, Freud entered the University of Vienna. His intention was to study law, but he instead gravitated towards medicine. His studies would include philosophy, physiology, and zoology, the latter subject under Darwinist professor, Carl Claus. Claus had the intention to prove that eels produce sexually, and set out to do this by locating a male eel.

The year 1876 would find the young Freud assisting with this mission at Claus’ zoological research station in Trieste, a seaport city in northeastern Italy. Claus gave young Freud a rather monotonous task. For four weeks in what felt like an exercise in futility, Freud dissected hundreds of eels to try to locate testes. “All the eels I have cut open are of the tenderer sex,” he would report until around eel number 400 when finally, he found the prize: gonads, buried in the abdominal cavity.