The strait between Cornwall and the Scilly Islands is renowned as a haunt of eels. I’d presumed these were conger eels, which live their entire lives at sea, but it seems that the common eel is also found in these waters. The common eel is at the centre of one of the weirder bits of Mythic European science, and I’ll want to include it as a vis source, or source of monsters, in the Cornwall book. Let’s collect some ideas.
In Mythic Europe, creatures can emerge spontaneously from unliving matter. This was the common belief in 1220, as people were unfamiliar with microscopic life, and that insects laid eggs. The main reference to this in the current rule set is that meat forced to degrade with destructive magic spontaneously generates flies and maggots. References are made to the idea elsewhere: bees come from rotting cow carcasses, while wasps come from rotting horses. Barnacle geese are not birds: they are a sort high-mobile mollusc. These stories are an obvious explanation for for Creo vis sources, but to people at the time this wasn’t any more magical than that some animals grow their offspring internally.
There’s a lengthy list of these sorts of things in Aristotle. Some of these would allow a covenant to develop industries, despite not having the sort of equipment required by modern agriculture. If scallops, clams and razorfish, as he says, emerge spontaneously from sand, you just need water and sand to create batch after batch. You don’t need to breed them, or even care for them beyond a brief growth stage. Between harvests you can drain the growth chambers entirely, and just fill them again when you are ready for a new batch. You can even swap your substrate to make batches of different animals: toss the sand out, add slime, and you can make oysters. Toss the slime out and get particular types of rock, and you can get barnacles, which might give you the oddly avian type above. Alternatively, you can make sponges.
On a related note, if you keep produce for a long time, it will eventually spontaneously generate something that will destroy it. Wool generates silverfish. Wheat generates mites. Even libraries, according to the architect Vitruvius, need to be careful of this, because bookworms are spontaneously generated. He advocates facing libraries east, because southern and western winds favour this undesired generation.
If spontaneous generation is related to the magic realm, Hermetic libraries likely make this problem worse. In real libraries the bookworm has a natural predator, the pseudoscorpion. I’ve written before about how I think that Durenmar likely has a hive of gigantic pseudooscorpions. We know they exist in Mythic Europe, because Aristotle describes one type of bookworm as like a tiny “scorpion without a tail”.
I wonder, could a Criamon from the group who memorises books by eating them just have a huge bookworm as her familiar, and throw books into it, gaining magical experience through the Silver cord? It’s certainly bizarre, horrific and useful enough to make it work developing.
Aristotle’s great proof of spontaneous emergence is the glass eel. Glass eels don’t have genitals, and yet they regularly appear in vast swarms, going up rivers throughout Europe. He said they came from decaying earthworms. Pliny said that was wrong, that they reproduced by budding, with tiny fragments of eel that were scraped off in daily life growing into complete eels. In the real world, we know these ideas aren’t true. In Mythic Europe, where Aristotle is correct, leptocephaluses, glass eels, elvers, yellow eels, and silver eels are all separate species. In the real world, they are the life-stages of a single species, and it only develops genitals in the final form.
A related issue is that eels turn up in puddles and dams far from their native rivers. It’s not all that odd, in some areas, to wander about after rain and see a thing which you initially mistake for a snake, then discover it is an eel. This is because, after rain, eels will leave their rivers and seek out new waterways. They even climb up the walls of artificial dams, so they turn up in all kinds of unlikely places. This makes spontaneous emergence seem more likely to the medieval mind.
A final point about eels is that their blood is poisonous. This was only demonstrated scientifically in the 20th Century by proving you can provoke anaphylaxis by injecting it into laboratory animals. I’d suggest it’s well-known on a folk level regardless, because places which eat food raw, like the salmon in the west and the tuna in Japan, always cook eels. Cooking breaks down the irritant in the blood. That being noted, it makes corrosive blood a lovely choice for a vast eel that lingers in the depths of the channel, picking over the bones of fallen Lyonesse.
Games From Folktales 