Among the curiosities gathered by Pliny the Elder in the Natural History, few have enjoyed such fortune as the druids' "serpent egg", which the Romans called anguinum. The passage (XXIX, 52-54) is short, yet it contains a complete story: a marvellous origin, a gathering technique, a test of authenticity, a practical use and even a piece of court news. It is worth reading closely.
How the egg is formed, according to Pliny
Pliny explains that in summer countless snakes twist together and, with the saliva and foam of their bodies, form a kind of ball. With their hissing they toss it into the air. Whoever wants to seize it must:
- catch it in mid-air in a cloak, before it touches the ground;
- flee at once on horseback, because the snakes give chase;
- reach safety only when a stream lies between him and his pursuers.
Pliny adds that the druids recommended gathering the egg at a particular phase of the moon. Once again, as with mistletoe, the lunar calendar sets the rhythm of the sacred act.
The test of authenticity
According to the account, a genuine egg would float against the current, even if bound in gold. It is a test with the typical structure of tales about marvellous objects: the true object is recognised because it defies natural laws.
Pliny had seen one
The most interesting detail is that Pliny says he saw an anguinum with his own eyes. He describes it as about the size of a medium round apple, with a cartilaginous rind dotted with small hollows like those on an octopus's arms. This description has prompted several hypotheses:
- a fossil, such as a fossil sea urchin, an object often collected and even placed in prehistoric graves;
- a mass of eggs from marine animals, such as those of some molluscs;
- a manufactured item, perhaps a decorated glass bead.
None of these is proven. What is certain is that a real object circulated under that name and was displayed as something precious.
What it was for
Pliny reports that, according to the druids, the egg brought success in lawsuits and eased access to the powerful. So it was not an object linked to war or health, but to speech and relationships: a talisman for those who had to speak before a judge or present themselves to a prince.
Pliny, as he often does, comments ironically: he considers all this one of the many "vanities of the magi". His attitude helps us understand the Roman point of view: respect for the rare object, suspicion of the magical claim.
The case of the Vocontian knight
The account ends with a historical episode. Pliny writes that a Roman knight from the Gaulish people of the Vocontii was put to death by the emperor Claudius because, during a trial, he was carrying a serpent egg in the fold of his garment. The detail matters for three reasons:
| Aspect | What it shows |
|---|---|
| The man | a Romanised Gaul of equestrian rank |
| The object | an amulet still in use in the first century AD |
| The reaction | Claudius' harshness towards druidic practices |
The episode fits Suetonius' statement that Claudius abolished the religion of the druids in Gaul. The amulet, then, was not merely a curiosity: it was a sign of belonging that could become dangerous.
The echo in British folklore
In Wales and Cornwall, modern folklore knows "adder stones" or "adders' eggs", small perforated stones or glass beads said to be formed by the breath of snakes gathered together. In Welsh they are called glain neidr. Seventeenth- and eighteenth-century antiquaries, such as Edward Lhuyd, linked these beliefs to Pliny's passage. The connection is evocative, but there is no evidence of unbroken continuity from Roman times to the modern age: it is wiser to speak of an image that has resurfaced several times.
A symbolic reading
In European traditions the serpent is often tied to the earth, to regeneration through the shedding of its skin, and to hidden wisdom. An egg born from the union of many snakes is an image of wholeness: something arising from disordered forces that becomes a compact, precious object. The catch before it touches the ground, the flight and the saving water are three moments of a small initiatory drama: to seize, to escape, to cross a threshold. It can be read as a parable of winning a knowledge that does not let itself be easily possessed.
In short
- Pliny describes the anguinum as a ball formed by intertwined snakes and tossed into the air.
- It had to be caught in a cloak, at a set lunar phase, fleeing until a stream was crossed.
- According to the druids it favoured success in lawsuits and access to the powerful.
- Claudius executed a Vocontian knight who carried one during a trial.
- Welsh folklore about "adder stones" echoes the account, without proven continuity.
