Everyone sort of assumes it is the chicken. Everyone thinks that the process of pickling was invented as a way of preserving food in a time long before refrigeration, and that people who tried it decided that it tasted great, too.
But what if it were the egg? What if someone in that long-ago time dropped a cucumber in a vat of vinegar and salt because he thought it would taste good, and later discovered to his surprise that the liquid also helped to preserve the vegetables?
Not that it matters. Pickles are wonderful, and they last a long time. They're the best of both worlds.
