The Natural History of Pliny, Volume 2 (of 6)

The barren eggs, which we have mentioned as “hypenemia,” are either conceived by the females when they are influenced by libidinous fancies, and couple with one another, or else at the moment when they are rolling themselves in the dust; they are produced not only by the pigeon, but by the common hen as well, the partridge, the pea-hen, the goose, and the chenalopex; these eggs are barren, smaller than the others, of a less agreeable flavour, and more humid. There are some who think that they are generated by the wind, for which reason they give them the name of “zephyria.” The eggs known as “urina,” and which by some are called “cynosura,”3110 are only laid in the spring, and at a time when the hen has discontinued sitting. Eggs, if soaked in vinegar, are rendered so soft thereby, that they may be twisted3111 round the finger like a ring. The best method of preserving them is to keep them packed in bean-meal, or chaff, during the winter, and in bran during the summer. It is a general belief, that if kept in salt, they will lose their contents.