In 1474, the magistrates of Bâle sentenced a cock to be burned at the stake “for the heinous and unnatural crime of laying an egg.” The _auto da fé_ was held on a height near the city called the Kohlenberg, with as great solemnity as would have been observed in consigning a heretic to the flames, and was witnessed by an immense crowd of townsmen and peasants. The statement made by Gross in his _Kurze Basler Chronik_, that the executioner on cutting open the cock found three more eggs in him, is of course absurd; we have to do in this case not with a freak of nature, but with the freak of an excited imagination tainted with superstition. Other instances of this kind have been recorded, one in the Swiss Prättigau as late as 1730, although in many cases the execution of the gallinaceous malefactor was more summary and less ceremonious than at Bâle. The _oeuf coquatri_ was supposed to be the product of a very old cock and to furnish the most active ingredient of witch ointment. When hatched by a serpent or a toad, or by the heat of the sun it brought forth a cockatrice or basilisk, which would hide in the roof of the house and with its baneful breath and “death-darting eye” destroy all the inmates. Many naturalists believed this fable as late as the eighteenth century, and in 1710 the French savant Lapeyronie deemed this absurd notion worthy of serious refutation, and read a paper, entitled “Observation sur les petits oeufs de poule sans jaune, que l’on appelle vulgairement oeufs de Coq,” before the Academy of Sciences in order to prove that cocks never lay and that the small and yolkless eggs attributed to them owe their peculiar shape and condition to a disease of the hen resulting in a hydropic malformation of the oviduct. A farmer brought him several specimens of this sort, somewhat larger than a pigeon’s egg, and assured him that they had been laid by a cock in his own barnyard. On opening one of them, M. Lapeyronie was surprised to find only a very slight trace of the yolk resembling “a small serpent coiled.” He now began to suspect that the cock might be an hermaphrodite, but on killing and dissecting it discovered nothing in support of this theory, the internal organs being all perfectly healthy and normal. But although the unfortunate chanticleer had fallen a victim to the scientific investigation of a popular delusion, the eggs in question continued to be produced, until the farmer by carefully watching the fowls detected the hen that laid them. The dissection showed that the pressure of a bladder of serous fluid against the oviduct had so contracted it, that the egg in passing had the yolk squeezed out of it, leaving merely a yellowish discoloration that looked like a worm. Another peculiarity of this hen was that she crowed like “a hoarse cock” (_un coq enroué_), only more violently; a phenomenon also a source of terror to the superstitious, but ascribed by M. Lapeyronie to the same morbid state of