The singular notions on which the Church of Rome founded this toleration--a toleration, however, which still exists in full force even at the present day--is as follows. The councils of the twelfth century permitted both the clergy and laity to eat Black Scoters during Lent because it was a generally-accepted idea, founded on the writings of Aristotle, that these birds were not produced from an egg, but had a vegetable origin. The learned of the Middle Ages and the Renaissance, seeing large flocks of these birds suddenly appear, while nothing was known whence they came, indulged in all kinds of conjectures to explain this mysterious fact. They attributed to them origins which were marvellous; one conjecturing that the feathery appearance in the ciliated tentacles of certain mollusks which inhabit the barnacle shell changed into Black Scoters; others imagined that these birds proceeded from the wood of rotten fir-trees which had been long floating about in the sea, or even from the fungi and marine mosses which cling to the _débris_ of wrecked ships; others, again, went so far as to assert that the north of Scotland, and especially the Orkney Isles, produced a tree the fruit of which, falling into the sea, developed into the bird which was called _Anser arboreus_, in order to commemorate its origin: this bird they imagined was the Black Scoter. The naturalists who gave expression to these transcendental views might certainly boast that they had Aristotle on their side; for this distinguished philosopher believed in the spontaneous generation of various kinds of animals. He asserted, for instance, that rats sprung from decayed vegetables, and that bees proceeded from the carcass of an ox. Who, for instance, is unacquainted with the fine episode of the fourth book of Virgil's Georgics, where this poetic fiction is related in beautiful verse? As a matter of fact, however, Pope Innocent III., better instructed than Aristotle in this department of natural history, passed sentence on all these tales by forbidding its use during Lent; but no one, either in the monasteries, the castles, or the taverns, has ever looked at this interdict of the sovereign pontiff in a serious point of view. This controverted question, however, met with an unexpected solution. Gerard Veer, a Dutch navigator, in one of his voyages to the north of Europe, found some eggs of the Velvet Duck. Being ignorant of their nature, he brought them home, put them under a hen, and, when they were hatched, the produce exactly resembled the birds which were asserted by the ancients to proceed from the decay of vegetable matter. Gerard Veer made the announcement that these birds bred in Greenland, thus affording a complete explanation of the absence of their eggs in southern countries.