No doubt the unprejudiced reader supposes when he reads this passage that there is some stone or stone-like body in the head of the toad which has a special beauty, or else was believed to possess magical or medicinal properties. And it is probable that Shakespeare himself did suppose that such a stone existed. As a matter of fact there is no stone or "jewel" of any kind in the head of the common toad nor of any species of toad--common or rare. This is a simple and certain result of the careful examination of the heads of innumerable toads, and is not merely "common knowledge," but actually the last word of the scientific expert. In these days of "nature study" writers familiar with toads and frogs and kindred beasts have puzzled over Shakespeare's words, and suggested that he was really referring to the beautiful eyes of the toad, which are like gems in colour and brilliance. This, however, is not the case. Shakespeare himself was simply making use of what was considered to be "common knowledge" in his day when he made the Duke compare adversity to the toad with a magic jewel in its head commonly known as "a toad-stone," although that "common knowledge" was really not knowledge at all, but--like an enormous mass of the accepted current statements in those times, about animals, plants and stones--was an absolutely baseless invention. Such baseless beliefs were due to the perfectly innocent but reckless habit of mankind, throughout long ages, of exaggerating and building up marvellous narrations on the one hand, and on the other hand of believing without any sufficient inquiry, and with delight and enthusiasm, such marvellous narrations set down by others. Each writer or "gossip" concerning the wonders of unexplored nature, consciously or unconsciously, added a little to the story as received by him, and so the authoritative statements as to marvels grew more and more astonishing and interesting.