These are the symptoms of blood-poisoning, vividly portrayed; of some contagion, communicable by infection. In foul old London Shakespeare had doubtless seen endemic, zymotic diseases of every description, and drew his picture from the life. Royal blood is notoriously unsound, royal habit leaves the porches of royal ears especially exposed. On our supposition the vial need not have contained very much, not even ebony. The dramatist had plenty of mystery ready to his hand, and the Hebona is perhaps intentionally ambiguous. Bacterial diseases were of old called plagues; they fell from heaven. Listen to King Lear: "Now, all the plagues that in the pendulous air Hang fated o'er men's faults, light on my daughters!" Or Caliban: "All the infections that the sun sucks up From bogs, fens, flats, on Prosper fall and make him By inch-meal a disease!" Or they were attributed, as already intimated, to unseen personal agencies: "This is the foul fiend Flibbertigibbet: he begins at curfew, and walks till the first cock; he gives the web and the pin, squints the eye, and makes the hare-lip; mildews the white wheat, and hurts the poor creature of earth." I quote this latter rather also to show the accuracy and compass of Shakespeare's vision. How many people, not farmers, have seen wheat whitened by the blight! And that is exactly the description, white not "to the harvest," but whiter still to sterility and death. But leaving aside all microscopic forms which may or may not be incidentally touched upon everywhere, we may turn our attention next to cryptogamic plants which are positively defined. The sudden springing of mushrooms, for instance, especially at night, so unreal and yet realities withal, made their creation a suitable trick for Prospero: "You demi-puppets that By moonshine do the green sour ringlets make, Whereof the ewe not bites, and you whose pastime Is to make midnight mushrooms, that rejoice To hear the solemn curfew." The "green sour ringlets on the fields whereof the ewe not bites" are "fairy rings." The same thing appears in the speech of Dame Quickly: "And nightly, meadow-fairies, look you sing, Like to the Garter's compass, in a ring; The expressure that it bears, green let it be, More fertile-fresh than all the field to see." Fungi, toadstools, mushrooms, and so forth, are fructifications only; the vegetative part of the plants permeates the soil, feeds on its organic matter, and spreads almost equally, we may assume, in all directions from the point of starting. When now this vegetative growth has accumulated energy to form fruit, the sporocarps or mushrooms rise all around at the limits of activity; hence, in a circle.