This is exactly what we see in the boletes that turn blue so readily. Could they, in fact, contain soluble, colorless indigo? One would say so, if certain properties did not give grounds for doubt. When subjected to prolonged exposure to the air, the boletes that are apt to turn blue, particularly the most remarkable, Boletus cyanescens, lose their color, instead of retaining the deep blue which would be a sign of real indigo. Be this as it may, these mushrooms contain a coloring principle which is very liable to change under the influence of the air. Why should we not regard it as the cause of the black tint when the maggots have liquefied the boletes which turn blue? The others, those with the white flesh, the edible bolete, for instance, do not assume this asphalty appearance once they are liquefied by the grubs. All the boletes that change to blue when broken have a bad reputation; the books treat them as dangerous, or at least open to suspicion. The name of Satanic awarded to one of them is an ample proof of our fears. The caterpillar and the maggot are of another opinion: they greedily devour what we hold in dread. Now here is a strange thing: those passionate devotees of Boletus Satanas absolutely refuse certain mushrooms which we find delightful eating, including the most celebrated of all, the oronge, the imperial mushroom, which the Romans of the empire, past masters in gluttony, called the food of the gods, cibus deorum, the agaric of the Caesars, Agaricus caesareus. It is the most elegant of all our mushrooms. When it prepares to make its appearance by lifting the fissured earth, it is a handsome ovoid formed by the outer wrapper, the volva. Then this purse gently tears and the jagged opening partly reveals a globular object of a magnificent orange. Take a hen's egg, boil it, remove the shell: what remains will be the imperial mushroom in its purse. Remove a part of the white at the top, uncovering a little of the yolk. Then you have the nascent imperial. The likeness is perfect. And so the people of my part, struck by the resemblance, call this mushroom lou rousset d'iou, or, in other words, yolk of egg. Soon, the cap emerges entirely and spreads into a disk softer than satin to the touch and richer to the eye than all the fruit of the Hesperides. Appearing amid the pink heather, it is an entrancing object.