Fresh Trufles: Truffle cultivation remains essentially empirical and small-scale: truffles are neither sown nor planted. They spring up spontaneously when the fungal spores encounter the rootlets of an oak tree (or another symbiotic species) and form a mycorrhiza, which takes its nutrients from the tree; the truffle itself is the fruiting body of the fungus.
     The many varieties of truffles are always gathered with the assistance of an animal (pig or dog) that can detect their presence. In some cases, the movement of a fly may reveal that truffles are nearby. Even some peasants, in areas where truffles are found, have taught themselves through long experience to recognize the places where they are hidden.