Truffle
2 of the 6 encyclopedias on this shelf carry an entry for Truffle. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a genus of fungi of the order Tuberacei, division Ascomycetes; globose, or nearly so; of a fleshy substance, with a distinct skin, the whole substance pervaded by a network of serpentine veins, which are the hymenium, and bear the spore-cases in minute cavities. The species are not numerous; they are very generally diffused in temperate parts of the world; they are subterranean, often found at the depth of a foot or more in the soil, usually near the roots of trees, or rarely living on the surface. Some of them are among the most highly valued or esculent fungi. They are said stimulating aphrodisiacal to have a quality. The common truffle (T. æstivum) is of a black color, and has a warty surface. It is the principal species sold in the English markets. It varies in size from that of a large plum to that of a large potato. On account of its agreeable flavor, it is used in the preparation of many dishes. It is common in central and southern Europe, chiefly in loose soils, in woods and pastures, as in the chestnut woods of France and Italy.
Aiton's Encyclopedia (1910)
a genus of subterranean fungi, much esteemed as a table delicacy. There are about fifty species. They have the shape of a potato and are black or bluish outside with a white interior. They range in size from that of a Brazil nut to that of a large potato. They grow limy soil, usually in birch or oak forests. They never appear above ground. In France hogs are trained to root them out. In England dogs are trained to locate them and indicate their presence by scratching. In both cases the finder is rewarded, the sow by an acorn, the dog by some other dainty. The truffles of France are the most celebrated. See Fungus; Mushroom
What Has Changed in the Last Century
Both accounts treat the truffle as something only found, never grown: Aiton's in 1910 describes hogs in France and dogs in England rooting them out of birch and oak woods. Cultivation is now routine, after French researchers in the 1970s worked out how to inoculate oak and hazel seedlings with the fungus; most Perigord black truffles (Tuber melanosporum) today come from planted orchards, and plantations have spread to Australia, New Zealand, Chile and the United States, where the northern truffle season falls in the southern summer. Dogs have almost entirely replaced pigs, which eat the crop; Italy banned truffle hogs in 1985. Two other things have shifted: the trees are no longer merely neighbours but partners, the truffle being an ectomycorrhizal symbiont living on their roots, and the old Tuberacei of Collier's have been folded into the order Pezizales, molecular work having shown that underground truffles evolved repeatedly from above-ground cup fungi. The aphrodisiac quality Collier's reports as hearsay has never been demonstrated.
Written for this edition, 2026.