By general consent Périgord is credited with producing the best truffles, the next in commercial repute being those obtained from Provence and Dauphiné; the finest of the former come from the canton of Sarlat, the best of Dauphiné from the cantons of Tain and Valence. Among authorities, Beauvilliers preferred the black product of Provence (T. melanosporum), of which there are two varieties, the so-termed violet and the grey; and Savarin the white species (T. magnatum), obtained preferably from Piedmont, where it occurs beneath poplars and oaks during summer. The whitish-brown truffle of Italy, in its early stage, similar to the whitebait described by Thackeray, possesses an "ambrosial flavour," and is difficult to surpass, combining as it does all the most ethereal qualities of the Allium tribe with the dulcet pungency of Gorgonzola when in its freshest flower. A species exists which emits a powerful scent of musk, while numerous others occur with odours so rank as to be utterly unfit for edible purposes. Northern Spain produces excellent truffles, but these are comparatively short-lived. T. æstivum, called "summer truffle," indigenous to many countries, is extremely plentiful in southern France. It is common to England, where it grows most frequently under beech-trees. This exhales a strong and penetrating smell which has been compared to that of sheep-folds. The effluvium of garlic is always very marked in the white truffle of Italy, and by some it is said to recall the odour of garlic mixed with onion, high game, and matured cheese. After standing for a time, when its garlic flavour has become somewhat modified, it is also suggestive of the flavour of vegetable-oysters. Indeed, the truffle is as strange in its odours as it is in its manner of growth, and in certain respects it brings to mind some characteristics of that strangest of flowers, the orchid. From November to March is the season when the prized dark tuber is most abundant, and during which its highest qualities are evolved. The black pearl of Provence and Périgord begins to take on its rich ebon hue in October, lasting until April: æstivum and its varieties being gathered during May and June in Provence, and from October to January in Burgundy and Champagne. The species of greatest repute in southern France is found at variable depths, mostly beneath certain oaks known as _chênes truffiers_, or truffle-oaks. With it often occurs another species, T. brumale, which is likewise held in much esteem and figures as a large commercial factor. Among the inhabitants the truffle harvest forms an extensive industry; pigs, dogs, and professional hunters being utilised for the quest, and the crop always commanding high prices, which are fixed by the Paris market. When the supply happens to be short, many inferior species are substituted or are mixed with the genuine.