M. Gasparin reported to the jurors of the Paris Exhibition of 1855, concerning the operations of M. Rousseau, of Carpentras, on the production of oak truffles in France. The acorns of evergreen and of common oaks were sown about five yards apart. In the fourth year of the plantation three truffles were found; at the date of the report the trees were nine years old, and over a yard in height. Sows were employed to search for the truffles. Although these plantations consist both of the evergreen and common oak, truffles cannot be gathered at the base of the latter species, it so happening that it arrives later at a state of production. The common oak, however, produces truffles like the evergreen oak, this report states, for a great number of the natural truffle-grounds at Vaucluse are planted with common oaks. It is remarked that the truffles produced from these are larger but less regular than those of the evergreen oak, which are smaller, but nearly always spherical. The truffles are gathered at two periods of the year; in May only white truffles are to be found, which never blacken and have no odour; they are dried and sold for seasoning. The black truffles (_Tuber melanosporum_) commence forming in June, enlarging towards the frosty season; then they become hard, and acquire all their perfume. They are dug a month before and a month after Christmas. It is also asserted that truffles are produced about the vine, or at any rate that the association of the vine is favourable to the production of truffles, because truffle-plots near vines are very productive. The observation of this decided M. Rousseau to plant a row of vines between the oaks. The result of this experiment altogether does not appear to have been by any means flattering, for at the end of eight years only little more than fifteen pounds were obtained from a hectare of land, which, if valued at 45 francs, would leave very little profit. M. Rousseau also called attention to a meadow manured (_sic_) with parings of truffles, which was said to have given prodigious results.