CULTIVATION. 261 



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 

 rnelanosporum) 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. 



The cultivation of minute fungi for scientific purposes has 

 been incidentally alluded to and illustrated in foregoing chapters, 

 and consequently will not require such full and particular details 

 here. Somewhat intermediately, we might allude to the species 

 of Sclerotium, which are usually compact, externally blackish, 

 rounded or amorphous bodies, consisting of a cellular mass of 

 the nature of a concentrated mycelium. Placed in favourable 

 conditions, these forms of Sclerotium will develop the peculiar 

 species of fungus belonging to them, but in certain cases the 

 production is more rapid and easy than in others. In this 

 country, Mr. IP. Currey has been the most successful in the cul- 

 tivation of S'clerotia. The method adopted is to keep them in 

 a moist, somewhat warm, but equable atmosphere, and with 

 patience await the results. The well-known ergot of rye, wheat, 

 and other grasses may be so cultivated, and Mr. Carrey has 

 developed the ergot of the common reed by keeping the stem 



