SUBTERRANEAN FUNGI— TUBERACEAE 193 



were placed in winter, either whole or in fragments, and that 

 after a lapse of time small Truffles were found in the compost. 

 But the result was discouraging rather than otherwise. The 

 most successful plan consisted in sowing acorns over a 

 considerable extent of land of a calcareous nature ; and when 

 the young oaks had attained the age of ten or twelve years, 

 Truffles were found in the intervals between the trees. This 

 process was carried on in the neighbourhood of Loudun, where 

 Truffle beds had formerly existed, but where they had long 

 ceased to be productive — a fact indicating the aptitude of the 

 soil for the purpose. In this case no attempt was made to 

 produce Truffles by placing ripe specimens in the earth ; but 

 they sprang up of themselves from spores probably contained 

 in the soil. The young trees were left rather wide apart, and 

 were cut for the first time about the twelfth year from the 

 sowing, and afterwards at intervals of from seven to nine years. 

 Truffles were thus obtained for a period of from twenty-five to 

 thirty years, after which the plantations ceased to be productive, 

 owing, it is said, to the ground being too much shaded by the 

 branches of the young trees — a remedy for which might have 

 been found by thinning out the trees, but this would not be 

 adopted till all the barren tracks had been planted. The 

 brushwood by being thus thinned out would be converted into 

 timber trees ; and the Truffle grounds rendered permanent, like 

 those of Poitou, which are commonly situated under the shade 

 of lofty trees. It is the opinion of MM. Tulasne that the regular 

 cultivation of the Truffle in gardens can never be so successful 

 as this so-called indirect culture at Loudun ; but they think 

 that a satisfactory result might be obtained in suitable soils 

 by planting fragments of mature Truffles in wooded localities, 

 taking care that the other conditions of the spots selected 

 should be analogous to those of the regular Truffle grounds ; 

 and they recommend a judicious thinning of the trees, and 

 clearing the surface of brushwood, etc., which prevents at once 

 the beneficial effects of rain and of the direct sun rays. It is 

 added that this species of industry has added much to the 

 value of certain districts of Loudun and Civray, which were 

 previously comparatively worthless, and has enriched many of 

 its proprietors, who now make periodical sowings of acorns, 



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