Cultivation of Truffles. 415 



than the real truffles, they can easily give such properties to the 

 soil of woods, that it produces none but swine-truffles. They 

 are usually found in abundance in such tracts of land as are not 

 mellow, but incline to sourness. Young plantations of truffles 

 may easily be spoilt, and all labour and expense be useless, if, 

 through inattention or want of knowledge, this swine-truffle is 

 transferred from its old place of growth into the new. As the 

 real truffle prefers the oak, so the swine-truffle seems to prefer 

 the whitethorn, to all other trees. Under its roots they are 

 formed from twenty to thirty together ; on the contrary, the 

 edible truffle seldom occurs so many together : it usually lives 

 singly. 



3. Small Truffle [Tuber minimiim). — This species of truffle 

 lives in much society, and always occurs in great numbers to- 

 gether. It attains only the size of a pea, and is of an irregular 

 form approaching to that of a sphere. Formerly it was thought 

 to be the young progeny of the edible truffle. 



4. The Stag-Triiffle {the Stag-rut Fungus^ Tuber cervlnum). 

 — This is the largest kind. It has a globular form and a loose 

 spongy flesh, which, in the midst of its body has so little co- 

 herence, that it forms a dusty core or heart. It is not used by 

 man, but red deer scrape it. 



All truffles draw nourishment from the earth ; not by means 

 of roots, of which no trace is to be found, but by absorbing ves- 

 sels which cover their whole superficies, in the form, generally, 

 of small warts. For this reason they can thrive in none but 

 moist situations, which offer them, in sufficient quantity, matter 

 dissolved in water. In proportion as the earth about them dries 

 up, the fungi must wither away. They have indeed, in their in- 

 terior, vessels which contain water, to enable them for a time to 

 do without external moisture ; but, if the drought continues, 

 their internal provision is exhausted, the truffle becomes un- 

 healthy, and must at length perish from thirst. 



Notv.'ithstanding the want of moisture is thus injurious to the 

 cultivation of truffles, too great a quantity is equally destructive 

 to them. Acids are generated, mould and numerous other 

 parasitic plants get a footing upon the surface of the tubes, and 

 by degrees obstruct the absorbing vessels, and the body of the 

 truffle is consumed or putrefies ; the mould also allures many 

 small worms which establish themselves upon the truffle and live 

 upon its flesh. 



Upon the first production of the truffle its size is scarcely per- 

 ceivable ; as it proceeds in its growth, the earth that is around 

 it is pressed together and pushed off. On this account the 

 truffle can prosper in none but a loose soil. If the soil is every- 

 where equally loose, the truffle assumes a globular form ; but 

 this is changed if there is on one side a greater opposition than 



