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ROYAL HORTICULTURAL SOCIETY. 



under oaks and Abele. The men who collect Truffles for 

 Covent G-arden obtain them chiefly under beech, and in mixed 

 plantations of fir and beech. The Truffle-grounds of France are 

 remarkable for the sterility of the surface, the cause of which has 

 given rise to many conjectures, viz. that Truffles exercise a pre- 

 judicial influence on all plants in contact with or proximity to 

 themselves, by appropriating their nutriment in a manner similar 

 to the Bhizoctonice ; but a more probable reason of this sterility 

 is the frequent digging to which the Truffle-grounds are sub- 

 jected by the collectors ; for, as Truffles are not truly parasitic, 

 it would attribute an inconceivable amount of influence to their 

 mycelium to suppose them capable by its means of destroying all 

 the surrounding vegetation. And we may remark, that some spe- 

 cies occur in grassy places, as in the forest of Vincennes, according 

 to Tulasne ; and so with T. macrosporvm and T. brumale, as I 

 find them. It seems to be a better explanation of this sterility, 

 so generally accompanying Truffles, that they can only succeed 

 well where they find a comparative freedom from other vegetable 

 growth, arising from causes independent of themselves, and that 

 they are the result, and not the cause, of this sterility. 



In common with many other Fungi, Truffles do not bear to be 

 disturbed in their early stages ; so that the collectors are careful 

 in their researches after the summer species, as T. cestivum and 

 T. mesenterictm, not to stir the ground more deeply than is abso- 

 lutely necessary, as by so doing they would destroy the winter 

 crop of the more valuable kinds, T. melanosporum and T. brumale. 

 Any disturbance of the soil in the winter, when the latter are 

 mature, does no harm, but rather aids in their culture, by render- 

 ing the mould more suitable for the germination of their spores 

 and the growth of their mycelium. From Messrs. Tulasnes' ob- 

 servations it would seem that three or four months suffice for the 

 development of these plants ; they state that they have met with 

 Tuber mesentericum about as large as grains of millet in the 

 beginning of October, which must acquire their full size before the 

 end of December ; for about that time they find this species in its 

 mature condition alone. And it is supposed that the warm rains 

 of August are highly conducive to the fertility of the Truffle- 

 ground, and that the abundance or scantiness of the crop depends 

 very much on the nature of that period. These plants grow with- 

 out any special care or tendance ; but as they are not unfrequently 

 found, both in France and Italy, on the borders of corn-fields, 

 where they are ploughed up in the cultivation of the land, it 



