Cultivation of Tmffles. 411 



that is assisted by a microscope, in water that contains organic 

 matter. Since no man either has seen, or can see, the seed of 

 fungi, it was assumed to be so small as not to be visible even by 

 the assistance of the best microscope. This seed, then, must 

 have filled the air, and laid hold of every small place which 

 made the germination and increase of the young plant possible. 

 Such a supposition was admissible in the case of those fungi 

 that grew in the open air, but impossible with regard to those 

 which were found in the earth. How, in this case, should the 

 fine seed escape out of its closed grave, drawn forth by the 

 attracting powers of the soil, and be carried to distant places to 

 produce in them new truffles ? 



The error, however, was the occasion of trials, which, being 

 founded upon a wrong supposition, could not be attended by a 

 successful result. In order to cultivate mushrooms and truffles, 

 old fungi were dug up, and planted in the places destined for 

 them, to shed their seed and be the origin of a new race of 

 fungi. Peculiar care was bestowed upon truffles : they were 

 cautiously dug up from their ancient place of growth, and taken 

 to the new soil, which, however, was neither properly prepared, 

 nor the mixture of earths given to it which was requisite to the 

 prosperity of the fungus. It then appeared to be inconceivable, 

 why, with all this attention, the experiment failed ; and the old 

 truffle soon died, without leaving any successors. It was ex- 

 pected to scatter seed in the soil, but had disappeared without 

 leaving a trace behind it. Was the proceeding here observed 

 at all different from cutting a hydatid out of one animal, and 

 inserting it into another ? or causing an intestinal worm to be 

 swallowed, and then imagining that the minute animal should be 

 increased in its new situation ? 



The hydatid and intestinal worm are not produced by trans- 

 fer, but by such changes taking place in the mixture of the 

 component parts of the animal bodies in which we find them, as 

 to occasion that species of worms to be produced and thrive. 

 We sometimes find newly born, and even unborn, animals in- 

 habited by worms, which, nevertheless, are not transferable. 

 Other animals, on the contrary, are free from worms to the 

 extreme of old age; for their bodies present not to these worms 

 such a habitation as is requisite to their thriving. Just in the 

 same manner fungi, viz. mushrooms and truffles, which are very 

 obstinate in their choice of situations (habitats), arise and thrive 

 only under favourable circumstances, in a soil suitable to their 

 nature. 



Many attempts failed before it was known how to raise mush- 

 rooms upon places where they were wanted, and yet this fungus 

 is not near so delicate in its choice of a habitat and mixture of 

 soil as the truffle, whose artificial increase was not successful. 



