INTRODUCTION TO CRYPTOGAMIC BOTANY. 257 



duction of mushroom is tolerably sure. Attempts have been 

 made to cultivate the common truffle, but at present with 

 little success. Nod's experiment of watering the ground in 

 woods with a decoction of truffles was successful, and Boletus 

 edulis has been raised in the same way ; but this is rather 

 promoting their natural production, than strict cultivation. 

 Efforts in this country have, at present, been fruitless, 

 though spawn at least has been produced. The attempts of 

 Bornholz and others may be mentioned, but they do not rest 

 on sufficient authority to make them worth quoting. In 

 Naples, a species of Agaric is raised upon the spent marc of 

 Coffee, and a favourite Polyporus (P. corylinus, Mauri) is 

 grown simply by toasting the stumps of cob-nut trees over 

 straw, and submitting them to a proper degree of moisture 

 in a dark cellar. The Fungus stone (Pietra Funghaia) is 

 constantly used in Italy, for the propagation of P. tuheraster ; 

 and I have seen specimens grown in England, in the nursery 

 of Lee and Kennedy. The Fungus stone is, however, nothing 

 more than a ball of earth matted together by mycelium, which 

 readily fructifies under proper conditions of temperature and 

 moisture. 



255, Polyporus fomentarkis, which is in great demand 

 for Amadou, has been artificially produced in Germany, but 

 not by direct propagation. Finally, Botrytis Bassiana, and 

 several epizoic Fungi, are readily propagated by inoculation, 

 while many species of moulds are capable of cultivation in 

 the house, by simply sowing their seed on rice paste, or any 

 other convenient matter, and several of the epiphyllous 

 species, as Erysiphe, in their Oidioid condition, are equally 

 capable of propagation by merely scattering their spores on 

 the leaves on which it is desired they should grow. Indeed, 

 many of the moulds will vegetate on any moist surface, or in 

 a drop of water placed in such conditions as will prevent 

 evaporation. 



256. Fungi are amongst the bodies which some naturalisis 

 consider capable of spontaneous generation. There is, how- 

 ever, no stronger ground in their case than in Algte. Their 

 sudden and unexpected appearance, their frequently inter- 



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