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FUNGI. 



THE old definition of Fungi is now scarcely 

 satisfactory, as it circumscribed them to cel- 

 lular plants, deriving nourishment by means of a 

 mycelium from the matrix, and never producing from 

 their component threads green bodies resembling, 

 chlorophyl. This definition was intended for the 

 distinguishing of fungi from lichens, the latter de- 

 riving nourishment from the surrounding medium, 

 and not from the matrix, constantly producing in 

 the thallus green bodies resembling chlorophyl. It 

 is very difficult, in a few words, to give an unim- 

 peachable definition of a fungus. Nor is this very 

 necessary in a book of this kind, since the general 

 notion of a fungus is not so restricted as it was in the 

 past, when only a few prominent types were popularly 

 recognized. It is, however, of some importance that 

 it should be known how widely these organisms are 

 distributed, and what an immense number of species 

 have been recognized by scientific men. It seems 

 but a few years since the botanical world only 

 accepted the possibility of some twenty thousand 

 species being known throughout the world, whilst 

 to-day w^e possess the knowledge of forty thousand 

 described species, and these are continually on the 



