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CHAPTER III. 



HABITATS OF FUNGI. 



It is difficult to point out any substance or situation where 

 conditions exist capable of supporting vegetation, in which 

 Fungi, in one or other of their forms, may not be developed. 

 The general notion is that Fungi are essentially the creatures 

 of decay ; but this notion arises only from a very limited ap- 

 prehension of the objects comprised under the name ; for not 

 only do we find them on putrescent logs or vegetables, but 

 they occur sometimes on bare flints, on glass, — as on our 

 window-panes and the lenses of microscopes, — or even on 

 smooth metallic surfaces ; but they establish themselves also 

 in the most poisonous solutions, and in fluids where no de- 

 composition has at present taken place. But more than this, 

 they are found on living structures, whether animal or vege- 

 table, at whose expense they grow. About fifteen years since, 

 when so much was said and written about Fungi in conse- 

 quence of the interest which was attached to the potato mur- 

 rain, it was a favourite dictum, even amongst men of some 

 pretensions to science, that Fungi could not grow upon healthy 

 substances. It is, however, now a well-established fact that 

 the most healthy tissues may be affected by Fungi, though 

 they rapidly become diseased under their influence. Deferring 



