196 THE PRINCIPLES OF FLORICULTURE 



164. Mode of life. In an excellent book on " Diseases 

 of Plants Induced by Cryptogamic Parasites," Karl F. 

 Von Tubeuf discusses the mode of life of fungi, as follows : 



" The parasitic fungi may be divided according to the 

 place of their occurrence, and their mode of attack on the 

 host, into two categories, which may be designated 

 epiphytic and endophytic parasites. The former have 

 their vegetative mycelium spread over the surface of the 

 host plant ; the latter penetrate into the plant and there 

 develop their mycelium. Both receive nourishment from 

 the cells of the host plant by means of special absorptive 

 regions inserted into the cells of the host, the so-called 

 haustoria. 



" We may distinguish the following groups of parasites 

 according to the degree of their penetration into the or- 

 gans of the host plant they attack : 



(1) Epiphytes 



(a) With haustoria which only sink into the outer 



membranes of the host. 

 (6) With haustoria penetrating into the cavity of the 



host cells. 



(2) Endopkytes 



(a) With a mycelium which grows in the walls of the 



host cell and is generally nourished without the 



aid of haustoria. 

 (6) With a mycelium which grows in the intercellular 



spaces only, and is nourished with or without 



haustoria. 



(c) With a mycelium which penetrates into the host 



cell and becomes an intercellular mycelium. 



(d) Lower fungi which live completely within the host 



cell." 



