58 British Uredinca and Ustila^inecs. 



&>' 



CHAPTER VIII. 



MYCELIUM OF THE USTILAGINEyE, 



The vegetative mycelium of the Ustilaginese is to the 

 parasite one of its most important organs, for by it, and 

 by it alone, does the fungus derive its nutriment from the 

 host-plant upon which it subsists. Yet the mycelium is 

 of all parts that which is least frequently observed ; nor 

 can this be wondered at when one remembers that, like 

 the mycelium of the Uredineae, it can be seen only by 

 careful search — by cutting and teazing out numerous 

 thin sections of the host-plant. We owe most of the 

 information we possess upon the mycelium of the Usti- 

 lagineae to Fischer von Waldheim,* although, among 

 others, both Kuhn t and Hoffmann J had previously 

 figured it. It exists most abundantly in the tissues 

 of the host-plant, in the immediate vicinity of those 

 places in which the spores are developed ; but it can also 

 be found in other parts of the affected plant — in the 

 monocotyledons particularly in the stem, but especially 

 in the nodes and in the root-stock. In the dicotyledons 

 it is not so easily found at a distance from the spore-beds ; 

 still, in them too it has been seen in the root-stock and 



* Fischer von Waldheim, " Pringsheim Jahrbiicher " (1869), vol. vii. 

 pp. I, 2. 



t Kiihn, " Krankheiten der Kulturgewachse," 2 aufl. 1859. 

 J Hoffmann, " Ueber der Flugbrand." 1866. 



