450 



I'KorKCriON ACAINST FlTi\(;l, 



the canker remains, wliich does not produce any sporocarps. 

 Hess stated (1900) that no one has yet succeeded in infecting 

 a tree artificially b}' the spores of this fungus, and that 



Fig. 2iy.— Old witclics-l.rooiii on the Silver-fir. a Ciiiikerous swelling caiis-ed l)y tli^ 

 niyceliuni of tbe fungus. 



