450 



PROTECTION 



Al NST I T \ < ; 



the canker remains, which does not produce any sporocarps. 

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

 a tree artificially by the spores of this fungus, and that 



Fig. 219. Old witches-broom on the Silver-fir. a Cankerous swelling caused by the 

 mycelium of the fungus. 



